- A new study looked at the impact of caffeine consumption on fat-burning during exercise
- The results indicate that caffeine before a workout does indeed increase fat-burning
- Researchers added that optimum results are achieved in the afternoon
A recent study published in the Journal of the International Society of Sports Nutrition found that ingesting caffeine half an hour before exercise considerably increases fat-burning.
“The recommendation to exercise on an empty stomach in the morning to increase fat oxidation is commonplace. However, this recommendation may be lacking 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,” explained lead author, Francisco José Amaro-Gahete.
Amaro-Gahete and colleagues wanted to know whether caffeine – which is commonly consumed to boost sports performance – actually assists with fat burning (oxidation) during exercise.
The link between body-fat oxidation and caffeine consumption
The research included 15 healthy men – with an average age of 32 – who were asked to complete a graded exercise test four times, each separated by seven days. Participants had to ingest 3mg/kg of caffeine (the equivalent of a strong coffee) or a placebo at 08:00 in the morning and at 17:00 in the afternoon.
All participants had to adhere to specific conditions prior to testing: they had to avoid vigorous activity one to two days before the test, adhere to a personalised diet, and fast for three hours before arriving.
Caffeine boosts fat-burning
“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,” explained co-author, Francisco J. Amaro.
The results also confirm previously reported diurnal variation in the whole-body fat oxidation rate, with fat oxidation levels being higher in the afternoon than in the morning with equal fasting time.
Overall, the findings suggest that caffeine ingestion combined with afternoon aerobic exercise allows for optimal fat-burning during exercise.