Research: vitamin C reduces exercise-induced stress

24 February 2011 - In research involving food supplements, it is difficult to determine whether a high dosage vitamin actually works. For that reason, tests are often carried out on people in special circumstances, for example under stress. One such study involving marathon runners demonstrated that vitamin C ensures that the levels of stress hormones rise less, following exercise.

During extended physical exercise, the body produces more cortisol, also known as the stress hormone. As a result, the immune system may be suppressed. Canadian scientists investigated this phenomenon by having 12 test subjects take 500 mg vitamin C or a placebo for 12 days, three times a day.

After the test subjects had run a half or full marathon, the concentration of cortisol in the blood was shown to have risen less during running in the athletes that had taken the vitamin C. The effect on the cortisol level was stronger after 8 days’ administration of the supplement than after 1 day of taking vitamin C.

Source: Carrillo AE, Murphy RJ, Cheung SS. Vitamin C supplementation and salivary immune function following exercise-heat stress. Int J Sports Physiol Perform 2008; 3(4):516-30