To conduct the study, researchers examined the effect of caffeine on an aerobic workout and fat oxidisation. Results were then compared between morning and afternoon workouts. They found that fat oxidisation increased by 10.7 per cent in the morning and a staggering 29 per cent in the afternoon after consuming a strong coffee half an hour before a 30-minute workout.
The reason why was put down to the hypothesis that endurance performance peaks in the afternoon, usually coinciding with the highest core body temperature reached during the day, which in turn increases energy metabolism and improves muscle function.
The study authors explained, “Overall, these results suggest that a combination of acute caffeine intake and exercise at moderate intensity in the afternoon provides the best scenario for individuals seeking to increase whole-body fat oxidation during aerobic exercise.”
That said, the sample size for the study was just 15 active men, with an average age of 32 - so whether these results are widely applicable remains to be seen. It also goes without saying that the study results apply to black coffee only - naturally, if you’re adding sugar and milk (or dare we say cream and toppings), the effectiveness will be compromised. Still, it’s good to know that a coffee pick-me up has benefits for the workout too.