Strength Training: It's Impact on Young People's Health
Last Updated: 11/17/2009
Strength training, properly performed, is not only for athletes. It is ideal for all ages, especially those who are between the ages of 10 to 18. These benefits can be grouped into 3 broad categories - physical, mental and behavioral.
The physical benefits begin with a disease called osteoporosis. This is the disease we are most familiar with in the elderly. As people age, their bone mineral density decreases, thereby weakening the bones. Eventually, selected bones of the body become too thin to handle any extra weight or force. As a result, a compression fracture may occur in the spine. There may also be an increased risk for hip and wrist fractures when an older person falls.
While osteoporosis may not occur until later in life, the disease often starts in the early teen years. For example, bone mineral density in youth may be associated with osteoporosis in later years. Experts estimate that a three- to five-percent increase in bone mineral density in a female teenager can result in a 20 to 30 percent reduction in her risk of bone fractures at an older age.
Strength training has been shown to help young people develop bone mineral density. How? Strength training provides stress where the muscle and tendon insert into the bone. The tug and pull of the muscle and/or tendon on the bone during movement signals the body to lay down more bone tissue in that area. The result is increased bone density.
Weight bearing exercises such as walking, running and jumping will stress the bones of the hip, legs and/or ankle. Unfortunately, the spine and upper body are not seriously affected with these types of exercise. Therefore, strength training in adolescence is the exercise of choice to challenge the spine, hip or other parts of the body. Strength or resistance training should be supported with a healthy diet that includes adequate calcium intake. As a result, resistance training and adequate diet make a great team to assure a lifetime of optimum bone strength and health.
Type 2 Diabetes is also positively affected by strength training. With this form of Diabetes the body loses its ability to adequately use the glucose circulating in the blood (humans obtain glucose from the food eaten). Insulin is the key which gives glucose access to the cells for normal function and storage. Without adequate amount of glucose and insulin it is impossible for a person to live.
Muscles are the prime insulin receiver. Muscle growth (as promoted by strength training) increases the number of insulin receptors. The increase allows the body to better use the glucose that the body needs for energy. Increasing lean body tissue (an important outcome of strength training) has a profound effect on the ability of the boy to handle glucose and avoid resistance to insulin. Both the inability to handle glucose and/or insulin resistance can lead to Type 2 Diabetes.
In addition to these special benefits, an increase in the level of lean body tissue positively influences a person's metabolic rate in at least two ways:
A third physical benefit has to do with improved circulation. When a person works their muscles against some form of resistance the muscles request more fuel from their bodily systems. As they continue exercising over the ensuing weeks, at more and more challenging levels, there is an increased demand for more oxygen and nutrients. This heightened appeal places new expectations on the peripheral vascular system (blood vessels of the extremities and elsewhere). The arteries in the arms, legs and elsewhere develop collateral circulation in the muscles being exercised. This is a fancy way of saying that the exercised muscles will have more tiny blood vessels (capillaries) per square inch than they had before engaging in a regular fitness regimen. Exercise scientists call this increase one key component of a 'training effect' on the muscles. This increase in tiny blood vessels may reduce resistance to blood flow and thereby decrease blood pressure and possible unwanted loads on the heart.*
Other physical benefits which occur as a result of strength training include improved cardiovascular fitness, decreased blood lipid (cholesterol and triglyceride) levels and lower body fat. All of these are associated with better health and greater longevity.
*Intense lifting, while holding the breath, causes a "Valsalva Maneuver". This maneuver causes a dramatic rise in blood pressure that is unhealthy. The good news is that proper breathing during the action phase of the lifitng eliminates the Valsalva Maneuver.
Strength training has been shown to have a positive effect on self-image. The phrase "self-image" refers to the idea that the mind uses a virtual self (inside the brain) that it sees whenever one thinks about one's self. A dog does not have a self-image (think how embarrassed it would be if it did). People use this sense of self in all their thoughts. This includes what they think they look like, how they deal with life and what happens when they interact with others.
In practical, personal terms-are you a person who sees a glass half full or half empty? Our perceptions have to do with how we look at life. As far as our brain is concerned, our virtual self is our actual self. As you can see we may have perceptions about ourselves which may or may not be the way others see us.
No matter how off-base a person's self-image is, it will direct his/her interactions with people and their environment. Interestingly, children who participate in strength training on a regular basis have been shown to positively alter their body image and also demonstrate a higher self-rating of their personal health. Consequently, all of this may translate to a healthier outlook on life.
Research suggests that children and adolescents who participate in resistance-type training programs will have a decreased risk of smoking in their teen years. Some researchers attribute this to the self-image concept mentioned previously. Others have suggested that strength training programs may play a role in helping reduce future drug and alcohol use and abuse. This form of training may also play a role in the treatment of individuals with eating disorders. But the evidence is less conclusive on the latter condition.