During two-day cross country skiing courses for beginners telemetric pulse measurements were carried out on male patients with recent myocardial infarction and middle-aged sportswomen (first day: instruction in techniques; seocnd day: walking tour). The following results were obtained: 1. The pulse frequency varied little during the different exercises. 2. With the exception of two people the established target pulse rate (work pulse) was not significantly exceeded. 3. In no instance during ski touring was the target pulse rate more than 10% higher than the mean pulse rate (values obtained by pulse counting). The results clearly show that cross country skiing is an extremely suitable sports activity for both preventive and rehabilitative cardiology, as it can be learned easily and carried out at different work loads.