Fig. 4From: A Randomised, Placebo-Controlled, Crossover Study Investigating the Optimal Timing of a Caffeine-Containing Supplement for Exercise PerformancePlasma caffeine (a), paraxanthine (b), theobromine (c), theophylline (d), glucose (e) and lactate (f) during the PLA, DUR, ONS and PRE trials. Data are mean for all participants ± SEM. Main effect for time: *, significant difference from − 70; #, significant difference from − 35; †, significant difference from − 20. Main effect for condition: (a) PRE significantly different to ONS, PRE and PLA; (b) ONS significantly different to DUR and PLA; (c) DUR significantly different to PLA and (d) DUR significantly different to DUR and PLABack to article page