Cardiovascular and metabolic responses to on-water upwind sailing in optimist sailors

Purpose: To explore the cardiovascular and metabolic responses of 9 Optimist sailors (12.7 ± 0.8 y, 153 ± 9 cm, 41 ± 6 kg, sailing career 6.2 ± 1 y, peak oxygen uptake [VO2peak] 50.5 ± 4.5 mL · min-1 · kg-1) during on-water upwind sailing with various wind intensities (W). Methods: In a laboratory session, peak VO2, beat-by-beat cardiac output (Q), mean arterial blood pressure (MAP), and heart rate (fH) were measured using a progressive cycle ramp protocol. Steady-state VO2, Q, MAP, and fH at 4 submaximal workloads were also determined. During 2 on-water upwind sailing tests (constant course and with tacks), W, Q, MAP, and fH were measured for 15 min. On-water VO2 was estimated on the basis of steady-state fH measured on water and of the individual ΔVO2/ΔfH relationship obtained in the laboratory. Results: VO2, fH, and Q expressed as percentage of the corresponding peak values were linearly related with W; exercise intensity during on-water sailing corresponded to 46-48% of VO2peak. MAP and total vascular peripheral resistance (TPR = MAP/Q) were larger (P <.005) during on-water tests (+39% and +50%, respectively) than during cycling, and they were correlated with W. These responses were responsible for larger values of the double (DP) and triple (TP) products of the heart during sailing than during cycling (P <.005) (+37% and +32%, respectively). Conclusions: These data indicate that the cardiovascular system was particularly stressed during upwind sailing even though the exercise intensity of this activity was not particularly high.