By Gabe Mirkin | Guest Writer
The best way to make your muscles stronger is to exercise them against resistance strong enough to damage the muscle fibres. Then, when they heal, they will be stronger.
A review of 22 studies published in the journal Human Movement in 2020 looked at how to grow larger and stronger muscles. It found that the best way for untrained people to grow muscles is to use lighter weights with more repetitions, even though most trained athletes gained more strength by using heavier weights with fewer repetitions. Lifting lighter weights with more repetitions reduces your chances of injury.
When middle-aged and older people start a weight lifting program, they often become injured, usually because they try to train like young people who pick the heaviest weight they can lift 10 times in a row and do three sets of 10 lifts. They feel sore for the next few days and when the soreness goes away, they lift heavy weights again, usually two or three times a week. This type of training often injures older novice weight lifters and ends their training program.
The best way for middle-aged and older people to prevent injuries is to lift lighter weights.
Muscles are made up of hundreds of thousands of individual fibres, just as a rope is made up of many strands. Each muscle fibre is innervated by a single motor nerve. With aging, you lose motor nerves, and with each loss of a nerve, you also lose the corresponding muscle fibre that it innervates. For example, the vastus medialis muscle in the front of your thigh contains about 800,000 muscle fibres when you are 20, but by age 60, it probably has only about 250,000 fibres. However, after a muscle fibre loses its primary nerve, nerves covering other fibres can move over to stimulate that fibre in addition to stimulating their own primary muscle fibres.
Lifelong competitive athletes over 50 who train four to five times per week didn’t lose as many of the nerves that innervate muscles and therefore retained more muscle size and strength with aging than their non-athlete peers, according to a study published in The Physician and Sportsmedicine in 2011.
Each muscle fibre is made of a series of blocks called sarcomeres that are lined up end to end. Each sarcomere is attached to the one next to it at a “Z line.” Muscle fibres don’t contract equally along their lengths; they contract only at each “Z line.”
To strengthen a muscle, you have to put enough force on the muscle to damage the Z-lines, as evidenced by bleeding and swelling into the Z-lines. You can tell you have damaged the Z-lines by the feeling of muscle soreness that begins eight to 24 hours after you have lifted weights or done any form of resistance exercise. That’s the amount of time it takes for the swelling to occur in the Z-lines, which is called delayed onset muscle soreness (DOMS). Exercising your muscles intensely enough to damage them makes muscles stronger so they can withstand higher loads and be more resistant to injury.
When a muscle is damaged, your immune system sends large amounts of the same cells (lymphocytes) and chemicals (cytokines) to the damaged tissue. These are used to kill germs when you have an infection. This causes inflammation, characterized by soreness (pain), increased blood flow to the injured fibres (redness), and increased flow of fluid into the damaged area (swelling). The immune cells release tissue growth factors to heal the damaged muscle fibres.
You should allow the muscle soreness to decrease or disappear before exercising intensely again. If you don’t wait until the soreness goes away before exercising intensely again, the fibres can be torn, the muscles weakened, and you can become injured.
If you aren’t already doing strength training, check with your doctor to make sure you do not have any condition that may be harmed by exercise. Then read about resistance exercises you can do at home (like the article on my site), or find a gym. For each exercise, pick the resistance that you can comfortably repeat 10 times in a row without straining or hurting your muscles. End the workout immediately if you feel pain that doesn’t go away as soon as you stop the movement.
If your muscles still feel sore 48 hours after your first workout, wait until the soreness is gone before you try again. As you become stronger and the resistance feels very easy for you, try to lift 15 times in a row, then perhaps 20 times. Only when you can lift that weight at least 20 times in a row, and not feel sore the next morning, should you try to increase the resistance level.
The key to this program is to avoid injuring your muscles by increasing the number of repetitions gradually so that you don’t cause muscle soreness that lasts longer than a day. You shouldn’t increase the weight (resistance) until you can lift a set of at least 20 repetitions in each exercise without feeling sore the next morning.
This program is designed for beginners and is intended to prevent injuries that plague older people when they first try to lift weights. It won’t build very large muscles, but it will increase your strength and provide all of the other benefits of a weight training program.
After many months (injury-free) on this program, if you wish to build larger muscles, you can transition to a more traditional weight training program, such as the strength training guidelines I discuss on my website.
Otherwise, you can continue with this safe and effective program of resistance exercise for the rest of your life.