The University of Valencia in Valencia, Spain was the site of a Vitamin C study recently. The study, largely initiated because some take Vitamin C supplements to combat oxidative stress, examined what impact Vitamin C had on training efficiency. In particular, they focused their study on 14 men aged 27 to 36 who received their 1g of Vitamin C daily over an 8-week period. The results were not exactly what fans of citrus fruits, peppers or even onions wanted to hear. Apparently, it’s not a good idea to have Vitamin C when training as it was found to decrease efficiency. Researchers concluded that the Vitamin C actually prevented some cellular adaptation to exercise. It appears that those in training may be better served to stick with Rocky Balboa’s raw eggs than they are to pick up a glass of orange juice.
Mari-Carmen Gomez-Cabrera, Elena Domenech, Marco Romagnoli, Alessandro Arduini, Consuelo Borras, Federico V Pallardo, Juan Sastre and Jose Viña, Oral administration of vitamin C decreases muscle mitochondrial biogenesis and hampers training-induced adaptations in endurance performance. American Journal of Clinical Nutrition, Vol. 87, No. 1, 142-149, January 2008.