While you do burn more calories when sweating, the amount of energy you expend during exercise is determined by your basal metabolic rate. Your BMR is a measure of how many calories are needed to keep your body functioning at rest. It includes everything from cellular growth and repair to digestion. If you have an increased BMR, it has little effect on whether or not exercise will increase weight loss because the extra energy required for exercise comes directly out of stored fat (not muscle).
Do I need to drink electrolyte drinks? Electrolyte drinks can help replace sodium lost through sweat during high-intensity activity; however, most people who sweat also consume enough salt in their diet that they don’t need additional supplementation. Although electrolytes can be important in preventing dehydration when exercising in hot weather—especially if there’s no water available to drink—drinking too much fluid can cause bloating and stomach cramps after strenuous activity; this suggests that drinking large amounts of fluids may actually interfere with fat burning rather than assisting it.