Fig. 1

Schematic representation of protocol. Intermittent exercise was carried out in six 15-min blocks 60 min after ingestion of caffeine (CAFF) or placebo (PLA). Plasma concentrations of insulin and free fatty acids were assessed following blood sampling (black arrows), leg muscle strength and power were determined using an isokinetic dynamometer (eccentric and concentric knee extensors and flexors, white arrows) and counter movement jump (CMJ) height was used as a concurrent measure of power (hashed arrows). Final measurements were taken the following day, approximately 12 h after the exercise protocol