Chronic Disease Prevention: Muscle vs. Fat, why is it critical?
By Dr. John Mishock, PT, DPT, DC
The world health organization reported that the population older than 60 years surpassed that of younger adolescents in 2020 and estimated that people aged > 60 years will be 20% by 2030. (WHO, 2022)
The older population increases the medical burden mainly because of the known risk of chronic disease as the population ages. As we age, we lose muscle mass, known as sarcopenia, if we don’t perform resistance exercise training. At age > 50 years, we lose 1-2% of muscle and 1.5-5% strength body per year. By age 80, most adults have lost 40% of their muscle mass. (Saini et al., 2009) When sarcopenia occurs, there is a loss of muscle mass, reduced immunity, energy loss (mitochondrial dysfunction), increased inflammation, and excessive fat accumulation. (Wang et al. 2015) Our lifestyle conveniences have led to a lack of physical activity in our daily lives. This sedentary living has led to an increase in obesity and a decrease in muscle mass. In this article, I will review how the changes in muscle mass and fat (adipose tissue) impact the incidence and chronic disease.
What happens to our muscles as we age?
Muscle volume peaks in our 20s-30s. As muscle mass decreases with normal aging, fat mass increases gradually until the 60s-70s. (Harmer et al., J of Mol Bio 2004) Our lack of physical activity, limited resistance exercise training, and poor diet expedite this negative change. The lack of muscle leads to limited mobility, altered function, increased risk of falls, and many chronic preventable diseases such as cardiovascular disease, diabetes, stroke, liver and kidney disease, dementia, and some cancers.
How does muscle communicate through myokines with other organs?
Myokines are communicating substances (bioactive mediators) secreted from the muscle that affect various organs (muscle, adipose tissue, liver, brain, kidney, pancreas, heart, bones, and immune system). These myokines are the link to keeping us healthy and preventing disease. Exercise (aerobic and resistance exercise) is a robust stimulus to modulate the production and release of myokines (Park et al. Metabolis, 2023). Resistance exercise can profoundly affect the release of myokines, preventing or minimizing the effects of chronic disease while improving function and quality of life as we age.
Why does our body get fat?
Throughout the history of man, energy to maintain our body and function has been king. Our body prioritizes energy storage, not knowing when the next meal will occur. With that, our bodies adapted to be very efficient in storing energy. We store this energy in the form of fat. We have had excess food (energy) for only a few generations. Not only do we have ample amounts of food, but it is also ultra proceeded with lots of calories (energy dense). Beyond this, it is highly flavorful, causing use to overeat.
How does excess fat (adipose tissue) lead to disease, adipokines?
Much like a muscle, fat tissue is an organ that secrets bioactive substances to other body organs (adipokines). These adipokines have been shown to coordinate energy homeostasis and immune reactions and function. Some of these adipokines are pro-inflammatory, a key factor in promoting chronic disease.
I am too old; how will resistance exercise help me?
You are never too old for resistance exercise and the health benefits it will bring. In 33 studies of older (>70), pre-frail and frail older adults showed significant enhancements in muscular strength, gait speed, and physical performance and function following an 8-12 weeks training program. (Jadczak et al. 2018; Liu and Latham 2009)
I am too old; can I gain muscle mass?
Senior individuals can gain strength and muscle mass with appropriate resistance exercise and good nutrition (appropriate protein, carbohydrates, and fats). In 49 randomized controlled resistance exercise trials, it was concluded that older adults could gain 2.5 lbs of lean body mass with 20.5 weeks of resistance exercise. (Peterson et al., 2011)
Is resistance exercise risky to my heart as I age?
Five studies evaluating adverse events during low-to-moderate intensity resistance exercise (30–69% of 1RM) in older adults with cardiovascular disease found that resistance exercise was actually associated with a lower rate of adverse cardiovascular complications, even beating out aerobic exercise. (Hollings et al. 2017). Before starting any exercise program, getting approval from your medical provider is essential.
What are the resistance exercise recommendations to prevent and treat insulin resistance and Type II Diabetes?
Exercise type: Whole body exercise progressive resistance
Frequency: 2-3 times per week, 24 hours rest before the next workout.
Duration: 8-12 weeks, then change the program.
Contraction type: Concentric (muscle contraction closing the joint angle), Isometric (muscle contraction without movement), and Eccentric “negative” (muscle contraction opening the joint angle)
Intensity (effort): 30-69% of 1 repetition maximum performed to muscle contraction fatigue. Keeping the intensity in this range will prevent excessive elevation of blood pressure. (MacDougall et al. 2008)
The evidence presented in this review demonstrates the beneficial effects of resistance exercise on reducing chronic disease risk (mobility, disability, type II diabetes, cardiovascular disease, and cancer) in both younger and older adults. Regular performance of resistance exercise improves muscle mass, strength, and function and can directly affect the primary prevention of several chronic diseases.
We can help!
If chronic disease, pain or limited function limits you from doing the activities you enjoy, call Mishock Physical Therapy for a Free Phone Consultation (610)327-2600. Email your questions to mishockpt@comcast.net. Visit our website to learn more about our treatment philosophy, our physical therapy staff, and our 7 convenient locations in Gilbertsville, Skippack, Phoenixville, Boyertown, Limerick, Pottstown, and Steiner Medical at www.mishockpt.com.
Schedule your visit by calling 610-327-2600 or visiting this link: https://mishockpt.com/request-appointment/
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Visit our website to read informative articles, meet our physical therapy staff, and learn about our treatment philosophy. Email your questions to mishockpt@comcast.net
Dr. Mishock is one of only a few clinicians with doctorate-level degrees in both physical therapy and chiropractic in the state of Pennsylvania. He has authored two books; “Fundamental Training Principles: Essential Knowledge for Building the Elite Athlete”, and “The Rubber Arm; Using Science to Increase Pitch Control, Improve Velocity, and Prevent Elbow and Shoulder Injury” both can be bought on Amazon and train2playsports.com.
