Drinking a cup of coffee before working out will burn the fat off faster compared to a decaffeinated session, according to a new study published by the University of Granada (UGR).
Scientists have claimed that taking a strong cup of coffee at least half an hour before exercise significantly increases the level of fat oxidation, reports Daily Mail.
However, the best results come after midday, especially in the afternoon.
Caffeine is one of the most popular performance-enhancing sport supplements and is taken by athletes around the world to improve endurance and physical abilities. Despite its widespread use, there is little scientific evidence for its oxidation or fat-burning powers.
Lead author Assistant Professor Francisco José Amaro-Gahete said: "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."
The researchers asked 15 men to complete an aerobic exercise test four times at seven-day intervals. Each time, they were given 3mg/kg of caffeine, equivalent to a strong cup of coffee, or a placebo at 8.00 am or 5.00 pm. Conditions before exercising were held in check, including the amount of time since their last meal.
They found drinking a coffee half an hour before breaking a sweat increased fat oxidation, especially in the afternoon.
Assistant Prof Amaro-Gahete said: "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. The existence of a diurnal variation in fat oxidation during exercise was confirmed, the values being higher in the afternoon than in the morning for equal hours of fasting."
Their results found that combining 'acute caffeine' and moderate exercise in the afternoon is the best way to burn fat.