Endurance training of trained athletes-an electromyogram study

Area of Science:

• Exercise Physiology
• Neurophysiology
• Sports Science

Background:

• The mechanisms underlying performance improvements from high-intensity interval training (HIT) remain unclear.
• Understanding neurophysiological changes is crucial for optimizing athletic training.

Purpose of the Study:

• To investigate the neurophysiological adaptations in well-trained cyclists following a 3-week high-intensity interval training (HIT) intervention.
• To assess the impact of HIT on neuromuscular changes and endurance performance.

Main Methods:

• Seven endurance cyclists (VO2max 64.6 ±4.8 ml.kg-1.min-1) replaced 15% of their training with 6 HIT sessions.
• Surface electromyography (SEMG) measured neuromuscular activity before and after the intervention.
• Performance was assessed via a 40 km time trial (TT40) pre- and post-training.

Main Results:

• SEMG analysis revealed a decrease in mean power frequency during the later stages of HIT intervals (50.2 ±5.1 to 47.5 ±4.2 Hz, P < 0.05).
• This indicates reduced muscle fatigue after the 3-week HIT program.
• Endurance performance, measured by TT40, was enhanced post-intervention.

Conclusions:

• High-intensity interval training (HIT) improves endurance performance in well-trained cyclists.
• HIT elicits positive neurophysiological changes, including reduced muscle fatigue.
• These adaptations may be attributed to the recruitment of additional slow-twitch motor units.