Strength training with weights is the practice of using resistance to create physical effort with muscular contraction. You can lift barbells, stretch bands or rubber tubes, or push against your own body weight. When you do any of these things, your muscles contract and then lengthen as you lower the resistance. This process builds strength as well as muscle mass.
The health benefits of weight training are well established. Weight training can help weight loss as well as help improve factors related to heart disease, cancer, diabetes, arthritis, Parkinson's disease, osteoporosis and multiple sclerosis. Some of the benefits are preventative in nature (helping prevent disease), while other benefits -- for Parkinson's and multiple sclerosis for example -- are therapeutic, alleviating symptoms in established disease.
In this article, you will see how the more functional (and observable) physical effects of strength training can help you live longer, or at least better -- with more muscle and lower body fat.
Muscle Maintenance and Enhancement
Muscle declines with age in men and women. Medical estimates place this decline at about 3% to 5% each decade after your thirties. Even if you exercise and train with weights, an age-related decline in hormones like testosterone will result in reduced muscle mass compared to when you were in your twenties.
An adequate diet is also likely to play a role in preventing deterioration or sarcopenia.
The term 'sarcopenia' is used to describe low muscle mass and reduced muscle function. It may also refer to non-specific weakness and disability, and diminished autonomy among older adults. It's not difficult to imagine how strength and mobility enhance independence in senior years. Maintaining muscle (and bone) bulk and strength is one key to self-reliance and independence as we age.
Technically, sarcopenia is characterized by a decrease in the size of the muscle, which may correspond with an increase in fat and an increase in fibrosis (scar tissue) in muscle fibers.
Resistance training has proven results for maintaining muscle mass and strength in aging adults.
Contrary to popular belief, muscle does not turn into fat if you don't weight train, nor does fat become muscle when you do train. In each case, one declines and the other increases. Training with weights can promote fat loss and muscle gain, and that should be your aim. In weight loss programs, weight training is especially useful because it optimizes muscle maintenance while you lose fat.
Unfortunately, because of declining hormone levels, genetic influences, and declining ability or determination to exercise into senior years, the propensity for fat to increase and muscle to decline is strong. Men, who were once slim with the 33 inch waist (84 centimeters) suddenly become older men with the 40 inch waist (100 centimeters).
Longevity, Self-Reliance and Independence
Maintaining low levels of body fat as you age, in conjunction with optimum functional muscle mass are key elements in the prevention of heart disease and diabetes because these fat and muscle conditions encourage good metabolic function and your ability to continue with physical activity. Other health conditions may also be ameliorated with maintenance of these two physical characteristics.
You can probably sense the 'cascade' in this process. Resistance training enhances muscle and strength and reduces body fat. A strong, lean senior body helps ward off the major lifestyle diseases, heart disease and diabetes, and helps maintain strong bones. This level of fitness allows you to be self-reliant and independent so that you can continue to be physically active, especially with weight training. It's a self-maintenance circle you don't want to break.
Med Sci Sports Exerc. 2011 Feb;43(2):249-58. Influence of resistance exercise on lean body mass in aging adults: a meta-analysis. Peterson MD, Sen A, Gordon PM.
Arch Gerontol Geriatr. 2012 Mar-Apr;54(2):e230-3. Association between muscle mass and disability in performing instrumental activities of daily living (IADL) in community-dwelling elderly in Japan. Tanimoto Y, Watanabe M, Sun W, Hirota C, Sugiura Y, Kono R, Saito M, Kono K.
J Am Geriatr Soc. 2002 May;50(5):889-96. Low relative skeletal muscle mass (sarcopenia) in older persons is associated with functional impairment and physical disability. Janssen I, Heymsfield SB, Ross R.