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Updated: Jun 17, 2026
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Application of Chronic Stimulation to Study Contractile Activity-induced Rat Skeletal Muscle Phenotypic Adaptations
Published on: January 25, 2018
Muscle contractile function and neural control after repetitive endurance cycling
Emma Z Ross1, Warren Gregson, Karen Williams
1Chelsea School Research Centre, University of Brighton, Eastbourne, United Kingdom. emma.ross@brunel.ac.uk
Medicine and Science in Sports and Exercise
|December 17, 2009
Summary
Repetitive endurance cycling significantly reduces knee extensor strength due to central and peripheral factors. Muscle function and corticomotor output remain impaired even after rest, impacting athletic performance.
Area of Science:
- Exercise Physiology
- Sports Science
- Neuromuscular Function
Background:
- Endurance athletes experience significant physiological stress during prolonged events.
- Understanding the neuromuscular consequences of such events is crucial for optimizing training and recovery.
Purpose of the Study:
- To investigate changes in muscle contractile properties, cortical excitability, and voluntary activation following 20 days of intense endurance cycling.
- To determine the time course of recovery for these neuromuscular parameters.
Main Methods:
- Eight elite male cyclists underwent a simulated 20-day Tour de France cycling protocol.
- Measurements included maximal voluntary contraction, evoked potentials (M-wave, twitch), and voluntary activation via electrical and magnetic stimulation.
- Assessments were performed before, during (days 9, 17), and after the cycling period.
Main Results:
- Maximal voluntary contraction decreased by 20% during the event.
- Peripheral muscle excitability (M-wave, twitch) reduced by up to 31% and 22%, respectively.
- Voluntary activation and corticomotor output (motor evoked potentials) were significantly depressed throughout and after the cycling period.
Conclusions:
- Reduced knee extensor strength post-endurance cycling stems from both central (corticomotor) and peripheral (sarcolemmal excitability) impairments.
- Impaired muscle function persists even after extended recovery periods (>18 hours).
- A lasting reduction in central drive impacts neuromuscular performance long-term.
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