Comparison of the acute effect of single session of submaximal exercise in hot and cold ambient temperatures on lipid profile

Coronary artery disease (CAD) is the most important clinical manifestation of atherosclerosis¹. A positive correlation exists between serum cholesterol and the risk of coronary heart disease and a negative correlation with high density lipoprotein cholesterol (HDL-C).^{2, 3} Physical exercise in both hot and cold causes acute changes in serum lipid profile.

The present study was aimed to compare the effects of single session of low intensity sub maximal exercise, in cold and hot ambient temperatures on Serum Lipid profile.

10 healthy university students (age 24.1±0.9, weight 65.1±7.6) participated in the randomized, repeated measure, experimental study. Subjects performed submaximal cycling exercise at 45–55% heart rate reserve (Karvonen Method)⁴ at ambient temperatures of 20 ±1°C (cold) and 42 ±1°C (hot), on static bicycle for 30 minutes. Blood samples were drawn at 10 minutes pre, 10–15 minutes and 24 hours post submaximal exercise and results were observed for changes in lipid profile.

There was a significant increase of 35.66% and 38.89% and of 20.8% and 23.07% in HDL-C for post 10 min and 24 hour respectively following exercise in hot and cold temperature respectively. Significant increase of 7.6% and 8.2% was observed for post 10 minute and 24 hour respectively following exercise in hot temperature only in Total cholesterol. Significant increase of 10.8% in Triglyceride concentration post 10 minute exercise exposure in cold with non significant changes following exposure in hot environment.

Exercise in moderately hot temperature more effectively alters lipid profile than exercise in moderately cold temperature.