Whether your goal is to lose weight, maintain your weight or to gain weight, exercise can play a key role in helping you find the right balance between calories in and calories out. Athletes on a rigorous training schedule may burn a significant number of calories, and some or all of those calories may need to be replaced to maintain good health and energy levels. However, investing more time in an exercise program doesn't necessarily mean you need to eat more. Your goals and your hunger level should be the deciding factors.
If you're already at a healthy body weight and want to amp up your exercise routine primarily to improve your cardiovascular fitness or your health in general, you may need to increase your caloric intake slightly to avoid weight loss. If you want to lose weight, increased exercise is an effective way to help you establish a calorie deficit. In this case, you'll probably want to cut calories as well as exercise more to meet your weight goals. If you're underweight and want to improve your fitness through more exercise, you will need to eat enough to compensate for the extra calories burned and to establish the calorie surplus necessary for weight gain. Discuss your weight goals and diet and exercise plans with your doctor before making any dramatic changes to your current regimen.
Changes in your exercise program may lead to fluctuations in your appetite. Exercise seems to affect people differently, stimulating appetite in some and decreasing it in others. When you increase your exercise routine, you may need to monitor your calorie intake for several weeks in to identify any unintentional changes in your eating patterns.
If you're unintentionally losing weight as a result of your expanded exercise routine, try increasing your food intake by 200-calorie increments until you get the effect you're after. If you want to lose weight but find that you're constantly hungry, try increasing your calorie intake by 100-calorie increments. As long as your calorie expenditure exceeds your intake, you will still lose weight. A slow rate of weight loss is healthier and more sustainable in the long run.
Most Americans don't get enough exercise. The recommendation is 30-60 minutes of moderate-intensity exercise at least five days a week, according to the American College of Sports Medicine. While 30-minute workouts won't likely have a significant impact on your calorie needs, regular intense sessions of an hour or more may warrant an increase in calories, even if your goal is weight loss. If you're losing weight at a rate of more than 2 to 3 pounds per week, you need to eat more energy-dense foods to support a healthy rate of weight loss.