The Importance of Strength Training - New Scientist

Our muscle strength peaks in our 30s, then slowly declines… Strength training could add years of life and protect you from some major killers.

Having stronger muscles seems to decrease the chance of getting cardiovascular disease, type 2 diabetes and cancer. There is even evidence that it can improve your memory and prevent cognitive decline… all adults should perform muscle strengthening activities 2 days a week.

Around age 30, we start to lose up to 5% of our muscle mass each decade, and this accelerates at 70. Over time, the kinds of fibres in our muscles change, with ‘type two’ fibres, which help us bear heavy loads for short spells, slowly being replaced with more ‘type one’ fibres that are more efficient over long periods, but less able to carry weight.

Our muscles also stop using protein as efficiently and so are less able to repair themselves. These age-related changes have many causes, including alteration in the levels of hormones such as testosterone, and a reorganization of brain cells that control movement.

Lifting weights for less than an hour a week reduces the risk of heart attack and stroke by up to 70% - independent of any aerobic training…. those women who did at least an hour a week of strength training significantly lowered their risk of type 2 diabetes, and people with greater grip strength – a proxy for overall muscle strength – have a lower risk of cardiovascular disease and cancer and are at reduced risk of premature death by any cause. One reason stronger muscles keep us healthier is that they help prevent the debilitating effects of wobbles, falls and problems moving, increasing well-being in the process.

Muscle also plays an important role in regulating the body’s glucose levels. .Bigger muscles mean a bigger sink for glucose and a higher number of cells that transport and clear glucose from the body… having bigger muscles is also linked with better survival rates for people with cancer, probably because the disease decreases muscle mass, so it is helpful to have a bigger resource to start with to keep the body going for longer.

Another surprising benefit of strength training is how it burns calories, even after the exercise is over. Weight training increases your basal metabolic rate … in two ways:

First, bigger muscles require more energy to fuel their tissue maintenance.

Second, lifting weights causes tiny tears in your tissue that require a relatively large amount of energy to remodel. This increase in energy demand can last 3 days after a workout. All of this helps if you want to decrease body fat, a factor associated with lower cholesterol, lower blood pressure and improved insulin sensitivity and glucose control, all of which contribute to a decreased risk of type 2 diabetes and cardiovascular disease.

But strength training really trumps aerobic exercise with its effect on bone. Our bones start to degrade as we age, losing mass and making us more prone to fractures. Strength training places stress on the bones, triggering the activity of osteoblasts and inhibiting osteoclasts, helping us to maintain and even build denser bones… building muscle can also boost your brain… people with a better grip strength score higher on tests of memory and reaction time, as well as on assessments of verbal and spatial abilities… grip strength can be used as a marker of cognitive decline.

Strength training seems to trigger the release of several brain chemicals, including one called BDNF, that support the health of neurons…adults should perform strength exercises on all major muscle groups – legs, hips, back, abdomen, chest, shoulders and arms – at least twice a week. If you exercise a particular group of muscles until it’s tired, it doesn’t really matter how heavy the weight is or how many times you lift it. The benefits… are broadly the same whether you lift a light weight 20 times, or a heavy weight 5 times. Both aerobic and strength exercises seem to boost our health in slightly different ways, and most studies point to a bit of both being better than either alone.

Vitamin D3 supplementation appears to have an effect on muscle strength...ballet dancers received D3 supplements over winter, resulting in a 19% increase in quadriceps strength and fewer injuries compared with dancers who took a placebo.

Vibration machines, plus smaller devices that localize vibrations over particular muscles, can help you get stronger probably due to a vibration-induced rise in growth hormone and other biochemicals that boost muscle performance, as well as increased muscle energy consumption.

You can build muscle just by using your imagination…2 groups with a hand immobilized for 4 weeks, both lost muscle strength, but the group who had performed imaginary exercises lost 50% less than the control group. The results suggest that mental workouts strengthen pathways in the brain that control muscle movements, which later translates into greater command over the target muscles, increasing their strength.

New Scientist (18 April 2020)