Effect of creatine loading on long-term sprint exercise performance and metabolism

Area of Science:

• Sports Science
• Exercise Physiology
• Nutritional Biochemistry

Background:

• Repeated-sprint exercise places high demands on the phosphagen system.
• Creatine supplementation is known to increase muscle phosphocreatine stores.
• The efficacy of creatine for prolonged, repeated-sprint performance requires further investigation.

Purpose of the Study:

• To determine if creatine supplementation enhances performance during 80 minutes of repeated-sprint exercise.
• To assess the impact of creatine on total work done and peak power during prolonged intermittent exercise.

Main Methods:

• Fourteen active males underwent repeated-sprint testing before and after 5 days of creatine (20 g/day) or placebo supplementation.
• Performance metrics included total work done and peak power across various sprint intervals and recovery periods.
• Muscle biopsies and blood samples were analyzed to assess creatine and phosphocreatine levels.

Main Results:

• Creatine supplementation significantly increased total work done by 6% and enhanced peak power across all sprint types.
• Muscle creatine and phosphocreatine concentrations were elevated post-supplementation, with higher phosphocreatine levels observed immediately and 3 minutes post-exercise.
• The placebo group showed no significant changes in performance or muscle phosphocreatine levels.

Conclusions:

• Creatine supplementation effectively improves performance in prolonged repeated-sprint exercise.
• Increased total creatine and enhanced phosphocreatine replenishment rates likely contribute to the observed performance benefits.
• This suggests creatine is beneficial for endurance-based intermittent high-intensity activities.