Does a 100-km Walking Affect Indicators of Vitamin Status?

Abstract

The status of thiamin (B1), riboflavin (B2), ascorbic acid (AA), and tocopherol was determined in 60 leisure athletes (age 46 +/- 10 y, BMI 23.7 +/- 2.0 kg.m-2, VO2max 39.4 +/- 6.5 ml.min-1.kg-1), who completed a 100-km walking race. Vitamin plasma levels and activities of erythrocyte transketolase (ETK) and glutathione reductase (EGR) were measured before start, immediately after finishing and 6 hours later. The participators finished the entire distance in 14.25 h (average speed 7 km.h-1). Before start, all participators showed an excellent vitamin status (prevalences of low vitamin status ranged between 1.7 and 1.8%). Plasma tocopherol concentrations correlated significantly with increased age (r = 0.35, p = 0.008). Compared to the values before start, plasma concentrations of B1 and B2 as well as ETK and/or EGR were increased significantly after finishing. The raised levels persisted 6 hours after finishing, whereas AA remained unaltered. The univariate analysis of variance revealed that the change in vitamin status after finish and 6 hours later was in part highly dependent on age, BMI and the level of physical fitness. Despite the long distance, the extensive character of the 100-km walking with its low intensity did not deteriorate the measured indicators of vitamin status.

The Effect of a Single Bout of Exercise on Vitamin B2 Status Is Not Different between High- and Low-Fit Females

“…The first finding implies that a short-term exercise intervention on the day prior to blood sampling does not affect the reliability of using EGRAC for vitamin B2 status determination. Moreover, our observations are similar to previous findings [21,28,30]. Ohno et al [30] demonstrated in 11 untrained males (age 20.3 ± 0.3 y) that a single bout of exercise (30-min cycling test at 75% VO 2 peak) significantly increased FAD-stimulated EGR activity and non-significantly increased unstimulated EGR activity [30], but EGRAC values were lacking.…”

“…We hypothesized that the single bout of exercise could affect vitamin B2 status as determined by EGRAC, as the short-term effects (<24 h) of exercise on EGR activity have been reported by previous studies [21,28,30]. We also hypothesized that the EGRAC values after the single bout of exercise would be higher, i.e., vitamin B2 status would be lower in high-fit compared to low-fit individuals, as regular aerobic exercise enhances vitamin B2-dependent processes that could increase vitamin B2 demand.…”

“…Large observational studies comparing the vitamin B2 status in athletes and recreationally active individuals also show inconsistent results [22][23][24][25][26][27]. Differences in experimental setup, including the selection of the study population [14][15][16][17][18][19][20][21][22][23][24][26][27][28] and the assessment of subjects' fitness levels [24,27] could be of importance. However, the inconsistent findings could also be related to alterations in the EGR enzymatic activity itself.…”

“…However, the inconsistent findings could also be related to alterations in the EGR enzymatic activity itself. EGR enzymatic activity was shown to increase upon a longer-term exercise intervention [21], but has also been found to alter upon a single bout of exercise [21,[28][29][30] and importantly, this has been linked to a lower EGRAC [21,28]. This implies that the long-and short-term effects of exercise on vitamin B2 status parameters could differ, but this has not yet been investigated, nor has the effect of long-term exercise on the EGRAC response to short-term exercise.…”

The Body Vitamin B1 Levels of Rats Fed a Diet Containing the Minimum Requirement of Vitamin B1 Is Reduced by Exercise

“…Some authors believe that it does (14,15), whereas other authors do not (16)(17)(18). To ascertain if exercise increases the requirement of vitamin B1, we investigated whether the concentrations of vitamin B1 in the liver and blood were reduced when rats were forced to exercise on alternate days after being fed a diet containing a sufficient amount of thiamin (4.720 mg thiamin/ kg diet) or a diet containing a minimum requirement of thiamin (0.786 mg thiamin/kg diet).…”