Fig. 3

Means and SD of plasma glucose (a), lactate (b), glycerol (c), NEFA (d) and epinephrine (e) with caffeine (full circles) and placebo (open circles). Participants were divided according to cardiorespiratory (left) or neuromuscular fitness (right), with high groups shown with solid lines and medium groups shown with dashed lines. One to 7 correspond to time points as follows: 1, 75 min before the start of the trial; 2, 15 min before the start of the trial; 3, between the 1st and 2nd periods; 4, immediately after the end of the 2nd period; 5, immediately before the start of the 3rd period; 6: between the 3rd and 4th periods; 7, at exhaustion. *Significant treatment effect (p ≤ 0.01). †Significant time effect (p < 0.001)