Mountain time trial in handcycling: Exercise intensity and predictors of race time in people with spinal cord injury

Abstract

Study design:Cross-sectional analyses.Objectives:To analyze exercise intensity during a mountain time trial in handcycling and to determine predictors of race time.Setting:Eight Dutch rehabilitation centers and Austrian mountain.Methods:Forty participants with spinal cord injury ( SCI; high lesion level ( >T6): N=11; low lesion level ( ≤T6): N=29) handcycled a 20.2-km mountain time trial. Heart rate ( HR) was monitored in 17 ( high: N=5, low: N=12) participants during the race to determine exercise intensity, expressed relative to the heart rate reserve ( %HRR). Two weeks before the race all participants completed laboratory tests to measure anthropometrics and peak values for power output ( POpeak), oxygen uptake ( VO2peak) and HR.Results:Mean race time was 4 h and 1 min ( s.d.: 1 h and 24 min), with no difference in race time between lesion groups. Mean exercise intensity during the race was 70±7%HRR. Exercise was mainly ( 73% of the race time) at a vigorous intensity ( 60-89%HRR), with 29% of the total time in the 80-89%HRR zone. No clear differences were found in exercise intensities between lesion groups. The strongest predictors for better race times were higher mean %HRR during race ( R 2 =57%), lower waist circumference ( R 2 =39%), higher POpeak ( R 2 =39%) and VO2peak ( R 2 =32%).Conclusion:A 20-km mountain time trial in a handcycle is intensive. Faster race times were achieved by those with a lower waist circumference, greater fitness level and ability to perform at higher average exercise intensities during the race. Level of SCI was not significantly associated with race time. © 2014 International Spinal Cord Society.