Twelve milligrams of capsiate did not improve ten cycling sprints in a double-blind crossover. The trial was well controlled — and included only 11 men

Capsiate is a non-pungent relative of capsaicin marketed around metabolism and exercise. Eleven physically active men completed a randomised, double-blind crossover experiment: on separate occasions they swallowed 12 mg of capsiate or placebo 45 minutes before ten six-second maximal cycling sprints, each separated by 30 seconds of recovery.

The supplement did not clearly change sprint performance, total work, fatigue index or quadriceps neuromuscular efficiency. Estimated aerobic, glycolytic and phosphagen contributions were also similar, as were perceived exertion and readiness to invest effort. The aerobic system remained the largest estimated contributor across the repeated sprints in both conditions.

A crossover is efficient because each person serves as his own control, and blinding reduces expectation effects. But eleven participants provide limited power, especially for modest benefits or harms, and the result applies to one dose, timing and exercise protocol in physically active men. It is a useful negative test of a specific claim, not a verdict on every capsiate product or type of exercise.