Let’s talk exercise. It’s time we did. For there is no area of health more misunderstood than exercise—its benefits, its drawbacks—what it will and won’t do. The medical profession continues to feed us the party line: It begins with “every calorie is unique…it doesn’t matter where it comes from…if you want to lose weight, all you have to do is burn calories through exercise.” This is absolutely untrue—in fact, exercise can sometimes be seriously detrimental to those who are considerably overweight. Nevertheless doctors, and the media, keep telling us that it works. And, like sheep, we just keep trusting them.
What happens? Well, when people find that it doesn’t work, they get depressed. They feel like failures. They stop exercising and start eating more because they’re disheartened. They figure that exercising is no use. This makes metabolic syndrome—Syndrome X—worse than ever. For metabolic syndrome and chronic high blood sugar levels are what makes us fat, and keep us that way. That’s the bad news. The good news about exercise is this: Whether you’re overweight or not, exercise done regularly, for as little as 15 minutes a day, is absolutely the single most important thing that you can do to improve your overall health.
TRUTH ABOUT CALORIES
Because of the media, the medical profession, and purveyors of diet supplements, just about everybody still believes that energy expenditure—and therefore calorie burning—comes with exercise. However the truth is that during physical activity, only the smallest amount of energy expenditure takes place. Exercise accounts for no more than 5% of the calories you burn, unless you happen to be a top athlete. I think this will surprise you too: The greatest percent of calorie burning takes place, not while you’re moving, but while you are sleeping. This phenomenon is called “resting energy expenditure”. Depending on how heavy or light you are, resting energy can account for as much as 60% of your total daily energy expenditure. Another way your body expends energy by burning calories is thanks to the “thermic effect of food”. This refers to the energy it takes your body to digest, absorb and metabolize the foods you have eaten This thermic effect accounts for about 10% of the energy that you burn during the day. So you can see by contrast just how low, in fact virtually insignificant, is the amount of calories burnt during most physical activities.
The idea most people have—that if they exercise they can lose weight—is also nothing more than a pipe dream. So what does exercise actually do for you? The answer is: some pretty wonderful things.
- Exercise enhances sensitivity to insulin. This helps your body make use of the fat that has accumulated in the liver and around other organs improving insulin sensitivity and lower ing insulin levels. It also improves both leptin signaling and leptin sensitivity in the cells., calming food cravings, improving muscle tone, and making you feel more vital.
- Exercise builds muscle. Most people, including most medical doctors, still wrongly equate BMI (Body Mass Index) with body fat. The truth is BMI does not measure the difference between muscle and fat, or between subcutaneous fat (the inessential fat) and visceral fat. Many studies looking at body composition before and after periods of exercise show that the percentage of fat goes down. But this is only because muscle has increased. As this takes place, a person’s metabolic facilities are also improved.
We are often told that we need to change our diet in order to prevent heart disease. Indeed this is quite true: However, the metabolic transformations that take place during regular moderate exercise are an even more powerful force than dieting for preventing disease—including heart disease. To take things further, exercise is actually a more effective force in preventing heart disease than losing weight! A study of almost 40,000 American men demonstrated quite clearly that physical activity was more important in preventing heart disease than being normal weight. These major gifts of exercise are more important than people realize, but they have nothing to do with controlling weight. Let’s look now at how exercise works, biochemically and physiologically.
NEW ENERGY FACTORIES
Regular exercise activates your sympathetic nervous system. This , in turn, tells your muscles to make new mitochondria. Mitochondria are the amazing little energy factories inside muscle cells that burn glucose or fatty acids, to produce vitality for your whole body. Regular exercise plays a big role not only in building new mitochondria, but in getting rid of the old, inefficient mitochondria. Old mitochondria do not function properly. As a result they produce free radicals to undermine your health and encourage rapid aging. Regular exercise clears away the old and helps your muscles make clean and efficient use of the energy stored within the new. This too improves insulin sensitivity, and enhances metabolic health all round.
Regular exercise lowers your stress levels. It’s true that blood cortisol levels go up temporarily when you start to exercise. This is a good thing, It keeps your blood sugar and blood pressure up while you are moving. They come back down quickly afterwards. In fact, one of the long term benefits of regular exercise is that it reduces blood pressure. This is thanks to exercise’s ability to lower stress levels all round. Regular exercise also encourages your body to release feel-good chemicals in the brain known as endorphins. This makes regularly moving the body one of the most effective treatments for depression, far better than drugs or psychotherapy. The way exercise increases endorphins always fascinated me. This was what made me become a regular runner. I was determined to experience what is known as the “runner’s high”. And I found it wonderful.
WHAT EXERCISE IS BEST
For a long time we’ve been told that the best kind of exercise is low-intensity, long interval, aerobic practices, now known as “cardio exercise”. We learned that cardio worked the heart in a beneficial way, and provided all sorts of cardiovascular benefits by pumping more blood to the heart, slowing heart rate, and increasing peripheral muscles. The one thing it was never able to do—although we were misled to believe that it did—was bring about weight loss. Recently, however, a number of studies have shown that high-intensity interval training, where you use an extreme activity for a very short period of time interspersed with a short recovery—as well as plain old weight training—brings equal improvements both in waist circumference and blood vessel flow. So the bottom line is this: It doesn’t matter what kind of exercise you choose. Just do it.
Whatever kind you decide to try, you need to do it regularly—at least five days a week. Why? Because the wonderful metabolic effects of exercise—which tell your mitochondria to divide and make new mitochondrial factories for vitality—slow and decline when you miss even a day of exercising. Miss two weeks, and your insulin sensitivity is likely to decline as well until it reaches the level it was before you started exercising. So whatever you decide to do, do it regularly. You need only do it for short periods, but do it every day.
A FINAL WORD
It is not only the overweight by the way who suffer from insulin resistance—metabolic syndrome. So do 40% of normal weight men and women, especially those who have fatty livers. Recent research shows that fitness not only helps mitigate the effects of overweight on visceral fat. In fact, it mitigates many other health complaints also provided you are consistent with doing it. This is also likely to increase your longevity. And...great news...if you are overweight, but not obese, exercising regularly can help you live significantly longer than that emaciated model on the cover of Harper’s Bazaar. Recent research shows that overweight people with BMIs between 25 and 30 tend to live longer than skinny people with BMIs of less than 19.
DO WHAT YOU LOVE
The most important thing for you to decide is what kind of exercise you want to do. It can be as simple as going for a walk each day for half an hour—not a power walk, just one where you feel the movements of, and a connection with, your body. It can be dance. It doesn’t have to be vigorous. It can be rebounding on a mini-trampoline. It can be moderate weight training, for 15-20 minutes a day. I personally like cycling on a wind-trainer. This is a device that your bicycle fits into. It allows you to regulate how hard you choose to pump while the wheels spin but the bicycle remains static. I use a wind trainer because I don’t like cycling on roads. The other exercise I do is on a Concept 2 rowing machine which I was given many years ago. I use it five days a week for 20 minutes at a time. I love doing it: It enables me to move my whole body, and brings me a rhythmic feeling of being completely connected to it. What exercise you do depends entirely on what you love. So begin to experiment. Let go of the idea that exercise is going to make you thin. It will not. What it will do for your health, your emotional and spiritual wellbeing, and to slow the aging process, is fantastic. It can also be a lot of fun. Discover the joys and great gifts that come with moving your body. The time is now.
P. Wen et al., "Minimum Amount of Physical Activity for Reduced Mortality and Extended Life Expectancy: A Prospective Cohort Study," Lancet 378 (2011)
S. Ludwig, "The Glycemic Index: Physiological Mechanisms Relating to Obesity, Diabetes, and Cardiovascular Disease," JAMA 287 (2002)
Stensvold et al., "Strength Training versus Aerobic Interval Training to Modify Risk Factors of Metabolic Syndrome," /. Appl. Physiol. 108 (2010)
P. Little et al, "Skeletal Muscle and Beyond: The Role of Exercise as a Mediator of Systemic Mitochondrial Biogenesis," Appl. Physiol. Nutr. Metab. 36 (2011)
K. J. Acheson et al., "Protein Choices Targeting Thermogenesis and Metabolism," Am. J. Clin. Nutr. 93 (2011)
Shaw et al., "Exercise for Overweight or Obesity," Cochrane Database Syst. Rev. CD003817 (2006)
M. J, Gibala et al, "Physiological Adaptations to Low-Volume, High-Intensity Interval Training in Health and Disease," /. Physiol. 590, no. 5 (2012)
A. McAuley et al., "Obesity Paradox and Cardiorespiratory Fitness in 12,417 M a l e Veterans Aged 40 to 70 Years," Mayo Clin. Proc. 85 (2010)
Bajpeyi et al., "Effect of Exercise Intensity and Volume on Persistence of Insulin Sensitivity During Training Cessation," /. Appl. Physiol. 106 (2009)