‘Lastly, if your nutrition is on point but you still have excess tummy fat, then you need to look at your training. There’s a real craze for high-intensity workouts and really pushing yourself at the moment, but training is a stress on the body, and if you’re not giving it the tools to manage that stress and recover from it, then it can lead things like excess belly fat.

Cross-training is important for a few reasons: First off, it makes you a stronger runner and reduces your risk of injury. “Running is only hard on your joints if you don’t have the muscle to support them,” Rubin says. Secondly, lifting will help you lose weight. “The more lean muscle mass you have, the more calories you’ll burn at rest,” she says. That's right, more muscle means more burned calories when you're just sitting around. To get started, try these 10 essential strength exercises for runners.
Caffeine also has a dramatic effects on the adrenal glands. The adrenal glands regulate hormone levels within the body. Most notably of theses hormones are the “fight or flight” hormones adrenaline and noradrenaline. Caffeine causes a release of these hormones which will give a short term energy burst. The problem is when there is chronic stimulation of the adrenal glands. This will lead to adrenal burnout which can negatively effect energy levels, metabolism, and digestion.

REALITY: Bro-scientists will insist that eating small portions every 2-3 hours will increase your metabolism. They base this on the thermic effect of food (TEF), which refers to the energy (calorie) cost of your body processing the food you consume. On average, 15 percent of the calories you consume are burned by processing them (although the rate varies by macronutrient). Someone took this idea and assumed that the more frequently people consume their meals, the more frequent TEF will take effect and thus increase fat oxidation.
With the body not able to use carbohydrates for energy it will begin producing ketones. Ketones are a by-product of fat oxidation and can be used as an energy source instead of carbs. With less carbs coming in insulin levels will be lower which leads to a greater rate of fat burning. As we now know, lower insulin levels are not always a good thing though.

The 2003 research indicated that exercise is a top weapon against visceral fat, backed up by a 2011 study which found that aerobic exercise is basically a magic bullet. Aerobic exercise is known to most people as cardio — activities such as running and cycling, as opposed to resistance training (where you lift heavy stuff around). While participants in the study worked fairly hard (jogging 20km per week at a high intensity), the researchers said lower-intensity but longer workouts should have similar benefits.

This may explain why the fat-burning effects of eating more protein were confirmed in a study published in the American Journal of Physiology. One group was fed a high-protein diet (just over 1 gram per pound of body weight per day) while the second group consumed an amount closer to the lower recommendation of the RDA (recommended dietary allowance). The group eating the higher-protein diet burned the most fat.