A comparison of three skating techniques and the diagonal stride on heart rate responses and speed in cross-country skiing.
The purpose of this study was to compare the heart rate responses and the speed of three different skating techniques and the diagonal stride in cross-country skiing. The subjects were ten elite male cross-country ski racers, 16 to 25 years of age. They skied a 3.04-km loop of various terrain four separate times, using a different technique for each trial. A thirty-minute recovery period was allowed between each trial. Heart rate and skiing velocities were analyzed over a flat, an uphill, and a downhill section, as well as for the total loop. No significant differences (p greater than 0.05) were found in heart rate values between the four techniques on all sections of the course, while heart rates were significantly different over the three different sections. Skiing velocities were significantly different (p less than 0.05) between the diagonal stride and all skating techniques, the diagonal stride being the slowest technique, and this, for all sections. Energy costs while skiing were estimated on the basis of individual HR/VO2 curve determined under laboratory conditions. Since no differences in HR were found between the four techniques, no differences in energy costs were found. These energy costs represented between 69 and 73% of max VO2, and between 87 and 89% of max HR for the 3.04-km loop. Thus, for the same estimated energy expenditure, greater speeds (16%) were achieved with the skating techniques than with the diagonal stride.