Table 4.  Heart rate (HR), rating of perceived exertion (RPE), oxygen uptake (VO2) 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.