A Comparison of Isocapnic Buffering Phase of Young Female Cross-Country and Alpine Skiers

The purpose of this study was to compare the isocapnic buffering phase in young female cross-country skiers and alpine skiers. International level young female skiers including ten cross-country skiers and eight alpine skiers took part in the study. Maximal oxygen uptake (VO2max), ventilatory threshold (VT) and respiratory compensation point (RCP) were determined using an incremental treadmill exercise test. VT and RCP were determined using the V-slope method. The isocapnic buffering (ICB) phase was calculated as the difference in VO2 (ICBVO2) and running speed (ICBSPEED) between RCP and VT and expressed in either absolute or relative values. The values of VO2, heart rate, and running speed corresponding to the VT and RCP were identified. Relative VT and RCP values were recorded as a percentage of VO2max and maximal running speed. Time to exhaustion was determined as the total duration of the test. VO2max, maximal running speed, time to exhaustion, both absolute and relative VT values and absolute RCP values were higher in the cross-country skiers than in the alpine skiers (P<0.05), whereas relative RCP showed similar values in both group (p>0.05). Absolute ICBSPEED showed similar values in both group (p>0.05), whereas absolute and relative ICBVO2 and relative ICBSPEED were found to be significantly higher in alpine skiers than in cross-country skiers (P<0.05). The results of this study indicated that the aerobic capacity and ventilatory threshold lower in alpine skiers than in cross-country skiers, while the isocapnic buffering phase and the high-intensity exercise tolerance were higher in alpine skiers