Fig. 2.

Verification of the effectiveness of the local heat stress and training intervention. a Mean estimated vastus lateralis temperature (T_mus) in the control (CON) and heated (HEAT) leg during the first threshold, moderate, heavy, and severe-intensity training session. b Peak oxygen uptake (V̇O₂peak), c first ventilatory threshold (VT₁), d second ventilatory threshold (VT₂), and e peak fat oxidation rate (PFO) before (PRE, week 1) and after (POST, week 5) the training intervention. One post-intervention datapoint for PFO was missed due to a technical error. The symbol ‘**’ indicates P < 0.01, and the symbol ‘****’ indicates P < 0.0001