A comparison of the psychological demands of well trained cyclists to field and laboratory mountain bike stimulation

Limited previous research has been undertaken on the physiological demands of mountain bike (MTB) racing. Five male well-trained MTB cross-country cyclists (VO2r, ax 72.0+4.6 ml kg- ~min-~, maximum power output (MPO) 5.4+0.3 W kg -~, maximum heart rate (HRmax) 188.6+6.5 bpm) performed two laps of a MTB course in the field with SRM power cranks fitted. A computer laboratory race simulation using a Hayes windbraked ergometer required subjects to match the average power output (W kg -1) and reach the peak power output once every 5 s period. Power output and heart rate were measured during field and laboratory trials, while oxygen uptake (VO2) was determined during the laboratory simulation. No difference was observed in the mean power output and heart rate between the field and laboratory trials (4.18+0.55 vs. 4.22+0.19 W kg -1, 175.4+8.7 vs. 170.0+8.1 bpm) respectively. During field and
laboratory trials subjects utilised 77.4 vs. 78.1% of MPO, 93.0 vs. 90.1% of HR~,~x respectively. Mean and peak VO2 for the simulation were 57.5+3.3 and 69.3+4.4 ml kg -1 min 4 respectively, with subjects working at -80%. In summary, power output and heart rate can be replicated in a laboratory simulation of MTB racing.