BackGive power to your muscles
Stronger muscles are more metabolically active, strengthen your bones and protect your joints
PremiumOTHERS :
It’s long been known that strong muscles are critical for living healthy. Strong muscles help keep balance and prevent you from injuring yourself. They help with voluntary movements like walking and involuntary movements like the blood-pumping action of the heart.
The human body has more than 650 different muscles that account for half the body weight. While all muscles play a role in the healthy functioning of the body, the skeletal muscles that we have control over are the ones that help with voluntary movement. Some of these muscles sheath our skeleton, abdomen, chest, biceps, hamstrings and calves.
A March study by professors Preethi Srikanthan and Arun Karlamangla from the David Geffen School of Medicine, University of California, Los Angeles, US, illuminates just how important it is to strengthen and increase the mass of our muscles to enhance longevity. The study, published in the American Journal Of Medicine, is the culmination of Prof. Srikanthan’s previous research into the role that muscles play in metabolic disorders like diabetes.
She says in a phone interview: “There has been an almost obsessive focus in the research community on using weight and body mass index (BMI—a number derived by dividing the weight in kilograms by squared height in metres) of a person as surrogate marker in many studies on health risks. But BMI is a poor marker of body composition and its associated risks. And our research suggests that muscle mass is a much better marker for assessing health risks."
A significant study published in April in The American Journal Of Clinical Nutrition, led by Caryl Nowson of Australia’s Deakin University, showed just how poor a marker BMI is for ill-health and its effects. The study examined how BMI levels correlated with the risk of death in people aged 65 and above. The study was a meta analysis that collated results from studies done over a decade with at least 190,000 people, and the results were surprising. As the BMI increased, or as people became heavier, their risk of dying by all causes decreased. If the BMI mattered for predicting death, you’d expect the exact opposite. “From examining the results of this study it was clear to us that there was an inherent flaw in using BMI as a predictor of health risks," says Prof. Srikanthan.
So Prof. Srikanthan and her colleagues decided to see if the amount of muscle a person has is a better marker. Muscle is by nature metabolically active and plays a crucial role in chewing up glucose in the bloodstream. About 85% of the glucose we get from our food is metabolized by muscle, and muscle doesn’t need insulin to absorb the glucose. Prof. Srikanthan says that her colleagues and she felt that if muscle plays such an important role in maintaining blood glucose levels, it was logical to think that it could play a role in diabetes prevention as well. “We found that the amount of muscle mass negatively correlated with the level of insulin resistance, a diabetes risk factor," she says. In other words, they found that the greater a person’s muscle mass, the less likely they were to get diabetes, all other factors considered.
The next step then was to see the relationship between muscle mass and the risk of death by all causes in older people.
For their March study, professors Srikanthan and Karlamangla analysed data collected by the US’ National Health and Nutrition Examination Survey III, from 1988-94. They focused on a group of 3,659 individuals that included men who were 55 or older and women who were 65 or older. They figured out how many of those people had died from natural causes, based on a follow-up survey done in 2004. When they analysed the data, the team found that the mortality rate correlated inversely with muscle mass. Statistically, in both men and women, significantly fewer people in the group with the highest amount of muscle per squared inch of height died compared to people with the least amount of muscle.
“These study results are a potential game changer in the way that we counsel our obese patients and patients with diabetes or at risk of diabetes," says Prof. Srikanthan. “One of the problems with a focus on weight is that it is often very difficult for people to reduce their weight and the amount of fat they have on their bodies. This can be a source of great frustration for some of my obese patients. I am happy that I can now counsel them to concentrate on building muscle through exercise than worrying about the weighing scale," she says.
One doesn’t need to a build a body like a wrestler to reap the benefits of exercising the muscles—just moving the muscles and providing them with resistance is important. With instruction, resistance training like push-ups and squats can be done at home.
Resistance training increases muscle mass over time, depending on how intensely you train, how much protein you eat, and your genetic make-up. Some people are better at putting on muscle for the same amount of effort and protein, while others find it hard.
The bottom line is that whether you increase muscle mass or not, you will become stronger with resistance training and stronger muscles are more metabolically active, strengthen your bones and protect your joints, says Prof. Srikanthan. So for the same amount of muscle mass, you are much better off having stronger muscles.
Apart from reducing the risk of diabetes, another clue to why muscle mass leads to a longer life can be found in a study published in March which shows that young adults with healthier skeletal muscles also have healthier cardiac muscles. The study conducted by L. Banks and colleagues from The Hospital for Sick Children (SickKids) in Canada, published in the journal Applied Nutrition Physiology And Metabolism, indicated that healthier cardiac muscles lead to a stronger heart, better circulation and lower blood pressure.
Sujata Kelkar Shetty, PhD, writes on public health issues and is a research scientist trained at the National Institutes of Health in Bethesda, US.
Unlock a world of Benefits! From insightful newsletters to real-time stock tracking, breaking news and a personalized newsfeed – it's all here, just a click away! Login Now!
