There are several different types of exercise that benefit the body. First, aerobic exercise, which uses large muscle groups, forces the heart and lungs to work harder to meet the muscles' demand for oxygen. These activities involve regular, repeated activity performed at a pace intense enough to quicken your breathing and get your heart pumping faster than usual. Over time, the heart and other muscles become more efficient at using oxygen and can work harder and longer using less energy. Ultimately, this improves cardiovascular fitness, resulting in a decreased resting heart rate and decreased blood pressure. This also makes routine daily activities, such as running around after a busy toddler or bringing groceries in from the car, easier and less fatiguing. Examples of aerobic exercise include brisk walking, jogging, swimming, cycling, and cross-country skiing.
Second, resistance training, such as lifting weights, develops muscular strength and size. The weights involved are usually handheld or built into exercise equipment, but a similar effect can be achieved by stretching large rubber bands or even lifting objects such as heavy books. Resistance training performed two to three times a week can improve muscular strength and endurance. To build muscle strength, select 8 to 10 different strength-building exercises that use the major muscles, and perform 8 to 15 repetitions of each exercise for each isolated muscle.
Just as the different foods groups are important to eating a balanced diet, different forms of exercise are important to a balanced program of physical activity and are vital to weight control. Aerobic exercise appears to benefit the heart the most, improving aerobic capacity and significantly burning calories, which aids weight loss. But resistance training increases lean body mass, which improves strength and balance, making it easier to perform aerobic exercises. Resistance training also speeds up metabolism. Stretching and flexibility exercises improve range of motion, making it easier to move muscles and joints, preventing injury while performing aerobic activities and resistance training.
Regular exercise brings not only physical, but also mental benefits. See the next page to learn the effects of exercise on body and mind.