Strong coffee half an hour before exercise increases fat burning

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

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

“The recommendation to exercise on an empty stomach in the morning to increase the oxidation of fats is common. However, this recommendation may lack a scientific basis, as it is not known whether this increase is due to exercise in the morning or for not eating for a longer period “, explains the main author of this research, Francisco José Amaro-Gahete, from the Department of Physiology at UGR.

Fifteen men (mean age 32 years) participated in the research, performing an exercise test four times at intervals of seven days. Participants ingested 3 mg / kg of caffeine or a placebo at 8 am and 5 pm (each subject completed the tests in all four conditions in random order). The conditions prior to each exercise test (hours elapsed since the last meal, physical exercise or consumption of stimulating substances) were strictly standardized and fat oxidation during exercise was calculated accordingly.

“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 diurnal variation in the oxidation of fats during exercise was confirmed, with values ​​higher in the afternoon than in the morning for equal hours of fasting.

These results also show that caffeine increases fat oxidation during morning exercises 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 aerobic exercise performed at moderate intensity in the afternoon provides the ideal setting for people looking to increase fat burning during exercise.

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