Coffee, mainly thanks to the caffeine it contains has been for a long time considered an unhealthy beverage. Research conducted in the last two decades has proven that this popular drink has many beneficial substances from the polyphenol group - very similar to those found in green tea. Of course consuming coffee as a healthy beverage is still controversial, especially when it comes to the optimum amount, but we could venture to say that a good coffee has its place in the healthy diet.
Caffeine is a stimulant. In the context of its usefulness in aiding physical effort, the available literature not only unmistakably points that caffeine ingested before training will not only increase your stamina, but also increase fat burn. Many sportsmen take supplements including this alkaloid before a meal, whereas not many people remember that a pretty good solution would be to have a good espresso. Polyphenols from coffee have the ability to "sensitize" the cells to hormones, mostly insulin and increase the activity of the enzymes responsible for burning stored fat. In addition to caffeine we have a go-to stimulant and thermogenic "2in1", which will not only help your stamina but boost your metabolism.
The stimulating and slimming effects of coffee can be intensified by adding in a dash of cayenne pepper (chili). The capsaicin in the chili has strong thermogenic properties, thus it additionally increases the energy expenditure. Nonetheless, you have to be careful with not to overdo it with chili - you only need a little bit. Too much will irritate the lining of the stomach and mouth, which will cause significant discomfort, and your training will not be enjoyable.
If you care to increase the amount of fat burned during exercise, I'd recommend not to sweeten your coffee - not with white sugar or as some people advise brown sugar or honey or anything else. Carbs provided before the exercise session can significantly decrease the burning of fatty acids during the training. If you need only a pick-me-up, some simple carbs will not do you harm.