Table 2

Respiratory and metabolic values during submaximal and maximal exercise

% of VO2max
30
45
63
Peak VO2

VE (L·min-1)




     PLA
28.0 ± 2.3
41.5 ± 2.4
56.6 ± 3.4
129.0 ± 15.8
     1.5
28.6 ± 3.0
42.7 ± 3.8
59.3 ± 5.3
129.1 ± 13.4
     3.0
28.5 ± 2.4
42.0 ± 3.2
59.5 ± 6.0
127.1 ± 12.3
Bf (breaths·min-1)




     PLA
19.3 ± 2.8
21.3 ± 2.8
23.5 ± 4.1
41.0 ± 8.3
     1.5
18.7 ± 3.1
20.8 ± 3.2
23.2 ± 4.4
38.8 ± 6.0
     3.0
18.0 ± 2.6
20.0 ± 3.3*
23.3 ± 4.1
38.9 ± 6.7
VT (L·breath-1)




     PLA
1.55 ± 0.23
2.02 ± 0.27
2.50 ± 0.41
3.21 ± 0.36
     1.5
1.63 ± 0.27
2.13 ± 0.28
2.64 ± 0.36
3.38 ± 0.31
     3.0
1.67 ± 0.19
2.22 ± 0.42
2.63 ± 0.41
3.32 ± 0.36
VO2(ml·kg-1·min-1)




     PLA
14.9 ± 1.6
22.6 ± 2.4
31.0 ± 3.3
49.7 ± 4.4
     1.5
14.8 ± 0.9
22.7 ± 1.7
31.4 ± 2.7
50.7 ± 5.6
     3.0
15.2 ± 1.0
23.0 ± 2.1
31.9 ± 3.2
50.3 ± 4.1
RER




     PLA
0.85 ± 0.04
0.90 ± 0.02
0.94 ± 0.03
1.21 ± 0.05
     1.5
0.86 ± 0.05
0.92 ± 0.03
0.96 ± 0.04
1.18 ± 0.06
     3.0
0.82 ± 0.06
0.88 ± 0.05*†
0.93 ± 0.03
1.16 ± 0.06*†
RPE




     PLA
8.4 ± 1.3
11.7 ± 1.5
13.8 ± 0.9
19.0 ± 0.6
     1.5
8.2 ± 1.3
11.0 ± 0.7
13.4 ± 1.0
19.1 ± 0.6
     3.0
7.9 ± 1.1
11.3 ± 1.2
13.4 ± 1.0
19.3 ± 0.6

Values listed as mean ± SD. VE, ventilation; Bf, breathing frequency; VT, tidal volume; VO2, oxygen consumption; RER, respiratory exchange ratio; RPE, rating of perceived exertion. PLA, placebo; 1.5 and 3.0 represent dose of caffeine in mg·kg body weight-1.

* Significantly different from placebo (p < 0.05).

Significantly different from 1.5 caffeine in mg·kg body weight-1. (p < 0.05).

McClaran and Wetter Journal of the International Society of Sports Nutrition 2007 4:11   doi:10.1186/1550-2783-4-11