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Elmer DJ, Asbill HW. Effect of cross-slope angle on running economy and gait characteristics at moderate running velocity. Eur J Appl Physiol 2024; 124:1259-1266. [PMID: 37993733 DOI: 10.1007/s00421-023-05358-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 10/28/2023] [Indexed: 11/24/2023]
Abstract
PURPOSE Outdoor running surfaces are designed with a cross-slope, which can alter kinetic and kinematic gait parameters. The purpose of this study was to evaluate running economy, gait characteristics, and muscle activation while running on a surface with cross-slopes similar to those encountered on roads and trails. METHODS Eleven recreational runners (females n = 6) completed 5-min running trials on a treadmill at 10 km h-1 with cross-slopes of 0, 1.15, 2.29, and 6 deg in a randomized order. RESULTS There were no significant differences in VO2, HR, RER, or VE across cross-slope conditions. Compared to 0 deg of cross-slope, ground contact time and duty factor increased at 2.29 and 6 deg, with significant decreases in absolute and relative flight times. Rear foot angles increased in the upslope leg at 2.29 and 6 deg cross-slopes and decreased in the downslope leg at 6 deg compared to 0 deg of cross-slope, with differences between legs for the 2.29 and 6 deg conditions. Knee flexion at foot strike increased in the upslope leg at a 6 deg cross-slope. Vastus lateralis, biceps femoris, gastrocnemius, and tibialis anterior activation were not affected by the cross-slope conditions. While cross-slopes up to 6 deg result in changes to some gait kinematics, these effects do not impact running economy at moderate running velocity.
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Affiliation(s)
- David J Elmer
- Department of Kinesiology, Berry College, 2277 Martha Berry Hwy, Mount Berry, GA, 30149, USA.
| | - Henry W Asbill
- Department of Kinesiology, Berry College, 2277 Martha Berry Hwy, Mount Berry, GA, 30149, USA
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Wong AK, Asatiani K, Chávez-Manzanera E, Elmer DJ, Heymsfield SB, Hong S, Ilesanmi-Oyelere L, Kagawa M, Klobucar S, Obeid OA, Plotnikoff RC, Sardinha LB, Sloughter JM, Silva AM, Shultz SP. Differences in segmental fat accumulation patterns by sex and ethnicity: An international approach. Clin Obes 2024:e12637. [PMID: 38169103 DOI: 10.1111/cob.12637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 10/13/2023] [Accepted: 12/12/2023] [Indexed: 01/05/2024]
Abstract
Excess fat on the body impacts obesity-related co-morbidity risk; however, the location of fat stores affects the severity of these risks. The purpose of this study was to examine segmental fat accumulation patterns by sex and ethnicity using international datasets. An amalgamated and cross-calibrated dataset of dual x-ray absorptiometry (DXA)-measured variables compiled segmental mass for bone mineral content (BMC), lean mass (LM), and fat mass (FM) for each participant; percentage of segment fat (PSF) was calculated as PSFsegment = (FMsegment /(BMCsegment + LMsegment + FMsegment )) × 100. A total of 30 587 adults (N = 16 490 females) from 13 datasets were included. A regression model was used to examine differences in regional fat mass and PSF. All populations followed the same segmental fat mass accumulation in the ascending order with statistical significance (arms < legs < trunk), except for Hispanic/Latinx males (arms < [legs = trunk]). Relative fat accumulation patterns differed between those with greater PSF in the appendages (Arab, Mexican, Asian, Black, American Caucasian, European Caucasian, and Australasian Caucasian females; Black males) and those with greater PSF in the trunk (Mexican, Asian, American Caucasian, European Caucasian, and Australasian Caucasian males). Greater absolute and relative fat accumulation in the trunk could place males of most ethnicities in this study at a higher risk of visceral fat deposition and associated co-morbidities.
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Affiliation(s)
- Arden K Wong
- Kinesiology Department, Seattle University, Seattle, Washington, USA
| | - Ketevan Asatiani
- Georgian Association for the Study of Obesity, European Association for the Study of Obesity, Tbilisi, Republic of Georgia
| | - Emma Chávez-Manzanera
- Obesity and Eating Disorders Clinic, Department of Endocrinology and Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - David J Elmer
- Department of Kinesiology, Berry College, Mount Berry, Georgia, USA
| | - Steven B Heymsfield
- Body Composition-Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
| | - Sangmo Hong
- College of Medicine, Hanyang University, Gyeonggi-do, Republic of Korea
| | - Lilian Ilesanmi-Oyelere
- School of Health Sciences, College of Health, Massey University, Palmerston North, New Zealand
| | - Masaharu Kagawa
- Institute of Nutrition Sciences, Kagawa Nutrition University, Saitama, Japan
- School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Sanja Klobucar
- Department of Endocrinology, Diabetes and Metabolic Diseases, Clinical Hospital Center Rijeka, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Omar A Obeid
- Department of Nutrition and Food Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut, Lebanon
| | - Ronald C Plotnikoff
- Centre for Active Living and Learning, The University of Newcastle, Callaghan, New South Wales, Australia
| | - Luís B Sardinha
- Exercise and Health Laboratory, CIPER, Faculdade Motricidade Humana, Universidade de Lisboa, Lisbon, Portugal
| | | | - Analiza M Silva
- Exercise and Health Laboratory, CIPER, Faculdade Motricidade Humana, Universidade de Lisboa, Lisbon, Portugal
| | - Sarah P Shultz
- Kinesiology Department, Seattle University, Seattle, Washington, USA
- School of Arts & Sciences, Fort Lewis College, Durango, Colorado, USA
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Smith MG, Elmer DJ, Hubbard EA. Effects Of 6-weeks Of Rpe-based, High-intensity Interval Training On Fitness And Walking In Older Adults. Med Sci Sports Exerc 2022. [DOI: 10.1249/01.mss.0000877840.21914.52] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Washington JK, Elmer DJ, Conn VA, Wheelen EE. UPPER BODY MUSCLE EXCITATION DURING SPRINTING. Med Sci Sports Exerc 2022. [DOI: 10.1249/01.mss.0000878684.87621.ab] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Hubbard EA, Motl RW, Elmer DJ. Feasibility and initial efficacy of a high-intensity interval training program using adaptive equipment in persons with multiple sclerosis who have walking disability: study protocol for a single-group, feasibility trial. Trials 2020; 21:972. [PMID: 33239079 PMCID: PMC7687792 DOI: 10.1186/s13063-020-04887-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 11/11/2020] [Indexed: 11/17/2022] Open
Abstract
Background There is considerable evidence for the efficacy of moderate-intensity continuous exercise benefitting clinically relevant outcomes in persons with multiple sclerosis (MS). However, persons with MS who have walking disability (pwMS-wd) are severely deconditioned and may achieve superior benefits by engaging in high-intensity interval training (HIIT), especially while utilizing adaptive equipment, such as recumbent arm/leg stepping (RSTEP). The proposed study will assess the feasibility of a 12-week, RSTEP HIIT program in pwMS-wd. The secondary aim will examine changes in aerobic fitness, physical activity, ambulation, upper arm function, cognition, fatigue, and depression as clinically relevant efficacy outcomes following the 12-week, RSTEP HIIT intervention. Methods The study will recruit 15 pwMS-wd. Feasibility will be measured via process, resource, management, and scientific outcomes throughout the entirety of the research study. The secondary, clinically relevant outcomes will consist of a neurological exam, aerobic capacity, physical activity, ambulation, cognition, upper arm function, fatigue, and depression. Outcomes will be assessed at baseline (T1), midpoint (T2, following 6 weeks), and post-intervention (T3, following 12 weeks). The intervention will involve 12 weeks of supervised, individualized HIIT sessions two to three times per week. The individual HIIT sessions will each involve 10 cycles of 60-s intervals at the wattage associated with 90% VO2peak followed by 60 s of active recovery intervals at 15 W, totaling 20 min in length plus 5-min warm-up and cool-down periods. Discussion The feasibility design of the proposed study will provide experience and preliminary data for advancing towards a proof-of-concept study comparing HIIT to moderate-intensity continuous RSTEP for improving clinically relevant outcomes in a randomized control trial design. The results will be disseminated via manuscripts for publication and a report for distribution among the National Multiple Sclerosis Society. Trial registration ClinicalTrials.gov NCT04416243. Retrospectively registered on June 4, 2020
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Affiliation(s)
| | - Robert W Motl
- Department of Physical Therapy, University of Alabama at Birmingham, Birmingham, AL, USA
| | - David J Elmer
- Department of Kinesiology, Berry College, Mount Berry, GA, USA
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Elmer DJ, Barron EN, Chavez JL. Acute Demands and Recovery From Common Interval Training Protocols. J Strength Cond Res 2019; 35:3041-3049. [PMID: 31356514 DOI: 10.1519/jsc.0000000000003280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Elmer, DJ, Barron, EN, and Chavez, JL. Acute demands and recovery from common interval training protocols. J Strength Cond Res XX(X): 000-000, 2019-The definition of interval training is quite broad, with no accepted procedure for classifying protocols with different workloads and work and recovery interval times. In addition, little is known about the differences in training load and recovery from common interval protocols. The purpose of this study was to evaluate the differences in acute physiological demands and perceived difficulty between 3 common interval training protocols and a moderate, continuous exercise session. Eight subjects completed the training sessions on a cycle ergometer in a randomized order, with at least 1 week between sessions: 30-second/4-minute, 1-minute/1-minute, 4-minute/3-minute, and a 45-minute continuous session. Metabolic variables were measured throughout exercise and 30 minutes of recovery. Training impulse (TRIMP), session-RPE, and RPE-training load were also measured. There were significant differences between protocols, including between interval training protocols, for average V[Combining Dot Above]O2 (p < 0.001) and heart rate (HR) (p = 0.02), total O2 consumption (p < 0.001), peak lactate (p < 0.001), TRIMP (p = 0.02), session-RPE (p = 0.01), and RPE-training load (p < 0.001). There were no significant differences between interval training protocols for peak V[Combining Dot Above]O2 or peak HR attained during exercise. There were also no differences in V[Combining Dot Above]O2 or HR after 5 or 30 minutes of recovery. Blood lactate was only significantly higher after 30 minutes of recovery from the 30-second/4-minute compared with the 4-minute/3-minute protocol (p = 0.001) and the 45-minute session (p < 0.001). These findings show a range of differences in acute physiological demands and perceptions from interval training protocols, which should be accounted for when planning training sessions or research studies or when interpreting past research.
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Affiliation(s)
- David J Elmer
- Department of Kinesiology, Berry College, Mount Berry, Georgia
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Abstract
PURPOSE The modified Dmax method can accurately determine the second lactate threshold (LT2), which is valuable for predicting aerobic performance and prescribing exercise. The purpose of this study is to determine if the modified Dmax method can accurately find thresholds in VE (VT2), VCO2 (VCO2T), RER (RERT), and RR (RRT) to estimate LT2. METHODS Forty-one participants (females n=23, males n=18) completed an incremental exercise test to determine LT2, VT2, VCO2T, RERT, RRT, and blood lactate=4 mmol/L (La4). RESULTS VT2 and RRT were strongly correlated with VO2 and HR at LT2, with very small bias and limits of agreement, indicating that VT2 and RRT provide accurate estimates of LT2 (VO2 at VT2-LT2 mean difference=0.37±1.91 ml/kg/min, p=0.95; HR at VT2-LT2 mean difference=0.25±2.58 bpm, p=0.99; VO2 at RRT-LT2 mean difference 0.26±2.11 ml/kg/min, p=0.99; HR at RRT-LT mean difference 0.44±3.31 bpm, p=0.99). VCO2T, RERT, and La4 were either accurate for VO2 or HR estimates of LT2, but not both. CONCLUSIONS VT2 and RRT provide accurate estimates of LT2 using the modified Dmax method. There is the potential to use RRT in developing field tests to estimate LT2 in practical settings.
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Affiliation(s)
- David J Elmer
- Berry College, Kinesiology, Mount Berry, United States
| | - Marissa Toney
- Berry College, Kinesiology, Mount Berry, United States
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Laird RH, Elmer DJ, Barberio MD, Salom LP, Lee KA, Pascoe DD. Evaluation of Performance Improvements After Either Resistance Training or Sprint Interval-Based Concurrent Training. J Strength Cond Res 2016; 30:3057-3065. [PMID: 26950345 DOI: 10.1519/jsc.0000000000001412] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Laird IV, RH, Elmer, DJ, Barberio, MD, Salom, LP, Lee, KA, and Pascoe, DD. Evaluation of performance improvements after either resistance training or sprint interval-based concurrent training. J Strength Cond Res 30(11): 3057-3065, 2016-The purpose of this investigation was to examine the effects of concurrent sprint interval and resistance training (CST) vs. resistance training (RT) on measures of strength, power, and aerobic fitness in recreationally active women. Twenty-eight women (20.3 ± 1.7 years; 63.0 ± 9.1; 51.1 ± 7.1 1 repetition maximum (1-RM) back squat (kg); V[Combining Dot Above]O2max: 35.4 ± 4.1 ml·kg·min) were recruited to complete an 11-week training program. Participants were matched-pair assigned to CST or RT cohorts after preliminary testing, which consisted of 1-RM back squats, maximal isometric squats, anaerobic power evaluations, and maximal oxygen consumption. All subjects trained 3 days per week with sprint-interval training occurring at least 4 hours after RT in the CST cohort. Both CST and RT resulted in significant improvements (p ≤ 0.05) in the 1-RM back squat (37.5 ± 7.8; 40.0 ± 9.6 kg), maximal isometric force (55.7 ± 51.3; 53.7 ± 36.7 kg), average peak anaerobic power testing (7.4 ± 6.2; 7.6 ± 6.4%), and zero-incline treadmill velocity, resulting in maximal oxygen consumption (1.8 ± 0.6; 0.8 ± 0.6 km·h). Only zero-incline treadmill velocity demonstrated a group-by-time interaction with a greater improvement after CST (p < 0.01). Rate of force development was not altered in either group. Results provide no evidence of interference to the adaptive process by CST. Coaches desiring improvements in strength, power, and endurance may want to evaluate how spring and high-intensity interval training might supplement programs already in place.
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Affiliation(s)
- Richard H Laird
- 1Department of Exercise Science & Physical Education, McDaniel College, Westminster, Maryland; 2Department of Kinesiology, Berry College, Mount Berry, Georgia; 3Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC; and 4School of Kinesiology, Auburn University, Auburn, Alabama
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Elmer DJ, Laird RH, Barberio MD, Pascoe DD. Inflammatory, lipid, and body composition responses to interval training or moderate aerobic training. Eur J Appl Physiol 2015; 116:601-9. [PMID: 26721463 DOI: 10.1007/s00421-015-3308-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 12/08/2015] [Indexed: 02/02/2023]
Abstract
PURPOSE The goal of this study was to compare the effect of work- and duration-matched interval training (HIIT) versus moderate aerobic endurance training (ET) on acute and chronic inflammation, along with changes in the lipid profile, to determine which may be more beneficial for improving cardiovascular health. METHODS Twelve sedentary males (maximal oxygen consumption = 41.6 ± 5.4 mL kg(-1) min(-1)) completed 8 weeks of aerobic interval training or moderate aerobic training, with variables including C-reactive protein (CRP) for chronic inflammation, interleukin-6 (IL-6) response for the acute inflammatory response, plasma concentrations of high-density lipoprotein (HDL), total cholesterol (TC), triglycerides (TRG), and low-density lipoprotein, and body composition measured before and after the training period. RESULTS HIIT decreased plasma TRG from 92 ± 32 to 61 ± 12 mg dL(-1), which was significantly different from ET, while ET improved the TC:HDL ratio from 4.67 ± 0.85 to 4.07 ± 0.96 and reduced the percentage of android fat from 36.78 ± 9.60 to 34.18 ± 11.39 %. Neither training protocol resulted in an acute IL-6 response on the first nor the last day of exercise, a change in chronic levels of CRP, or a significant increase in HDL, despite previous research finding these changes. CONCLUSIONS It seems that in order to maximize the health outcomes from physical activity, both HIIT and ET should be included. The acute inflammatory response and reductions in chronic inflammation resulting from exercise training may not be as common as the literature suggests.
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Affiliation(s)
- David J Elmer
- Department of Kinesiology, Berry College, 2277 Martha Berry Hwy, Mount Berry, GA, 30149-5026, USA.
| | - Richard H Laird
- Department of Exercise Science and Physical Education, McDaniel College, Westminster, MD, USA
| | - Matthew D Barberio
- Center for Genetic Medicine Research, Children's National Medical Center, Washington, DC, USA
| | - David D Pascoe
- School of Kinesiology, Auburn University, Auburn, AL, USA
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Barberio MD, Elmer DJ, Laird RH, Lee KA, Gladden B, Pascoe DD. Systemic LPS and inflammatory response during consecutive days of exercise in heat. Int J Sports Med 2014; 36:262-70. [PMID: 25525952 DOI: 10.1055/s-0034-1389904] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
This investigation studied circulating LPS activity, potential intestinal damage, and the systemic inflammatory response (SIR) during the exercise heat acclimation process. 8 healthy males (Age=24±3 years) ran in a hot environment on 5 consecutive days until core temperature (Tc) was elevated 2°C above rest. Plasma was obtained pre-, post-, 1 h post-, and 3 h post-exercise on the 1(st), 3(rd), and 5(th) day of exercise and analyzed for TNF-α, IL-6, IL-10, IL-1ra, LPS, and intestinal fatty acid-binding protein (I-FABP). Plasma LPS (1.1 EU·ml(-1)±0.1 vs. 0.7 EU·ml(-1)±0.03; P<0.01) and I-FABP (930.7 pg·ml(-1)±149.0 vs. 640.2 pg·ml(-1)±125.0; P<0.001) were significantly increased post-exercise each. The SIR remained largely unchanged during the study except for TNF-α. Plasma TNF-α was significantly lower on Day 5 at 1 h (3.2 pg·ml(-1)±0.6 vs. 4.5 pg·ml(-1)±0.8; P=0.01) and 3 h (3.6 pg·ml(-1)±0.8 vs. 4.8 pg·ml(-1)±0.9; P=0.05) post-exercise as compared to Day 1. Findings indicate that adaptations to exercise in the heat resulting in reductions of intestinal damage and plasma LPS activity require longer time periods in moderately trained males.
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Affiliation(s)
- M D Barberio
- Children's National Medical Center, Center for Genetic Medicine Research, Washington, D.C., United States
| | - D J Elmer
- Department of Kinesiology, Berry College, Mount Berry, GA, United States
| | - R H Laird
- Children's National Medical Center, Center for Genetic Medicine Research, Washington, D.C., United States
| | - K A Lee
- School of Kinesiology, Auburn University, Auburn, AL, United States
| | - B Gladden
- School of Kinesiology, Auburn University, Auburn, AL, United States
| | - D D Pascoe
- School of Kinesiology, Auburn University, Auburn, AL, United States
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