Many people believe they'll lose more weight through long sessions of moderate aerobic exercise. This is known as working out while your heart beats in "the fat-burning zone." While this will help burn calories, it's not necessarily better than more intense forms of exercise. The best heart rate for weight loss, then, is whichever one will keep you exercising long enough and hard enough to burn a high number of calories.
Understanding Weight Loss
You lose weight by burning more calories than you consume. If your body needs 2,000 calories to get through the day and if you consume 2,000 calories, you can create an energy deficit by working out to burn 500 calories a day. Doing this every day will result in about a pound of weight loss every week.
What's better—walking for two hours or running hard for 30 minutes? If it's weight loss you're worried about, the answer is whichever activity burns more calories. This depends on several factors, including your size and the intensity of your activity (how fast you are going and whether you are walking or running uphill.)
Anaerobic activity does little to get your heart pumping, but it does plenty for weight loss. Muscles are calorie-burning machines: it takes calories to develop them, it takes calories to maintain them, and it takes calories simply for them to exist. Training expert Rachel Cosgrove writes that just five pounds of muscle burns more than 18,000 calories in the course of a year. That's a little more than five pounds of fat—all for an activity that barely gets your heart beat above a resting rate.
What's Best For You?
Working out and weight loss are highly individual. That's why there are personal trainers. Personal trainers can help you develop a program that is appropriate to your age and ability, and one that will help you meet your weight-loss goals through a sensible combination of aerobic and anaerobic activity. If you have a heart condition, or if you just like taking things slowly, your trainer may recommend long and moderate sessions of cardiovascular exercise. But if you're heart-healthy or in a hurry, a 30-minute jog and a few quick sets with the barbells may be all you need.