The Acute Role of Glucocorticoids during Exercise on Lipid Metabolism

Glucocorticoids play a key role in regulating lipid metabolism but there is debate whether they are predominantly lipolytic versus lipogenic [1]. It is necessary that we have a clear understanding of their role in the regulation of metabolism, yet little is known about their immediate response, especially in conjunction with exercise. For this study, Wistar rats were randomly divided into four groups: sedentary vehicle (SV), sedentary corticosterone (SC), exercise vehicle (EV), and exercise corticosterone (EC). All animals received an injection of their treatment and exercisers performed a 45-minute exercise on metabolic treadmills. SC animals had more fluctuation in their respiratory exchange ratio over time compared to SV, while there were no differences between exercisers. Lipolytic enzyme activity measures indicated that there was an enhanced lipolytic capacity in SC animals compared to EC, but not different from SV (p = 0.047). Analyses indicate that GCs may acutely induce lipolysis when sedentary, but not in an exercise state.