Abstract des Autors

The aim of the study was to analyze the exercise intensity of recreational cyclists participating in a cycling-touring event. In 14 male healthy recreational cyclists heart rate (HR) monitoring was performed during the Ötztal Radmarathon 1999 (distance: 230 km; altitude difference: 5500 m) in order to evaluate the HR response and to estimate the cardiopulmonary strains for the less-trained athlete confronted with such a marathon. Four different exercise intensities were defined as percentages of maximal HR (HRmax) as follows: recovery HR (HRre) < 70 % of HRmax; moderate aerobic HR (HRma) = 70 - 80 %; intense aerobic HR (HRia) = 80 - 90 %; and anaerobic HR (HRan) > 90 %. All athletes finished the competition successfully. The mean racing time was 10 h 14 min, the average speed 22.5 km/h. The mean HRmax was 188 bpm, the average value of the measured HRs (HRaverage) was 145 bpm resulting in a mean HRaverage/HRmax ratio of 0.77. Athletes spent 18.5 % (1 h 54 min) of total race time within HRre, 28 % (2 h 52 min) within HRma, 39.5 % (4 h 02 min) within HRia, and 14 % (1 h 26 min) within HRan. The vast majority of exercise was done under "aerobic conditions" (HRre + HRma + HRia = 86 % or 8 h 48 min) - confirming the knowledge that the aerobic energy supply is crucial for the performance of long-term exercise. The large amount of high exercise intensities (HRia + HRan = 53.5 % or 5 h 30 min), however, features the intense cardiopulmonary strains evoked by such competitions. The HR response was related to the course profile with HRs significantly declining in all subjects to an extent of 10 % during the course of race. Our findings show that the exercise intensity borne by recreational cyclists during a cycle-touring event is high and very similar to that of professionals. With respect to the high cardio-vascular strains a thorough medical screening is advisable for any participant of such an event combining both high volume and high intensity loads. Verf.-Referat