You’d probably like to live a long life, assuming the extra years of life were happy, productive, and functional ones. You hear a lot about eating a healthy diet and getting aerobic exercise to maximize life span – but what about strength training? Can strength training not only add muscle mass to your body, but also help you live longer as well?
Muscle Mass and Mortality
The idea that having more muscle might prolong life is supported by science. In healthy older adults, body composition is a predictor of mortality – and it’s not just how much fat you carry on your frame but also how much muscle. One study showed that death rate from all causes was lower in older adults in the highest quartile of muscle mass versus the lowest.
The same link between muscle mass and morality was seen in a study evaluating people with heart disease. Researchers examined data from the National Health and Nutrition Examination Survey that ran from 1999 to 2004. This study looked at the mortality rates among 6,451 men and women with cardiovascular disease. They divided the participants into four group based on their body composition:
High muscle mass and high fat mass
High muscle mass and low fat mass
Low muscle mass and low fat mass
Low muscle mass and high fat mass
The researchers analyzed the body composition of participants using one of the most accurate measurements for determining body composition, dual x-ray absorptiometry. What they found was having a higher muscle mass was associated with a lower risk of dying from cardiovascular disease or any cause.
Having more muscle also works in your favor should you become seriously ill. Studies show that people admitted to the intensive care unit of hospitals have a lower death rate when they have more skeletal muscle mass. This makes sense since serious illnesses and injuries, particularly burns, can send your body into a catabolic state. If your body breaks down muscle, your chances of survival will be greater if you have more muscle tissue on your frame. So, whether you’re healthy or ill, having more muscle is beneficial.
What Body Composition Says about Health and Longevity
Although muscle mass is strongly linked with mortality, you can’t ignore other aspects of body composition. We know that a large waist circumference is linked with mortality, including a high waist-to-hip ratio. A higher waist-to-hip ratio is a marker of insulin resistance and a greater risk of heart disease and other health issues. Women with a waist-to-hip ratio of 0.85 or larger and men with a waist-to-hip ratio of 0.95 or larger are at an elevated risk of cardiovascular disease.
Not surprisingly, the combination of low muscle mass and a large waist size or waist-to-hip ratio is strongly correlated with increased mortality. In one study, mortality was lowest in men with greater than average muscle mass and low waist circumference. More muscle mass and a small waist size seem to be the ideal combination, from a body composition standpoint, for health and longevity.
Having more muscle mass and a smaller waist size is metabolically more favorable as well. A large waist size is a marker for excess visceral fat, deep belly fat, the type that’s most strongly linked with health problems, like type 2 diabetes, cardiovascular disease, and some forms of cancer. Plus, studies equate more muscle mass with better balance and a lower risk of falling.
Is BMI a Good Measure of Healthy Body Composition?
Health care professionals often use BMI, or body mass index, as a marker for a healthy body from a weight standpoint. Unfortunately, BMI is not very accurate, especially for athletes and older individuals because it says nothing about body composition. An athlete may have a high BMI because they have so much muscle, whereas an older person may have a BMI in the normal range and still have an unhealthy body composition. As you lose muscle mass due to aging, BMI goes down – but it’s for the wrong reason. Many elderly individuals are sarcopenic, meaning they’ve lost muscle due to aging. A sarcopenic individual may have a “normal” BMI, yet have an unhealthy body composition because loss of muscle tissue is pulling their BMI down into the so-called healthy range. Remember, BMI is calculated by dividing body weight by the square of height. It says nothing about the composition of your body weight.
Muscle Mass is a Strong Predictor of Healthy Aging
Too often, we think in terms of expanding lifespan when we should focus on health span. Health span is the length of time a person is healthy rather than the total years of life they live. Strength training improves health span as well. The main reason older people become feeble and less functional is the loss of muscle mass related to aging. We know that the best way to slow this process is to strength train. What’s more, studies show that older adults may need a more intense training stimulus to stimulate muscle growth. Adults over the age of 65 have some degree of anabolic resistance, meaning their muscles don’t respond to growth stimuli as readily as the muscle of younger people. In addition, older people may benefit from consuming more protein as well.
Unfortunately, it’s common for older people to believe they should slow down with age and lighten up on their training when the opposite is true. When you hit a certain age, you may have to work harder to maintain a healthy body composition – but the effort is worth it when you consider strength training improves lifespan AND health span.
The Bottom Line
More muscle mass on your frame equates with lower mortality from all causes as well as a longer health span, years that you’re healthy and functional. The best way to maintain muscle mass is to strength train. Now, you know why it’s so important – for lifespan AND for health span.
References:
Science Daily. “Higher muscle mass associated with lower mortality risk in people with heart disease”
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