. Author manuscript; available in PMC: 2013 Dec 15.

Published in final edited form as: Am J Cardiol. 2012 Sep 13;110(12):1809–1813. doi: 10.1016/j.amjcard.2012.08.015

Table 5.

Test-retest variability of peak exercise variables

	Test 1	Test 2	P-Value	Absolute Change (2 – 1)	% 2 > 1	% 1 > 2	cv
Exercise Time (seconds)	577 (411, 720)	598 (439, 720)	0.003^*	22 (−50, 90)	54	25	4.9%
Indexed oxygen uptake (ml/kg/min)	14.4 (11.1, 18.0)	14.3 (11.6, 18.0)	0.79	−0.05 (−1.50, 1.37)	40	52	4.9%
Ventilatory threshold (ml/min)	845 (581, 1177)	840 (603, 1064)	0.81	−5 (−175, 190)	45	53	9.3%
Ventilation per carbon dioxide slope	30.5 (25.3, 36.3)	31.1 (24.9, 36.8)	0.04^*	0.7 (−2.2, 3.8)	65	35	4.5%
Respiratory exchange ratio	1.13 (1.07, 1.21)	1.14 (1.06, 1.24)	0.55	0.01 (−0.07, 0.07)	50	44	3.0%
Oxygen uptake efficiency slope (ml/min*L/min)	1567 (1074, 2071)	1553 (1107, 2076)	0.67	−14 (−243, 341)	40	60	8.5%

Values expressed as mean (10^th percentile, 90^th percentile) unless noted otherwise. P-Value corresponds to a paired t-test of the null hypothesis that the mean of test 2 minus the mean of test 1 = 0.

paired t-test of the null hypothesis that the mean of test 2 minus the mean of test 1 =0.