Neither days of reported aerobic nor days of strength exercise participation were significantly associated with TSH in men or women. Thyroid hormones play an important role in metabolism, growth, tissue differentiation, fatty acid oxidation, and thermoregulation in response to exercise training [51–53]. Previous studies evaluating thyroid function in athletes have shown contradicting results . In elite soccer players, TSH levels have been shown to increase over a competitive season . However, in other studies, both power and aerobic athletes have been shown to have a lower serum TSH , indicating a possible increased sensitivity of the thyroid gland to TSH in athletes. Although, specific training plans may affect thyroid hormones in circulation, the present data does not support evidence of different levels of TSH in the active population compared to the more sedentary population.