Table 1 Effect of caffeine or placebo on the total amount of work done, mean power and energy expenditure during 15 min of steady state cycling (Phase A). Values are means (±SD, n = 10).

	Time	Placebo	Caffeine	Mean change (%) ± 90% confidence limits	P
Work done (J·kg-1)	5 min	281 (86)	271 (66)	-.11 (.19)
	10 min	279 (74)	273 (64)	-.07 (.11)
	15 min	277 (73)	280 (81)	.03 (.09)
	Total	837 (232)	825 (210)	.05 (.08)	.39
Mean power (Watts)	5 min	55 (15)	54 (15)	-.06 (.20)
	10 min	56 (15)	56 (14)	-.03 (.09)
	15 min	56 (16)	56 (15)	-.01 (.10)
	Overall	57 (16)	55 (14)	-.12 (.14)	.80
Energy (kJ·min-1)	5 min	20 (5)	21 (4)	.20 (.20)
	10 min	21 (5)	21 (4)	.08 (.19)
	15 min	20 (5)	22 (5)	.48 (.25)
Energy (kJ)	Total	304 (296)	322 (315) *	.25 (.14)	.07

P indicates interaction effect of time and trial.* indicates a significant difference (p = 0.01) in total energy (kJ) values between trials based on results from a one-way ANOVA analysis.