Central Nervous System and Muscle Fatigue following Fast and Slow Muscle Contractions
Disciplines
Sports Sciences
Abstract (300 words maximum)
Varying muscle contraction speed may uniquely affect central (nervous system) and peripheral (muscle) fatigue. This study sought to compare parameters of peripheral and central fatigue resulting from RAPID and RAMP MVICs. Eleven, recreationally active, healthy males (22±2 yrs) performed, on separate days, RAPID (“kick out as hard and fast as possible”) or RAMP (steady increase in torque over 2 sec) MVICs until peak torque decreased to 50% of baseline. Assessments of peripheral and central fatigue using transcutaneous femoral nerve stimulation (PNS) and transcranial magnetic stimulation (TMS) were performed before and after (post) each protocol. Voluntary activation (capacity of central nervous system to activate muscle) and supraspinal excitability was assessed through superimposed twitch magnitude from PNS and TMS, respectively. Impulse (184.0 N⋅s vs. 180.3 N⋅s) was similar, but the number of MVICs to achieve ~50% peak torque decrease was greater in RAPID (25) than RAMP (21). Peak torque decrements were similar at post (RAPID: -38.4% vs. RAMP: -34.9%). Voluntary activation decreased (p=0.001) similarly (RAPID: -12.1% vs. RAMP: -6.6%). Supraspinal excitability was unaffected by fatigue (p>0.05). All singlet and doublet twitch parameters were similar between fatigue protocols, except RAMP had greater relative reductions in 10 Hz peak twitch (-39.7%) than 100 Hz peak twitch (-28.3%) and a decreased 10 Hz:100 Hz twitch ratio (p
Academic department under which the project should be listed
WCHHS - Exercise Science and Sport Management
Primary Investigator (PI) Name
Garrett M. Hester
Additional Faculty
Trisha VanDusseldorp, WCHHS - Exercise Science and Sport Management Robert Buresh, WCHHS - Exercise Science and Sport Management
Central Nervous System and Muscle Fatigue following Fast and Slow Muscle Contractions
Varying muscle contraction speed may uniquely affect central (nervous system) and peripheral (muscle) fatigue. This study sought to compare parameters of peripheral and central fatigue resulting from RAPID and RAMP MVICs. Eleven, recreationally active, healthy males (22±2 yrs) performed, on separate days, RAPID (“kick out as hard and fast as possible”) or RAMP (steady increase in torque over 2 sec) MVICs until peak torque decreased to 50% of baseline. Assessments of peripheral and central fatigue using transcutaneous femoral nerve stimulation (PNS) and transcranial magnetic stimulation (TMS) were performed before and after (post) each protocol. Voluntary activation (capacity of central nervous system to activate muscle) and supraspinal excitability was assessed through superimposed twitch magnitude from PNS and TMS, respectively. Impulse (184.0 N⋅s vs. 180.3 N⋅s) was similar, but the number of MVICs to achieve ~50% peak torque decrease was greater in RAPID (25) than RAMP (21). Peak torque decrements were similar at post (RAPID: -38.4% vs. RAMP: -34.9%). Voluntary activation decreased (p=0.001) similarly (RAPID: -12.1% vs. RAMP: -6.6%). Supraspinal excitability was unaffected by fatigue (p>0.05). All singlet and doublet twitch parameters were similar between fatigue protocols, except RAMP had greater relative reductions in 10 Hz peak twitch (-39.7%) than 100 Hz peak twitch (-28.3%) and a decreased 10 Hz:100 Hz twitch ratio (p