Heart rate responses of male orienteers aged 21-67 years during competition

Orienteering is a sport in which it is common for most participants to be aged over 40 years, but research into the demands of the sport has focused almost exclusively on elite participants aged 21-35 years. The aim of the present study was to examine the heart rate responses of older male orienteers. Thirty-nine competitive male orienteers were divided into three groups: group 1 (international competitive standard, n = 11, age 21-67 years), group 2 (national competitive standard, n = 15, age 24-66 years) and group 3 (club competitive standard, n = 13, age 23-60 years). Each participant had his heart rate monitored during two orienteering races of contrasting technical difficulty. The results were analysed using analysis of covariance, with age as a covariate, and Pearson product-moment correlation coefficients to determine whether age was related to the observed heart rate responses. The groups did not differ in their peak (175 +/- 12 beats x min(-1), P = 0.643) or mean (159 +/- 13 beats x min(-1), P = 0.171) heart rates during the races. There was a decline of 6 beats x min(-1) x decade(-1) (P = 0.001) for peak heart rate and 5 beats x min(-1) x decade(-1) (P < 0.001) for mean heart rate. Mean heart rates were 86 +/- 6% of the participants' maximal heart rates and were not associated with age. The orienteers in group 1 displayed a lower (P < 0.005) within-race standard deviation in heart rate (6 +/- 2 beats x min(-1)) than those in groups 2 and 3 (10 +/- 3 and 10 +/- 4 beats x min(-1), respectively). In conclusion, the mean heart rates indicated that all three groups of orienteers ran at a relative high intensity and the international competitive standard orienteers displayed a less variable heart rate, which may have been related to fewer instances of slowing down to relocate and being able to navigate while running at relatively high speeds.