Cardiovascular, or cardio, exercise consists of any physical activity that significantly increases your heart rate. It plays an important part in helping you maintain a healthy weight and reducing your risks for diseases ranging from heart disease to diabetes. While regular cardiovascular exercise is important to include in your weekly schedule, it is possible to include too much cardio.
Purpose of Cardio
Cardiovascular exercise has several purposes when it comes to your exercise routine. One of the primary reasons to include cardio is the increased amount of calories it burns. Cardio exercises require more energy to sustain the same intensity of exercise than strength training or resistance exercises. As such, more calories are burned to replace the used energy. Cardio is also important for building cardiovascular strength due to its effects on your heart. It can help increase your lung endurance when made a regular habit.
Overtraining occurs when you push your muscles too far past their healthy threshold. In any cardio workout, the muscles undergo stress, which in turn activates muscular hypertrophy, or muscle building. However, when you push the muscle too hard, the stress can cause potentially serious damage including muscle pulls, muscle tears or damage to other supportive tissues such as your ligaments and tendons.
Fat vs. Muscle
Whenever you exercise, you burn both fat and a small amount of muscle. However, the amount of muscle you typically lose is not significant. When you do too much cardio at once, you run the risk of increasing the amount of muscle you burn as the body struggles to keep up with the increased level of energy being used by the body. When you combine excess cardio with an improper diet, such as one that drops your total calorie intake below 1500 calories, the risk of burning significant muscle increases.
All adults should aim for 150 minutes of moderately intense aerobic exercise each week. Moderately intense aerobic exercise includes activities like walking, jogging, light swimming, hiking and biking. For better results, the Centers for Disease Control and Prevention recommends increasing these types of exercises to 300 minutes per week or increasing the intensity level if only 150 minutes are done per week. If you plan to exercise more than 300 minutes per week, talk to your doctor first to make sure that the level of exercise is appropriate for your individual health condition and to avoid overtraining.