Vitamin C may have exercise benefits for obese people

New US research says that daily vitamin C supplementation may decrease heart rate during moderate exercise for obese people and reduce their perception of fatigue and exertion.

In the study, 20 obese adults (mean BMI of 34.3 kg/m2 and average age of 35 years) consumed a calorie-controlled diet for four weeks with or without a daily supplementation of 500 mg vitamin C (1). At the begin-ning and the end of the study, the participants performed 60 minutes of moderate exercise (walking) at an intensity of 50% predicted maximal oxygen consumption. The study results showed that both groups lost about four kilograms and there were no differences in breathing between the groups. However, the vitamin C group had significantly lower heart rates (an average of 11 fewer heart beats per minute) during exercise, compared with the control group. In addition, the ratings of perceived exertion and perceived fatigue were also significantly reduced in the vitamin C group.

The researchers concluded that this data indicates that vitamin C supplementation can decrease perception of fatigue and exertion during moderate exercise for obese people. Thus, increased vitamin C intake may be a strategy to improve adherence to exercise protocols for obese. According to the researchers, perceived exertion is typically correlated to heart rate and blood lactate concentrations and considered a gauge for muscular effort, fatigue, and muscle aches. Since heart rate is a contributing factor to perceived effort, the significant decrease in the exercising heart rate noted for the vitamin C group may have influenced the reported reduced perceived exertion.

1. Huck C. J. et al. Vitamin C status and perception of effort during exercise in obese adults adhering to a calorie- reduced diet. Nutrition. Published online June 2012.