The effect of caffeine ingestion on heart rate and blood lactate response during recovery from aerobic exercise among trained young men

The purpose of this investigation was to examine the effects of 3mg/kg bodyweight of orally ingested caffeine on heart rate and blood lactate response during recovery from aerobic exercise among aerobically trained young men. Participants (n = 9) were assigned to two treatments in a random, double-blind, crossover fashion: 1) ingest caffeine first, then placebo; or 2) ingest placebo first, then caffeine. Supplementation occurred twice daily for 7 days, followed by a 7-day washout period, and then crossover to supplementation with the other treatment for another 7 days. The intervention lasted 28 days and participants were tested on three separate occasions. Each occasion consisted of a treadmill running VO2max test to volitional exhaustion. Resting heart rate and blood lactate were measured before each test. Following testing, heart rate and blood lactate concentration at 1, 3, and 10 minutes during active recovery were measured. Repeated measures ANOVA (P < 0.05) revealed no significant mean difference between treatments at any time point in either heart rate or blood lactate.