The skinny on exercise

The skinny on exercise

A McMaster University researcher shows that even a little exercise can produce results, no matter what shape you're in
January 1, 2008
Visions of sugar plums may be fine during the holidays, but for many of us, the New Year usually brings dreams of tighter butts and six-pack abs. All too often though, these dreams disappear faster than Valentine’s Day chocolates.

Our ambitions need not end so soon, according to Stuart Phillips. As an investigator with McMaster University’s Exercise Metabolism Research Group, Phillips marvels at how much we benefit from even the most modest levels of physical activity, and how readily anyone can maintain lifelong fitness.

“We all retain the ability for our muscles to respond to exercise,” he says, noting that this ability transcends the effects of aging or injury. “It’s not something that takes weeks, months, or years to see a change—it happens within days.”

Phillips has assembled remarkable evidence for this conclusion in his laboratory—a facility he and his colleagues have spent the past eight years outfitting. The resulting combination of technology and expertise lets researchers investigate exercise dynamics in unprecedented physiological detail.

In particular, Phillips has studied the effect of exercise on individuals with crippling spinal cord injuries. Participants were suspended over a treadmill, enabling them to work out even with their paralyzed limbs. Thanks to equipment like powerful mass spectrometers, researchers were able to assess factors such as bone formation, changes in blood lipids, and glucose tolerance.

These measurements revealed that the participants had significantly increased their lean body mass. The higher your lean body mass, the more efficiently you can burn calories. Despite their paralysis, the research subjects also increased the size of their leg muscles, which responded positively to the activity.

Equally striking insights emerged from another experiment, in which young men who didn’t exercise regularly followed a comprehensive weight-training regime, five days a week for three months. Participants saw a 50-percent increase in the amount of weight they could lift and an increase in their lean body mass.

Nor is age a barrier to progress. Another lab member, Maureen MacDonald, uses Doppler ultrasound detectors to take stock of how key blood vessels perform during a workout. She looked at a group of men in their sixties, asking them to conduct simple hand-grip exercises for a few minutes a day.

“We showed that with eight weeks of this training, their resting blood pressure dramatically decreased,” she says, noting the same effect occurs even among individuals who take medication to control high blood pressure.

These findings mean good news for all of us—they demonstrate how quickly we can see results, regardless of our age and previous physical condition. In addition, Phillips says results actually come during periods of rest and recovery as our bodies rebuild and adapt to the work they have already done.

His latest research has also revealed that one of the most helpful parts of our diet could also be one of the most familiar—a plain old glass of milk. Using test subjects who consumed different beverages after athletic workouts, Phillips compared the effect of milk with that of popular soy-based or carbohydrate-loaded products.

The outcome was extraordinary: over 12 weeks, the milk drinkers, on average, lost nearly twice as much fat as those drinking carbohydrate beverages, and those drinking soy lost no fat at all. At the same time, the milk drinkers gained significantly more muscle mass than the others.

Phillips is still considering the metabolic processes that make milk the ideal post-workout drink and plans to further research milk’s key components, including the calcium, vitamins, and proteins found in whey and casein. But he is pleased to have discovered that one of our most venerable foodstuffs can hold its own against heavily marketed synthetic products. “Sometimes you come back to basic, simple ideas, and lo and behold, there’s something there,” he says. “There’s nothing revolutionary in exercise—nothing. And there’s nothing revolutionary in diet.”



As Stuart Phillips explains, his well-equipped lab is the first to attempt to measure the subtle metabolic factors that reveal how diet and exercise affect our bodies. In this way, he and his colleagues at McMaster University are achieving entirely new levels of understanding about how we can best stay active and healthy.

Phillips maintains that exercising just a few times a week can produce physical results. And the activity doesn’t have to be especially gruelling as he found out not through research, but through his own experience. Phillips recalls challenging himself to the point of exhaustion in his younger days. He now gets the same results with a combination of running and weight training that is nowhere near as rigorous. “The dose of exercise that you need is relatively small,” he says. “I focus on quality, rather than quantity.”

Fellow researcher Maureen MacDonald recommends fitness choices that dovetail with your way of life. “The bigger the change, the more dramatic it is, the less likely it is to become a complete lifestyle change for you,” she says, adding that people are more likely to adopt change for the long term if it’s closer to their personalities and existing lifestyles.

So for New Year’s resolutions, they both advise eating foods and pursuing activities you like, rather than adopting burdensome new routines that you will give up on at the first opportunity.

And their cutting-edge research reinforces the perspective that preventing health problems is easier and less expensive than the massive investments we often make to treat diseases after the fact. That is especially true for chronic ailments such as diabetes or cardiovascular problems, which can often be staved off or minimized with physical activity.

In fact, what they have found flies in the face of the harsh “no pain, no gain” exercise regimen. Exhausting hours spent working out are not only unnecessary, but undesirable, since the toughest part of any exercise program is sticking to it.

MacDonald sums it up this way: “If you do a little bit and do it forever, that’s more beneficial than deciding for one weekend you’re going to run 10K, then getting hurt and thinking, ‘That was horrible, I’m never doing it again.’”


The work of Stuart Phillips and his colleagues has attracted the food industry’s attention, from small university spin-off firms to multinational giants like General Mills, both of which have long-standing interests in the health benefits of various products. For example, the Canadian Institutes of Health Research (CIHR) and the U.S. National Dairy Council sponsored the research into the benefits of drinking milk.

The Exercise Metabolism Research Group’s laboratory itself has been set up to promote an unprecedented degree of interdisciplinary partnership. Phillips’ own work draws on contributions from faculty and graduate students in fields ranging from biochemistry and veterinary science to biomedical engineering. “The discipline of kinesiology and human kinetics is really beginning to mature now,” says Phillips. With the help of the other faculties, Phillips and his lab group continue to reveal new physiological findings.

Learn More

Read more about milk and muscle building.

Calculate your lean body mass.

Find out what kind of physical activity best suits your lifestyle and goals.

Get healthy living guides for all ages or explore the latest research from the Canadian Society for Exercise Physiology.