Carbohydrate Supplementation Does Not Improve 10 km Swimming Intermittent Training

Area of Science:

• Sports Science
• Exercise Physiology
• Nutrition Science

Background:

• Elite open-water swimmers require optimized fueling strategies for sustained performance.
• Carbohydrate (CHO) supplementation is common in endurance sports, but its efficacy in intermittent training needs further investigation.

Purpose of the Study:

• To evaluate the impact of carbohydrate (CHO) feeding on performance, perceived exertion, and glycaemia in elite open-water swimmers during a 10-km intermittent training workout.

Main Methods:

• A randomized crossover design was employed with elite swimmers completing two 10-km intermittent training sessions.
• Participants consumed either water (WAT) or a carbohydrate (CHO) solution (120g CHO in 1L water) every 2.5 km.
• Performance (relative velocity), rating of perceived exertion (RPE), and glycaemia were monitored throughout the sessions.

Main Results:

• No significant differences in overall or final 500-m relative velocity were observed between the water and CHO trials.
• Average rating of perceived exertion (RPE) was similar across both conditions.
• Glycaemia levels were significantly higher in the final 500-m during the CHO trial compared to the water trial.

Conclusions:

• Carbohydrate (CHO) ingestion at a rate of 60 g·h⁻¹ did not improve performance or affect perceived exertion in elite open-water swimmers during a 10-km intermittent training session.
• While CHO supplementation increased glycaemia, this did not lead to measurable performance benefits under these specific training conditions.