Multiple stepwise regression analysis of variables independently associated with the delta log serum FGF21 levels (model 1) and free fatty acids (model 2).

The analyses also included age, duration of exercise, creatinine, waist to hip ratio, fat percentage, body mass index, mean resting heart rate, systolic and diastolic blood pressure, which were all excluded in the final models. FFAs = free fatty acids. MHR = maximum heart rate. Delta = Final – Basal levels. Parameters of model 1: F = 3.48; r2 = 0.54, p<0.001. Parameters of model 2: F = 3.4; r2 = 0.44, p = 0.001. Maximum = maximum value obtained during each test. Mean = sum of values/number of tests.