Are you one of the millions who finds it hard to get up and exercise regularly? You’re definitely not alone, and new research shows that those who tend to stay active may have been born with different genes. For years, diet and exercise have been prescribed as the best way to stay in shape and maintain one’s health, but a lack of motivation to exercise could be the result of an unlucky drawing in the genetic lottery.
The research was conducted by Professor Gregory Steinberg and his team at McMaster University in Canada. The team was studying health mice that had been specifically bred for the study; some of the mice had two genes removed which are essential in exercise. The two genes are responsible for controlling a protein called AMP-activated protein kinase, or AMPK. The enzyme is “switched on” when an organism such as a mouse or human exercises.
“Mice love to run,” said Professor Steinberg, who is the associate professor of medicine at the Michael G. DeGroote School of Medicine as well as the Canada Research Chair in Metabolism and Obesity. Steinberg described how the removal of the two exercise genes caused an immediate change in the physical capabilities of the mice: “While the normal mice could run for miles, those without the genes in their muscle could only run the same distance as down the hall and back. It was remarkable. The mice looked identical to their brothers or sisters but within seconds we knew which ones had the genes and which one didn’t.”
Those mice lacking the genes that controlled AMPK had decreased mitochondria — the powerhouses that provide energy to cells — and a subsequent dysfunction in the ability of the muscle cells to utilize glucose to generate energy.
“When you exercise you get more mitochondria growing in your muscle. If you don’t exercise, the number of mitochondria goes down,” says Steinberg. “By removing these genes we identified the key regulator of the mitochondria is the enzyme AMPK.”
While there are many research teams around the world studying AMPK and its implications, Professor Steinberg’s team is the first to outline the importance of its role in exercise. Their findings are published in the Proceedings of the National Academy of Sciences.
According to Professor Steinberg, the team’s findings have important implications for individuals who find it difficult to exercise, including disabled people, asthmatics and the obese. When regular physical exercise is neglected over a long-term period, additional complications such as diabetes and heart disease can occur.
“As we remove activity from our lives due to emerging technology, the base level of fitness in the population is going down and that is reducing the mitochondria in people’s muscles. This in turn makes it so much harder for people to start exercising,” says Professor Steinberg. With the lack of exercise required in our modern lives, and the subsequent reduction of mitochondria in our cells, our risk of developing serious complications has risen as industrial technology has taken over and reduced the need for frequent physical exertion.
Steinberg says that he rides his bicycle or runs to work to stay in shape: “It is the only way that I can manage to make sure I stay fit.” Regular exercise has a variety of health benefits, from reducing weight and fighting illnesses and disease to improving mood, increasing energy levels and encouraging healthy sleep patterns.
