Table 4 Heart rate (HR), rating of perceived exertion (RPE), oxygen uptake (VO) and respiratory exchange ratio (RER) during 10 min of self-selected intensity cycling (Phase B). Values are means (±SD, n=10).
Time Placebo Caffeine Mean change (%)
± 90% confidence limits
P
HR 5 min 159 (17) 169 (14) .59 (.50)
10 min 167 (21) 178 (10) .53 (.49) .69
RPE 5 min 13 (2) 13 (2) -.06 (.38)
10 min 15 (2) 14 (2) -.14 (.60) .79
VO2(mL.kg-1.min-1) 5 min 21.74 (3.41) 23.59 (4.28) .54 (.69)
10 min 22.97 (4.43) 25.22 (4.31) .51 (.69) .75
RER 5 min .99 (.08) 1.01 (.09) .23 (.59)
10 min .94 (.05) .95 (.06) .08 (.63) .43
P indicates interaction effect of time and trial.