Differences in oxygen uptake but equivalent energy expenditure between a brief bout of cycling and running

Nutrition & Metabolism

Table 1 Absolute energy expenditure between cycling and uphill running.

Component	Cycling	Running	Sig. (p)
VO₂ max (ml·kg·min^-1)	57.0 ± 12.9	59.3 ± 13.7	0.44
Exercise O₂ (kJ)	31.7 ± 7.7	41.4 ± 6.9	0.0001
△blood lactate (kJ)	32.7 ± 8.9	22.5 ± 11.1	0.009
Exercise O₂ + △blood lactate (kJ)	64.3 ± 12.2	63.9 ± 10.1	0.90
EPOC (kJ)	53.7 ± 21.6	61.5 ± 11.7	0.21
Exercise O₂ + EPOC (kJ)	85.4 ± 20.2	103.0 ± 13.5	0.008
Total Energy Expenditure (kJ)	118.0 ± 21.9	125.4 ± 19.2	0.36

Mean ± SD. See methods section for energy expenditure conversions. Total energy expenditure equals exercise oxygen uptake + △blood lactate + modified EPOC. Power output was preset at 250 Watts for each 1-minute test. Peak power outputs during max testing were 279 ± 33 Watts for cycling and an estimated 281 ± 65 Watts for uphill treadmill running (highest treadmill work rate achieved). Resting oxygen uptake was subtracted from exercise oxygen uptake and EPOC measurements. Resting energy expenditure was not different between trials (9.3 ± 1.6 kJ min^-1, cycle; 9.5 ± 2.1 kJ min^-1, run) (p = 0.62). Respiratory exchange ratio (RER) at rest was not different between trials (0.84 ± 0.05, cycle; 0.83 ± 0.06, run) (p = 0.52).

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