A strong coffee half an hour before exercise increases fat burning

Scientists from the Department of Physiology of the University of Granada (UGR) have shown that caffeine (about 3 mg / kg, the equivalent of a strong coffee) ingested half an hour before aerobic exercise significantly increases the rate of fat burning . They also found that if exercise is performed in the afternoon, the effects of caffeine are more pronounced than in the morning.

In his study, published in Journal of the International Society of Sports Nutrition, the researchers wanted to determine whether caffeine, one of the most widely used ergogenic substances in the world to improve athletic performance, actually increases oxidation or “burning” of fat during exercise. Although its consumption in the form of supplements is very common, scientific evidence of its beneficial claims is scarce.

“The recommendation to exercise on an empty stomach in the morning to increase fat oxidation is common. However, this recommendation may not have a scientific basis, as it is unknown whether this increase is due to exercise. in the morning or to go without food for a longer period of time “, explains the main author of this research, Francisco José Amaro-Gahete, of the Department of Physiology of the UGR.

A total of 15 men (mean age, 32 years) participated in the research, performing an exercise test four times at seven-day intervals. Subjects ingested 3 mg / kg of caffeine or a placebo at 8:00 and 17:00 (each subject completed the tests in all four conditions in a random order). Conditions prior to each exercise test (hours elapsed since the last meal, exercise, or stimulant use) were strictly standardized and fat oxidation was calculated during exercise.

“The results of our study showed that acute caffeine intake 30 minutes before performing an aerobic exercise test increased maximum fat oxidation during exercise regardless of the time of day,” explains Francisco J. Amaro. The existence of a diurnal variation in fat oxidation during exercise was confirmed, with the values ​​being higher in the afternoon than in the morning for equal hours of fasting.

These results also show that caffeine increases the oxidation of fats during exercise in the morning in a similar way to that observed without caffeine intake in the afternoon.

In summary, the findings of this study suggest that the combination of acute caffeine intake and moderate-intensity aerobic exercise in the afternoon provides the optimal setting for people who want to increase fat burning during exercise. .

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