1
|
Smith ZH, Martin RA, Casto E, Bigelow C, Busa MA, Kent JA. Muscle Torque-Velocity Relationships and Fatigue With Reduced Knee Joint Range of Motion in Young and Older Adults. J Appl Biomech 2024; 40:261-269. [PMID: 38663850 DOI: 10.1123/jab.2023-0130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 02/29/2024] [Accepted: 03/08/2024] [Indexed: 07/31/2024]
Abstract
The purpose of this study was to evaluate the influence of knee joint range of motion (RoM) on the torque-velocity relationship and fatigue in the knee extensor muscles of 7 young (median = 26 y) and 7 older (68 y) adults. Each leg was assigned a RoM (35° or 75°) over which to perform a torque-velocity protocol (maximal isokinetic contractions, 60-300°·s-1) and a fatigue protocol (120 maximal contractions at 120°·s-1, 0.5 Hz). Six older participants were unable to reach 300°·s-1 over 35°. Therefore, the velocity eliciting 75% of peak torque at 60°·s-1 (V75, °·s-1) was calculated for each RoM from a fit of individual torque-velocity curves (60-240°·s-1), and ΔV75 (35°-75°) was determined. Fatigue (final torque/initial torque) was used to calculate Δfatigue (35°-75°). ΔV75 was not different from 0 in young (-28.3°·s-1 [-158.6 to 55.7], median [range], P = .091) or older (-18.5°·s-1 [-95.0 to 23.9], P = .128), with no difference by age (P = .710). In contrast, fatigue was greater for 75° in young (Δfatigue = 25.9% [17.5-30.3], P = .018) and older (17.2% [11.9-52.9], P = .018), with no effect of age (P = .710). These data indicate that, regardless of age, RoM did not alter the torque-velocity relationship between 60 and 240°·s-1, and fatigue was greater with a larger RoM.
Collapse
Affiliation(s)
- Zoe H Smith
- Muscle Physiology Laboratory, Department of Kinesiology, University of Massachusetts, Amherst, MA, USA
| | - R Anthony Martin
- Muscle Physiology Laboratory, Department of Kinesiology, University of Massachusetts, Amherst, MA, USA
| | - Erica Casto
- Center for Human Health and Performance, Institute for Applied Life Sciences, University of Massachusetts, Amherst, MA, USA
| | - Carol Bigelow
- Department of Biostatistics & Epidemiology, University of Massachusetts Amherst, Amherst, MA, USA
| | - Michael A Busa
- Center for Human Health and Performance, Institute for Applied Life Sciences, University of Massachusetts, Amherst, MA, USA
| | - Jane A Kent
- Muscle Physiology Laboratory, Department of Kinesiology, University of Massachusetts, Amherst, MA, USA
| |
Collapse
|
2
|
Fitzgerald LF, Bartlett MF, Kent JA. Muscle fatigue, bioenergetic responses and metabolic economy during load- and velocity-based maximal dynamic contractions in young and older adults. Physiol Rep 2023; 11:e15876. [PMID: 37996974 PMCID: PMC10667588 DOI: 10.14814/phy2.15876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 11/07/2023] [Accepted: 11/07/2023] [Indexed: 11/25/2023] Open
Abstract
We evaluated whether task-dependent, age-related differences in muscle fatigue (contraction-induced decline in normalized power) develop from differences in bioenergetics or metabolic economy (ME; mass-normalized work/mM ATP). We used magnetic resonance spectroscopy to quantify intracellular metabolites in vastus lateralis muscle of 10 young and 10 older adults during two maximal-effort, 4-min isotonic (20% maximal torque) and isokinetic (120°s-1 ) contraction protocols. Fatigue, inorganic phosphate (Pi), and pH (p ≥ 0.213) differed by age during isotonic contractions. However, older had less fatigue (p ≤ 0.011) and metabolic perturbation (lower [Pi], greater pH; p ≤ 0.031) than young during isokinetic contractions. ME was lower in older than young during isotonic contractions (p ≤ 0.003), but not associated with fatigue in either protocol or group. Rather, fatigue during both tasks was linearly related to changes in [H+ ], in both groups. The slope of fatigue versus [H+ ] was 50% lower in older than young during isokinetic contractions (p ≤ 0.023), consistent with less fatigue in older during this protocol. Overall, regardless of age or task type, acidosis, but not ME, was the primary mechanism for fatigue in vivo. The source of the age-related differences in contraction-induced acidosis in vivo remains to be determined, as does the apparent task-dependent difference in the sensitivity of muscle to [H+ ].
Collapse
Affiliation(s)
- Liam F. Fitzgerald
- Muscle Physiology Laboratory, Department of KinesiologyUniversity of MassachusettsAmherstMassachusettsUSA
| | - Miles F. Bartlett
- Muscle Physiology Laboratory, Department of KinesiologyUniversity of MassachusettsAmherstMassachusettsUSA
| | - Jane A. Kent
- Muscle Physiology Laboratory, Department of KinesiologyUniversity of MassachusettsAmherstMassachusettsUSA
| |
Collapse
|
3
|
Kathia MM, Bommarito JC, Hinks A, Leake E, Shannon J, Pitman J, Connolly B, Burr JF, Vallis LA, Power GA, Millar PJ. Physiological and clinical responses to cycling 7850 km over 85 days in a physically active middle-aged man with idiopathic Parkinson's disease. Physiol Rep 2023; 11:e15772. [PMID: 37474301 PMCID: PMC10359154 DOI: 10.14814/phy2.15772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/29/2023] [Accepted: 07/05/2023] [Indexed: 07/22/2023] Open
Abstract
This case characterizes the clinical motor, perceived fatigue, gait and balance, cardiovascular, neuromuscular, and cardiopulmonary responses after cycling 7850 km over 85 days in a physically active 57-year-old male with idiopathic Parkinson's disease (PD). The participant cycled 73/85 days (86%); averaging 107.5 ± 48.9 km/day over 255.4 ± 108.8 min. Average cycling heart rate was 117 ± 11 bpm. The Unified Parkinson Disease Rating Scale (UPDRS) Part III motor score decreased from 46 to 26 (-44%), while the mean Parkinson Fatigue Scale (PFS-16) score decreased from 3.4 to 2.3 (-32%). Peak power output on a maximal aerobic exercise test increased from 326 to 357 W (+10%), while peak isotonic power of single-leg knee extension increased from 312 to 350 W (+12%). Maximal oxygen uptake following the trip was 53.1 mL/min/kg or 151% of predicted. Resting heart rate increased from 48 to 71 bpm (+48%). The systolic and diastolic blood pressure responses to a 2-min submaximal static handgrip exercise were near absent at baseline (∆2/∆2 mm Hg) but appeared normal post-trip (∆17/∆9 mm Hg). Gait and static balance measures were unchanged. This case report demonstrates the capacity for physiological and clinical adaptations to a high-volume, high-intensity cycling regiment in a physically active middle-aged male with PD.
Collapse
Affiliation(s)
- Muhammad M. Kathia
- Human Cardiovascular Physiology Laboratory, Department of Human Health and Nutritional Sciences, College of Biological SciencesUniversity of GuelphGuelphOntarioCanada
| | - Julian C. Bommarito
- Human Cardiovascular Physiology Laboratory, Department of Human Health and Nutritional Sciences, College of Biological SciencesUniversity of GuelphGuelphOntarioCanada
| | - Avery Hinks
- Neuromechanical Performance Research Laboratory, Department of Human Health and Nutritional Sciences, College of Biological SciencesUniversity of GuelphGuelphOntarioCanada
| | - Elira Leake
- Neuromechanical Performance Research Laboratory, Department of Human Health and Nutritional Sciences, College of Biological SciencesUniversity of GuelphGuelphOntarioCanada
| | - Julia Shannon
- Gait Biomechanics Laboratory, Department of Human Health & Nutritional Sciences, College of Biological SciencesUniversity of GuelphGuelphOntarioCanada
| | - Jenna Pitman
- Gait Biomechanics Laboratory, Department of Human Health & Nutritional Sciences, College of Biological SciencesUniversity of GuelphGuelphOntarioCanada
| | - Barbara Connolly
- Division of Neurology, Department of MedicineMcMaster UniversityHamiltonOntarioCanada
| | - Jamie F. Burr
- Human Performance and Health Research Laboratory, Department of Human Health & Nutritional SciencesUniversity of GuelphGuelphOntarioCanada
| | - Lori Ann Vallis
- Gait Biomechanics Laboratory, Department of Human Health & Nutritional Sciences, College of Biological SciencesUniversity of GuelphGuelphOntarioCanada
| | - Geoffrey A. Power
- Neuromechanical Performance Research Laboratory, Department of Human Health and Nutritional Sciences, College of Biological SciencesUniversity of GuelphGuelphOntarioCanada
| | - Philip J. Millar
- Human Cardiovascular Physiology Laboratory, Department of Human Health and Nutritional Sciences, College of Biological SciencesUniversity of GuelphGuelphOntarioCanada
| |
Collapse
|
4
|
Boyer KA, Hayes KL, Umberger BR, Adamczyk PG, Bean JF, Brach JS, Clark BC, Clark DJ, Ferrucci L, Finley J, Franz JR, Golightly YM, Hortobágyi T, Hunter S, Narici M, Nicklas B, Roberts T, Sawicki G, Simonsick E, Kent JA. Age-related changes in gait biomechanics and their impact on the metabolic cost of walking: Report from a National Institute on Aging workshop. Exp Gerontol 2023; 173:112102. [PMID: 36693530 PMCID: PMC10008437 DOI: 10.1016/j.exger.2023.112102] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 01/09/2023] [Accepted: 01/19/2023] [Indexed: 01/22/2023]
Abstract
Changes in old age that contribute to the complex issue of an increased metabolic cost of walking (mass-specific energy cost per unit distance traveled) in older adults appear to center at least in part on changes in gait biomechanics. However, age-related changes in energy metabolism, neuromuscular function and connective tissue properties also likely contribute to this problem, of which the consequences are poor mobility and increased risk of inactivity-related disease and disability. The U.S. National Institute on Aging convened a workshop in September 2021 with an interdisciplinary group of scientists to address the gaps in research related to the mechanisms and consequences of changes in mobility in old age. The goal of the workshop was to identify promising ways to move the field forward toward improving gait performance, decreasing energy cost, and enhancing mobility for older adults. This report summarizes the workshop and brings multidisciplinary insight into the known and potential causes and consequences of age-related changes in gait biomechanics. We highlight how gait mechanics and energy cost change with aging, the potential neuromuscular mechanisms and role of connective tissue in these changes, and cutting-edge interventions and technologies that may be used to measure and improve gait and mobility in older adults. Key gaps in the literature that warrant targeted research in the future are identified and discussed.
Collapse
Affiliation(s)
- Katherine A Boyer
- Department of Kinesiology, University of Massachusetts Amherst, MA, USA; Department of Orthopedics and Physical Rehabilitation, University of Massachusetts Medical School, Worcester, MA, USA.
| | - Kate L Hayes
- Department of Kinesiology, University of Massachusetts Amherst, MA, USA
| | | | | | - Jonathan F Bean
- New England GRECC, VA Boston Healthcare System, Boston, MA, USA; Department of PM&R, Harvard Medical School, Boston, MA, USA; Spaulding Rehabilitation Hospital, Boston, MA, USA
| | - Jennifer S Brach
- Department of Physical Therapy, University of Pittsburgh, Pittsburgh, PA, USA
| | - Brian C Clark
- Ohio Musculoskeletal and Neurological Institute and the Department of Biomedical Sciences, Ohio University, Athens, OH, USA
| | - David J Clark
- Brain Rehabilitation Research Center, Malcom Randall VA Medical Center, Gainesville, FL, USA; Department of Physiology and Aging, University of Florida, Gainesville, FL, USA
| | - Luigi Ferrucci
- Intramural Research Program of the National Institute on Aging, NIH, Baltimore, MD, USA
| | - James Finley
- Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, USA
| | - Jason R Franz
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, NC, USA
| | - Yvonne M Golightly
- College of Allied Health Professions, University of Nebraska Medical Center, Omaha, NE, USA; Thurston Arthritis Research Center, Division of Rheumatology, Allergy, and Immunology, Department of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Tibor Hortobágyi
- Hungarian University of Sports Science, Department of Kinesiology, Budapest, Hungary; Institute of Sport Sciences and Physical Education, University of Pécs, Hungary; Somogy County Kaposi Mór Teaching Hospital, Kaposvár, Hungary; Center for Human Movement Sciences, University of Groningen Medical Center, Groningen, the Netherlands
| | - Sandra Hunter
- Department of Physical Therapy, Marquette University, Milwaukee, WI, USA
| | - Marco Narici
- Neuromuscular Physiology Laboratory, Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Barbara Nicklas
- Section on Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, USA
| | - Thomas Roberts
- Department of Ecology and Evolutionary Biology, Brown University, USA
| | - Gregory Sawicki
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, USA
| | - Eleanor Simonsick
- Intramural Research Program of the National Institute on Aging, NIH, Baltimore, MD, USA
| | - Jane A Kent
- Department of Kinesiology, University of Massachusetts Amherst, MA, USA
| |
Collapse
|
5
|
Grosicki GJ, Zepeda CS, Sundberg CW. Single muscle fibre contractile function with ageing. J Physiol 2022; 600:5005-5026. [PMID: 36268622 PMCID: PMC9722590 DOI: 10.1113/jp282298] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 10/07/2022] [Indexed: 01/05/2023] Open
Abstract
Ageing is accompanied by decrements in the size and function of skeletal muscle that compromise independence and quality of life in older adults. Developing therapeutic strategies to ameliorate these changes is critical but requires an in-depth mechanistic understanding of the underlying physiology. Over the past 25 years, studies on the contractile mechanics of isolated human muscle fibres have been instrumental in facilitating our understanding of the cellular mechanisms contributing to age-related skeletal muscle dysfunction. The purpose of this review is to characterize the changes that occur in single muscle fibre size and contractile function with ageing and identify key areas for future research. Surprisingly, most studies observe that the size and contractile function of fibres expressing slow myosin heavy chain (MHC) I are well-preserved with ageing. In contrast, there are profound age-related decrements in the size and contractile function of the fibres expressing the MHC II isoforms. Notably, lifelong aerobic exercise training is unable to prevent most of the decrements in fast fibre contractile function, which have been implicated as a primary mechanism for the age-related loss in whole-muscle power output. These findings reveal a critical need to investigate the effectiveness of other nutritional, pharmaceutical or exercise strategies, such as lifelong resistance training, to preserve fast fibre size and function with ageing. Moreover, integrating single fibre contractile mechanics with the molecular profile and other parameters important to contractile function (e.g. phosphorylation of regulatory proteins, innervation status, mitochondrial function, fibre economy) is necessary to comprehensively understand the ageing skeletal muscle phenotype.
Collapse
Affiliation(s)
- Gregory J. Grosicki
- Biodynamics and Human Performance Center, Georgia Southern University (Armstrong Campus), Savannah, Georgia, USA
| | - Carlos S. Zepeda
- Exercise and Rehabilitation Sciences Graduate Program, Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin, USA
| | - Christopher W. Sundberg
- Exercise and Rehabilitation Sciences Graduate Program, Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin, USA
- Athletic and Human Performance Research Center, Marquette University, Milwaukee, Wisconsin, USA
| |
Collapse
|
6
|
Performance fatigability during isometric vs. concentric quadriceps fatiguing tasks in men and women. J Electromyogr Kinesiol 2022; 67:102715. [PMID: 36274441 DOI: 10.1016/j.jelekin.2022.102715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 09/13/2022] [Accepted: 10/10/2022] [Indexed: 12/12/2022] Open
Abstract
In the present study, we aimed to provide a robust comparison of the fatigability of the knee extensors following isometric (ISO) and concentric (CON) tasks. Twenty young adults (25 ± 4 yr, 10 women) randomly performed the ISO and CON quadriceps intermittent fatigue test, consisting of ten (5 s on/5-s off, ISO) or one-hundred (0.5-s on/0.5-s off, CON) contractions with 10 % increments per stage until exhaustion. Performance fatigability was quantified as maximal isometric (MVIC) and concentric (MVCC) torque loss. Voluntary activation and contractile function (peak-twitch) were investigated using peripheral nerve stimulation. Number of stages (6.2 ± 0.7 vs. 4.9 ± 0.8; P < 0.001) and torque-time integral (20,166 ± 7,821 vs. 11,285 ± 4,933 Nm.s; P < 0.001) were greater for ISO than CON. MVIC, MVCC and voluntary activation decreased similarly between sessions (P > 0.05) whereas peak-twitch amplitude decreased more for CON (P < 0.001). The number of contractions was similar across sexes (ISO: men = 62 ± 8, women = 61 ± 5; CON: men = 521 ± 67, women = 458 ± 76, P > 0.05). MVCC was more reduced in women for both sessions (all P < 0.05), while MVIC loss was similar between sexes. We concluded that, despite greater torque-time integral and duration for ISO, both sessions induced a similar performance fatigability at exhaustion. Contractile function was more altered in CON. Finally, sex-related difference in fatigability depends on the contraction mode used during testing.
Collapse
|
7
|
Harper SA, Thompson BJ. Interaction between age and fatigue on antagonist muscle coactivation during an acute post-fatigue recovery phase. FRONTIERS IN AGING 2022; 3:1005080. [PMID: 36263146 PMCID: PMC9574075 DOI: 10.3389/fragi.2022.1005080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 09/14/2022] [Indexed: 11/30/2022]
Abstract
This study investigated the age-related changes in antagonist muscle coactivation of the biceps femoris (BF) during an acute recovery period following a leg extensor fatiguing protocol. Twenty-three young (mean ± SD: age = 25.1 ± 3.0 years) and twenty-three old men (age = 71.5 ± 3.9 years) participated. Surface electromyography (sEMG) was recorded from the BF muscles for antagonist muscle coactivation. Testing involved participants performing leg extension isometric maximal voluntary contractions (MVCs) and isokinetic MVCs at 240°·s-1 at baseline (Pre) and again after the fatigue protocol at 0 (Post0), 7 (Post7), 15 (Post15), and 30 (Post30) minutes post fatigue. Root mean square (RMS) values were computed from the BF sEMG and were calculated as the first 200 ms from onset for the isometric (IsomCoact200ms) and dynamic isokinetic 240°·s-1 (DynCoact200ms) MVCs, and for the final 10° of the leg extension (DynCoact10°) on the isokinetic 240°·s-1 MVCs. Two-way ANOVAs [age group (young vs. old) × time (Pre vs. Post0 vs. Post7 vs. Post15 vs. Post30)] showed that DynCoact200ms had an effect for time (p = 0.018), with greater antagonist coactivation in Pre than Post0 (p = 0.009) and recovering by Post7 (p = 0.011) with no group differences. DynCoact10° had no age × time interaction (p = 0.070), but had a main effect for time (p = 0.020) with the Post0 being lower than the Pre. However, for this variable the young group showed a more severe Pre to Post0 fatigue decline (-45.9%) than the old group (-6.7%) indicating this may be a more sensitive variable for capturing age-related antagonist coactivation post-fatigue responses. Leg extensor fatigue affects some BF coactivation sEMG variables more than others, and any altered post-fatigue coactivation response recovers rapidly (<7 min) from baseline levels.
Collapse
Affiliation(s)
- Sara A. Harper
- Department of Kinesiology and Health Science, Utah State University, Logan, UT, United States,Sorenson Legacy Foundation Center for Clinical Excellence, Dennis Dolny Movement Research Clinic, Utah State University, Logan, UT, United States
| | - Brennan J. Thompson
- Department of Kinesiology and Health Science, Utah State University, Logan, UT, United States,Sorenson Legacy Foundation Center for Clinical Excellence, Dennis Dolny Movement Research Clinic, Utah State University, Logan, UT, United States,*Correspondence: Brennan J. Thompson,
| |
Collapse
|
8
|
Paris MT, McNeil CJ, Power GA, Rice CL, Dalton BH. Age-related performance fatigability: a comprehensive review of dynamic tasks. J Appl Physiol (1985) 2022; 133:850-866. [PMID: 35952347 DOI: 10.1152/japplphysiol.00319.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Adult ageing is associated with a myriad of changes within the neuromuscular system, leading to reductions in contractile function of old adults. One of the consequences of these age-related neuromuscular adaptations is altered performance fatigability, which can limit the ability of old adults to perform activities of daily living. Whereas age-related fatigability of isometric tasks has been well characterized, considerably less is known about fatigability of old adults during dynamic tasks involving movement about a joint, which provides a more functionally relevant task compared to static contractions. This review provides a comprehensive summary of age-related fatigability in dynamic contractions, where the importance of task specificity is highlighted with a brief discussion of the potential mechanisms responsible for differences in fatigability between young and old adults. The angular velocity of the task is critical for evaluating age-related fatigability, as tasks which constrain angular velocity (i.e., isokinetic) produce equivocal age-related differences in fatigability, whereas tasks involving unconstrained velocity (i.e., isotonic-like) consistently induce greater fatigability of old compared to young adults. These unconstrained velocity tasks, that are more closely associated with natural movements, offer an excellent model to uncover the underlying age-related mechanisms of increased fatigability. Future work evaluating the mechanisms of increased age-related fatigability of dynamic tasks should be evaluated using task-specific contractions (i.e., dynamic), particularly for assessment of spinal and supra-spinal components. Advancing our understanding of age-related fatigability is likely to yield novel insights and approaches for improving mobility limitations in old adults.
Collapse
Affiliation(s)
- Michael T Paris
- School of Kinesiology, University of Western Ontario, London, ON, Canada
| | - Chris J McNeil
- School of Health and Exercise Science, University of British Columbia, Kelowna, BC, Canada
| | - Geoffrey A Power
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Charles L Rice
- School of Kinesiology, University of Western Ontario, London, ON, Canada.,Department of Anatomy and Cell Biology, University of Western Ontario, London, ON, Canada
| | - Brian H Dalton
- School of Health and Exercise Science, University of British Columbia, Kelowna, BC, Canada
| |
Collapse
|
9
|
Davidson B, Hinks A, Dalton BH, Akagi R, Power GA. Power attenuation from restricting range of motion is minimized in subjects with fast RTD and following isometric training. J Appl Physiol (1985) 2022; 132:497-510. [PMID: 35023762 DOI: 10.1152/japplphysiol.00688.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Time-dependent measures consisting of rate of torque development (RTD), rate of velocity development (RVD), and rate of neuromuscular activation can be used to evaluate explosive muscular performance, which becomes critical when performing movements throughout limited ranges of motion (ROM). Using a HUMAC NORM dynamometer, seven males (27 ± 7 years) and six females (22 ± 3 years) underwent 8 weeks of maximal isometric dorsiflexion training 3 days/week. One leg was trained at 0° (short-muscle tendon unit (MTU) length) and the other at 40° of plantar flexion (long-MTU length). RTD and rate of neuromuscular activation were evaluated during 'fast' maximal isometric contractions. Power, RVD, and rate of neuromuscular activation were assessed during maximal isotonic contractions in four conditions (small (40° to 30° of plantar flexion) ROM at 10 and 50% MVC; large (40° to 0° of plantar flexion) ROM at 10 and 50% MVC) for both legs, pre- and post-training. Despite no change in rate of neuromuscular activation following training, peak power, RTD, and RVD increased at both MTU lengths (p < 0.05). Strong relationships (R2=0.73) were observed between RTD and peak power in the small ROM, indicating that fast time-dependent measures are critical for optimal performance when ROM is constrained. Meanwhile, strong relationships (R2=0.90) between RVD and power were observed at the 50% load, indicating that RVD is critical when limited by load and ROM is not confined. Maximal isometric dorsiflexion training can be used to improve time-dependent measures (RTD, RVD) to minimize power attenuation when ROM is restricted.
Collapse
Affiliation(s)
- Brooke Davidson
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Avery Hinks
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Brian H Dalton
- School of Health and Exercise Sciences, University of British Columbia, Kelowna, BC, Canada
| | - Ryota Akagi
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada.,College of Systems Engineering and Science, Shibaura Institute of Technology, Saitama, Japan
| | - Geoffrey A Power
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
| |
Collapse
|
10
|
Wu R, De Vito G, Lowery MM, O'Callaghan B, Ditroilo M. Age-related fatigability in knee extensors and knee flexors during dynamic fatiguing contractions. J Electromyogr Kinesiol 2021; 62:102626. [PMID: 34998161 DOI: 10.1016/j.jelekin.2021.102626] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 11/08/2021] [Accepted: 12/14/2021] [Indexed: 12/01/2022] Open
Abstract
This study investigated the effects of dynamic knee extension and flexion fatiguing task on torque and neuromuscular responses in young and older individuals. Eighteen young (8 males; 25.1 ± 3.2 years) and 17 older (8 males; 69.7 ± 3.7 years) volunteered. Following a maximal voluntary isometric contraction test, participants performed a fatiguing task involving 22 maximal isokinetic (concentric) knee extension and flexion contractions at 60°/s, while surface EMG was recorded simultaneously from the knee extensors (KE) and flexors (KF). Fatigue-induced relative torque reductions were similar between age groups for KE (peak torque decrease: 25.15% vs 26.81%); however, KF torque was less affected in older individuals (young vs older peak torque decrease: 27.6% vs 11.5%; p < 0.001) and this was associated with greater increase in hamstring EMG amplitude (p < 0.001) and hamstrings/quadriceps peak torque ratio (p < 0.01). Furthermore, KE was more fatigable than KF only among older individuals (peak torque decrease: 26.8% vs 11.5%; p < 0.001). These findings showed that the age-related fatigue induced by a dynamic task was greater for the KE, with greater age-related decline in KE compared to KF.
Collapse
Affiliation(s)
- Rui Wu
- School of Electrical & Electronic Engineering, University College Dublin, Dublin, Ireland; School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland
| | - Giuseppe De Vito
- School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland; Biomedical Sciences Department, Neuromuscular Physiology Laboratory, University of Padova, Italy
| | - Madeleine M Lowery
- School of Electrical & Electronic Engineering, University College Dublin, Dublin, Ireland
| | - Ben O'Callaghan
- School of Electrical & Electronic Engineering, University College Dublin, Dublin, Ireland
| | - Massimiliano Ditroilo
- School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland
| |
Collapse
|
11
|
Senefeld JW, Keenan KG, Ryan KS, D'Astice SE, Negro F, Hunter SK. Greater fatigability and motor unit discharge variability in human type 2 diabetes. Physiol Rep 2021; 8:e14503. [PMID: 32633071 PMCID: PMC7379048 DOI: 10.14814/phy2.14503] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
This study determined the discharge characteristics of motor units from two lower limb muscles before and after fatiguing exercise in people with type 2 diabetes (T2D) with no symptoms of polyneuropathy and activity‐matched controls. Seventeen people with T2D (65.0 ± 5.6 years; 8 women) and 17 controls (63.6 ± 4.5 years; 8 women) performed: (a) intermittent, isometric contractions at 50% maximal voluntary isometric contraction (MVIC) sustained to failure with the ankle dorsiflexors, and (b) a dynamic fatiguing task (30% MVIC load) for 6 min with the knee extensors. Before and after the fatiguing tasks, motor unit characteristics (including coefficient of variation (CV) of interspike intervals (ISI)) were quantified from high‐density electromyography and muscle contractile properties were assessed via electrical stimulation. Fatigability was ~50% greater for people with T2D than controls for the dorsiflexors (time‐to‐failure: 7.3 ± 4.1 vs. 14.3 ± 9.1 min, p = .010) and knee extensors (power reduction: 56.7 ± 11.9 vs. 31.5 ± 25.5%, p < .001). The CV of ISI was greater for the T2D than control group for the tibialis anterior (23.1 ± 11.0 vs. 21.3 ± 10.7%, p < .001) and vastus lateralis (27.8 ± 20.2 vs. 24.5 ± 16.1%, p = .011), but these differences did not change after the fatiguing exercises. People with T2D had greater reductions in the electrically evoked twitch amplitude of the dorsiflexors (8.5 ± 5.1 vs. 4.0 ± 3.4%·min‐1, p = .013) and knee extensors (49.1 ± 10.0 vs. 31.8 ± 15.9%, p = .004) than controls. Although motor unit activity was more variable in people with T2D than controls, the greater fatigability of the T2D group for lower limb muscles was due to mechanisms involving disruption of contractile function of the exercising muscles rather than motor unit behavior.
Collapse
Affiliation(s)
- Jonathon W Senefeld
- Exercise Science Program, Marquette University, Milwaukee, WI, USA.,Department of Physical Therapy, Marquette University, Milwaukee, WI, USA.,Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, USA
| | - Kevin G Keenan
- Department of Kinesiology, University of Wisconsin, Milwaukee, WI, USA.,Center for Aging and Translational Research, University of Wisconsin, Milwaukee, WI, USA
| | - Kevin S Ryan
- Exercise Science Program, Marquette University, Milwaukee, WI, USA.,Department of Physical Therapy, Marquette University, Milwaukee, WI, USA
| | - Sarah E D'Astice
- Exercise Science Program, Marquette University, Milwaukee, WI, USA.,Department of Physical Therapy, Marquette University, Milwaukee, WI, USA
| | - Francesco Negro
- Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Sandra K Hunter
- Exercise Science Program, Marquette University, Milwaukee, WI, USA.,Department of Physical Therapy, Marquette University, Milwaukee, WI, USA
| |
Collapse
|
12
|
Fitzgerald LF, Bartlett MF, Nagarajan R, Francisco EJ, Sup FC, Kent JA. Effects of old age and contraction mode on knee extensor muscle ATP flux and metabolic economy in vivo. J Physiol 2021; 599:3063-3080. [PMID: 33876434 DOI: 10.1113/jp281117] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 04/14/2021] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS We used 31-phosphorus magnetic resonance spectroscopy to quantify in vivo skeletal muscle metabolic economy (ME; mass-normalized torque or power produced per ATP consumed) during three 24 s maximal-effort contraction protocols: (1) sustained isometric (MVIC), (2) intermittent isokinetic (MVDCIsoK ), and (3) intermittent isotonic (MVDCIsoT ) in the knee extensor muscles of young and older adults. ME was not different between groups during the MVIC but was lower in older than young adults during both dynamic contraction protocols. These results are consistent with an increased energy cost of locomotion, but not postural support, with age. The effects of old age on ME were not due to age-related changes in muscle oxidative capacity or ATP flux. Specific power was lower in older than young adults, despite similar total ATP synthesis between groups. Together, this suggests a dissociation between cross-bridge activity and ATP utilization with age. ABSTRACT Muscle metabolic economy (ME; mass-normalized torque or power produced per ATP consumed) is similar in young and older adults during some isometric contractions, but less is known about potential age-related differences in ME during dynamic contractions. We hypothesized that age-related differences in ME would exist only during dynamic contractions, due to the increased energetic demand of dynamic versus isometric contractions. Ten young (Y; 27.5 ± 3.9 years, 6 men) and 10 older (O; 71 ± 5 years, 5 men) healthy adults performed three 24 s bouts of maximal contractions: (1) sustained isometric (MVIC), (2) isokinetic (120°·s-1 , MVDCIsoK ; 0.5 Hz), and (3) isotonic (load = 20% MVIC, MVDCIsoT ; 0.5 Hz). Phosphorus magnetic resonance spectroscopy of the vastus lateralis muscle was used to calculate ATP flux (mM ATP·s-1 ) through the creatine kinase reaction, glycolysis and oxidative phosphorylation. Quadriceps contractile volume (cm3 ) was measured by MRI. ME was calculated using the torque-time integral (MVIC) or power-time integral (MVDCIsoK and MVDCIsoT ), total ATP synthesis and contractile volume. As hypothesized, ME was not different between Y and O during the MVIC (0.12 ± 0.03 vs. 0.12 ± 0.02 Nm. s. cm-3 . mM ATP-1 , mean ± SD, respectively; P = 0.847). However, during both MVDCIsoK and MVDCIsoT , ME was lower in O than Y adults (MVDCIsoK : 0.011 ± 0.003 vs. 0.007 ± 0.002 J. cm-3 . mM ATP-1 ; P < 0.001; MVDCIsoT : 0.011 ± 0.002 vs. 0.008 ± 0.002; P = 0.037, respectively), despite similar muscle oxidative capacity, oxidative and total ATP flux in both groups. The lower specific power in older than young adults, despite similar total ATP synthesis between groups, suggests there is a dissociation between cross-bridge activity and ATP utilization with age.
Collapse
Affiliation(s)
- Liam F Fitzgerald
- Muscle Physiology Laboratory, Department of Kinesiology, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Miles F Bartlett
- Muscle Physiology Laboratory, Department of Kinesiology, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Rajakumar Nagarajan
- Human Magnetic Resonance Center, Institute for Applied Life Sciences, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Ericber Jimenez Francisco
- Mechatronics and Robotics Laboratory, Department of Mechanical & Industrial Engineering, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Frank C Sup
- Mechatronics and Robotics Laboratory, Department of Mechanical & Industrial Engineering, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - Jane A Kent
- Muscle Physiology Laboratory, Department of Kinesiology, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| |
Collapse
|
13
|
Slysz JT, Boston M, King R, Pignanelli C, Power GA, Burr JF. Blood Flow Restriction Combined with Electrical Stimulation Attenuates Thigh Muscle Disuse Atrophy. Med Sci Sports Exerc 2021; 53:1033-1040. [PMID: 33105390 DOI: 10.1249/mss.0000000000002544] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE This study aimed to investigate the effects of blood flow restriction (BFR) combined with electrical muscle stimulation (EMS) on skeletal muscle mass and strength during a period of limb disuse. METHODS Thirty healthy participants (22 ± 3 yr; 23 ± 3 kg·m-2) were randomly assigned to control (CON; n = 10), BFR alone (BFR; n = 10), or BFR combined with EMS (BFR + EMS; n = 10). All participants completed unloading of a single leg for 14 d, with no treatment (CON), or while treated with either BFR or BFR + EMS (twice daily, 5 d·wk-1). BFR treatment involved arterial three cycles of 5-min occlusion using suprasystolic pressure, each separated by 5 min of reperfusion. EMS (6 s on, 15 s off; 200 μs; 60 Hz; 15% maximal voluntary contraction [MVC]) was applied continuously throughout the three BFR cycles. Quadriceps muscle mass (whole-thigh lean mass via dual-energy x-ray absorptiometry and vastus lateralis [VL] muscle thickness via ultrasound) and strength (via knee extension MVC) were assessed before and after the 14-d unloading period. RESULTS After limb unloading, whole-thigh lean mass decreased in the control group (-4% ± 1%, P < 0.001) and BFR group (-3% ± 2%, P = 0.001), but not in the BFR + EMS group (-0.3% ± 3%, P = 0.8). VL muscle thickness decreased in the control group (-4% ± 4%, P = 0.005) and was trending toward a decrease in the BFR group (-8% ± 11%, P = 0.07) and increase in the BFR + EMS group (+5% ± 10%, P = 0.07). Knee extension MVC decreased over time (P < 0.005) in the control group (-18% ± 15%), BFR group (-10% ± 13%), and BFR + EMS group (-18% ± 15%), with no difference between groups (P > 0.5). CONCLUSION Unlike BFR performed in isolation, BFR + EMS represents an effective interventional strategy to attenuate the loss of muscle mass during limb disuse, but it does not demonstrate preservation of strength.
Collapse
|
14
|
Muscle Performance Changes with Age in Active Women. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18094477. [PMID: 33922474 PMCID: PMC8122865 DOI: 10.3390/ijerph18094477] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/12/2021] [Accepted: 04/20/2021] [Indexed: 01/16/2023]
Abstract
The purpose of this study was to examine age-related differences in muscle performance in women divided into young (YW, 20–39 years, n = 29) middle-aged (MAW, 40–59 years, n = 33), and older (OW, ≥60 years, n = 40) age groups. Methods: Hand grip strength, vertical jump performance, and knee extensor (KE) strength (0 deg/s, 60 deg/s, and 240 deg/s), speed of movement (SoM; at 1 Nm, 20%, 40%, and 60% isometric strength), and endurance (30-repetition test at 60 degs/s and 240 deg/s) were assessed. Computed tomography-acquired muscle cross-sectional area (mCSA) was measured and included to determine specific strength (KE strength/mCSA). Results: Hand grip strength was similar across groups, while jump performance declined with age (YW and MAW > OW, p < 0.001). KE strength declined significantly with age (all conditions p < 0.01), while specific strength was similar across groups. SoM was significantly higher for YW and MAW compared to OW (both p < 0.01). An age × velocity interaction revealed YW KE endurance was similar between conditions, whereas MAW and OW displayed significantly better endurance during the 60 deg/s condition. OW displayed impaired KE endurance at 240 deg/s (vs. YW and MAW, p < 0.01) but improved at 60 deg/s (vs. YW, p < 0.01). Dynamic torque decline increased with age (YW < OW, p = 0.03) and was associated with intramuscular adipose tissue (r = 0.21, p = 0.04). Conclusions: Performance declines were most evident among OW, but few performance deficits had emerged in MAW. Interestingly, strength declines disappeared after normalizing to mCSA and endurance appears to be velocity-dependent.
Collapse
|
15
|
Aging and Recovery After Resistance-Exercise-Induced Muscle Damage: Current Evidence and Implications for Future Research. J Aging Phys Act 2020; 29:544-551. [PMID: 33291066 DOI: 10.1123/japa.2020-0201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/09/2020] [Accepted: 08/21/2020] [Indexed: 11/18/2022]
Abstract
Aging is anecdotally associated with a prolonged recovery from resistance training, though current literature remains equivocal. This brief review considers the effects of resistance training on indirect markers of muscle damage and recovery (i.e., muscle soreness, blood markers, and muscle strength) in older males. With no date restrictions, four databases were searched for articles relating to aging, muscle damage, and recovery. Data from 11 studies were extracted for review. Of these, four reported worse symptoms in older compared with younger populations, while two have observed the opposite, and the remaining studies (n = 6) proposed no differences between age groups. It appears that resistance training can be practiced in older populations without concern for impaired recovery. To improve current knowledge, researchers are urged to utilize more ecologically valid muscle-damaging bouts and investigate the mechanisms which underpin the recovery of muscle soreness and strength after exercise in older populations.
Collapse
|
16
|
Rivière JR, Peyrot N, Cross MR, Messonnier LA, Samozino P. Strength-Endurance: Interaction Between Force-Velocity Condition and Power Output. Front Physiol 2020; 11:576725. [PMID: 33162900 PMCID: PMC7583360 DOI: 10.3389/fphys.2020.576725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 09/04/2020] [Indexed: 11/13/2022] Open
Abstract
Context Strength-endurance mainly depends on the power output, which is often expressed relative to the individual’s maximal power capability (Pmax). However, an individual can develop the same power, but in different combinations of force and velocity (force-velocity condition). Also, at matched power output, changing the force-velocity condition results in a change of the velocity-specific relative power (Pmaxv), associated with a change in the power reserve. So far, the effect of these changing conditions on strength-endurance remains unclear. Purpose We aimed to test the effects of force-velocity condition and power output on strength-endurance. Methods Fourteen sportsmen performed (i) force- and power-velocity relationships evaluation in squat jumps and (ii) strength-endurance evaluations during repeated squat jump tests in 10 different force-velocity-power conditions, individualized based on the force- and power-velocity relationships. Each condition was characterized by different (i) relative power (%Pmax), (ii) velocity-specific relative power (%Pmaxv), and (iii) ratio between force and velocity (RFv). Strength-endurance was assessed by the maximum repetitions (SJRep), and the cumulated mechanical work (Wtot) performed until exhaustion during repeated squat jump tests. Intra and inter-day reliability of SJRep were tested in one of the 10 conditions. The effects of %Pmax, %Pmaxv, and RFv on SJRep and Wtot were tested via stepwise multiple linear regressions and two-way ANOVAs. Results SJRep exhibited almost perfect intra- and inter-day reliability (ICC=0.94 and 0.92, respectively). SJRep and Wtot were influenced by %Pmaxv and RFv (R2 = 0.975 and 0.971; RSME=0.243 and 0.234, respectively; both p < 0.001), with the effect of RFv increasing with decreasing %Pmaxv (interaction effect, p = 0.03). %Pmax was not considered as a significant predictor of strength-endurance by the multiple regressions analysis. SJRep and Wtot were higher at lower %Pmaxv and in low force-high velocity conditions (i.e., lower RFv). Conclusion Strength-endurance was almost fully dependent on the position of the exercise conditions relative to the individual force-velocity and power-velocity relationships (characterized by %Pmaxv and RFv). Thus, the standardization of the force-velocity condition and the velocity-specific relative power should not be overlooked for strength-endurance testing and training, but also when setting fatiguing protocols.
Collapse
Affiliation(s)
- Jean Romain Rivière
- Univ Savoie Mont Blanc, Laboratoire Interuniversitaire de Biologie de la Motricité, EA 7424, Chambéry, France
| | - Nicolas Peyrot
- Le Mans Université, Movement-Interactions-Performance, MIP, EA 4334, Le Mans, France
| | - Matthew R Cross
- Univ Savoie Mont Blanc, Laboratoire Interuniversitaire de Biologie de la Motricité, EA 7424, Chambéry, France
| | - Laurent A Messonnier
- Univ Savoie Mont Blanc, Laboratoire Interuniversitaire de Biologie de la Motricité, EA 7424, Chambéry, France
| | - Pierre Samozino
- Univ Savoie Mont Blanc, Laboratoire Interuniversitaire de Biologie de la Motricité, EA 7424, Chambéry, France
| |
Collapse
|
17
|
Wu R, Ditroilo M, Delahunt E, De Vito G. Age Related Changes in Motor Function (II). Decline in Motor Performance Outcomes. Int J Sports Med 2020; 42:215-226. [PMID: 33137831 DOI: 10.1055/a-1265-7073] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Age-related impairments in motor performance are caused by a deterioration in mechanical and neuromuscular functions, which have been investigated from the macro-level of muscle-tendon unit to the micro-level of the single muscle fiber. When compared to the healthy young skeletal muscle, aged skeletal muscle is: (1) weaker, slower and less powerful during the performance of voluntary contractions; (2) less steady during the performance of isometric contractions, particularly at low levels of force; and (3) less susceptible to fatigue during the performance of sustained isometric contractions, but more susceptible to fatigue during the performance of high-velocity dynamic contractions. These impairments have been discussed to be mainly the result of: a) loss of muscle mass and selective atrophy of type II muscle fibers; b) altered tendon mechanical properties (decreased tendon stiffness); c) reduced number and altered function of motor units; d) slower muscle fiber shortening velocity; e) increased oscillation in common synaptic input to motor neurons; and f) altered properties and activity of sarcoplasmic reticulum. In this second part of a two-part review we have detailed the age-related impairments in motor performance with a reference to the most important mechanical and neuromuscular contributing factors.
Collapse
Affiliation(s)
- Rui Wu
- School of Public Health Physiotherapy and Sports Science, University College Dublin, Dublin
| | - Massimiliano Ditroilo
- School of Public Health Physiotherapy and Sports Science, University College Dublin, Dublin
| | - Eamonn Delahunt
- School of Public Health Physiotherapy and Sports Science, University College Dublin, Dublin
| | | |
Collapse
|
18
|
Fitzgerald LF, Ryan MM, Bartlett MF, Miehm JD, Kent JA. Muscle architecture, voluntary activation, and low-frequency fatigue do not explain the greater fatigue of older compared with young women during high-velocity contractions. PLoS One 2020; 15:e0234217. [PMID: 33141870 PMCID: PMC7608879 DOI: 10.1371/journal.pone.0234217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 10/18/2020] [Indexed: 11/18/2022] Open
Abstract
Although high-velocity contractions elicit greater muscle fatigue in older than young adults, the cause of this difference is unclear. We examined the potential roles of resting muscle architecture and baseline contractile properties, as well as changes in voluntary activation and low-frequency fatigue in response to high-velocity knee extensor work. Vastus lateralis muscle architecture was determined in quiescent muscle by ultrasonography in 8 young (23.4±1.8 yrs) and 8 older women (69.6±1.1). Maximal voluntary dynamic (MVDC) and isometric (MVIC), and stimulated (80Hz and 10Hz, 500ms) isometric contractions were performed before and immediately after 120 MVDCs (240°.s-1, one every 2s). Architecture variables did not differ between groups (p≥0.209), but the half-time of torque relaxation (T1/2) was longer in older than young women at baseline (151.9±6.0 vs. 118.8±4.4 ms, respectively, p = 0.001). Older women fatigued more than young (to 33.6±4.7% vs. 55.2±4.2% initial torque, respectively; p = 0.004), with no evidence of voluntary activation failure (ΔMVIC:80Hz torque) in either group (p≥0.317). Low-frequency fatigue (Δ10:80Hz torque) occurred in both groups (p<0.001), as did slowing of T1/2 (p = 0.001), with no differences between groups. Baseline T1/2 was inversely associated with fatigue in older (r2 = 0.584, p = 0.045), but not young women (r2 = 0.147, p = 0.348). These results indicate that differences in muscle architecture, voluntary activation, and low-frequency fatigue do not explain the greater fatigue of older compared with young women during high-velocity contractions. The inverse association between baseline T1/2 and fatigue in older women suggests that factors related to slower muscle contractile properties may be protective against fatigue during fast, repetitive contractions in aging.
Collapse
Affiliation(s)
- Liam F. Fitzgerald
- Department of Kinesiology, University of Massachusetts Amherst, Amherst, Massachusetts, United States of America
| | - Margaret M. Ryan
- Department of Kinesiology, University of Massachusetts Amherst, Amherst, Massachusetts, United States of America
| | - Miles F. Bartlett
- Department of Kinesiology, University of Massachusetts Amherst, Amherst, Massachusetts, United States of America
| | - Jules D. Miehm
- Department of Kinesiology, University of Massachusetts Amherst, Amherst, Massachusetts, United States of America
| | - Jane A. Kent
- Department of Kinesiology, University of Massachusetts Amherst, Amherst, Massachusetts, United States of America
| |
Collapse
|
19
|
Otieno LA, Semmler JG, Sidhu SK. Single joint fatiguing exercise decreases long but not short-interval intracortical inhibition in older adults. Exp Brain Res 2020; 239:47-58. [PMID: 33098654 DOI: 10.1007/s00221-020-05958-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 10/13/2020] [Indexed: 12/18/2022]
Abstract
Ageing is accompanied by neuromuscular changes which may alter fatigue in older adults. These changes may include changes in corticospinal excitatory and inhibitory processes. Previous research has suggested that single joint fatiguing exercise decreases short-(SICI) and long-(LICI) interval intracortical inhibition in young adults. However, this is yet to be established in older adults. In 19 young (23 ± 4 years) and 18 older (69 ± 5 years) adults, SICI (2 ms interstimulus interval; ISI) and LICI (100 ms ISI) were measured in a resting first dorsal interosseous (FDI) muscle using transcranial magnetic stimulation (TMS) before and after a 15 min sustained submaximal contraction at 25% of their maximum EMG. Subsequent ten 2-min contractions held at 25% EMG were also performed to sustain fatigue for a total of 30 min, while SICI and LICI were taken immediately after each contraction. There was no change in SICI post-fatiguing exercise compared to baseline in both young and older adults (P = 0.4). Although there was no change in LICI post-fatiguing exercise in younger adults (P = 1.0), LICI was attenuated in older adults immediately post-fatiguing exercise and remained attenuated post-fatigue (PF)1 and PF2 (P < 0.05). Contrary to previous studies, the lack of change in SICI and LICI in young adults following a sustained submaximal EMG contraction suggests that GABA modulation may be dependent on the type of fatiguing task performed. The reduction in LICI in older adults post-fatiguing exercise suggests an age-related decrease in GABAB-mediated activity with sustained submaximal fatiguing exercise.
Collapse
Affiliation(s)
- Lavender A Otieno
- Discipline of Physiology, Adelaide Medical School, The University of Adelaide, S433, Helen Mayo South, Frome Rd, Adelaide, South Australia, 5005, Australia
| | - John G Semmler
- Discipline of Physiology, Adelaide Medical School, The University of Adelaide, S433, Helen Mayo South, Frome Rd, Adelaide, South Australia, 5005, Australia
| | - Simranjit K Sidhu
- Discipline of Physiology, Adelaide Medical School, The University of Adelaide, S433, Helen Mayo South, Frome Rd, Adelaide, South Australia, 5005, Australia.
| |
Collapse
|
20
|
Skrzat JM, Carp SJ, Dai T, Lauer R, Hiremath SV, Gaeckle N, Tucker CA. Use of Surface Electromyography to Measure Muscle Fatigue in Patients in an Acute Care Hospital. Phys Ther 2020; 100:897-906. [PMID: 32157308 DOI: 10.1093/ptj/pzaa035] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Accepted: 11/29/2019] [Indexed: 01/19/2023]
Abstract
BACKGROUND Functional outcomes with early rehabilitation in the acute care setting have improved; however, an improved understanding of muscle fatigue using surface electromyography (sEMG) is warranted to better guide patient-centered exercise prescription. OBJECTIVES The objectives of this study were to assess the safety and feasibility of collecting sEMG at the acute care bedside and to determine differences in muscle fatigue during isometric and dynamic submaximal contractions among patients in the hospital, healthy younger participants, and healthy older participants. DESIGN The study used an observational cohort design. METHODS There were 37 participants. Median frequency (Fmed) of the myoelectric signal of the quadriceps femoris muscles and time to task failure (TTTF) were measured using sEMG during an isometric and dynamic fatiguing contraction. Primary analysis compared TTTF between groups for both types of contractions. Secondary analysis compared Fmed at initiation and termination of fatiguing contraction. RESULTS High-quality sEMG measures were safe and feasible to collect at the acute care bedside with no adverse events. There was a statistically significant difference in TTTF between groups after isometric and dynamic contractions; hospitalized patients fatigued faster than healthy younger and healthy older participants after both contractions. With the exception of the vastus lateralis during a dynamic contraction in healthy younger and hospitalized patients, there was a statistically significant difference between Fmed at initiation and termination of contraction, indicating that subjects' muscles did truly fatigue. LIMITATIONS A limitation of the study was the small sample size of patients who were hospitalized without matched controls. CONCLUSIONS sEMG is a lab quantitative technique that was found to be safe and feasible to assess muscle fatigue in the acute care environment. The protocol yielded similar results to previously published literature for healthy younger and healthy older people. Further research is needed to better understand how to integrate sEMG findings into patient-centered exercise prescriptions.
Collapse
Affiliation(s)
- Julie M Skrzat
- Department of Physical Therapy, College of Public Health, Temple University, Philadelphia, Pennsylvania; and Physical Therapy Program, DeSales University, 2755 Station Avenue, Center Valley, PA 18034 (USA)
| | - Stephen J Carp
- Physical Therapy Program, DeSales University. S.J. Carp is a Board Certified Clinical Specialist in Geriatric Physical Therapy
| | - Ting Dai
- Department of Educational Psychology, College of Education, University of Illinois at Chicago, Chicago, Illinois
| | - Richard Lauer
- Department of Physical Therapy, College of Public Health, Temple University
| | - Shivayogi V Hiremath
- Department of Physical Therapy, College of Public Health, Temple University; and Department of Electrical and Computer Engineering, College of Engineering, Temple University
| | - Nathaniel Gaeckle
- Division of Pulmonary and Critical Care, Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Carole A Tucker
- Department of Physical Therapy, College of Public Health, Temple University; and Department of Electrical and Computer Engineering, College of Engineering, Temple University
| |
Collapse
|
21
|
Age-related neuromuscular fatigue and recovery after cycling: Measurements in isometric and dynamic modes. Exp Gerontol 2020; 133:110877. [DOI: 10.1016/j.exger.2020.110877] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 02/08/2020] [Accepted: 02/10/2020] [Indexed: 01/02/2023]
|
22
|
Englund DA, Price LL, Grosicki GJ, Iwai M, Kashiwa M, Liu C, Reid KF, Fielding RA. Progressive Resistance Training Improves Torque Capacity and Strength in Mobility-Limited Older Adults. J Gerontol A Biol Sci Med Sci 2019; 74:1316-1321. [PMID: 30165595 PMCID: PMC6625591 DOI: 10.1093/gerona/gly199] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Progressive resistance training (PRT) is consistently shown to improve muscle strength in older adults. The efficacy of PRT to improve muscle fatigue in older adults with demonstrated mobility limitations remains unclear. METHODS Mobility-limited (Short Physical Performance Battery [SPPB] ≤ 9) older adults (age 70-92 years) were recruited for this study and randomized to either PRT or home-based flexibility (FLEX) 3 d/wk for 12 weeks. Muscle fatigue and strength outcomes were assessed at baseline and 12 weeks. The primary outcome was torque capacity, a composite measure of strength and fatigue, defined as the sum of peak torques from an isokinetic fatigue test. RESULTS Seventy participants were randomized (mean [SD] age 78.9 [5.4] years; 60% female; mean [SD] SPPB 7.5 [1.6]). At follow-up, the PRT group improved significantly in torque capacity, mean between-group difference (95% confidence interval) 466.19 (138.4, 793.97) Nm (p = .006), and maximal strength 127.3 (60.96, 193.61) Nm (p = .0003), when compared with FLEX group. Neither group demonstrated significant changes in muscle fatigue or torque variability. CONCLUSION Twelve weeks of PRT improved torque capacity, as well as strength in mobility-limited older adults. These results demonstrate PRT improves multiple age-related muscular impairments.
Collapse
Affiliation(s)
- Davis A Englund
- Nutrition, Exercise Physiology, and Sarcopenia Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts
| | - Lori Lyn Price
- Institute for Clinical Research and Health Policy Studies, Tufts Medical Center, Boston, Massachusetts
- Tufts Clinical and Translational Science Institute, Tufts University, Boston, Massachusetts
| | - Gregory J Grosicki
- Nutrition, Exercise Physiology, and Sarcopenia Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts
| | | | | | - Christine Liu
- Nutrition, Exercise Physiology, and Sarcopenia Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts
- Geriatrics Section, Department of Medicine, Boston Medical Center, Massachusetts
| | - Kieran F Reid
- Nutrition, Exercise Physiology, and Sarcopenia Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts
| | - Roger A Fielding
- Nutrition, Exercise Physiology, and Sarcopenia Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts
| |
Collapse
|
23
|
Effect of Aging on the Lower Limb Kinematics in Karate Practitioners: Comparing Athletes and Their Senseis. JOURNAL OF HEALTHCARE ENGINEERING 2019; 2019:2672185. [PMID: 31281614 PMCID: PMC6589306 DOI: 10.1155/2019/2672185] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 03/24/2019] [Accepted: 04/17/2019] [Indexed: 11/17/2022]
Abstract
With the life expectancy increasing, older adult population has gained the attention of many researchers. Aging is known to lead to a general decline in bodily functions, which affect the quality of life. The aim of this study was to analyze how the aging process affects veteran active karate practitioners, in the kinematic and temporal structure of the frontal kick. Nine black belt karate practitioners over 50 years old and 24 black belt karate practitioners, aged between 20 and 30 years old, all male, performed the frontal kick mae-geri. Results showed that knee is the structure that holds most differences between young and veterans, both for linear and for angular variables during the mae-geri performance. Statistical differences were found in linear velocity for the knee; linear acceleration of the knee, hip, and RASIS; maximum angular velocity for knee and hip; maximum angular acceleration for ankle and hip; and in the range of motion of knee. The temporal variables show differences, between groups, in maximum linear velocity, maximum linear acceleration, and maximum angular acceleration. However, no differences were found between groups for the time before contact in the maximum linear and angular acceleration, which allow us to remark both the effects of the aging process and the effect of training. This study corroborates the ability of older people to achieve benefits from sports practice, achieving higher efficiency than the younger adults in task execution, but using different motor control strategies.
Collapse
|
24
|
Wu R, Delahunt E, Ditroilo M, Ferri Marini C, De Vito G. Torque steadiness and neuromuscular responses following fatiguing concentric exercise of the knee extensor and flexor muscles in young and older individuals. Exp Gerontol 2019; 124:110636. [PMID: 31195103 DOI: 10.1016/j.exger.2019.110636] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 05/16/2019] [Accepted: 06/09/2019] [Indexed: 11/17/2022]
Abstract
The purpose of this study was to investigate the age-related alterations in the ability to exert maximal and to sustain submaximal isometric muscle torques after a fatiguing concentric exercise conducted with knee extensor (KE) and flexor (KF) muscles. Sixteen young (aged 19-30 years; 8 women) and 17 older (aged 65-75 years; 9 women) volunteers participated. The following tasks were performed before and immediately after 22 maximal concentric efforts of the right KE and KF at 1.05 rad/s: (1) a maximal voluntary isometric contraction (MVIC) task involving both KE and KF; and (2) a KE torque-steadiness task at a submaximal target contraction intensity (20% MVIC). During the dynamometric tests, surface EMG was recorded simultaneously from the KE and KF muscles. Fatigue-induced reductions in knee extension MVIC were similar (~15%) between groups, but young participants showed more pronounced declines in agonist (i.e. quadriceps) EMG responses in both time (RMS amplitude; ~15% vs. ~10%, p < 0.001) and frequency (median frequency; ~14% vs. ~8%, p < 0.01) domains. Torque steadiness exhibited a similar post-fatigue decrease in the two age groups (p < 0.01), but interestingly agonist activation (~17%; p < 0.001) and antagonist (i.e. hamstrings) co-activation (~16%; p < 0.001) declined only in the older participants. These findings suggest that the fatiguing concentric KE and KF exercise results in similar relative reductions (%) in maximal torque and steadiness of the KE in young and older individuals, but they are sustained by different age-related neuromuscular strategies.
Collapse
Affiliation(s)
- Rui Wu
- School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland.
| | - Eamonn Delahunt
- School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland; Institute for Sport and Health, University College Dublin, Dublin, Ireland
| | - Massimiliano Ditroilo
- School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland; Institute for Sport and Health, University College Dublin, Dublin, Ireland
| | - Carlo Ferri Marini
- Department of Biomolecular Science, University of Urbino Carlo Bo, Italy
| | - Giuseppe De Vito
- School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland; Institute for Sport and Health, University College Dublin, Dublin, Ireland
| |
Collapse
|
25
|
Sundberg CW, Prost RW, Fitts RH, Hunter SK. Bioenergetic basis for the increased fatigability with ageing. J Physiol 2019; 597:4943-4957. [PMID: 31018011 DOI: 10.1113/jp277803] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 04/18/2019] [Indexed: 12/25/2022] Open
Abstract
KEY POINTS The mechanisms for the age-related increase in fatigability during dynamic exercise remain elusive. We tested whether age-related impairments in muscle oxidative capacity would result in a greater accumulation of fatigue causing metabolites, inorganic phosphate (Pi ), hydrogen (H+ ) and diprotonated phosphate (H2 PO4 - ), in the muscle of old compared to young adults during a dynamic knee extension exercise. The age-related increase in fatigability (reduction in mechanical power) of the knee extensors was closely associated with a greater accumulation of metabolites within the working muscle but could not be explained by age-related differences in muscle oxidative capacity. These data suggest that the increased fatigability in old adults during dynamic exercise is primarily determined by age-related impairments in skeletal muscle bioenergetics that result in a greater accumulation of metabolites. ABSTRACT The present study aimed to determine whether the increased fatigability in old adults during dynamic exercise is associated with age-related differences in skeletal muscle bioenergetics. Phosphorus nuclear magnetic resonance spectroscopy was used to quantify concentrations of high-energy phosphates and pH in the knee extensors of seven young (22.7 ± 1.2 years; six women) and eight old adults (76.4 ± 6.0 years; seven women). Muscle oxidative capacity was measured from the phosphocreatine (PCr) recovery kinetics following a 24 s maximal voluntary isometric contraction. The fatiguing exercise consisted of 120 maximal velocity contractions (one contraction per 2 s) against a load equivalent to 20% of the maximal voluntary isometric contraction. The PCr recovery kinetics did not differ between young and old adults (0.023 ± 0.007 s-1 vs. 0.019 ± 0.004 s-1 , respectively). Fatigability (reductions in mechanical power) of the knee extensors was ∼1.8-fold greater with age and was accompanied by a greater decrease in pH (young = 6.73 ± 0.09, old = 6.61 ± 0.04) and increases in concentrations of inorganic phosphate, [Pi ], (young = 22.7 ± 4.8 mm, old = 32.3 ± 3.6 mm) and diprotonated phosphate, [H2 PO4 - ], (young = 11.7 ± 3.6 mm, old = 18.6 ± 2.1 mm) at the end of the exercise in old compared to young adults. The age-related increase in power loss during the fatiguing exercise was strongly associated with intracellular pH (r = -0.837), [Pi ] (r = 0.917) and [H2 PO4 - ] (r = 0.930) at the end of the exercise. These data suggest that the age-related increase in fatigability during dynamic exercise has a bioenergetic basis and is explained by an increased accumulation of metabolites within the muscle.
Collapse
Affiliation(s)
- Christopher W Sundberg
- Department of Biological Sciences, Marquette University, Milwaukee, WI, USA.,Department of Physical Therapy, Marquette University, Milwaukee, WI, USA
| | - Robert W Prost
- Department of Radiology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Robert H Fitts
- Department of Biological Sciences, Marquette University, Milwaukee, WI, USA
| | - Sandra K Hunter
- Department of Physical Therapy, Marquette University, Milwaukee, WI, USA
| |
Collapse
|
26
|
Sundberg CW, Fitts RH. Bioenergetic basis of skeletal muscle fatigue. CURRENT OPINION IN PHYSIOLOGY 2019; 10:118-127. [PMID: 31342000 DOI: 10.1016/j.cophys.2019.05.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Energetic demand from high-intensity exercise can easily exceed ATP synthesis rates of mitochondria leading to a reliance on anaerobic metabolism. The reliance on anaerobic metabolism results in the accumulation of intracellular metabolites, namely inorganic phosphate (Pi) and hydrogen (H+), that are closely associated with exercise-induced reductions in power. Cellular and molecular studies have revealed several steps where these metabolites impair contractile function demonstrating a causal role in fatigue. Elevated Pi or H+ directly inhibits force and power of the cross-bridge and decreases myofibrillar Ca2+ sensitivity, whereas Pi also inhibits Ca2+ release from the sarcoplasmic reticulum (SR). When both metabolites are elevated, they act synergistically to cause marked reductions in power, indicating that fatigue during high-intensity exercise has a bioenergetic basis.
Collapse
Affiliation(s)
- Christopher W Sundberg
- Department of Biological Sciences, Marquette University, Milwaukee, WI.,Department of Physical Therapy, Marquette University, Milwaukee, WI
| | - Robert H Fitts
- Department of Biological Sciences, Marquette University, Milwaukee, WI
| |
Collapse
|
27
|
Lavin KM, Roberts BM, Fry CS, Moro T, Rasmussen BB, Bamman MM. The Importance of Resistance Exercise Training to Combat Neuromuscular Aging. Physiology (Bethesda) 2019; 34:112-122. [PMID: 30724133 PMCID: PMC6586834 DOI: 10.1152/physiol.00044.2018] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 11/05/2018] [Accepted: 11/05/2018] [Indexed: 12/15/2022] Open
Abstract
Older adults undergoing age-related decrements in muscle health can benefit substantially from resistance exercise training, a potent stimulus for whole muscle and myofiber hypertrophy, neuromuscular performance gains, and improved functional mobility. With the use of advancing technologies, research continues to elucidate the mechanisms of and heterogeneity in adaptations to resistance exercise training beyond differences in exercise prescription. This review highlights the current knowledge in these areas and emphasizes knowledge gaps that require future attention of the field.
Collapse
Affiliation(s)
- Kaleen M Lavin
- UAB Center for Exercise Medicine, University of Alabama at Birmingham , Birmingham, Alabama
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Brandon M Roberts
- UAB Center for Exercise Medicine, University of Alabama at Birmingham , Birmingham, Alabama
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham , Birmingham, Alabama
| | - Christopher S Fry
- Department of Nutrition and Metabolism, University of Texas Medical Branch , Galveston, Texas ; and
- Sealy Center on Aging, University of Texas Medical Branch , Galveston, Texas
| | - Tatiana Moro
- Department of Nutrition and Metabolism, University of Texas Medical Branch , Galveston, Texas ; and
- Sealy Center on Aging, University of Texas Medical Branch , Galveston, Texas
| | - Blake B Rasmussen
- Department of Nutrition and Metabolism, University of Texas Medical Branch , Galveston, Texas ; and
- Sealy Center on Aging, University of Texas Medical Branch , Galveston, Texas
| | - Marcas M Bamman
- UAB Center for Exercise Medicine, University of Alabama at Birmingham , Birmingham, Alabama
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham , Birmingham, Alabama
| |
Collapse
|
28
|
Age Does Not Attenuate Maximal Velocity Adaptations in the Ipsilateral and Contralateral Limbs During Unilateral Resistance Training. J Aging Phys Act 2019; 27:1-8. [DOI: 10.1123/japa.2017-0297] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
29
|
Xu L, Chen X, Cao S, Zhang X, Chen X. A Fatigue Involved Modification Framework for Force Estimation in Fatiguing Contraction. IEEE Trans Neural Syst Rehabil Eng 2018; 26:2153-2164. [PMID: 30281465 DOI: 10.1109/tnsre.2018.2872554] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
To alleviate the negative impacts of muscle fatigue on a force estimation model, a modification framework taking use of fatigue index was put forward in this paper. Muscle force and surface electromyography were first collected using high-density electrode grid and dynamometer. Then, multi-step signal pre-processing and a nonnegative matrix factorization-based signal optimization were conducted, with fatigue indices being extracted in the same time. Next, a degree 4 polynomial fitting model was employed to undertake the training process, and the relationship between the generated model parameters and fatigue indices was built up. In the end, the parameter-index relationship was applied on different testing sets to complete fatigue-modified force estimation. Significant improvement was found in most testing cases across different sexes and ages. Relative decreases of 36.5%, 20.7%, and 20.4% in the percentage root mean square error were achieved by young males, young females, and elderly males. The proposed method can boost the performances of force estimation models, thereby contributing to the development of a variety of fields including biomechanical study, rehabilitation treatment, and prosthesis research.
Collapse
|
30
|
KRÜGER RENATAL, ABOODARDA SAIEDJALAL, SAMOZINO PIERRE, RICE CHARLESL, MILLET GUILLAUMEY. Isometric versus Dynamic Measurements of Fatigue: Does Age Matter? A Meta-analysis. Med Sci Sports Exerc 2018; 50:2132-2144. [DOI: 10.1249/mss.0000000000001666] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
31
|
Sundberg CW, Hunter SK, Trappe SW, Smith CS, Fitts RH. Effects of elevated H + and P i on the contractile mechanics of skeletal muscle fibres from young and old men: implications for muscle fatigue in humans. J Physiol 2018; 596:3993-4015. [PMID: 29806714 PMCID: PMC6117549 DOI: 10.1113/jp276018] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Accepted: 04/27/2018] [Indexed: 01/09/2023] Open
Abstract
KEY POINTS The mechanisms responsible for the loss in muscle power and increased fatigability with ageing are unresolved. We show that the contractile mechanics of fibres from the vastus lateralis of old men were well-preserved compared to those of young men, but the selective loss of fast myosin heavy chain II muscle was strongly associated with age-related decrements in whole-muscle strength and power. We reveal that the combination of acidosis (H+ ) and inorganic phosphate (Pi ) is an important mediator of muscle fatigue in humans by inhibiting the low- to high-force state of the cross-bridge cycle and peak power, but the depressive effects of these ions on cross-bridge function were similar in fibres from young and old men. These findings suggest that the age-related loss in muscle power is primarily determined by the atrophy of fast fibres, but the age-related increased fatigability cannot be explained by an increased sensitivity of the cross-bridge to H+ and Pi . ABSTRACT The present study aimed to identify the mechanisms responsible for the loss in muscle power and increased fatigability with ageing by integrating measures of whole-muscle function with single fibre contractile mechanics. After adjusting for the 22% smaller muscle mass in old (73-89 years, n = 6) compared to young men (20-29 years, n = 6), isometric torque and power output of the knee extensors were, respectively, 38% and 53% lower with age. Fatigability was ∼2.7-fold greater with age and strongly associated with reductions in the electrically-evoked contractile properties. To test whether cross-bridge mechanisms could explain age-related decrements in knee extensor function, we exposed myofibres (n = 254) from the vastus lateralis to conditions mimicking quiescent muscle and fatiguing levels of acidosis (H+ ) (pH 6.2) and inorganic phosphate (Pi ) (30 mm). The fatigue-mimicking condition caused marked reductions in force, shortening velocity and power and inhibited the low- to high-force state of the cross-bridge cycle, confirming findings from non-human studies that these ions act synergistically to impair cross-bridge function. Other than severe age-related atrophy of fast fibres (-55%), contractile function and the depressive effects of the fatigue-mimicking condition did not differ in fibres from young and old men. The selective loss of fast myosin heavy chain II muscle was strongly associated with the age-related decrease in isometric torque (r = 0.785) and power (r = 0.861). These data suggest that the age-related loss in muscle strength and power are primarily determined by the atrophy of fast fibres, but the age-related increased fatigability cannot be explained by an increased sensitivity of the cross-bridge to H+ and Pi .
Collapse
Affiliation(s)
- Christopher W. Sundberg
- Exercise Science ProgramMilwaukeeWIUSA
- Clinical & Translational Rehabilitation Health Sciences ProgramDepartment of Physical TherapyMarquette UniversityMilwaukeeWIUSA
| | - Sandra K. Hunter
- Exercise Science ProgramMilwaukeeWIUSA
- Clinical & Translational Rehabilitation Health Sciences ProgramDepartment of Physical TherapyMarquette UniversityMilwaukeeWIUSA
| | - Scott W. Trappe
- Human Performance LaboratoryBall State UniversityMuncieINUSA
| | | | - Robert H. Fitts
- Department of Biological SciencesMarquette UniversityMilwaukeeWIUSA
| |
Collapse
|
32
|
Internal Loads, but Not External Loads and Fatigue, Are Similar in Young and Middle-Aged Resistance-Trained Males during High Volume Squatting Exercise †. J Funct Morphol Kinesiol 2018; 3:jfmk3030045. [PMID: 33466974 PMCID: PMC7739293 DOI: 10.3390/jfmk3030045] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 08/11/2018] [Accepted: 08/20/2018] [Indexed: 11/18/2022] Open
Abstract
Little is known about the internal and external loads experienced during resistance exercise, or the subsequent fatigue-related response, across different age groups. This study compared the internal (heart rate, OMNI ratings of perceived exertion (RPE), session RPE) and external loads (peak velocity and power and volume load) during high volume squatting exercise (10 × 10 at 60% one-repetition maximum (1RM)) and the fatigue-related response (maximal voluntary contraction (MVC), voluntary activation (VA), resting doublet force, peak power, and blood lactate) in young (n = 9; age 22.3 ± 1.7 years) and middle-aged (n = 9; age 39.9 ± 6.2 years) resistance-trained males. All internal load variables and peak velocity illustrated unclear differences between groups during exercise. Peak power and volume load were likely higher in the young group compared to their middle-aged counterparts. The unclear differences in MVC, VA and blood lactate between groups after exercise were accompanied by very likely greater decrements in resting doublet force and peak power at 20 and 80% 1RM in the middle-aged group compared to the young group. These data indicate that internal load is not different between young and middle-aged resistance-trained males, though certain external load measures and the fatigue response are.
Collapse
|
33
|
Abstract
Performance fatigability is characterized as an acute decline in motor performance caused by an exercise-induced reduction in force or power of the involved muscles. Multiple mechanisms contribute to performance fatigability and originate from neural and muscular processes, with the task demands dictating the mechanisms. This review highlights that (1) inadequate activation of the motoneuron pool can contribute to performance fatigability, and (2) the demands of the task and the physiological characteristics of the population assessed, dictate fatigability and the involved mechanisms. Examples of task and population differences in fatigability highlighted in this review include contraction intensity and velocity, stability and support provided to the fatiguing limb, sex differences, and aging. A future challenge is to define specific mechanisms of fatigability and to translate these findings to real-world performance and exercise training in healthy and clinical populations across the life span.
Collapse
Affiliation(s)
- Sandra K Hunter
- Exercise Science Program, Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin 53201
| |
Collapse
|
34
|
Uematsu A, Hortobágyi T, Tsuchiya K, Kadono N, Kobayashi H, Ogawa T, Suzuki S. Lower extremity power training improves healthy old adults' gait biomechanics. Gait Posture 2018; 62:303-310. [PMID: 29609158 DOI: 10.1016/j.gaitpost.2018.03.036] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 03/14/2018] [Accepted: 03/23/2018] [Indexed: 02/02/2023]
Abstract
PURPOSE Age-related slowing of gait speed predicts many clinical conditions in later life. We examined the kinematic and kinetic mechanisms of how lower extremity power training increases healthy old adults' gait speed. METHODS We randomly allocated old adults to a training (age 74.3 y, 9 males, 6 females) and a control group (age 73.6 y, 3 males, 4 females) and compared the biomechanics of habitual and fast gait before and after 16 sessions (8 weeks) of lower extremity power training. RESULTS Training increased maximal leg press load by ∼40% (P < 0.05) and maximal voluntary force in five groups of leg muscles by ∼32% (P < 0.05) in the training group. Training vs. control tended to increase habitual (10.8 vs. 7.6%) and fast gait speed (17.6 vs. 9.0%; all P < 0.05) more. In the training group only, these increases in gait speed correlated with increases in stride length (habitual: r2 = 0.84, fast: r2 = 0.89). Training made old adults' gait more erect: hip and knee extension increased in the stance phase of gait. Training increased ankle joint positive work by 3.3 J (control: -0.4 J, Group by Time interaction: P < 0.05), which correlated r2 = 0.58 and r2 = 0.67 with increases in habitual and fast gait speed without changes in hip and knee joint powers. CONCLUSION Increases in leg muscle power increased healthy old adults' gait speed through correlated increases in stride length and ankle plantarflexor work generation.
Collapse
Affiliation(s)
- Azusa Uematsu
- Dokkyo Medical University, 880, Kitakobayashi, Mibu-machi, Shimotsuga-gun, Tochigi, 321-0293, Japan.
| | - Tibor Hortobágyi
- University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Kazushi Tsuchiya
- Department of Physical Therapy, Yamagata Prefectural University of Health Sciences, Yamagata, Japan
| | - Norio Kadono
- Advanced Research Center for Human Sciences, Waseda University, Tokorozawa, Japan; Department of Movement Arts, Health Promotion & Leisure Studies, Bridgewater State University, Bridgewater, USA
| | - Hirofumi Kobayashi
- Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Japan
| | - Tomoya Ogawa
- School of Human Sciences, Waseda University, Tokorozawa, Japan
| | - Shuji Suzuki
- Faculty of Human Sciences, Waseda University, Tokorozawa, Japan
| |
Collapse
|
35
|
Sundberg CW, Kuplic A, Hassanlouei H, Hunter SK. Mechanisms for the age-related increase in fatigability of the knee extensors in old and very old adults. J Appl Physiol (1985) 2018; 125:146-158. [PMID: 29494293 DOI: 10.1152/japplphysiol.01141.2017] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The mechanisms for the age-related increase in fatigability during high-velocity contractions in old and very old adults (≥80 yr) are unresolved. Moreover, whether the increased fatigability with advancing age and the underlying mechanisms differ between men and women is not known. The purpose of this study was to quantify the fatigability of knee extensor muscles and identify the mechanisms of fatigue in 30 young (22.6 ± 0.4 yr; 15 men), 62 old (70.5 ± 0.7 yr; 33 men), and 12 very old (86.0 ± 1.3 yr; 6 men) men and women elicited by high-velocity concentric contractions. Participants performed 80 maximal velocity contractions (1 contraction per 3 s) with a load equivalent to 20% of the maximum voluntary isometric contraction. Voluntary activation and contractile properties were quantified before and immediately following exercise (<10 s) using transcranial magnetic stimulation and electrical stimulation. Absolute mechanical power output was 97 and 217% higher in the young compared with old and very old adults, respectively. Fatigability (reductions in power) progressively increased across age groups, with a power loss of 17% in young, 31% in old, and 44% in very old adults. There were no sex differences in fatigability among any of the age groups. The age-related increase in power loss was strongly associated with changes in the involuntary twitch amplitude ( r = 0.75, P < 0.001). These data suggest that the age-related increased power loss during high-velocity fatiguing exercise is unaffected by biological sex and determined primarily by mechanisms that disrupt excitation contraction coupling and/or cross-bridge function. NEW & NOTEWORTHY We show that aging of the neuromuscular system results in an increase in fatigability of the knee extensors during high-velocity exercise that is more pronounced in very old adults (≥80 yr) and occurs similarly in men and women. Importantly, the age-related increase in power loss was strongly associated with the changes in the electrically evoked contractile properties suggesting that the increased fatigability with aging is determined primarily by mechanisms within the muscle for both sexes.
Collapse
Affiliation(s)
- Christopher W Sundberg
- Exercise Science Program, Department of Physical Therapy, Marquette University , Milwaukee, Wisconsin.,Clinical and Translational Rehabilitation Health Sciences Program, Department of Physical Therapy, Marquette University , Milwaukee, Wisconsin
| | - Andrew Kuplic
- Exercise Science Program, Department of Physical Therapy, Marquette University , Milwaukee, Wisconsin.,Clinical and Translational Rehabilitation Health Sciences Program, Department of Physical Therapy, Marquette University , Milwaukee, Wisconsin
| | - Hamidollah Hassanlouei
- Exercise Science Program, Department of Physical Therapy, Marquette University , Milwaukee, Wisconsin
| | - Sandra K Hunter
- Exercise Science Program, Department of Physical Therapy, Marquette University , Milwaukee, Wisconsin.,Clinical and Translational Rehabilitation Health Sciences Program, Department of Physical Therapy, Marquette University , Milwaukee, Wisconsin
| |
Collapse
|
36
|
Van Driessche S, Delecluse C, Bautmans I, Vanwanseele B, Van Roie E. Age-related differences in rate of power development exceed differences in peak power. Exp Gerontol 2017; 101:95-100. [PMID: 29155242 DOI: 10.1016/j.exger.2017.11.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 11/08/2017] [Accepted: 11/14/2017] [Indexed: 11/19/2022]
Affiliation(s)
- Stijn Van Driessche
- KU Leuven, Department of Movement Sciences, Physical Activity, Sports and Health Research Group, Belgium.
| | - Christophe Delecluse
- KU Leuven, Department of Movement Sciences, Physical Activity, Sports and Health Research Group, Belgium
| | - Ivan Bautmans
- Vrije Universiteit Brussel (VUB), Gerontology Department, Frailty in Aging Research Group, Belgium
| | - Benedicte Vanwanseele
- KU Leuven, Department of Movement Sciences, Human Movement Biomechanics Research Group, Belgium
| | - Evelien Van Roie
- KU Leuven, Department of Movement Sciences, Physical Activity, Sports and Health Research Group, Belgium
| |
Collapse
|
37
|
Argaud S, Pairot de Fontenay B, Blache Y, Monteil K. Explosive movement in the older men: analysis and comparative study of vertical jump. Aging Clin Exp Res 2017; 29:985-992. [PMID: 27844453 DOI: 10.1007/s40520-016-0660-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 10/13/2016] [Indexed: 11/24/2022]
Abstract
BACKGROUND Loss of power has been demonstrated to have severe functional consequences to perform physical daily living tasks in old age. PURPOSE This study aimed to assess how moment and velocity were affected for each joint of the lower limbs during squat jumping for older men in comparison with young adults. METHODS Twenty-one healthy older men (74.5 ± 4.6 years) and 22 young men (21.8 ± 2.8 years) performed maximal squat jumps. Inverse dynamics procedure was used to compute the net joint power, moment and velocity produced at the hip, knee and ankle joints. RESULTS AND DISCUSSION Vertical jump height of the elderly was 64 % lower than the young adults. The maximal power of the body mass center (P maxbmc ) was 57 % lower in the older population. For the instant at P maxbmc , the vertical ground reaction force and the vertical velocity of the body mass center were 26 % and 35 % less in the older adults than in the young adults, respectively (p < 0.05; ES = -1.64 for vertical ground reaction force; p < 0.05; ES = -1.10). A lower value of the hip (-60 %), knee (-72 %) and ankle (-68 %) joint powers was observed in older adults. This was explained by both lower values of joint moments (-64, -57 and -61 % for the hip, knee and ankle, respectively) and angular velocities (-59, -49 and -52 % for the hip, knee and ankle, respectively). CONCLUSION This study showed a lower joint power when performing vertical jump. This smaller power resulted from both a lower moment and angular velocity produced at each joint.
Collapse
Affiliation(s)
- Sébastien Argaud
- Laboratoire Inter-Universitaire de Biologie de la Motricité (LIBM), Université Claude Bernard Lyon1, Lyon, France.
| | | | - Yoann Blache
- Laboratoire Inter-Universitaire de Biologie de la Motricité (LIBM), Université Claude Bernard Lyon1, Lyon, France
| | - Karine Monteil
- Laboratoire Inter-Universitaire de Biologie de la Motricité (LIBM), Université Claude Bernard Lyon1, Lyon, France
| |
Collapse
|
38
|
Oliveira LF, Palinkas M, Vasconcelos PBD, Regalo IH, Cecilio FA, Oliveira EF, Semprini M, Siéssere S, Regalo SCH. Influence of age on the electromyographic fatigue threshold of the masseter and temporal muscles of healthy individuals. Arch Oral Biol 2017; 84:1-5. [PMID: 28926743 DOI: 10.1016/j.archoralbio.2017.09.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 08/30/2017] [Accepted: 09/07/2017] [Indexed: 11/24/2022]
Affiliation(s)
- Lígia Franco Oliveira
- Department of Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo, Brazil
| | - Marcelo Palinkas
- Department of Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo, Brazil.
| | - Paulo Batista de Vasconcelos
- Department of Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo, Brazil
| | - Isabela Hallak Regalo
- Department of Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo, Brazil
| | - Flávia Argentato Cecilio
- Department of Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo, Brazil
| | - Erica Franco Oliveira
- Department of Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo, Brazil
| | - Marisa Semprini
- Department of Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo, Brazil
| | - Selma Siéssere
- Department of Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo, Brazil
| | - Simone Cecilio Hallak Regalo
- Department of Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo, Brazil
| |
Collapse
|
39
|
Lanning AC, Power GA, Christie AD, Dalton BH. Influence of sex on performance fatigability of the plantar flexors following repeated maximal dynamic shortening contractions. Appl Physiol Nutr Metab 2017. [PMID: 28636840 DOI: 10.1139/apnm-2017-0013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose was to determine sex differences in fatigability during maximal, unconstrained velocity, shortening plantar flexions. The role of time-dependent measures (i.e., rate of torque development, rate of velocity development, and rate of neuromuscular activation) in such sex-related differences was also examined. By task termination, females exhibited smaller reductions in power and similar changes in rate of neuromuscular activation than males, indicating females were less fatigable than males.
Collapse
Affiliation(s)
- Amelia C Lanning
- a Department of Human Physiology, University of Oregon, Eugene, OR 97403, USA
| | - Geoffrey A Power
- b Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Anita D Christie
- a Department of Human Physiology, University of Oregon, Eugene, OR 97403, USA
| | - Brian H Dalton
- c School of Health and Exercise Sciences, The University of British Columbia, ART 360, 1147 Research Road, Kelowna, BC V1V 1V7, Canada
| |
Collapse
|
40
|
Miller JD, Herda TJ, Trevino MA, Sterczala AJ, Ciccone AB, Nicoll JX. Age-related differences in twitch properties and muscle activation of the first dorsal interosseous. Clin Neurophysiol 2017; 128:925-934. [PMID: 28402868 DOI: 10.1016/j.clinph.2017.03.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 02/08/2017] [Accepted: 03/12/2017] [Indexed: 01/08/2023]
Abstract
OBJECTIVE To examine twitch force potentiation and twitch contraction duration, as well as electromyographic amplitude (EMGRMS) and motor unit mean firing rates (MFR) at targeted forces between young and old individuals in the first dorsal interosseous (FDI). Ultrasonography was used to assess muscle quality. METHODS Twenty-two young (YG) (age=22.6±2.7years) and 14 older (OD) (age=62.1±4.7years) individuals completed conditioning contractions at 10% and 50% maximal voluntary contraction, (MVC) during which EMGRMS and MFRs were assessed. Evoked twitches preceded and followed the conditioning contractions. Ultrasound images were taken to quantify muscle quality (cross-sectional area [CSA] and echo intensity [EI]). RESULTS No differences were found between young and old for CSA, pre-conditioning contraction twitch force, or MFRs (P>0.05). However, OD individuals exhibited greater EI and contraction duration (P<0.05), and EMGRMS (YG=35.4±8.7%, OD=43.4±13.2%; P=0.034). Twitch force potentiation was lower for OD (0.311±0.15N) than YG (0.619±0.26N) from pre- to post-50% conditioning contraction (P<0.001). CONCLUSIONS Lower levels of potentiation with elongated contraction durations likely contributed to greater muscle activation during the conditioning contractions in the OD rather than altered MFRs. Ultrasonography suggested age-related changes in muscle structure contributed to altered contractile properties in the OD. SIGNIFICANCE Greater muscle activation requirements can have negative implications on fatigue resistance at low to moderate intensities in older individuals.
Collapse
Affiliation(s)
- Jonathan D Miller
- Neuromechanics Laboratory, Department of Health, Sport and Exercise Sciences, University of Kansas, Lawrence, KS 66044, USA.
| | - Trent J Herda
- Neuromechanics Laboratory, Department of Health, Sport and Exercise Sciences, University of Kansas, Lawrence, KS 66044, USA.
| | - Michael A Trevino
- Neuromechanics Laboratory, Department of Health, Sport and Exercise Sciences, University of Kansas, Lawrence, KS 66044, USA.
| | - Adam J Sterczala
- Neuromechanics Laboratory, Department of Health, Sport and Exercise Sciences, University of Kansas, Lawrence, KS 66044, USA.
| | - Anthony B Ciccone
- Neuromechanics Laboratory, Department of Health, Sport and Exercise Sciences, University of Kansas, Lawrence, KS 66044, USA.
| | - Justin X Nicoll
- Neuromechanics Laboratory, Department of Health, Sport and Exercise Sciences, University of Kansas, Lawrence, KS 66044, USA.
| |
Collapse
|
41
|
Age differences in dynamic fatigability and variability of arm and leg muscles: Associations with physical function. Exp Gerontol 2016; 87:74-83. [PMID: 27989926 DOI: 10.1016/j.exger.2016.10.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 09/27/2016] [Accepted: 10/24/2016] [Indexed: 12/25/2022]
Abstract
INTRODUCTION It is not known whether the age-related increase in fatigability of fast dynamic contractions in lower limb muscles also occurs in upper limb muscles. We compared age-related fatigability and variability of maximal-effort repeated dynamic contractions in the knee extensor and elbow flexor muscles; and determined associations between fatigability, variability of velocity between contractions and functional performance. METHODS 35 young (16 males; 21.0±2.6years) and 32 old (18 males; 71.3±6.2years) adults performed a dynamic fatiguing task involving 90 maximal-effort, fast, concentric, isotonic contractions (1 contraction/3s) with a load equivalent to 20% maximal voluntary isometric contraction (MVIC) torque with the elbow flexor and knee extensor muscles on separate days. Old adults also performed tests of balance and walking endurance. RESULTS Old adults had greater fatigue-related reductions in peak velocity compared with young adults for both the elbow flexor and knee extensor muscles (P<0.05) with no sex differences (P>0.05). Old adults had greater variability of peak velocity during the knee extensor, but not during the elbow flexor fatiguing task. The age difference in fatigability was greater for the knee extensor muscles (35.9%) compared with elbow flexor muscles (9.7%, P<0.05). Less fatigability of the knee extensor muscles was associated with greater walking endurance (r=-0.34, P=0.048) and balance (r=-0.41, P=0.014) among old adults. CONCLUSIONS An age-related increase in fatigability of a dynamic fatiguing task was greater for the knee extensor compared with the elbow flexor muscles in males and females, and greater fatigability was associated with lesser walking endurance and balance.
Collapse
|
42
|
Hunter SK, Pereira HM, Keenan KG. The aging neuromuscular system and motor performance. J Appl Physiol (1985) 2016; 121:982-995. [PMID: 27516536 PMCID: PMC5142309 DOI: 10.1152/japplphysiol.00475.2016] [Citation(s) in RCA: 226] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 08/08/2016] [Indexed: 12/25/2022] Open
Abstract
Age-related changes in the basic functional unit of the neuromuscular system, the motor unit, and its neural inputs have a profound effect on motor function, especially among the expanding number of old (older than ∼60 yr) and very old (older than ∼80 yr) adults. This review presents evidence that age-related changes in motor unit morphology and properties lead to impaired motor performance that includes 1) reduced maximal strength and power, slower contractile velocity, and increased fatigability; and 2) increased variability during and between motor tasks, including decreased force steadiness and increased variability of contraction velocity and torque over repeat contractions. The age-related increase in variability of motor performance with aging appears to involve reduced and more variable synaptic inputs that drive motor neuron activation, fewer and larger motor units, less stable neuromuscular junctions, lower and more variable motor unit action potential discharge rates, and smaller and slower skeletal muscle fibers that coexpress different myosin heavy chain isoforms in the muscle of older adults. Physical activity may modify motor unit properties and function in old men and women, although the effects on variability of motor performance are largely unknown. Many studies are of cross-sectional design, so there is a tremendous opportunity to perform high-impact and longitudinal studies along the continuum of aging that determine 1) the influence and cause of the increased variability with aging on functional performance tasks, and 2) whether lifestyle factors such as physical exercise can minimize this age-related variability in motor performance in the rapidly expanding numbers of very old adults.
Collapse
Affiliation(s)
- Sandra K Hunter
- Exercise Science Program, Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin; and
| | - Hugo M Pereira
- Exercise Science Program, Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin; and
| | - Kevin G Keenan
- Department of Kinesiology, College of Health Sciences, University of Wisconsin, Milwaukee, Wisconsin
| |
Collapse
|
43
|
Gray VL, Ivanova TD, Garland SJ. A single session of open kinetic chain movements emphasizing speed improves speed of movement and modifies postural control in stroke. Physiother Theory Pract 2016; 32:113-23. [DOI: 10.3109/09593985.2015.1110848] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
44
|
Wallace JW, Power GA, Rice CL, Dalton BH. Time-dependent neuromuscular parameters in the plantar flexors support greater fatigability of old compared with younger males. Exp Gerontol 2015; 74:13-20. [PMID: 26657724 DOI: 10.1016/j.exger.2015.12.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 11/29/2015] [Accepted: 12/01/2015] [Indexed: 11/19/2022]
Abstract
Older adults are more fatigable than young during dynamic tasks, especially those that involve moderate to fast unconstrained velocity shortening contractions. Rate of torque development (RTD), rate of velocity development (RVD) and rate of neuromuscular activation are time-dependent neuromuscular parameters which have not been explored in relation to age-related differences in fatigability. The purpose was to determine whether these time-dependent measures affect the greater age-related fatigability in peak power during moderately fast and maximal effort shortening plantar flexions. Neuromuscular properties were recorded from 10 old (~ 78 years) and 10 young (~ 24 years) men during 50 maximal-effort unconstrained velocity shortening plantar flexions against a resistance equivalent to 20% maximal voluntary isometric contraction torque. At task termination, peak power, and angular velocity, and torque at peak power were decreased by 30, 18, and 16%, respectively, for the young (p < 0.05), and 46, 28, 30% for the old (p < 0.05) compared to pre-fatigue values with the old exhibiting greater reductions across all measures (p<0.05). Voluntary RVD and RTD decreased, respectively, by 24 and 26% in the young and by 47 and 40% in the old at task termination, with greater decrements in the old (p < 0.05). Rate of neuromuscular activation of the soleus decreased over time for both age groups (~ 47%; p < 0.05), but for the medial gastrocnemius (MG) only the old experienced significant decrements (46%) by task termination. All parameters were correlated strongly with the fatigue-related reduction in peak power (r = 0.81-0.94, p < 0.05), except for MG and soleus rates of neuromuscular activation (r = 0.25-0.30, p > 0.10). Fatigue-related declines in voluntary RTD and RVD were both moderately correlated with MG rate of neuromuscular activation (r = 0.51-0.52, p < 0.05), but exhibited a trend with soleus (r = 0.39-0.41, p = 0.07-0.09). Thus, time-dependent factors, RVD and RTD, are likely important indicators of intrinsic muscle properties leading to the greater age-related decline in peak power when performing a repetitive dynamic fatigue task, which may be due to greater fatigue-related central impairments for the older men than young.
Collapse
Affiliation(s)
- Jonathan W Wallace
- Department of Human Physiology, University of Oregon, Eugene, OR, United States
| | - Geoffrey A Power
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada
| | - Charles L Rice
- Canadian Centre for Activity and Aging, School of Kinesiology, Faculty of Health Sciences, The University of Western Ontario, London, Ontario, Canada; Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Brian H Dalton
- Department of Human Physiology, University of Oregon, Eugene, OR, United States.
| |
Collapse
|
45
|
Power GA, Minozzo FC, Spendiff S, Filion ME, Konokhova Y, Purves-Smith MF, Pion C, Aubertin-Leheudre M, Morais JA, Herzog W, Hepple RT, Taivassalo T, Rassier DE. Reduction in single muscle fiber rate of force development with aging is not attenuated in world class older masters athletes. Am J Physiol Cell Physiol 2015; 310:C318-27. [PMID: 26632598 DOI: 10.1152/ajpcell.00289.2015] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 11/20/2015] [Indexed: 12/25/2022]
Abstract
Normal adult aging is associated with impaired muscle contractile function; however, to what extent cross-bridge kinetics are altered in aging muscle is not clear. We used a slacken restretch maneuver on single muscle fiber segments biopsied from the vastus lateralis of young adults (∼23 yr), older nonathlete (NA) adults (∼80 yr), and age-matched world class masters athletes (MA; ∼80 yr) to assess the rate of force redevelopment (ktr) and cross-bridge kinetics. A post hoc analysis was performed, and only the mechanical properties of "slow type" fibers based on unloaded shortening velocity (Vo) measurements are reported. The MA and NA were ∼54 and 43% weaker, respectively, for specific force compared with young. Similarly, when force was normalized to cross-sectional area determined via the fiber shape angularity data, both old groups did not differ, and the MA and NA were ∼43 and 48% weaker, respectively, compared with young (P < 0.05). Vo for both MA and NA old groups was 62 and 46% slower, respectively, compared with young. Both MA and NA adults had approximately two times slower values for ktr compared with young. The slower Vo in both old groups relative to young, coupled with a similarly reduced ktr, suggests impaired cross-bridge kinetics are responsible for impaired single fiber contractile properties with aging. These results challenge the widely accepted resilience of slow type fibers to cellular aging.
Collapse
Affiliation(s)
- Geoffrey A Power
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada; Faculty of Kinesiology, Human Performance Laboratory, University of Calgary, Calgary, Alberta, Canada;
| | - Fábio C Minozzo
- Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada; The Muscle Physiology and Biophysics Laboratory, McGill University, Montreal, Quebec, Canada
| | - Sally Spendiff
- Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada
| | - Marie-Eve Filion
- Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada
| | - Yana Konokhova
- Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada
| | - Maddy F Purves-Smith
- Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada
| | - Charlotte Pion
- Département de Kinanthropologie, Université du Québec a' Montréal, Montreal, Quebec, Canada
| | | | - José A Morais
- Department of Medicine, McGill University, Montreal, Quebec, Canada
| | - Walter Herzog
- Faculty of Kinesiology, Human Performance Laboratory, University of Calgary, Calgary, Alberta, Canada
| | - Russell T Hepple
- Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada; Department of Medicine, McGill University, Montreal, Quebec, Canada; Meakins Christie Laboratories, McGill University, Montreal, Quebec, Canada; and
| | - Tanja Taivassalo
- Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada
| | - Dilson E Rassier
- Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada; The Muscle Physiology and Biophysics Laboratory, McGill University, Montreal, Quebec, Canada; Meakins Christie Laboratories, McGill University, Montreal, Quebec, Canada; and Department of Physics, McGill University, Montreal, Quebec, Canada
| |
Collapse
|
46
|
Hortobágyi T, Lesinski M, Gäbler M, VanSwearingen JM, Malatesta D, Granacher U. Effects of Three Types of Exercise Interventions on Healthy Old Adults' Gait Speed: A Systematic Review and Meta-Analysis. Sports Med 2015; 45:1627-43. [PMID: 26286449 PMCID: PMC4656792 DOI: 10.1007/s40279-015-0371-2] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Habitual walking speed predicts many clinical conditions later in life, but it declines with age. However, which particular exercise intervention can minimize the age-related gait speed loss is unclear. PURPOSE Our objective was to determine the effects of strength, power, coordination, and multimodal exercise training on healthy old adults' habitual and fast gait speed. METHODS We performed a computerized systematic literature search in PubMed and Web of Knowledge from January 1984 up to December 2014. Search terms included 'Resistance training', 'power training', 'coordination training', 'multimodal training', and 'gait speed (outcome term). Inclusion criteria were articles available in full text, publication period over past 30 years, human species, journal articles, clinical trials, randomized controlled trials, English as publication language, and subject age ≥65 years. The methodological quality of all eligible intervention studies was assessed using the Physiotherapy Evidence Database (PEDro) scale. We computed weighted average standardized mean differences of the intervention-induced adaptations in gait speed using a random-effects model and tested for overall and individual intervention effects relative to no-exercise controls. RESULTS A total of 42 studies (mean PEDro score of 5.0 ± 1.2) were included in the analyses (2495 healthy old adults; age 74.2 years [64.4-82.7]; body mass 69.9 ± 4.9 kg, height 1.64 ± 0.05 m, body mass index 26.4 ± 1.9 kg/m2, and gait speed 1.22 ± 0.18 m/s). The search identified only one power training study, therefore the subsequent analyses focused only on the effects of resistance, coordination, and multimodal training on gait speed. The three types of intervention improved gait speed in the three experimental groups combined (n = 1297) by 0.10 m/s (±0.12) or 8.4% (±9.7), with a large effect size (ES) of 0.84. Resistance (24 studies; n = 613; 0.11 m/s; 9.3%; ES: 0.84), coordination (eight studies, n = 198; 0.09 m/s; 7.6%; ES: 0.76), and multimodal training (19 studies; n = 486; 0.09 m/s; 8.4%, ES: 0.86) increased gait speed statistically and similarly. CONCLUSIONS Commonly used exercise interventions can functionally and clinically increase habitual and fast gait speed and help slow the loss of gait speed or delay its onset.
Collapse
Affiliation(s)
- Tibor Hortobágyi
- Center for Human Movement Sciences, University Medical Center Groningen, University of Groningen, A. Deusinglaan 1, 9700 AD, Groningen, The Netherlands.
- Faculty of Health and Life Sciences, Northumbria University, Newcastle Upon Tyne, UK.
| | - Melanie Lesinski
- Division of Training and Movement Sciences, University of Potsdam, Potsdam, Germany
| | - Martijn Gäbler
- Center for Human Movement Sciences, University Medical Center Groningen, University of Groningen, A. Deusinglaan 1, 9700 AD, Groningen, The Netherlands
| | - Jessie M VanSwearingen
- Department of Physical Therapy, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Davide Malatesta
- Institute of Sport Sciences University of Lausanne (ISSUL), University of Lausanne, Lausanne, Switzerland
- Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Urs Granacher
- Division of Training and Movement Sciences, University of Potsdam, Potsdam, Germany
| |
Collapse
|
47
|
Yoon T, Doyel R, Widule C, Hunter SK. Sex differences with aging in the fatigability of dynamic contractions. Exp Gerontol 2015; 70:1-10. [PMID: 26159162 DOI: 10.1016/j.exger.2015.07.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 07/01/2015] [Accepted: 07/02/2015] [Indexed: 01/18/2023]
Abstract
This study determined the sex difference with aging in fatigability of the elbow flexor muscles during a dynamic fatiguing task, and explored the associated mechanisms. We compared fatigability of the elbow flexor muscles in 18 young (20.2 ± 1 years: 9 men) and 36 old adults (73.5 ± 1 years: 16 men) during and in recovery from repeated dynamic contractions (~60°/s) with a load equivalent to 20% of maximal voluntary isometric contraction (MVIC) torque until failure. Transcranial magnetic stimulation (TMS) was used to assess supraspinal fatigue (an increase in the superimposed twitch, SIT) and the peak rate of muscle relaxation. Time to failure was briefer for the men than the women (6.1 ± 2.1 vs. 9.7 ± 5.5 min, respectively; P=0.02) with no difference between young and old adults (7.2 ± 2.9 vs. 8.4 ± 5.2 min, respectively, P=0.45) and no interaction (P>0.05). The relative decline in peak relaxation rate with fatigability was similar for young and old adults (P=0.11), but greater for men than women (P=0.046). Supraspinal fatigue increased for all groups and was associated with the time to failure (P<0.05). Regression analysis however, indicated that the time to failure was best predicted by the peak relaxation rate (baseline values and slowing with fatigability) (r(2)=0.55). Rate-limiting contractile mechanisms (e.g. excitation-contraction coupling) were responsible for the increased fatigability of the elbow flexors of men compared with women for a dynamic fatiguing task of slow angular velocity, and this sex difference was maintained with aging. The age difference in fatigability for the dynamic task was diminished for both sexes relative to what is typically observed with isometric fatiguing contractions.
Collapse
Affiliation(s)
- Tejin Yoon
- Exercise Science Program, Department of Physical Therapy, Marquette University, Milwaukee, WI, United States; Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, MI, United States
| | - Ryan Doyel
- Exercise Science Program, Department of Physical Therapy, Marquette University, Milwaukee, WI, United States; Creighton University School of Medicine, Omaha, NE, United States
| | - Claire Widule
- Exercise Science Program, Department of Physical Therapy, Marquette University, Milwaukee, WI, United States; Uniformed Services University of the Health Sciences, F. Edward Hebert School of Medicine, Bethesda, MD, United States
| | - Sandra K Hunter
- Exercise Science Program, Department of Physical Therapy, Marquette University, Milwaukee, WI, United States.
| |
Collapse
|
48
|
Dalton BH, Power GA, Paturel JR, Rice CL. Older men are more fatigable than young when matched for maximal power and knee extension angular velocity is unconstrained. AGE (DORDRECHT, NETHERLANDS) 2015; 37:9790. [PMID: 25943700 PMCID: PMC4420757 DOI: 10.1007/s11357-015-9790-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 04/27/2015] [Indexed: 06/04/2023]
Abstract
The underlying factors related to the divergent findings of age-related fatigue for dynamic tasks are not well understood. The purpose here was to investigate age-related fatigability and recovery between a repeated constrained (isokinetic) and an unconstrained velocity (isotonic) task, in which participants performed fatiguing contractions at the velocity (isokinetic) or resistance (isotonic) corresponding with maximal power. To compare between tasks, isotonic torque-power relationships were constructed prior to and following both fatiguing tasks and during short-term recovery. Contractile properties were recorded from 9 old (~75 years) and 11 young (~25 years) men during three testing sessions. In the first session, maximal power was assessed, and sessions 2 and 3 involved an isokinetic or an isotonic concentric fatigue task performed until maximal power was reduced by 40 %. Compared with young, the older men performed the same number of contractions to task failure for the isokinetic task (~45 contractions), but 20 % fewer for the isotonic task (p < 0.05). Regardless of age and task, maximal voluntary isometric contraction strength, angular velocity, and power were reduced by ~30, ~13, and ~25 %, respectively, immediately following task failure, and only isometric torque was not recovered fully by 10 min. In conclusion, older men are more fatigable than the young when performing a repetitive maximal dynamic task at a relative resistance (isotonic) but not an absolute velocity (isokinetic), corresponding to maximal power.
Collapse
Affiliation(s)
- Brian H Dalton
- Department of Human Physiology, University of Oregon, 1240 University of Oregon, 122C Esslinger Hall, Eugene, OR, 97403, USA,
| | | | | | | |
Collapse
|
49
|
Morel B, Rouffet DM, Saboul D, Rota S, Clémençon M, Hautier CA. Peak torque and rate of torque development influence on repeated maximal exercise performance: contractile and neural contributions. PLoS One 2015; 10:e0119719. [PMID: 25901576 PMCID: PMC4406491 DOI: 10.1371/journal.pone.0119719] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Accepted: 01/16/2015] [Indexed: 11/28/2022] Open
Abstract
Rapid force production is critical to improve performance and prevent injuries. However, changes in rate of force/torque development caused by the repetition of maximal contractions have received little attention. The aim of this study was to determine the relative influence of rate of torque development (RTD) and peak torque (Tpeak) on the overall performance (i.e. mean torque, Tmean) decrease during repeated maximal contractions and to investigate the contribution of contractile and neural mechanisms to the alteration of the various mechanical variables. Eleven well-trained men performed 20 sets of 6-s isokinetic maximal knee extensions at 240°·s-1, beginning every 30 seconds. RTD, Tpeak and Tmean as well as the Rate of EMG Rise (RER), peak EMG (EMGpeak) and mean EMG (EMGmean) of the vastus lateralis were monitored for each contraction. A wavelet transform was also performed on raw EMG signal for instant mean frequency (ifmean) calculation. A neuromuscular testing procedure was carried out before and immediately after the fatiguing protocol including evoked RTD (eRTD) and maximal evoked torque (eTpeak) induced by high frequency doublet (100 Hz). Tmean decrease was correlated to RTD and Tpeak decrease (R²=0.62; p<0.001; respectively β=0.62 and β=0.19). RER, eRTD and initial ifmean (0-225 ms) decreased after 20 sets (respectively -21.1±14.1, -25±13%, and ~20%). RTD decrease was correlated to RER decrease (R²=0.36; p<0.05). The eTpeak decreased significantly after 20 sets (24±5%; p<0.05) contrary to EMGpeak (-3.2±19.5 %; p=0.71). Our results show that reductions of RTD explained part of the alterations of the overall performance during repeated moderate velocity maximal exercise. The reductions of RTD were associated to an impairment of the ability of the central nervous system to maximally activate the muscle in the first milliseconds of the contraction.
Collapse
Affiliation(s)
- Baptiste Morel
- Center of Research and Innovation on Sport, University of Lyon 1, Villeurbanne, France
- * E-mail:
| | - David M. Rouffet
- Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Australia
| | - Damien Saboul
- Center of Research and Innovation on Sport, University of Lyon 1, Villeurbanne, France
- Almerys, Clermont-Ferrand, France
| | - Samuel Rota
- Center of Research and Innovation on Sport, University of Lyon 1, Villeurbanne, France
| | - Michel Clémençon
- Center of Research and Innovation on Sport, University of Lyon 1, Villeurbanne, France
| | - Christophe A. Hautier
- Center of Research and Innovation on Sport, University of Lyon 1, Villeurbanne, France
| |
Collapse
|
50
|
Morel B, Clémençon M, Rota S, Millet GY, Bishop DJ, Brosseau O, Rouffet DM, Hautier CA. Contraction velocity influence the magnitude and etiology of neuromuscular fatigue during repeated maximal contractions. Scand J Med Sci Sports 2014; 25:e432-41. [DOI: 10.1111/sms.12358] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/07/2014] [Indexed: 11/28/2022]
Affiliation(s)
- B. Morel
- Center of Research and Innovation on Sport; University of Lyon 1; Villeurbanne France
| | - M. Clémençon
- Center of Research and Innovation on Sport; University of Lyon 1; Villeurbanne France
| | - S. Rota
- Center of Research and Innovation on Sport; University of Lyon 1; Villeurbanne France
| | - G. Y. Millet
- Human Performance Laboratory; University of Calgary; Calgary Alberta Canada
| | - D. J. Bishop
- Institute of Sport, Exercise and Active Living; Victoria University; Melbourne Victoria Australia
| | - O. Brosseau
- Maison des Consultants - Médipôle; Bourgoin-Jailleux France
| | - D. M. Rouffet
- Institute of Sport, Exercise and Active Living; Victoria University; Melbourne Victoria Australia
- Australian Institute of Sport; Belconnen Australian Capital Territory Australia
| | - C. A. Hautier
- Center of Research and Innovation on Sport; University of Lyon 1; Villeurbanne France
| |
Collapse
|