Although you'll need to consider several factors to determine how long you should exercise each day to lose 10 lbs., choosing a workout you enjoy will motivate you to stick with it. Daily exercise is key when it comes to losing weight -- the American College of Sports Medicine recommends an hour or more of moderate cardiovascular activity five times a week to lose weight.
Safe Rate of Weight Loss
Set a goal to lose between 1 and 2 lbs. of weight each week. Too much weight loss can create a cycle of unhealthy yo-yo dieting and can lead to health problems. Charles F. Bellows, M.D. at the Baylor College of Medicine points out that people who lose more than 3.3 lbs. a week put themselves at greater risk for gallstone formation. Repeated weight loss and weight gain also increases this particular health risk. Gallstones aren't the only health problem you can develop when you attempt to lose weight too quickly, however. Crash dieting can make you fatigued and irritable, and cause hair and muscle loss. People who repeatedly try to lose weight at a rapid pace may have an increased risk of heart attack, according to registered dietitian Robin Gaff at the Ohio State Medical Center.
Your Current Weight
Your current weight affects the length of time you will need to exercise each day in order to lose weight. People who are significantly overweight tend to lose weight at a faster rate than those who are already close to a healthy weight. This is because it requires more energy to move your body if you weigh 200 lbs. than it does if you weigh 150 lbs. The more energy your body must use, the more calories you will burn. For example, if you weigh 200 lbs., you can burn 635 calories during an hour-long game of racquetball, whereas a 150 lb. person will burn approximately 150 fewer calories during the same game. Therefore, if you weigh 200 lbs. and play racquetball for an hour on a daily basis, you could lose 10 lbs. in an eight-week period. While if you weigh 150 lbs., you will need to play racquetball for an hour and 15 minutes to lose the same amount of weight. One pound of fat equals 3,500 calories.
Type of Exercise
The type of exercise you do influences the amount of time you will need to spend exercising to lose weight. If you weigh 150 lbs. and walk every day at a 3 mph pace for eight weeks, you will need to walk for 2 hours and 50 minutes to lose 10 lbs. during that eight-week period. On the other hand, if you choose to cycle at 12 mph, you'll need to exercise one hour and 10 minutes each day to achieve the same results.
It can be difficult to lose weight exercising if you don't consider diet. When you exercise, you increase your metabolism and burn calories, which can trigger an increase in appetite. If you don't monitor your calorie intake each day, you are likely to consume extra calories and remain at your current weight. This is normal, as the body likes to create a state of homeostasis -- meaning it makes adjustments to keep your weight stable. You will have to deliberately subvert this process to lose weight. Write down your calorie intake each day to keep your weight loss on track.