Effect of different protocols of caffeine intake on metabolism and endurance performance

Gregory Cox, Ben Desbrow, Megan Anderson, Clinton Bruce, Theodore Macrides, Angela Moquin, John Hawley, Louise Burke

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190 Citations (Scopus)


Competitive athletes completed two studies of 2-h steady-state (SS) cycling at 70% peak O2uptake followed by 7 kJ/kg time trial (TT) with carbohydrate (CHO) intake before (2 g/kg) and during (6% CHO drink) exercise. In Study A, 12 subjects received either 6 mg/kg caffeine 1 h preexercise (Precaf), 6 × 1 mg/kg caffeine every 20 min throughout SS (Durcaf), 2 × 5 ml/kg Coca-Cola between 100 and 120 min SS and during TT (Coke), or placebo. Improvements in TT were as follows: Precaf, 3.4% (0.2–6.5%, 95% confidence interval); Durcaf, 3.1% (−0.1–6.5%); and Coke, 3.1% (−0.2–6.2%). In Study B, eight subjects received 3 × 5 ml/kg of different cola drinks during the last 40 min of SS and TT: decaffeinated, 6% CHO (control); caffeinated, 6% CHO; decaffeinated, 11% CHO; and caffeinated, 11% CHO (Coke). Coke enhanced TT by 3.3% (0.8–5.9%), with all trials showing 2.2% TT enhancement (0.5–3.8%; P < 0.05) due to caffeine. Overall,1) 6 mg/kg caffeine enhanced TT performance independent of timing of intake and 2) replacing sports drink with Coca-Cola during the latter stages of exercise was equally effective in enhancing endurance performance, primarily due to low intake of caffeine (∼1.5 mg/kg).
Original languageEnglish
Pages (from-to)990-999
Number of pages10
JournalJournal of Applied Physiology
Issue number3
Publication statusPublished - 2002


Cite this

Cox, G., Desbrow, B., Anderson, M., Bruce, C., Macrides, T., Moquin, A., ... Burke, L. (2002). Effect of different protocols of caffeine intake on metabolism and endurance performance. Journal of Applied Physiology, 93(3), 990-999. https://doi.org/10.1152/japplphysiol.00249.2002