A resposta de frequência cardíaca durante as competi？？es de "mountain bike cross-country"

the aim of this study was to verify and describe the intensity profile of cross-country mountain-biking races using heart rate (hr) recorded during races. fourteen mountain bikers participated in two groups: elite (n = 6; 26.5 ± 3.6 years old; 69.1 ± 2.1 kg; 174.0 ± 1.2 cm; 5.9 ± 0.9 % bf; 9.0 ± 1.3 years of training) and amateurs (n = 8; 25.6 ± 7.7 years; 67.7 ± 7.0 kg; 175.5 ± 5.5 cm; 5.8 ± 2.1 % bf; 8.3 ± 5.7 years of training). each cyclist was submitted to an incremental exercise test to determine the metabolic thresholds and the hr values at each threshold. after four days, only the athletes of elite category were tested during brazilian round of xco world cup. two weeks later both groups were evaluated in xco brazilian national championship. the results showed that hr averaged 91-92% of hrmax. the exercise intensity zones showed different percentage of time spent during the races (10.0-14.8% easy; 23.1-30.1% moderate; 55.1-66.9% hard). this study shows that cross-country events are conducted at very high intensity, especially at the start of the race.