Healthspan is the number of years that you live in good health, free from chronic disease and disability. While many typically aspire for a longer lifespan, they should instead aim for a greater healthspan so that they can enjoy a better quality of life with age. Muscle is becoming increasingly recognized as one of the most important biological drivers of healthspan.
Most people underappreciate the importance of their muscles until they injure or lose them. Have you ever pulled a muscle from a lack of proper stretching before use or from overuse during strenuous exercise? As you age, do you notice that lifting heavy objects becomes more strenuous? Muscle loss is a normal progression of aging, but it can be accelerated by physical inactivity and muscle disuse in the form of injury, illness, hospitalization, or surgery. As we age, we also lose our ability to fully recover our muscle mass and function from these events.
Skeletal muscle is comprised of thousands of elastic fibers that produce movement through controlled waves of contraction and relaxation. “Maintaining physical activity and keeping your muscles healthy slows aging on the whole-body, cellular, and molecular levels. By maintaining an active lifestyle, you will [positively] affect your muscles, your tissues, and your body,” remarks Dr. Drummond.
Did you know that your muscles help reduce the risk of chronic disease? For example, muscle tissue regulates glucose uptake and insulin sensitivity, which is important in preventing type 2 diabetes.1,2 Stronger muscles also support a healthy heart by aiding in blood circulation, lowering blood pressure, and reducing cholesterol levels, all of which decrease the risk of heart disease.1,3,4 Additionally, a higher muscle to fat ratio helps to decrease inflammation in the body and supports a stronger immune system, decreasing the risk of total cancer by 12%.1
There is also a close association between skeletal muscle and bone health. Muscle directly supports bone health by applying stress to bones during physical activity, stimulating bone growth and increasing bone density.5 This process is especially important for preventing osteoporosis, a condition that weakens bones and increases the risk of fractures.6
Lastly, studies have shown that strength has a strong influence on cognitive health. A study of over 4,800 individuals from the United States showed that smaller muscles and decreased grip strength increase the development of depression.7 In young adults averaging 29 years old, having strong knee muscles decreased depression nearly 5-fold.8 Another study including over 162,000 UK Biobank samples from individuals aged 38-70 showed that grip strength was inversely associated with depression and anxiety.9 There was also an association between reduced muscle mass and a decline in global cognition in older men aged 60+.10
“Muscle is more than just a tissue that helps you lift heavy objects or move from point A to point B,” says Dr. Drummond. “On a cellular level, muscle cells house energy molecules that are important for expending energy both while we are active and at rest.” Muscle aids in movement, metabolism, digestion, blood circulation, breathing, and other necessary biological functions.11 “It’s one of the most metabolically active tissues that we have in our body,” adds Dr. Drummond.
Historically, healthspan has not kept up with the rapid increase in global lifespan. If more individuals are living to 100 but cannot enjoy those additional decades of life because of a lack of physical independence, then their quality of life during those additional years is at risk. Research shows that greater muscle strength and mass are positively associated with a longer lifespan and lower risk of all-cause mortality, independent of other health factors.12–14 “Understanding how to promote muscle health can help offset the negative effects of age-related disease and conditions,” states Dr. Drummond.
The World Health Organization (WHO) has suggested physical fitness goals for muscle maintenance in different age groups, which can also benefit other areas of health. Adolescents aged 5-17 should engage in at least 60 minutes of moderate to vigorous exercise daily to promote fitness, metabolic health, motor skill development, cardiorespiratory fitness, bone health, cognitive function, mental health, and academic success.15 Adults aged 18-64 are recommended to participate in 150-300 minutes of moderate-intensity exercise or at least 75-100 minutes of vigorous-intensity exercise weekly, as well as muscle-strengthening activities at least twice per week.15 According to the WHO, the positive health-related outcomes from physical activity include a decline in all-cause mortality, cardiovascular disease, type-2 diabetes, hypertension, colon and breast cancer, adiposity, cognitive impairment, and mental health disorders, while also improving sleep and quality of life.15 Lastly, people aged 65+ should perform balance and strength training at least three days a week to improve functional capacity, prevent osteoporosis, and lower the risk of frailty, falls, and hospitalization.15 Therefore, physical activity is a preventative medicine that optimizes the functional capacity of our muscles to improve well-being with age.
“I'd be all for living to 100 years old if the new 100 means being biologically similar to a 60-year-old,” remarks Dr. Drummond. “I don't think we're very far from that aspect. I think people are going to live longer and healthier than we currently are now.”
Dr. Drummond concludes with an inspiring reminder that “muscle is medicine, and that it's never too late to start building your muscle!”
