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.