L-tryptophan supplementation can decrease fatigue perception during an aerobic exercise with supramaximal...

Area of Science:

• Exercise Physiology
• Neuroscience
• Nutritional Biochemistry

Background:

• Physical exercise capacity is often limited by neural factors rather than muscle fatigue.
• The serotonergic system plays a role in regulating neural drive during exercise.
• L-tryptophan, a serotonin precursor, may influence serotonergic activity and thus exercise performance.

Purpose of the Study:

• To investigate the effects of L-tryptophan supplementation on physical performance in athletes.
• To determine if modulating the serotonergic system can enhance exercise capacity.

Main Methods:

• A double-blind, randomized, placebo-controlled study was conducted with 20 healthy young sportsmen.
• Participants performed a cycling protocol involving submaximal and supramaximal efforts, followed by a sustained endurance test.
• The protocol was repeated twice, once with L-tryptophan supplementation and once with a placebo.

Main Results:

• L-tryptophan supplementation significantly increased peak power output, average anaerobic power output, and sustained power output.
• Athletes covered a greater distance during the final 20 minutes of exercise with L-tryptophan compared to placebo (12,526 m vs. 11,959 m).

Conclusions:

• L-tryptophan supplementation can improve physical performance, particularly in exercise protocols that mimic team sports.
• Modulating the serotonergic system through L-tryptophan may be a viable strategy to enhance athletic capacity.