Assessment of physiological demand in kitesurfing

To evaluate the physiological demands of kitesurfing, ten elite subjects performed an incremental running test on a 400-m track and a 30-min on-water crossing trial during a light crosswind (LW, 12–15 knots). Oxygen uptake \( \left( {\dot{V}{\text{O}}_{ 2} } \right) \) was estimated from the heart rate (HR) recorded during the crossing trial using the individual HR-\( \dot{V}{\text{O}}_{2} \) relationship determined during the incremental test. Blood lactate concentration [La_b] was measured at rest and 3 min after the exercise completion. Mean HR and estimated \( \dot{V}{\text{O}}_{2} \) values represented, respectively 80.6 ± 7.5% of maximal heart rate and 69.8 ± 11.7% of maximal oxygen uptake for board speeds ranging from 15 to 17 knots. Low values for [La_b] were observed at the end of crossing trial (2.1 ± 1.2 mmol l⁻¹. This first analysis of kitesurfing suggests that the energy demand is mainly sustained by aerobic metabolism during a LW condition.