Regular moderate exercise training can alter the urinary excretion of thiamin and riboflavin.

Background/objectives: Physical exercise promotes energy producing pathways requiring thiamin and riboflavin as a coenzyme. Therefore, this study investigated the effects of regular exercise training on urinary excretion of thiamin and riboflavin.

Materials/methods: Fifty rats were randomly assigned to one of two groups: non-exercise training (NT, n = 25) and regular exercise training (ET, n = 25) for 5 weeks. The rats performed moderate exercise on a treadmill (0.5-0.8 km/hour) for 30 min/day, 5 days/week. Twenty-four hour urine samples were collected at the end of the 0 week, 3(rd) week, and 5(th) week of training and thiamin and riboflavin were analyzed.

Results: No significant differences in thiamin and riboflavin intakes for each week were observed between the NT and ET groups. Urinary thiamin excretion of each group was the highest at the 5(th) week compared to the levels at 0 and 3(rd) week. Urinary thiamin at the 5(th) week was significantly lower in the ET group than in the NT group. Urinary riboflavin excretion was increased by training duration, however, no difference was observed between NT and ET for each week. At 0 and 3(rd) week, no significant relationships were observed between dietary intake and urinary excretion of thiamin and riboflavin, however, at the 5(th) week, urinary excretion was significantly increased by dietary intake only in the NT group (P < 0.05). Thiamin excretion of both NT and ET groups was significantly increased with riboflavin excretion at the 5(th) week (P < 0.01).

Conclusion: Regular moderate exercise training increased urinary excretion of thiamin. Dietary intakes and urinary excretions of thiamin and riboflavin showed positive correlation in both the exercise training and non-exercise training groups as the exercise training period went by, while the correlations in the exercise training group were weaker than those in the non-exercise training group. Therefore, regular exercise training can alter the urinary excretion of thiamin and riboflavin in rats.