|The HIIT exercise in the study at hand was slightly less demanding ;)|
Yes, the scientists determined the changes in whole body fat mass, abdominal fat area, and a handful of other parameters in response to the 4-week exercise program (3 sessions per week), but eventually Sasaki et al. were interested in the effects of HIIT on the exercised-induced GH secretion.
As a SuppVersity reader you are well aware that the growth hormone, testosterone & cortisol response to exercise alone does not determine the study outcomes.
In fact, a seminal paper by West et al. revealed a correlation between high levels of the allegedly catabolic hormone cortisol and increases in skeletal muscle mass.
|Figure 1: Growth hormone (top) and cortisol (bottom) response to HIIT & LISS (Sasaki. 2014).|
|Figure 2: Changes in BMI, body fat and VO2max (fitness) in response to HIIT vs. LISS (Sasaki. 2014)|