How Many Weeks After Exercising Do You Start to Lose Weight?

Exercise burns calories, and burning calories can help you lose weight. Many people faithfully head to the gym in hopes of losing weight, but find the number on the scale doesn't budge. You may wonder how many weeks it will take for you to start to see changes. The answer to that question depends on numerous factors, including how much you are exercising, at what intensity level, what type of exercise you perform and what you put on your plate once you get home.

Weight Loss

• The basic equation for weight loss is to take in fewer calories than you expend. Exercise helps you expend calories, but that is only part of this equation. If you are burning an extra 300 calories per day with a brisk walk around the neighborhood, but reward yourself with a 350-calorie bowl of ice cream, you may actually experience a gradual weight gain. Combining exercise with a calorie-controlled eating plan can help you lose weight. How fast this happens depends on the calorie deficit you create. If you burn 300 calories per day and take in 200 calories fewer than your body burns through daily activity, you create a 500-calorie deficit that, over the course of a week, will add up to 3,500 calories lost – or one pound. If you successfully monitor calorie intake and output, you will start seeing weight-loss results as soon as one week after you begin.

Frequency

• While any activity is positive, certain intensity levels and durations are more likely to result in weight loss. The American College of Sports Medicine reports that performing 250 minutes of moderate-intensity cardio exercise per week results in significant weight loss. Moderate-intensity cardio gets your heart beating faster and your breath coming heavier – think fast walking, swimming laps or cycling on a relatively flat terrain. Members of the National Weight Control Registry, a group of more than 4,000 people who have successfully lost at least 30 pounds and kept it off for one year or longer, exercise 60 to 90 minutes per day to lose and maintain weight loss. If you are hitting the gym for 30 minutes, five times per week at a low intensity, chances are it will take months to see any change in your weight – if you see any change at all.

Intensity

• If you exercise intensely and burn 400 calories or more per session, you will lose weight faster, according to a study published in the November 2008 issue of “Medicine and Science in Sports and Exercise.” In this study, participants who exercised at an intensity greater than their lactate threshold – a perceived exertion of approximately 16 on a scale of 1 to 20, with 20 being maximum output – lost more body fat and weight, especially at their midsection, after 16 weeks than participants who exercised at a low intensity but burned the same number of calories. Choose to run instead of walk, or perform sprints on a stationary bike instead of pedaling comfortably to create this higher intensity level.

Strength Training

• Strength-training sessions don’t burn as many calories as cardio exercise, but they also contribute to weight loss. By building lean muscle mass, you change your metabolism. Muscle tissue burns more energy at rest than fat tissue, so your body uses the calories you consume more efficiently. The changes you see from strength training will be gradual, however. If you are brand new to exercise, you can put on muscle more quickly than a person who has been strength training for several months or years. Muscle tissue weighs more than fat, so you may even gain weight with a focused strength-training program as you lose fat and add muscle. Consider relying on body fat analysis, which can be done by a certified trainer, and the way your clothes fit to evaluate if you are changing your body for the better. Depending on your strength-training regimen and your starting weight, you may see results in as few as two weeks – or it may take four to 12 weeks to notice a change.