If you’re interested in losing weight, you want to burn a significant number of calories per day. Every time you burn 3,500 more calories than you consume, you lose a pound. Therefore, getting in two workouts in a day is beneficial because you’ll make more strides toward that caloric deficit. In addition, your metabolic rate is elevated for a period after each of your workouts. This means that when you’re finished with your workout, you’re still burning an increased rate of calories. By getting in two workouts, that time your metabolic rate is elevated is doubled. Multiple workouts also are beneficial for those just starting out with exercise, as according to the American Council on Exercise, doing multiple, shorter workouts throughout the day is just as beneficial as one longer duration session.
Jumping right into multiple workouts can lead to overtraining or injury. After each of your workouts, your body works to heal and recover from the stress it has undertaken. Overtraining occurs when your workout volume and intensity is exceeding your body’s recovery rate. Your body is not able to recover adequately in between workouts. As a result, your performance will plateau and then decline. You’ll feel fatigued and find that you’re unmotivated to work out. In addition, this fatigue increases your risk of injury because your neuromuscular system won’t be performing at its best.
Avoid doing two weight-training workouts per day, unless you’re targeting different muscle groups. When you lift weights, you’re breaking down and damaging your muscular fibers. The time in between your lifting sessions is when your muscles heal, grow in size and increase their force production. They need 48 to 72 hours for this healing process to occur. If they’re not able to fully recover, your strength and size benefits will be significantly limited.
If you’re going to work out multiple times in a day, start out slow and choose two different types of activities. Work out twice a day two to three days per week to start and then incorporate more multiple-workout days as your body adapts to the stress. Do one type of workout, such as cardio, in the morning, and a different one, such as weight training or yoga, in the evening. If you’re starting to feel fatigued, cut back on your workout frequency.