New Scientist 18APRIL2020 pp34 “Discover Your Inner Strength”. “There’s an underrated aspect of fitness that boosts health and brainpower and extends your lifespan-no steps needed Helen Thomson lifts the lid”
Strength training is less trumpeted than aerobic exercise but benefits are many including a lower risk of type 2 diabetes, cardiovascular disease, cancer and improved brainpower. Just training your major muscle groups, until each group is tired, twice a week or one hour will produce gains.
As it is, our musculature peaks by age 30 and slowly declines thereafter until older age when the fall-off is even more dramatic. Experts claim, as we age, our muscles are more efficient but less able to carry weight including our own weight presumably. In metabolic terms, we use protein less efficiently and are less able to repair damaged muscle. “The weaker your muscles [sarcopenia] , the greater your risk of dying prematurely. For every five kg loss in grip strength [a crude estimate of muscle power] the risk of death…goes up considerably.”
What are the causes of sarcopenia or age-related loss of muscle mass?
Experts cite a decline in Testosterone and other hormones as a principle cause of sarcopenia. Surprisingly, changes in parts of our brain that control movement also contribute to muscle atrophy.
Why do we benefit from strength-training?
Strength training (ST) consumes calories while exercising and for several days after. The "after effect" represents energy consumed recovering from ST. During ST muscle fibers are in a small way damaged. Repairing or remodeling these fibers burns calories. A lesser known benefit of having more muscle, especially as we age, is the reserve muscle tissue provides against the catabolic impact of major illness. Sickness draws on all our energy resources, including muscle, to enable a successful recovery.
There's a muscle brain connection as well. With ST, muscles stimulate the release of Brain Derived Neurotropic Factor (BDNF) which improves neural connectivity and brain function. ST is well known to help maintain our skeletal bone and prevent age-related loss of bone (osteopenia). Force generated during ST induces healthy remodeling and consequent strengthening of our bone. With better brain function-more muscle-and-bone mass you will experience mproved movement, fewer “wobbles”/falls and an improved sense of wellbeing.
What are other underlying physiologic mechanisms for these improvements?
Muscle consumes glucose and having more muscle means better glucose control, insulin sensitivity, lower cholesterol, lower blood pressure and an increase basal metabolic rate. These improvement equate to lower risk of type 2 diabetes, obesity, inflammation, cardiovascular disease and cancer
What exercise regimen is recommended?
First, don’t wait for old age. Start early a balance regimen of ST and aerobic training. You don’t need to work like a body building might. Instead, exercise your major muscle groups-legs, hips, back, abdomen, chest, shoulders and arms preferably twice a week for as little as 30 minutes. The key is to “tire” each muscle group. For non-athletes five repetitions with a heavy weight is equivalent to twenty repetitions with a lessor weight. Finally, you can do this at home, online or at the gym, alone or with others.