Glucose ingestion during endurance training does not alter adaptation.

Area of Science:

• Exercise Physiology
• Metabolic Adaptations
• Sports Nutrition

Background:

• Glucose ingestion during exercise can affect metabolic enzyme activation and transport protein expression.
• Understanding how concurrent glucose intake influences training adaptations is crucial for optimizing performance.

Purpose of the Study:

• To investigate the effects of glucose ingestion during training on fatty acid metabolism, skeletal muscle adaptations, and endurance performance.
• To test the hypothesis that glucose intake during training attenuates training-induced improvements.

Main Methods:

• Nine male subjects underwent 10 weeks of one-legged knee extensor training.
• One leg trained with glucose (Glc) ingestion, the other with a placebo (Plc).
• Evaluated changes in peak power, time to fatigue, enzyme activities (CS, beta-HAD), muscle glycogen, and substrate oxidation rates.

Main Results:

• Endurance training significantly improved peak power and time to fatigue in both legs.
• No significant differences were observed between the glucose and placebo conditions for enzyme activities, glycogen content, or substrate oxidation rates.
• Training adaptations in substrate metabolism and performance were not altered by concurrent glucose ingestion.

Conclusions:

• Glucose ingestion during endurance training does not modify training adaptations related to substrate metabolism.
• Concurrent glucose intake does not influence mitochondrial enzyme activity, muscle glycogen content, or performance enhancements.
• The findings suggest that consuming glucose during training does not negatively impact physiological adaptations to exercise.