Why Exercise Is The Best Medicine

You’re likely aware that exercise is good for you, and you’ve probably done a workout or two in your time. But despite your interest and practice, I’ll bet there have been a few times when you’ve struggled to get to the gym or out for that run. I’ll also bet that your mind has begged you to slow down or take extra rest during a tough workout.

To help you get to the gym, out for a run or on your bike, and to do your absolute best while there, I thought I’d share the physiological science behind the power of exercise. Over the years of working with athletes at all levels, I’ve found that when people understand what their training does to their bodies, they perform better in the practice session. By showing you the power of a few little molecules, I believe I can help you train better to be healthier and achieve your dreams – whatever those might be!

exercise medicine

Exercise as Medicine

Exercise is the most potent medicine known to humankind. Cardiovascular exercise and strength training can help to prevent and treat almost every chronic disease that afflicts us. Movement can help to improve the function of your heart and lungs, stimulate the creation of new red blood cells that carry oxygen throughout your body, promote the growth of new muscle tissue, and make your bones stronger. It even helps to prevent infections by enhancing your immune system.

Exercise has been shown to prevent or lessen the impact of certain cancers, cardiovascular disease, type 2 diabetes, metabolic syndrome, muscle atrophy from aging, osteoporosis, depression, Alzheimer’s disease, and a host of other illnesses. There are documented benefits for almost every organ in the body.

How It Works

How does exercise create all these powerful benefits? The answer is very complicated, but a few molecules can provide some clues. Those molecules are called mTOR, PGC-1 and BDNF.

The mTOR molecule is activated inside your muscles when you exercise. When you do strength training, mTOR works to stimulate the growth of new muscle tissue. So the next time you’re lifting weights, don’t think about the muscle burn. Think about all the microscopic mTOR molecules you just activated that are circulating around and building your muscle fibers so that they become stronger.

Endurance exercise works a little differently. When you go for a run, ride, swim, row or other cardio-type exercise, a little molecule called PGC-1 is activated inside your muscles. PCG-1 then works to assemble proteins to make new mitochondria. Mitochondria are the energy factories inside almost every cell in your body. That’s why aerobic activities help to build your endurance: they stimulate your body to build new mitochondria.

The final molecule I want to mention is brain-derived neuropeptide factor (BDNF). When we exercise, there are powerful positive benefits for most organs in the body, especially the brain. This surprises people who think that the mind and body are separate. Some amazing new discoveries have been made recently using magnetic resonance imaging, which has shown that people with high levels of aerobic fitness have larger hippocampus volumes (a structure inside the brain). An increase in hippocampal volume is related to better memory. The benefits of exercise in the brain are thought to be because of BDNF, which increases with exercise. It also appears that when mTOR is activated in skeletal muscle, levels of BDNF increase in the brain.

The Takeaway

All of these relationships are being explored by scientists and it’s an area that we don’t understand very well yet. But what you can take away is that endurance exercise and strength training not only build up your body, they build up your brain as well.

I hope this helps you appreciate how wonderful your workouts are for you. This is a hot area for research, so stay tuned for more amazing discoveries. In the meantime, please use exercise as medicine to improve your performance and health.


dr greg wells

Dr. Greg Wells is an assistant professor in kinesiology at the University of Toronto and an associate scientist in physiology and experimental medicine at the Hospital for Sick Children. You can follow him on Twitter at @drgregwells or visit his website at drgregwells.com.

Image by SaRo Photography