Figure 1. Composition of a single exercise session. Each session consisted of a 5 min warm-up, followed by 4 min at low, moderate and high intensities interspersed by 2 min active rest and a 10 min passive resting phase preceding a 10 min high intensity interval training (HIIT). HIIT included alternating intervals of 1 min at >90% (or short radius turns for alpine skiing) and 1 min at 60% of maximal heart rate (or active/passive resting for alpine skiing). This was followed by a passive resting phase of 10 min until pulse wave analysis measurement. Legend: AS: alpine skiing, HIIT: high intensity interval training, HR_max: maximal heart rate during maximal cycle ergometry, IC: indoor cycling, Pulse wave analysis: heart rate and pulse wave analysis measurement using Mobil-o-Graph®, Rest: active recovery at IC and passive recovery at XCS and AS of around 2 min, XCS: cross-country skiing.