Energy production and the rebuilding and repair of muscle tissue by physical activity require folate and vitamin B₁₂ as a cofactor. Thus, this study investigated the effects of regular moderate exercise training and durations of acute aerobic exercise on plasma folate and vitamin B₁₂ concentrations in moderate exercise trained rats.

Fifty rats underwent non-exercise training (NT, n = 25) and regular exercise training (ET, n = 25) for 5 weeks. The ET group performed moderate exercise on a treadmill for 30 min/day, 5 days/week. At the end of week 5, each group was subdivided into 4 groups: non-exercise and 3 exercise groups. The non-exercise group (E0) was sacrificed without exercising and the 3 exercise groups were sacrificed immediately after exercising on a treadmill for 0.5 h (E0.5), 1 h (E1), and 2 h (E2). Blood samples were collected and plasma folate and vitamin B₁₂ were analyzed.

After exercise training, plasma folate level was significantly lower and vitamin B₁₂ concentration was significantly higher in the ET group compared with the NT group ( P < 0.05). No significant associations were observed between plasma folate and vitamin B₁₂ concentrations. In both the NT and ET groups, plasma folate and vitamin B₁₂ were not significantly changed by increasing duration of aerobic exercise. Plasma folate concentration of E0.5 was significantly lower in the ET group compared with that in the NT group. Significantly higher vitamin B₁₂ concentrations were observed in the E0 and E0.5 groups of the ET group compared to those of the NT group.

Regular moderate exercise training decreased plasma folate and increased plasma vitamin B₁₂ levels. However, no significant changes in plasma folate and vitamin B₁₂ concentrations were observed by increasing duration of acute aerobic exercise.