Physiological Profile of an Uphill Time Trial in Elite Cyclists.

Abstract

While a number of studies have researched road-cycling performance, few have attempted to investigate the physiological response in field conditions. To describe the physiological and performance profile of an uphill time trial (TT) frequently used in cycling competitions. Fourteen elite road cyclists (mean ± SD age 25 ± 6y, height 174 ± 4.2cm, body mass 64.4 ± 6.1kg, fat mass 7.48% ± 2.82%) performed a graded exercise test to exhaustion to determine maximal parameters. They then completed a field-based uphill TT in a 9.2-km first-category mountain pass with a 7.1% slope. Oxygen uptake (VO2), power output, heart rate (HR), lactate concentration, and perceived-exertion variables were measured throughout the field-based test. During the uphill TT, mean power output and velocity were 302 ± 7W (4.2 ± 0.1W/kg) and 18.7 ± 1.6km/h, respectively. Mean VO2 and HR were 61.6 ± 2.0mL · kg-1 · min-1 and 178 ± 2beats/min, respectively. Values were significantly affected by the 1st, 2nd, 6th, and final kilometers (P < .05). Lactate concentration and perceived exertion were 10.87 ± 1.12mmol/L and 19.1 ± 0.1, respectively, at the end of the test, being significantly different from baseline measures. The studied uphill TT is performed at 90% of maximum HR and VO2 and 70% of maximum power output. To the authors' knowledge, this is the first study assessing cardiorespiratory parameters combined with measures of performance, perceived exertion, and biochemical variables during a field-based uphill TT in elite cyclists.