Submaximal exercise accompanied with mild dehydration increases oxidative load on Unacclimatized humans

Benefits of submaximal exercise in maintaining good health and in prevention of diseases are well known. However, there is conflict of studies reporting interaction between submaximal exercise and pro-oxidant/antioxidant balance. Generation of excess free radicals is known to impair many physiological and biochemical functions resulting in overall performance decrement. Therefore to address this issue, various oxidative stress parameters were estimated in plasma samples of unacclimatized human participants who were challenged with submaximal exercise accompanied with mild dehydration of 2% body weight at 450C in human climatic chamber. Exposure of unacclimatized human volunteers to submaximal exercise and dehydration at 450C in human climatic chamber resulted in significant increase in various oxidative parameters. Malondialdehyde, marker of lipid peroxidation was significantly increased (from 0.74±0.08 µmol/l to 1.01±0.11 µmol/l, p<0.001) post exercise. Similarly, a significant increase in hydroperoxide (p<0.001) and advanced oxidation protein products (p<0.01) was also observed. Though there was a significant increase in antioxidant level (GSH; p<0.001), the overall ratio of GSH/GSSG decreased implicating an increased oxidative stress. Submaximal exercise accompanied with mild dehydration in heat is associated with increased oxidative stress in unacclimatized human subjects.