SPORTS MEDICINE
WHAT IS SARCOPENIA?
Muscle Matters
The most important, but often under-appreciated tissue we need to work as we age BY STUART PHILLIPS Stuart Phillips is a Professor and Canada Research Chair in Muscle Health and Aging in the Department of Kinesiology at McMaster University in Hamilton, ON. MACKINPROF
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ver the last century, we have added more than 30 years to the human lifespan. Sadly, healthspan — the period of our lives during which we’re in good health — has not kept pace with the increase in longevity. So why is healthspan more important than lifespan? While longevity is great, who wants to live to be 120 and feel like they’re 120? In the search for behaviours that might help us age well, there are many axioms. People talk about mental or brain health, bone health, metabolic health, heart health, but we rarely hear about muscle health. That changes now. Simply put, muscle matters. Muscle is most obviously the tissue of locomotion. Without muscle, or with weaker muscles, we can’t or don’t move well.
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Various disorders of neural or muscular origin serve as potent reminders of how much more difficult life is when our physical mobility is compromised. However, all of us are under the influence of one process that causes just about all our biological systems to decline: aging. As we age, the loss of muscle is termed sarcopenia. Derived from Greek, the word literally means ‘poverty of flesh.’ So, can we prevent this ‘poverty’ and manage sarcopenia? Preventing any normal age-related process is next to impossible; however, we can slow the decline and, in doing so, preserve our mobility in later life. Muscle plays many roles in our general health beyond locomotion. For example, muscle plays a central role in regulating blood sugar. Following consumption of a higher carbohydrate-containing
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Sarcopenia is the term given to the gradual age-related loss of muscle mass and strength. Many view sarcopenia as a natural part of aging, which is understandable as there are some things that we have to accept as we age. We are unsure exactly what causes sarcopenia, but it is likely a combination of diet, physical activity levels, hormone concentrations, and natural, biological, aging processes. It is at this point when many ask when sarcopenia begins? The answer is that we don’t know; however, population data shows that starting somewhere in our 40-50s we lose, on average, about one percent of muscle mass and about one-two percent of our muscle strength per year. That means someone in their 50s can, by the time they reach their 80s, expect to have lost almost 30 percent of their muscle mass and between 30-60 percent of their strength. On a scale, their body weight may have stayed the same. Why? Sadly, they have replaced their muscle weight with body fat, which is not atypical.
meal, particularly one composed of ‘simple sugars’, like a can of pop or a bowl of white rice, our blood sugar levels rise. If these levels remain elevated, which is a hallmark of Type 2 diabetes, then the elevated sugars can cause damage. Muscle is like a sink for blood sugar. As such, it is the single largest site for disposal and storage of post-meal blood sugar. In short, having a large and active — you still need those muscles to move — muscle mass is important in regulating blood sugar and may reduce our risk of developing Type 2 diabetes and its complications. ➝