Strong Coffee Before Exercising Shown to Boost Fat-Burning
A new research study has shown that drinking a strong cup of coffee about half an hour before exercising increases the rate of fat-burning. Also it was shown that the effect of caffeine on exercising are more marked in the afternoon than the morning. This confirms the established finding that beyond the elevated heart rate and boost to mental stimulation, caffeine increases in endurance by elevating the level of fatty acids in the bloodstream.
Coffee has many general health benefits as well.
A new study, published in the Journal of the International Society of Sports Nutrition demonstrated that drinking the equivalent of around 3 mg of caffeine per kilogram of body weight about 30 minutes an hour before aerobic exercise increases the rate of fat-burning. They also found that the benefits of caffeine ingestion were more marked during exercise in the afternoon, than in the morning.
The study group consisted of a group of 15 men with a mean age of 32 years. Each participant completed the same exercise test 4 times at 7-day intervals. Subjects consumed the equivalent of 3 mg/kg of caffeine, in strong coffee, or a placebo (decaffeinated coffee) at 8 AM and 5 PM on each day of the test. The pre-exercise condition of each subject was carefully standardized in terms of:
- physical exercise,
- hours elapsed since last meal,
- prior consumption of stimulant substances.
A graded cycling test was undertaken under supervision by each of the subjects. Maximum oxygen uptake (VO2 max) and MFO (Maximal Fat Oxidation) and were measured by indirect calorimetry. The exercise intensity required to produced MFO (Fatmax) was calculated
The study found that:
- VO2max, Fatmax and MFO were all significantly lower in the morning than in the afternoon
- Ingesting caffeine boosted the mean MFO by 11% in the morning, and by a mean 29% in the afternoon
- Ingesting caffeine increased the mean Fatmax by 11% in the morning, and by 13% in the afternoon.
Conclusions
- These findings confirm previous studies that demonstrated a significant diurnal variation in the fat oxidation rate during exercise, with higher rates in the afternoon.
- Consumption of 3 mg/kg of caffeine, about 30 minutes before exercise increases VO2max, MFO, and Fatmax and independent of the time of day when the exercise is done.
