Studying Changes of Lactic Acid and Fat Oxidation in Different Environmental Temperatures, Followed by an Aerobic Exercise on a Treadmill

ABSTRACT: The aim of this study is to compare the effects of different environmental temperatures on lactic acid and fat oxidation after an aerobic exercise on a treadmill. For this purpose, 15 active and healthy students with an average VO_2max of 42 ml per kg per minute, Age of 22.14 ± 1.79 years, height of 161 ± 5.09 cm and weight of 55.85 ± 5.19 kg carried out aerobic exercises on a treadmill in two different days with one week span at the two maximum temperature (40 ° C) and minimum temperature (20 ° C). Before and after carrying out the protocol, lactic acid levels were measured and heart rates and respiratory gases were also recorded during the activity, and fat oxidation rates were calculated using stoichiometry equations. To evaluate the data, statistical test of repeated dependent-t and Pearson correlation coefficient was employed. Results showed that the average fat oxidation (1.05 grams per minute versus 1.29 g per minute, p = 0.05) and lactic acid (11.30 millimole per liter versus 7.96 millmole per liter p = 0.001), were significantly different respectively at the maximum environmental temperature in comparison with the minimum environmental temperature. According to the findings of this research, It can be concluded that fat oxidation at the minimum temperature was higher than the fat oxidation in maximum temperature and that the lactic acid has significantly increased in the maximum temperature.