All muscles in the body, including those of the skeletal system and cardiac muscle, may benefit from regular exercise. Various involuntary systems and processes combine their effort to bring oxygenated blood to the working muscles. The result may be improved strength, a slimmer body and better overall health.
There are three types of muscles, including skeletal, cardiac and smooth. Both skeletal muscles, which assist in locomotion and posture and cardiac, found in the heart, benefit from regular activity. Hypertrophy is an increase in skeletal muscle size, one of the most obvious effects of exercise on the muscular system, especially from resistance or strength training. Smooth muscle such as in the stomach and intestines is controlled by the autonomic nervous system and isn’t affected.
The body’s muscular, cardiopulmonary, and nervous systems all respond to increased demand of the muscles for oxygenated blood. This gets diverted from non-vital organs to increase energy within the muscles. Byproducts from the increased activity such as lactic acid, hydrogen ions and carbon dioxide stimulate the respiratory system to increase breathing for better oxygen exchange.
Effects of exercise on the muscular system show up in cardiac muscle too. A strong heart can pump more blood each time it beats, carrying nutrients and oxygen to all parts of the body. The pulse rate of a person who exercises regularly will be slower than most people, because the heart doesn’t need to pump as much to move the same amount of blood. Steady aerobic exercise using the major muscle groups, enough to cause an obvious increase in respiration, is best for continued cardiac health.
Two interesting effects of exercise on the muscular system are the decrease of inhibitory neural feedback and synchronous activation. The first process means the nervous system lets the muscle work longer and harder than it would if the muscle were untrained, where it might be injured. Synchronous activation allows more muscle fibers to work in tandem, giving the muscle an enhanced ability to handle the increased activity and perform at a higher level. The result is a measurable strength gain, particularly in women’s muscles and those of adolescents. In addition, strength training with weights and resistance bands can reverse muscular decline that comes with aging.
Warming up and cooling down can be vitally important to a proper workout. These may prevent adverse effects of exercise on the muscular system like strain injuries resulting from a lack of good preparation. The muscles need adequate blood and oxygen flow to begin vigorous activity. Stretching after the workout keeps them from tightening up and also keeps them flexible long after the workout is finished.
Weight-bearing exercises also contribute to bone density, a primary concern especially for women, who are more prone to osteoporosis. Tension on muscles improves strength and balance, which when combined with higher bone density makes fall injuries less likely. Strong, conditioned muscles at rest burn more calories than weak muscles. Regular exercise also helps prevent obesity, a major cause of health problems at any age.