To banish stubborn belly fat, you have to ramp up your workouts. In a study published in the journal Medicine and Science in Sports and Exercise, people who completed a high-intensity workout regimen lost more belly fat than those who followed a low-intensity plan. (In fact, the low-intensity exercises experienced no significant changes at all.) "You need to exercise at full intensity because the end goal is to burn more calories, and high intensity exercise does just that," says Natalie Jill, a San Diego, Calif.-based certified personal trainer. High intensity workouts mean you're going all out for as long as you can. If this sounds intimidating, think of it this way: you'll burn more calories in less time.
• Fasted training: If you train fasted, supplementing with BCAA’s can offset any potential muscle loss. Anecdotally, people tend to perform better when they consume BCAA’s during their workout, especially if training early in the day. But is it absolutely necessary? No. If you do train fasted, aim to consume some protein (20-30g) post workout and you’ll be fine.
The prevailing formula for a long time on how much fat you’re going to burn was calories in minus calories out, based on your basal metabolic rate (BMR) and exercise efforts, explains strength and performance specialist Joel Seedman, Ph.D., owner of Advanced Human Performance in Atlanta. But with all the different biochemical reactions in the body, hormonal response, and endocrine function, there are an infinite number of factors that can affect how your body is storing and breaking down calories.