Drinking strong coffee before an afternoon workout can increase fat-burning

GRANADA, Spain — Many people associate strong coffee and exercise with the normal morning routine. A new study, however, reveals that a shot of caffeine before an afternoon workout may improve your fat-burning goals. Researchers say having caffeine 30 minutes before exercising in the afternoon maximizes the body’s ability to burn fat.

A team from the University of Granada discovered that about 3 mg/kg of caffeine (the amount in a strong coffee) is enough to significantly jumpstart fat-burning during aerobic exercise. Their study also finds working out in the morning is not as effective as breaking a sweat later in the day.

Researchers note caffeine is one of the most commonly consumed substances with the aim of improving physical performance and stamina. Since scientific proof about the benefits of caffeine is still lacking, the Spanish team set out to see if it really does increase fat oxidation.

“The recommendation to exercise on an empty stomach in the morning to increase fat oxidation is commonplace. However, this recommendation may be lacking a scientific basis, as it is unknown whether this increase is due to exercising in the morning or due to going without food for a longer period of time,” explains lead author Francisco José Amaro-Gahete of the UGR’s Department of Physiology in a university release.

Caffeine helps burn fat at any time of the day

Study authors examined 15 men with an average age of 32 during a month-long experiment. They tested each participant four times at seven-day intervals, giving each man 3 mg/kg of caffeine or a placebo at 8am and 5pm. Researchers also strictly controlled how many hours passed between meals and how many stimulants participants consumed before each exercise test.

“The results of our study showed that acute caffeine ingestion 30 minutes before performing an aerobic exercise test increased maximum fat oxidation during exercise regardless of the time of day,” Francisco J. Amaro reports.

The study also confirmed that there is a noticeable difference in daily fat burning ability depending on the time. Fat oxidation levels were higher during afternoon sessions than morning workouts with equal amounts of fasting. Scientists discovered caffeine still increases fat oxidation during morning exercise, but only to a level on par with working out in the afternoon without caffeine.

Researchers conclude the best combination to burn the most fat is acute caffeine intake shortly before an afternoon workout routine.

The study appears in the Journal of the International Society of Sports Nutrition.