Muscles weaken with age even if you exercise

With age, you can expect to lose muscle size and strength, which increases your risk of lifestyle diseases and disabilities (Gyro flag, 2020; 42: 1547-1578), as:

• Heart attack (Eur Geriatric Med, 2016; 7(3):220-3)
• diabetic (Med J Ost, 2016; 205 (7): 329–33).
osteoporosis and fractures (Endocrinol Metab Arch2015; 59 (1): 59-65; J Gerontol A Biol Sci Med Sci, 2018; 73(9):1199-204)
Depression and memory loss (Gyro flag, 2020; 42: 1547-1578)
loss of bodily independence (Healthy Aging Clin, 2020; 24 (3): 339-45; 2019; 23(2):128-37)

The gradual loss of muscle begins around the age of 25. It is caused primarily by the loss of muscle fibers and to a lesser extent by the reduction of type 2 fast-twitch fibers (J from neuroscienceApril 1, 1988; 84 (2-3): 275-294).

Why do you lose muscle with age?

Every muscle in your body is made up of thousands of muscle fibers just as a rope is made up of many strands. Each muscle fiber is innervated by one nerve. With age you lose nerves, and when you lose a nerve attached to a muscle fiber, you lose those muscle fibers as well. A 20-year-old might have 800,000 muscle fibers in the vastus lateralis muscle in the front of his upper leg, but by age 60, that muscle probably only has about 250,000 fibers. For a 60-year-old to be as strong as a 20-year-old, the average muscle fiber would have to be three times stronger than the muscle fibers of a 20-year-old. You can’t stop the loss of muscle fiber count with age, but you can certainly enlarge each muscle fiber and slow the loss of strength by exercising the muscle against progressive resistance, by using strength training machines or by lifting weights (Experimental GerontologyAugust 13, 2013).

How to strengthen muscles

To enlarge and strengthen muscles, you must exercise them against resistance with enough force to damage the muscle fibers. You’ll know you’ve done it because you’ll feel a sore muscle during those late lifts and the next day your muscles will ache. Then you lift lighter weights, or do other sports, for several days until your muscles heal. You can tell this has happened when the pain goes away. When your muscles feel fresh again, try lifting weights several times in a row or lighter weights several times in a row. You can get really strong with 10 to 15 strength-training machines or exercises (for different muscle groups) three times a week. Always stop immediately if you feel any excessive pain, tearing, or burning sensation.

Inactivity accelerates the loss of strength

When young people’s muscles are immobilized for two weeks, they lose strength equivalent to that of 40- or 50-year-olds. Once you stop moving, your muscles start to weaken and the older you get, the more muscle you have to lose. Younger, stronger people lose strength faster than older, weaker people (J from Rehab MedJune 26, 2015).

Even if you already do resistance training, be aware that quitting for a long time will result in a significant loss in muscle size and strength. People who lift weights and then stop lose muscle mass faster than those who never lift weights. After just one week of being bedridden, you can lose up to two pounds of muscle (Clin Rev, April 2013; 71 (4): 195-208. Even if you’re not immobilized, you can lose about 11 percent of your muscle mass after ten days without exercise (Scand G Med Sports Sciences2011 Apr; 21 (2): 215-234.

A weightlifter can lose up to 20 percent of muscle size after taking a week off from lifting, but this loss of muscle size is not primarily due to the loss of muscle fibers; The main reason is the loss of water and glycogen (sugar) stored in the muscles (Scand G Med Sports Sciences1999 Aug; 9 (4): 209-13; Eur J Clin Nutr1999 Feb; 53(2):126-33.) When a weightlifter resumes lifting, sugar and water can refill their previous levels in the muscles very quickly (Physiol, April 2013; 113 (4): 975-85. Weightlifters who have been completely immobilized for two weeks due to an injury or illness will likely take more than six weeks to regain full muscle strength (J Rahabil Med2015 Jun.; 47 (6): 552-60.

my recommendations

I believe that every healthy person should have a progressive resistance program as part of their regular exercise program. It can help ward off disability and disease. If you’ve never lifted weights before, you should first see your doctor for any potential problems and, first, look for instructions on progressive resistance training.

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Gabe Mirkin

Longtime sports medicine physician, fitness guru, and radio host Gabby Mirkin, MD, brings you news and advice on your healthy lifestyle. A practicing physician for over 50 years and radio talk show host for 25 years, Dr. Mirkin is a graduate of Harvard University and Baylor University College of Medicine. He is one of very few physicians who are board certified in four specialties: Sports Medicine, Allergy and Immunology, Pediatrics and Pediatric Immunology.

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