Research

Macro partitioning

Ingesting 5 mg/kg of caffeine one hour before submaximal cycling (70% VO2 max) significantly reduces muscle glycogen utilization by 42% and increases muscle triglyceride utilization by 150% compared to a placebo.

Take 5 mg of caffeine per kg of body weight one hour before your workout. For a 70 kg person, this is 350 mg. This dose has been shown to significantly spare muscle glycogen and increase fat usage during moderate-intensity cycling, potentially extending endurance.

ModerateSupportsMEDIUM confidence
A caffeine solution (250 ml; 5 mg/kg body weight) ingested 1 h prior to exercise (CAF trial) decreased the use of muscle glycogen by 42% (P < 0.025) in seven subjects when compared to a decaffeinated control trial (CON). There was a modest increase in serum FFA and muscle triglyceride use was 150% greater in the CAF as compared to the CON trial.
David A. Essig et al. · International Journal of Sports Medicine · 1980

Why this rating

Small sample size (n=7), short duration (30 min), and lack of long-term performance data limit generalizability.

Source

Effects of Caffeine Ingestion on Utilization of Muscle Glycogen and Lipid During Leg Ergometer Cycling

David A. Essig et al. · International Journal of Sports Medicine · 1980

DOI 10.1055/s-2008-1034637

crossover · n=7Cited 189×
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DOI resolved against Crossref · corpus check 2026-06-10

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