Paul W Marshall1,2, Thomas Forward3, Roger M Enoka4. 1. Department of Exercise Sciences, University of Auckland, Building 907, Newmarket, 1023, Auckland, New Zealand. p.marshall@auckland.ac.nz. 2. Human Performance Laboratory, School of Health Sciences, Western Sydney University, Penrith, Australia. p.marshall@auckland.ac.nz. 3. Human Performance Laboratory, School of Health Sciences, Western Sydney University, Penrith, Australia. 4. Department of Integrative Physiology, University of Colorado, Boulder, CO, USA.
Abstract
PURPOSE: Fatigability after gym-based resistance exercises with high and low loads has not been well described, thus limiting the translation of exhaustive low-weight prescription into athletic practice. We compared the fatigability and recovery of the knee extensor muscles for up to 1H after sessions that involved either high- or low-load resistance exercises. METHODS: 16 trained men performed two resistance exercise sessions between 5 and 7 days apart. The LIGHT session involved five sets to task failure at 50% of maximal knee-extension strength, whereas the HEAVY session accrued repetitions across seven sets at intensities ≥ 80% maximal knee-extension strength. Measures of quadriceps maximal torque and rate of torque development were measured before, after, and 1H after each exercise session. Muscle activation (electromyography and voluntary activation) and contractility were measured from doublet stimulation of the femoral nerve during and after maximal contractions, respectively. RESULTS: Greater declines in maximal rate of torque development were observed after the LIGHT compared with the HEAVY session (p < 0.001), with full recovery after 1H. Voluntary activation (100-Hz doublet stimulation) and surface electromyograms were reduced immediately after the HEAVY session only (p < 0.05), with greater declines in quadriceps twitch amplitudes after the LIGHT session (p < 0.01). Voluntary activation (100-Hz doublet stimulation) was reduced at 1H after both the HEAVY and LIGHT sessions (p < 0.05). CONCLUSIONS: Despite differences in the decreases in muscle activation and contractility after high- and low-load resistance-exercise sessions, recovery of neuromuscular function was essentially complete after 1H of rest for both sessions.
PURPOSE: Fatigability after gym-based resistance exercises with high and low loads has not been well described, thus limiting the translation of exhaustive low-weight prescription into athletic practice. We compared the fatigability and recovery of the knee extensor muscles for up to 1H after sessions that involved either high- or low-load resistance exercises. METHODS: 16 trained men performed two resistance exercise sessions between 5 and 7 days apart. The LIGHT session involved five sets to task failure at 50% of maximal knee-extension strength, whereas the HEAVY session accrued repetitions across seven sets at intensities ≥ 80% maximal knee-extension strength. Measures of quadriceps maximal torque and rate of torque development were measured before, after, and 1H after each exercise session. Muscle activation (electromyography and voluntary activation) and contractility were measured from doublet stimulation of the femoral nerve during and after maximal contractions, respectively. RESULTS: Greater declines in maximal rate of torque development were observed after the LIGHT compared with the HEAVY session (p < 0.001), with full recovery after 1H. Voluntary activation (100-Hz doublet stimulation) and surface electromyograms were reduced immediately after the HEAVY session only (p < 0.05), with greater declines in quadriceps twitch amplitudes after the LIGHT session (p < 0.01). Voluntary activation (100-Hz doublet stimulation) was reduced at 1H after both the HEAVY and LIGHT sessions (p < 0.05). CONCLUSIONS: Despite differences in the decreases in muscle activation and contractility after high- and low-load resistance-exercise sessions, recovery of neuromuscular function was essentially complete after 1H of rest for both sessions.
Authors: Manuela Besomi; Paul W Hodges; Edward A Clancy; Jaap Van Dieën; François Hug; Madeleine Lowery; Roberto Merletti; Karen Søgaard; Tim Wrigley; Thor Besier; Richard G Carson; Catherine Disselhorst-Klug; Roger M Enoka; Deborah Falla; Dario Farina; Simon Gandevia; Aleš Holobar; Matthew C Kiernan; Kevin McGill; Eric Perreault; John C Rothwell; Kylie Tucker Journal: J Electromyogr Kinesiol Date: 2020-06-10 Impact factor: 2.368
Authors: Gerson E R Campos; Thomas J Luecke; Heather K Wendeln; Kumika Toma; Fredrick C Hagerman; Thomas F Murray; Kerry E Ragg; Nicholas A Ratamess; William J Kraemer; Robert S Staron Journal: Eur J Appl Physiol Date: 2002-08-15 Impact factor: 3.078