Cardiovascular reactions during exhausting isometric exercise while windsurfing on a simulator or at sea.

Eleven amateurs and two internationally ranked windsurfers performed isometric exercise on a windsurfing simulator to the point of exhaustion. The two professional windsurfers maintained their position during exercise two times longer than those of the other group. The following mean values (n = 11) were measured during the exercise: the blood pressure increased from 114 +/- 6.6/70 +/- 11.5 to 177 +/- 8.6/93 +/- 10.3 mmHg, the heart rate from 63 +/- 13 to 103 +/- 16 bts/min, blood flow in the forearm from 6.4 to 7.4 ml/(100 ml tissue x min), and the lactate level in the capillary blood from 0.9 +/- 0.2 to 1.9 +/- 0.4 mmol/l. The post-exercise hyperemia reached values of 28.2 ml/ (100 ml tissue X min). There was neither a significant correlation between the time of exercise and the handgrip force (MVC = maximal voluntary) nor the calculated force of the forearm. Motivation was interpreted as an exercise-prolonging factor. At sea and with high wind (7 Beaufort), the heart rate reached a maximum of 200 bts/min, but the lactate level did not reach more than 3.0 mmol/l.