All participants performed better in the caffeine TT ( caffeine 19.7 3.3 ; placebo 20.5 3.5 min ; p = 0.006 ) , while ratings of perceived exertion ( caffeine 12.0 0.6 ; placebo 12.9 0.7 ; p = 0.004 ) and heart rate ( caffeine 175 6 ; placebo 167 11 bpm ; p = 0.085 ) were lower in the caffeine TS .