Effects of thiamine supplementation on exercise-induced fatigue.

High-dose thiamine (vitamin B1) supplementation (100 mg/day) may be helpful in preventing or accelerating recovery from exercise-induced fatigue. Sixteen volunteer male athletes volunteer, 8 with a blood thiamine level of 40 ng/ml or more (normal thiamine group) and 8 with levels below that level (low thiamine group) were selected as subjects. They exercised on a bicycle ergometer and the effects of thiamine supplementation were compared with placebo. Blood thiamine level markedly increased following supplementation of thiamine for 3 days before exercise. Exercise-induced changes in hemodynamic parameters and cardiopulmonary function indicated the onset of fatigue. Thiamine supplementation significantly suppressed the increase in blood glucose in the normal thiamine group and significantly decreased the number of complaints shortly after exercise in the subjective fatigue assessment of 30 items.