Home workouts can be effective, but you have to put in the maximum effort.
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If you pay attention to TV or online fitness ads, chances are you've heard about P90X. The home-based fitness program is touted as a highly effective workout that burns hundreds of calories per session and transforms your body within a period of 90 days. Calorie estimates can be an effective marketing tool, but if you want to get a more accurate reading of the calories you'll burn during this workout, you'll have to dig deeper.
The Basic Numbers
Fortunately, some exercise experts have examined P90X closely to find out what actual results you can expect to see. During a study conducted by researchers at the University of Wisconsin-Lacrosse and published by the American Council on Exercise, men burned between 10.5 and 16.2 calories a minute doing P90X workouts, while women burned between 7.2 and 12.6 calories per minute. In a single workout, that averaged out to between 441 and 699 calories for men and 301 and 544 calories for women.
It Depends on the Workout
The P90X program places a big focus on what its leaders call "muscle confusion." It's based on the notion that your body is incredibly efficient at adapting to training, so "tricking" it by mixing up your workouts can help you prevent training plateaus. The standard P90X program includes 12 different workouts -- meaning you'll repeat a workout once every two weeks or so. But because the workouts are different, they tend to burn varying numbers of calories. In the ACE-sponsored study, the calorie count tended to vary widely based on the workout. The Plyometrics workout involved the highest number of calories burned, with an average of 14.7 calories burned per minute. Second in the study was the Legs and Back workout at 12.4 calories per minute, followed by the CardioX workout at 12 calories per minute and then the Chest, Shoulders and Triceps workout at 9.0 calories per minute.
Don't Trust the Estimates
The number of calories you burn during any given activity depends on your age, weight, gender and level of exertion. Even in a controlled study, the number of calories burned varied depending on the participant. That should be a good reminder that it can be unproductive to rely on blanket calorie estimates. If you relied on the claims that you'll burn an average of 1,000 calories with each workout, you might overindulge, thinking you've created more of a caloric deficit than you really have.
Monitoring Your Heart Rate
The P90X program includes a meal plan meant to help you meet weight-loss goals and to help you stay fueled for your workouts -- meaning you might not have to overthink the number of calories you're burning. However, if you want a more accurate estimate of the number of calories you're burning during a particular P90X workout, try monitoring your heart rate. A heart rate monitor watch can be handy so that you don't have to stop your workout to check your rate. However you do it though, use the following formula to estimate the number of calories you burned per minute. For women, calories per minute equals (-20.4022 + 0.4472 x HR - 0.1263 x weight in kilograms + 0.074 x age) / 4.184. For men, calories per minute equals (-55.0969 + 0.6309 x HR + 0.1988 x weight in kilograms + 0.2017 x age) / 4.184.