Ergometric and metabolic adaptation to a 5-s sprint training programme

Area of Science:

• Exercise Physiology
• Sports Science
• Muscle Physiology

Background:

• Maximal power output is crucial for athletic performance.
• Sprint training is a common method to enhance power.
• Understanding the physiological adaptations to sprint training is essential.

Purpose of the Study:

• To investigate the effects of 7 weeks of sprint training on maximal power output.
• To examine the relationship between muscle phosphocreatine stores and performance.
• To determine the metabolic and morphological adaptations following sprint training.

Main Methods:

• Ten students underwent 7 weeks of repeated 5-s all-out sprint training on a cycle ergometer.
• Maximal power output was assessed using force-velocity tests and a 30-s Wingate test.
• Muscle biopsies were analyzed for phosphocreatine (PCr) levels, enzyme activity (PFK, LDH), and muscle fiber type distribution.

Main Results:

• Sprint training increased peak power output (Wv,max and Wpeak) by 25% and 30-s total work by 16%.
• The velocity reached with no load (v0) correlated with resting muscle PCr stores, suggesting PCr limits high-velocity capacity.
• Training led to increased lactate production, higher phosphofructokinase and lactate dehydrogenase activity, and a shift from fast-twitch b to slow-twitch fibers.

Conclusions:

• Sprint training enhances peak performance through increased anaerobic glycolysis and adaptive changes in muscle fiber composition.
• Low resting phosphocreatine stores may limit the ability to achieve high velocities.
• Slow-twitch fibers adapt favorably to high-intensity intermittent training, potentially due to their greater oxidative capacity.