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Simmons R, Leicht A, Sinclair W, Bowman P, Dobbin M, Doma K. Acute Response to Training after Returning from the Off-Season in Elite Rugby League Athletes. J Hum Kinet 2024; 92:133-146. [PMID: 38736597 PMCID: PMC11079931 DOI: 10.5114/jhk/185442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 02/27/2024] [Indexed: 05/14/2024] Open
Abstract
The purposes of this study were to quantify the physiological response to the initial two-week preseason period in elite male rugby league (RL) athletes, and to determine if a repeated bout effect (RBE) occurs. Eighteen RL players were monitored for the initial two-week preseason period. Blood samples were collected on days (D)1, D2, D4, D5, D8, D9, D11 and D12 to measure creatine kinase (CK). Neuromuscular power was assessed on D1, D5, D8 and D12. During field-based sessions, the external training load was quantified using global positioning system technology, whilst the internal load was quantified using the training impulse and the session rating of perceived exertion. Resistance-based gym session volume was quantified by total repetitions x weight lifted. Perceived measures of fatigue and muscle soreness were assessed on all training days. Two-way (day x week) repeated measures analysis of variance and Bonferroni's corrected post-hoc tests identified significant changes. There were no significant changes in CK activity (649.2 ± 255.0 vs. 673.8 ± 299.1 µL; p = 0.63) or internal training load measures from week 1 to week 2. External training load measures including total distance (4138.1 ± 198.4 vs. 4525.0 ± 169.2 m; p < 0.001) and repeated high-intensity efforts (12.6 ± 1.8 vs. 17.5 ± 1.8 au; p < 0.001) significantly increased in week 2 compared to week 1. Internal training loads and CK activity did not change in response to an increase in external training loads during the initial preseason. The current results provide support for a 'real world' perspective of the RBE phenomenon that may be more applicable for team sport practitioners.
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Affiliation(s)
- Ryan Simmons
- Sport and Exercise Science, College of Healthcare Sciences, James Cook University, Townsville, Australia
| | - Anthony Leicht
- Sport and Exercise Science, College of Healthcare Sciences, James Cook University, Townsville, Australia
| | - Wade Sinclair
- Sport and Exercise Science, College of Healthcare Sciences, James Cook University, Townsville, Australia
- North Queensland Cowboys Rugby League Football Club, Townsville, Australia
| | - Paul Bowman
- North Queensland Cowboys Rugby League Football Club, Townsville, Australia
| | | | - Kenji Doma
- Sport and Exercise Science, College of Healthcare Sciences, James Cook University, Townsville, Australia
- Orthopeadic Institute of Queensland, Townsville, Australia
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Doma K, Matoso B, Protzen G, Singh U, Boullosa D. The Repeated Bout Effect of Multiarticular Exercises on Muscle Damage Markers and Physical Performances: A Systematic Review and Meta-Analyses. J Strength Cond Res 2023; 37:2504-2515. [PMID: 38015738 DOI: 10.1519/jsc.0000000000004628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
Abstract
ABSTRACT Doma, K, Matoso, B, Protzen, G, Singh, U, and Boullosa, D. The repeated bout effect of multiarticular exercises on muscle damage markers and physical performances: a systematic review and meta-analyses. J Strength Cond Res 37(12): 2504-2515, 2023-This systematic review and meta-analysis compared muscle damage markers and physical performance measures between 2 bouts of multiarticular exercises and determined whether intensity and volume of muscle-damaging exercises affected the outcomes. The eligibility criteria consisted of (a) healthy male and female adults; (b) multiarticular exercises to cause muscle damage across 2 bouts; (c) outcome measures were compared at 24-48 hours after the first and second bouts of muscle-damaging exercise; (d) at least one of the following outcome measures: creatine kinase (CK), delayed onset of muscle soreness (DOMS), muscle strength, and running economy. Study appraisal was conducted using the Kmet tool, whereas forest plots were derived to calculate standardized mean differences (SMDs) and statistical significance and alpha set a 0.05. After screening, 20 studies were included. The levels of DOMS and CK were significantly greater during the first bout when compared with the second bout at T24 and T48 (p < 0.001; SMD = 0.51-1.23). Muscular strength and vertical jump performance were significantly lower during the first bout compared with the second bout at T24 and T48 (p ≤ 0.05; SMD = -0.27 to -0.40), whereas oxygen consumption and rating of perceived exertion were significantly greater during the first bout at T24 and T48 (p < 0.05; SMD = 0.28-0.65) during running economy protocols. The meta-analyses were unaffected by changes in intensity and volume of muscle-damaging exercises between bouts. Multiarticular exercises exhibited a repeated bout effect, suggesting that a single bout of commonly performed exercises involving eccentric contractions may provide protection against exercise-induced muscle damage for subsequent bouts.
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Affiliation(s)
- Kenji Doma
- Sport and Exercise Science, College of Healthcare Sciences, James Cook University, Douglas, Australia
- Orthopeadic Research Institute of Queensland, Townsville, Australia
| | - Bruno Matoso
- Integrated Institute of Health, Federal University of Mato Grosso do Sul, Campo Grande, Brazil
| | - Gabriel Protzen
- Physical Education College, Federal University of Pelotas, Pelotas, Brazil; and
| | - Utkarsh Singh
- Sport and Exercise Science, College of Healthcare Sciences, James Cook University, Douglas, Australia
| | - Daniel Boullosa
- Sport and Exercise Science, College of Healthcare Sciences, James Cook University, Douglas, Australia
- Integrated Institute of Health, Federal University of Mato Grosso do Sul, Campo Grande, Brazil
- Faculty of Physical Activity and Sports Sciences, Universidad de León, Ponferrada, Spain
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Boyd L, Deakin GB, Devantier-Thomas B, Singh U, Doma K. The Effects of Pre-conditioning on Exercise-Induced Muscle Damage: A Systematic Review and Meta-analysis. Sports Med 2023; 53:1537-1557. [PMID: 37160563 PMCID: PMC10356650 DOI: 10.1007/s40279-023-01839-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/06/2023] [Indexed: 05/11/2023]
Abstract
BACKGROUND Several studies have utilised isometric, eccentric and downhill walking pre-conditioning as a strategy for alleviating the signs and symptoms of exercise-induced muscle damage (EIMD) following a bout of damaging physical activity. OBJECTIVES This systematic review and meta-analysis examined the effects of pre-conditioning strategies on indices of muscle damage and physical performance measures following a second bout of strenuous physical activity. DATA SOURCES PubMed, CINAHL and Scopus. ELIGIBILITY CRITERIA Studies meeting the PICO (population, intervention/exposure, comparison, and outcome) criteria were included in this review: (1) general population or "untrained" participants with no contraindications affecting physical performance; (2) studies with a parallel design to examine the prevention and severity of muscle-damaging contractions; (3) outcome measures were compared using baseline and post-intervention measures; and (4) outcome measures included any markers of indirect muscle damage and muscular contractility measures. PARTICIPANTS Individuals with no resistance training experiences in the previous 6 or more months. INTERVENTIONS A single bout of pre-conditioning exercises consisting of eccentric or isometric contractions performed a minimum of 24 h prior to a bout of damaging physical activity were compared to control interventions that did not perform pre-conditioning prior to damaging physical activity. STUDY APPRAISAL Kmet appraisal system. SYNTHESIS METHODS Quantitative analysis was conducted using forest plots to examine standardised mean differences (SMD, i.e. effect size), test statistics for statistical significance (i.e. Z-values) and between-study heterogeneity by inspecting I2. RESULTS Following abstract and full-text screening, 23 articles were included in this paper. Based on the meta-analysis, the pre-conditioning group exhibited lower levels of creatine kinase at 24 h (SMD = - 1.64; Z = 8.39; p = 0.00001), 48 h (SMD = - 2.65; Z = 7.78; p = 0.00001), 72 h (SMD = - 2.39; Z = 5.71; p = 0.00001) and 96 h post-exercise (SMD = - 3.52; Z = 7.39; p = 0.00001) than the control group. Delayed-onset muscle soreness was also lower for the pre-conditioning group at 24 h (SMD = - 1.89; Z = 6.17; p = 0.00001), 48 h (SMD = - 2.50; Z = 7.99; p = 0.00001), 72 h (SMD = - 2.73; Z = 7.86; p = 0.00001) and 96 h post-exercise (SMD = - 3.30; Z = 8.47; p = 0.00001). Maximal voluntary contraction force was maintained and returned to normal sooner in the pre-conditioning group than in the control group, 24 h (SMD = 1.46; Z = 5.49; p = 0.00001), 48 h (SMD = 1.59; Z = 6.04; p = 0.00001), 72 h (SMD = 2.02; Z = 6.09; p = 0.00001) and 96 h post-exercise (SMD = 2.16; Z = 5.69; p = 0.00001). Range of motion was better maintained by the pre-conditioning group compared with the control group at 24 h (SMD = 1.48; Z = 4.30; p = 0.00001), 48 h (SMD = 2.20; Z = 5.64; p = 0.00001), 72 h (SMD = 2.66; Z = 5.42; p = 0.00001) and 96 h post-exercise (SMD = 2.5; Z = 5.46; p = 0.00001). Based on qualitative analyses, pre-conditioning activities were more effective when performed at 2-4 days before the muscle-damaging protocol compared with immediately prior to the muscle-damaging protocol, or 1-3 weeks prior to the muscle-damaging protocol. Furthermore, pre-conditioning activities performed using eccentric contractions over isometric contractions, with higher volumes, greater intensity and more lengthened muscle contractions provided greater protection from EIMD. LIMITATIONS Several outcome measures showed high inter-study heterogeneity. The inability to account for differences in durations between pre-conditioning and the second bout of damaging physical activity was also limiting. CONCLUSIONS Pre-conditioning significantly reduced the severity of creatine kinase release, delayed-onset muscle soreness, loss of maximal voluntary contraction force and the range of motion decrease. Pre-conditioning may prevent severe EIMD and accelerate recovery of muscle force generation capacity.
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Affiliation(s)
- Lachlan Boyd
- College of Healthcare Sciences, Sports and Exercise Science, James Cook University, 1 James Cook Drive, Rehabilitation Sciences Building, Douglas, Townsville, QLD, 481, Australia
| | - Glen B Deakin
- College of Healthcare Sciences, Sports and Exercise Science, James Cook University, 1 James Cook Drive, Rehabilitation Sciences Building, Douglas, Townsville, QLD, 481, Australia
| | - Baily Devantier-Thomas
- College of Healthcare Sciences, Sports and Exercise Science, James Cook University, 1 James Cook Drive, Rehabilitation Sciences Building, Douglas, Townsville, QLD, 481, Australia
| | - Utkarsh Singh
- College of Healthcare Sciences, Sports and Exercise Science, James Cook University, 1 James Cook Drive, Rehabilitation Sciences Building, Douglas, Townsville, QLD, 481, Australia
| | - Kenji Doma
- College of Healthcare Sciences, Sports and Exercise Science, James Cook University, 1 James Cook Drive, Rehabilitation Sciences Building, Douglas, Townsville, QLD, 481, Australia.
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Burt D, Doma K, Connor J. The effects of exercise-induced muscle damage on varying intensities of endurance running performance: A systematic review and meta-analysis. Sci Sports 2023. [DOI: 10.1016/j.scispo.2022.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Šuc A, Šarko P, Pleša J, Kozinc Ž. Resistance Exercise for Improving Running Economy and Running Biomechanics and Decreasing Running-Related Injury Risk: A Narrative Review. Sports (Basel) 2022; 10:sports10070098. [PMID: 35878109 PMCID: PMC9319953 DOI: 10.3390/sports10070098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/20/2022] [Accepted: 06/22/2022] [Indexed: 02/01/2023] Open
Abstract
It is well-accepted that at least a certain amount of resistance exercise (RE) is recommended for most endurance athletes. In this review, we aim to summarize the evidence regarding the effects of RE on running economy, running biomechanics, and running-related injury risk in endurance runners. The evidence robustly shows that lower limb RE is effective for improving running economy and performance, with a combination of strength and plyometric training being recommended to improve RE. Isometric training is also emerging as a possible alternative to implement during periods of high overall training load. Lower limb RE may change some aspects of joint kinematics during running; however, the evidence regarding the effects on kinetics is limited. Lower limb RE may help reduce running-related injury risk, but further evidence is needed.
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Affiliation(s)
- Anja Šuc
- Faculty of Health Sciences, University of Primorska, Polje 42, SI-6310 Izola, Slovenia; (A.Š.); (P.Š.); (J.P.)
| | - Pija Šarko
- Faculty of Health Sciences, University of Primorska, Polje 42, SI-6310 Izola, Slovenia; (A.Š.); (P.Š.); (J.P.)
| | - Jernej Pleša
- Faculty of Health Sciences, University of Primorska, Polje 42, SI-6310 Izola, Slovenia; (A.Š.); (P.Š.); (J.P.)
| | - Žiga Kozinc
- Faculty of Health Sciences, University of Primorska, Polje 42, SI-6310 Izola, Slovenia; (A.Š.); (P.Š.); (J.P.)
- Andrej Marušič Institute, University of Primorska, Muzejski trg 2, SI-6000 Koper, Slovenia
- Correspondence:
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Effects of Exercise Sequence and Velocity Loss Threshold During Resistance Training on Following Endurance and Strength Performance During Concurrent Training. Int J Sports Physiol Perform 2021; 16:811-817. [PMID: 33547266 DOI: 10.1123/ijspp.2020-0483] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 07/02/2020] [Accepted: 07/09/2020] [Indexed: 11/18/2022]
Abstract
PURPOSE This study aimed to analyze the response to 4 concurrent training interventions differing in the training sequence and in the velocity loss (VL) threshold during strength training (20% vs 40%) on following endurance and strength performance. METHODS A randomized crossover research design was used. Sixteen trained men performed 4 training interventions consisting of endurance training (ET) followed by resistance training (RT), with 20% and 40% VL, respectively (ET + RT20 and ET + RT40), and RT with 20% and 40% VL, respectively, followed by ET (RT20 + ET and RT40 + ET). The ET consisted of running for 10 minutes at 90% of maximal aerobic velocity. The RT consisted of 3 squat sets with 60% of 1-repetition maximum. A 5-minute rest was given between exercises. The oxygen uptake throughout the ET and repetition velocity during RT were recorded. The blood lactate concentration, vertical jump, and squat velocity were measured at preexercise and after the endurance and strength exercises. RESULTS The RT40 + ET protocol showed an impaired running time along with higher ventilatory equivalents compared with those protocols that performed the ET without previous fatigue. No significant differences were observed in the repetitions per set performed for a given VL threshold, regardless of the exercise sequence. The protocols consisting of 40%VL induced greater reductions in jump height and squat velocity, along with elevated blood lactate concentration. CONCLUSIONS A high VL magnitude (40%VL) induced higher metabolic and mechanical stress, as well as greater residual fatigue, on the following ET performance.
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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.
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8
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Stožer A, Vodopivc P, Križančić Bombek L. Pathophysiology of exercise-induced muscle damage and its structural, functional, metabolic, and clinical consequences. Physiol Res 2020; 69:565-598. [PMID: 32672048 DOI: 10.33549/physiolres.934371] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Extreme or unaccustomed eccentric exercise can cause exercise-induced muscle damage, characterized by structural changes involving sarcomere, cytoskeletal, and membrane damage, with an increased permeability of sarcolemma for proteins. From a functional point of view, disrupted force transmission, altered calcium homeostasis, disruption of excitation-contraction coupling, as well as metabolic changes bring about loss of strength. Importantly, the trauma also invokes an inflammatory response and clinically presents itself by swelling, decreased range of motion, increased passive tension, soreness, and a transient decrease in insulin sensitivity. While being damaging and influencing heavily the ability to perform repeated bouts of exercise, changes produced by exercise-induced muscle damage seem to play a crucial role in myofibrillar adaptation. Additionally, eccentric exercise yields greater hypertrophy than isometric or concentric contractions and requires less in terms of metabolic energy and cardiovascular stress, making it especially suitable for the elderly and people with chronic diseases. This review focuses on our current knowledge of the mechanisms underlying exercise-induced muscle damage, their dependence on genetic background, as well as their consequences at the structural, functional, metabolic, and clinical level. A comprehensive understanding of these is a prerequisite for proper inclusion of eccentric training in health promotion, rehabilitation, and performance enhancement.
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Affiliation(s)
- A Stožer
- Institute of Physiology, Faculty of Medicine, University of Maribor, Slovenia.
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Lima LCR, Nosaka K, Chen TC, Pinto RS, Greco CC, Denadai BS. Decreased running economy is not associated with decreased force production capacity following downhill running in untrained, young men. Eur J Sport Sci 2020; 21:84-92. [PMID: 32090683 DOI: 10.1080/17461391.2020.1727570] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The present study investigated the relationships between changes in running economy (RE) and indirect muscle damage markers following downhill running (DHR) to test the hypothesis that decreased RE after DHR would be associated with decreases in muscle function. Forty-five young men ran downhill (-15%) for 30 min at the velocity corresponding to 70% of their peak oxygen uptake (VO2peak). Oxygen uptake (VO2) and other parameters possibly associated with RE (blood lactate concentration, perceived exertion, stride length and frequency) were measured during 5-minute level running at the velocity corresponding to 80%VO2peak before, immediately after and 1-3 days after DHR. Knee extensor maximal voluntary contraction torque (MVC), rate of torque development, vertical jump performance, muscle soreness and serum creatine kinase activity were assessed at the same time points. The values of the dependent variables were compared among time points by one-way ANOVAs followed by Bonferroni post-hoc tests when appropriate. Pearson's correlation tests were used to examine relationships between changes in VO2 (RE parameter) and changes in muscle damage parameters. VO2 during the level run increased (p < 0.05) immediately after DHR (18.3 ± 4.6%) and sustained until 2 days post-DHR (11.7 ± 4.2%). MVC decreased (p < 0.05) immediately (-21.8 ± 6.1%) to 3 days (-13.6 ± 5.9%) post-DHR, and muscle soreness developed 1-3 days post-DHR. The magnitude of changes in VO2 did not significantly (p < 0.05) correlate with the changes in muscle damage makers (r = -0.02-0.13) nor stride length (r = -0.05) and frequency (r = -0.05). The absence of correlation between the changes in VO2 and MVC suggests that strength loss was not a key factor affecting RE.
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Affiliation(s)
- Leonardo C R Lima
- Human Performance Laboratory, São Paulo State University, Rio Claro, Brazil
| | - Kazunori Nosaka
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia
| | - Trevor C Chen
- Department of Physical Education, National Taiwan Normal University, Taipei City, Taiwan
| | - Ronei S Pinto
- School of Physical Education, Physiotherapy and Dance, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Camila C Greco
- Human Performance Laboratory, São Paulo State University, Rio Claro, Brazil
| | - Benedito S Denadai
- Human Performance Laboratory, São Paulo State University, Rio Claro, Brazil
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A Systematic Review Examining the Exercise Parameters Required to Induce the Repeated Bout Effect: Implications for Acute Care Physical Therapists. JOURNAL OF ACUTE CARE PHYSICAL THERAPY 2019. [DOI: 10.1097/jat.0000000000000105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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11
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Implications of Impaired Endurance Performance following Single Bouts of Resistance Training: An Alternate Concurrent Training Perspective. Sports Med 2018; 47:2187-2200. [PMID: 28702901 DOI: 10.1007/s40279-017-0758-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
A single bout of resistance training induces residual fatigue, which may impair performance during subsequent endurance training if inadequate recovery is allowed. From a concurrent training standpoint, such carry-over effects of fatigue from a resistance training session may impair the quality of a subsequent endurance training session for several hours to days with inadequate recovery. The proposed mechanisms of this phenomenon include: (1) impaired neural recruitment patterns; (2) reduced movement efficiency due to alteration in kinematics during endurance exercise and increased energy expenditure; (3) increased muscle soreness; and (4) reduced muscle glycogen. If endurance training quality is consistently compromised during the course of a specific concurrent training program, optimal endurance development may be limited. Whilst the link between acute responses of training and subsequent training adaptation has not been fully established, there is some evidence suggesting that cumulative effects of fatigue may contribute to limiting optimal endurance development. Thus, the current review will (1) explore cross-sectional studies that have reported impaired endurance performance following a single, or multiple bouts, of resistance training; (2) identify the potential impact of fatigue on chronic endurance development; (3) describe the implications of fatigue on the quality of endurance training sessions during concurrent training, and (4) explain the mechanisms contributing to resistance training-induced attenuation on endurance performance from neurological, biomechanical and metabolic standpoints. Increasing the awareness of resistance training-induced fatigue may encourage coaches to consider modulating concurrent training variables (e.g., order of training mode, between-mode recovery period, training intensity, etc.) to limit the carry-over effects of fatigue from resistance to endurance training sessions.
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12
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Prevention of downhill walking-induced muscle damage by non-damaging downhill walking. PLoS One 2017; 12:e0173909. [PMID: 28288187 PMCID: PMC5348007 DOI: 10.1371/journal.pone.0173909] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 02/28/2017] [Indexed: 11/19/2022] Open
Abstract
PURPOSE Mountain trekking involves level, uphill, and downhill walking (DW). Prolonged DW induces damage to leg muscles, reducing force generating ability and muscle coordination. These increase risks for more serious injuries and accidents in mountain trekking, thus a strategy to minimize muscle damage is warranted. It has been shown that low-intensity eccentric contractions confer protective effect on muscle damage induced by high-intensity eccentric contractions. This study tested the hypothesis that 5-min non-damaging DW would attenuate muscle damage induced by 40-min DW, but 5-min level walking (LW) would not. METHODS Untrained young men were allocated (n = 12/group) to either a control or one of the two preconditioning groups (PRE-DW or PRE-LW). The PRE-DW and PRE-LW groups performed 5-min DW (-28%) and 5-min LW, respectively, at 5 km/h with a load of 10% body mass, 1 week before 40-min DW (-28%, 5 km/h, 10% load). The control group performed 40-min DW only. Maximal knee extension strength, plasma creatine kinase (CK) activity, and muscle soreness (0-100 mm visual analogue scale) were measured before and 24 h after 5-min DW and 5-min LW, and before and 24, 48, and 72 h after 40-min DW. RESULTS No significant changes in any variables were evident after 5-min DW and 5-min LW. After 40-min DW, the control and PRE-LW groups showed significant (P<0.05) changes in the variables without significant differences between groups (control vs. PRE-LW; peak strength reduction: -19.2 ± 6.9% vs. -18.7 ± 11.0%, peak CK: 635.5 ± 306.0 vs. 639.6 ± 405.4 U/L, peak soreness: 81.4 ± 14.8 vs. 72.0 ± 29.2 mm). These changes were significantly (P<0.05) attenuated (47-64%) for the PRE-DW group (-9.9 ± 9.6%, 339.3 ± 148.4 U/L, 27.8 ± 16.8 mm). CONCLUSIONS The results supported the hypothesis and suggest that performing small volume of downhill walking is crucial in preparation for trekking.
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Mechanisms underpinning protection against eccentric exercise-induced muscle damage by ischemic preconditioning. Med Hypotheses 2016; 98:21-27. [PMID: 28012598 DOI: 10.1016/j.mehy.2016.11.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 11/17/2016] [Indexed: 01/27/2023]
Abstract
Eccentric exercise training is effective for increasing muscle mass and strength, and improving insulin sensitivity and blood lipid profiles. However, potential muscle damage symptoms such as prolonged loss of muscle function and delayed onset of muscle soreness may restrict the use of eccentric exercise, especially in clinical populations. Therefore, strategies to reduce eccentric exercise-induced muscle damage (EIMD) are necessary, and an extensive number of scientific studies have tried to identify potential intervention modalities to perform eccentric exercises without adverse effects. The present paper is based on a narrative review of current literature, and provides a novel hypothesis by which an ischemic preconditioning (IPC) of the extremities may reduce EIMD. IPC consists of an intermittent application of short-time non-lethal ischemia to an extremity (e.g. using a tourniquet) followed by reperfusion and was discovered in clinical settings in an attempt to minimize inflammatory responses induced by ischemia and ischemia-reperfusion-injury (I/R-Injury) during surgery. The present hypothesis is based on morphological and biochemical similarities in the pathophysiology of skeletal muscle damage during clinical surgery and EIMD. Even though the primary origin of stress differs between I/R-Injury and EIMD, subsequent cellular alterations characterized by an intracellular accumulation of Ca2+, an increased production of reactive oxygen species or increased apoptotic signaling are essential elements for both. Moreover, the incipient immune response appears to be similar in I/R-Injury and EIMD, which is indicated by an infiltration of leukocytes into the damaged soft-tissue. Thus far, IPC is considered as a potential intervention strategy in the area of cardiovascular or orthopedic surgery and provides significant impact on soft-tissue protection and downregulation of undesired excessive inflammation induced by I/R-Injury. Based on the known major impact of IPC on skeletal muscle physiology and immunology, the present paper aims to illustrate the potential protective effects of IPC on EIMD by discussing possible underlying mechanisms.
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14
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Marcello RT, Greer BK, Greer AE. Acute Effects of Plyometric and Resistance Training on Running Economy in Trained Runners. J Strength Cond Res 2016; 31:2432-2437. [PMID: 27806012 DOI: 10.1519/jsc.0000000000001705] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Marcello, RT, Greer, BK, and Greer, AE. Acute effects of plyometric and resistance training on running economy in trained runners. J Strength Cond Res 31(9): 2432-2437, 2017-Results regarding the acute effects of plyometrics and resistance training (PRT) on running economy (RE) are conflicting. Eight male collegiate distance runners (21 ± 1 years, 62.5 ± 7.8 ml·kg·min V[Combining Dot Above]O2 peak) completed V[Combining Dot Above]O2 peak and 1 repetition maximum (1RM) testing. Seven days later, subjects completed a 12 minutes RE test at 60 and 80% V[Combining Dot Above]O2 peak, followed by a PRT protocol or a rested condition of equal duration (CON). The PRT protocol consisted of 3 sets of 5 repetitions at 85% 1RM for barbell squats, Romanian deadlifts, and barbell lunges; the same volume was used for resisted lateral lunges, box jumps, and depth jumps. Subjects completed another RE test immediately after the treatments and 24 hours later. Subjects followed an identical protocol 6 days later with condition assignment reversed. Running economy was determined by both relative V[Combining Dot Above]O2 (ml·kg·min) and energy expenditure (EE) (kcal·min). There was a significant (p ≤ 0.05) between-trial increase in V[Combining Dot Above]O2 (37.1 ± 4.2 ml·kg·min PRT vs. 35.5 ± 3.9 ml·kg·min CON) and EE (11.4 ± 1.3 kcal·min PRT vs. 11.0 ± 1.4 kcal·min CON) immediately after PRT at 60% V[Combining Dot Above]O2 peak, but no significant changes were observed at 80% V[Combining Dot Above]O2 peak. Respiratory exchange ratio was significantly (p ≤ 0.05) reduced 24 hours after PRT (0.93 ± 0.0) as compared to the CON trial (0.96 ± 0.0) at 80% V[Combining Dot Above]O2 peak. Results indicate that high-intensity PRT may acutely impair RE in aerobically trained individuals at a moderate running intensity, but that the attenuation lasts less than 24 hours in duration.
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Affiliation(s)
- Richard T Marcello
- Department of Physical Therapy and Human Movement Science, Sacred Heart University, Fairfield, Connecticut
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