Like getting enough sleep during stressful periods, getting enough exercise is another one of those no-brainers—but few of us follow through on what we know we should be doing. Ideally we've all experienced that feeling of postexercise relaxation that comes from elevated endorphins and lowered stress hormones. Aside from the feel-good, mind-clearing effects of exercise, however, are the obvious general health benefits for the heart and muscles, and also the general antistress benefits that help to control appetite, regulate blood sugar, curb overeating, and improve sleep.
The high-stress/low-sleep/no-exercise cycle is a vicious one—but breaking it, even by doing a small amount of exercise several days a week, can yield dramatic benefits. The key point here is that you don't need to become an Ironman triathlete or start training for a marathon. A simple game of racquetball, a walk around the block, or a quick circuit of sit-ups and push-ups before you head out the door to work will go a long way toward getting those cortisol levels back into a healthy range. Even light physical activity in small, manageable doses will trigger a cascade of stress-busting benefits, from lowering blood pressure to improving mood.
Exercise and Diet as a Fountain of Youth
As we age, our metabolic rate drops, and most of us begin to pack on the pounds. If, in response to stress, we add fat in our abdominal area, our body shape changes from one resembling an hourglass to one more resembling a shot glass—and repeated diets only compound the problem.
Recall from Chapter 6 that most of us will experience a drop in metabolism of about 0.5 percent per year after the age of twenty. This phenomenon is largely due to a loss of about five to ten pounds of muscle tissue every decade—and that often translates into your fifty-year-old body carrying around thirty extra pounds of fat compared to when you were twenty! And this result specifically comes from a slight decline in your metabolic rate.
Many people attempt to eat "right" and follow a regular exercise program, and yet they still seem to gain weight. One of the reasons for this may be a change in their thermogenic potential (their ability to burn sufficient calories) because of some small (but important) dietary choices. For example, researchers at the University of Massachusetts have shown that certain dietary patterns, such as eating one or more midday snacks, are associated with a reduced risk of obesity (39 percent reduction in the case of healthy snacking), while other dietary habits, such as skipping breakfast, can increase obesity risk (450 percent increase in obesity risk from skipping breakfast). The dramatic difference here is largely due to a change in metabolic rate (snacking increases it, while skipping breakfast reduces it)—so dietary patterns that encourage a greater expenditure of calories are also those that tend to result in a lower body weight over time. In the case of breakfast, even our grandmothers told us that it is the "most important meal of the day," and when it comes to dieting you should consider breakfast a "free" meal! This is because eating breakfast increases your metabolic rate by 100–200 calories—while skipping breakfast slows down your metabolism by about the same amount. This means that by skipping breakfast (as compared to eating it), the overall difference balances out at 200–400 calories of lost calorie burning (thus the whopping 450 percent increase in obesity risk noted by the University of Massachusetts researchers).
Before we continue with our discussion of ways to enhance thermogenesis, let's consider a few guidelines that everyone who's attempting to lose weight should be aware of:
Caution: Calorie restriction will reduce your overall metabolic rate.
Acute calorie restriction typically causes a sharp decline in body temperature and the number of calories that you'll burn in a given day. By spacing appropriate meals and snacks throughout the day, and eating them in the right proportions (see below), you'll balance calorie levels to counteract this drop in metabolic rate.
Caution: Dehydration will reduce your thermogenic potential.
Drink plenty of water! Water is an important catalyst for weight loss because proper hydration is essential for fat burning, maintenance of muscle mass, and boosting overall metabolism. If you're dehydrated, even to a slight degree, your cortisol levels will rise and your metabolic rate will drop. Your hydration needs vary based on environmental conditions and exercise levels, but the basic rule of thumb to drink eight glasses of water each day is a good one. This rule is based upon a chemical estimate of how much water is needed to metabolize 1,500–2,000 calories from a mixed diet.
Where Does Exercise Fit In?
Remember from earlier sections that the key benefit of exercise for weight control is not that it burns a significant number of calories. Exercise certainly burns some calories, but far fewer than you may think. Instead, the primary value of exercise as part of a weight-control regimen lies in its profound effects on modulating levels of cortisol, testosterone, growth hormone, serotonin, and metabolic rate (with cortisol and serotonin control being responsible for many of the "feel good" effects of a workout).
The metabolic benefits of exercise are far-reaching, but from a weight-control perspective, a regular exercise program "teaches" our muscles to transport glucose more efficiently and to respond to cortisol more effectively. Exercise also improves our body's sensitivity to both insulin and cortisol, so we are able to get by with much lower levels of both of these powerful metabolic hormones and therefore avoid many of the health problems (such as weight gain) that are associated with chronically elevated levels.
An interesting side effect of optimizing your cortisol levels is an increase both in general caloric expenditure and in specific burning of fat (otherwise known as thermogenesis). This means that exercise on its own will influence, to a certain degree, each of the primary metabolic control points (MCPs) related to body-weight regulation—so get out there and do it.
Regular exercise is often promoted as a tool for preventing weight gain, and there is good evidence that people who are more active have a reduced risk of gaining weight. One study from the School of Public Health at Harvard University followed a large group of men over two years. At the beginning of the study, the most active men and those who watched fewer hours of television were less likely to be overweight, and after two years those who were most active and who watched fewer hours of television had gained less weight. Data from several national surveys (in both the United States and other countries) clearly show that people who maintain higher levels of physical activity are less likely to gain weight, or at least tend to gain less weight than their inactive counterparts.
Overall, then, whether exercise is a good tool for promoting weight loss is controversial. A number of recent scientific reviews of studies related to the effect of physical activity on weight loss concluded that adding exercise to a reduced-calorie diet only leads to modest additional weight loss (five to seven pounds over several months), but that regular exercise is strongly associated with maintenance of weight loss. Therefore, although exercise may be a less important tool for initial weight loss than calorie reduction, it is an important factor in the prevention of weight regain.
So, with most of the available evidence suggesting that physical activity plays a more important role in reducing age-related weight gain than it does in actually promoting weight loss, the obvious question is "Why isn't exercise more effective in promoting weight loss?" The answer is because it is simply very difficult to promote a substantial negative energy balance with exercise. Negative energy balance is the state where a person expends more energy (calories) than he or she consumes. To achieve a state of negative energy balance, one must consume fewer calories, expend more energy, or both. This seems like a pretty simple task, but the reality is that most adult Americans lack a good understanding of the energy value of different foods and exercises. Most people, including professional dieticians and physiologists, tend to underestimate the caloric value of food and overestimate the caloric value of exercise.
As you can see, it is easy to wipe out the calories burned off by exercise with a few bites of the wrong foods. With a caloric deficit of thirty-five hundred calories needed to lose one pound of fat, and a general goal to lose about one pound of pure fat per week (with no loss of muscle), this would require a caloric deficit of five hundred to one thousand calories each day. For most people, this would mean thirty to sixty minutes of intense exercise daily (which I'd love to see more people doing)—but since most American adults are extremely sedentary and since about 40 percent get no physical activity, this level of exercise would be difficult to adhere to for most people.
In one study from the University of Pennsylvania, women who had lost weight were followed over the subsequent twelve months. The threshold level of exercise needed to prevent weight regain corresponded to approximately eighty minutes of brisk walking per day. People enrolled in the National Weight Control Registry (NWCR) report a similar level of activity. (The NWCR is a large database of individuals who have maintained a minimum thirty-pound weight loss for at least one year.) In addition, recent data from researchers in Japan, Colorado, and Massachusetts suggest that accumulating twelve thousand to sixteen thousand steps per day (measured with pedometers) can really help one to prevent weight regain.
What Type of Exercise Should You Do?
Any type of exercise will work—as long as you do it! You simply need to get out there and move your body for at least three to six hours each week (thirty to sixty minutes per day, six days a week). If our goal were simply to burn as many calories as possible with exercise, then we'd be shooting for as much intensity as we could stand (exercising as hard as possible for as many minutes as we could).
If you're "too busy" to exercise (the most common excuse for not exercising), then you need to accept the fact that you will never lose those last twenty pounds, because without exercise your metabolic control of blood sugar and cortisol will never be optimized. Think about all the things in which you invest thirty to sixty minutes each day—television, newspapers, Internet surfing, etc.—and then ask yourself if investing that same amount of time in your health, in your body, and in yourself is worth it. I think we both know what the answer will be.
The exercise recommendations that we follow as part of the SENSE program attempt to maximize the most metabolic benefits within the shortest time commitment possible. This is because most people do not have a lot of time in their stressful lives to devote to exercise. For this reason, we utilize a three-times-weekly regimen of interval training (either running or walking). After a five- to ten-minute warm-up, the exercise alternates between high- and low-intensity levels as follows:
1 minute high intensity / 1 minute low intensity*
2 minutes high intensity / 2 minutes low intensity
3 minutes high intensity / 3 minutes low intensity
2 minutes high intensity / 2 minutes low intensity
1 minute high intensity / 1 minute low intensity
*Note that the intensity levels will be relative to your individual fitness level. A general guideline is that "high" intensity is not an "all-out effort" but rather a level that gets you breathing hard enough that you have difficulty carrying on a conversation with your exercise buddy. The "low" intensity intervals are easy enough to allow full recovery before your next hard interval—and also easy enough for you to talk without getting out of breath.
These eighteen minutes of interval training are followed by five to ten minutes of easy cool-down exercise—for a total duration of about thirty minutes. Compared to exercising at a "steady moderate" pace for this same thirty-minute period, the interval approach will burn more than double the number of calories (401 versus 189) and will result in better control of cortisol, testosterone, and growth hormone.
Many of our participants use walking as their primary form of exercise—and we encourage them to walk as fast as they can. The faster you walk, the more calories you burn. For example, a sixty-minute walk at three miles per hour (twenty minutes to cover each mile) burns about 240 calories (for a 150-pound person)—but speeding up to four miles per hour (fifteen minutes/mile) burns that many calories in about forty minutes. Walking at five miles per hour (which is a pretty fast twelve-minute mile) burns even more calories.
Follow this regimen for three to five days each week for a year, and you're burning off about ten pounds of pure fat. In our SENSE program, we encourage walking whenever possible. If you find it tough to maintain a fast walking pace, try doing short intervals of faster walking (maybe for a minute) followed by periods of slower walking. A popular workout for our participants (similar to the interval regimen above) is to walk for thirty minutes and to alternate one minute of fast walking with four minutes of moderate walking for the entire half hour (e.g., walk at a moderate pace for four minutes, then speed it up for one minute, then go back to your moderate pace for four minutes, and then go back up to the faster one for one minute—repeat).
See the Resources section for some excellent ideas to get you started on a regular stress-busting exercise program, and also review the list below to jump-start your thinking about ways to sneak small increments of exercise into your daily routine:
- At the mall or grocery store, add a few hundred yards of walking to your daily activity tally by parking in the middle or back of the lot instead of at the front.
- If you use public transportation, try riding your bike to the train station or bus stop, or park your car a few blocks away and walk the rest of the way to catch your ride.
- At the airport, be a rebel and take the stairs instead of the escalator (be sure to smile at the people on the escalator; you'll feel better just by doing that).
- Put a basket on the front of your bicycle. You might look like Mary Poppins, but now you can use the bike to run short errands to the store.
- Instead of having a neighborhood kid (or your own kids) do your exercise for you, get out there yourself to mow the lawn, sweep the steps, rake the leaves, and shovel the driveway.
Kristen was about as Type C (high cortisol) as anyone you could imagine. An honor student and champion distance runner during her college years, she now worked for a large hospital group as a director of nursing. Among her fellow nurses, Kristen was notorious for putting in long hours, taking paperwork home with her, and being on call at all hours of the day and night. Kristen considered herself to have a "high-energy" personality; she felt she thrived on the demands and stress that came with managing a large department.
For six years Kristen did just fine. Despite the high-stress work that followed her home, and despite having chronically elevated cortisol levels from that high stress—as well as from inadequate sleep and a poor diet—she seemed to be able to handle her stress load perfectly well. She was promoted several times at work, maintained her athletic figure and healthy body weight from college, and enjoyed a loving relationship with her former college boyfriend, and now husband, Jim.
Everything in Kristen's life was going according to plan—everything was perfect—and then all hell broke loose. The straw that broke the camel's back, so to speak, was the birth of Kristen's first child. Having a baby was something that both Kristen and Jim had been planning and looking forward to since before they were married, so they were both well prepared mentally for the arrival of their new bundle of joy. The problem, however, was that Kristen was trying to maintain her prebaby work schedule along with her new motherhood duties. Jim helped with the baby as much as possible, but his travel schedule as a district sales manager meant that he was out of town on business at least a few times each month, leaving Kristen to juggle work, day care, and nightly feedings for the baby. The combination of this being Kristen's first baby and her self-described tendency to be a "worrier" (about the baby, about her work, and about Jim when he was traveling) caused her to experience some of the highest stress levels—and highest cortisol levels—of her entire life. Couple these high stress levels with changes in her exercise program (rarely having the time) and in her diet (grabbing whatever junk food happened to be most convenient), and Kristen was on a crash course with cortisol.
Kristen’s elevated cortisol levels manifested themselves primarily in the form of an inability to lose the "baby weight" she had gained during pregnancy, a growing struggle to stay focused on the complex tasks required of her at work, and great difficulty in falling asleep at night and then in getting back to sleep after waking with the baby.
Kristen started following the SENSE program with the primary goal of using it as a structure to control her diet and lose the excess pregnancy weight. As a former competitive athlete, she knew the importance of regular exercise for general health, but with the demands placed on her at home and work, there simply were not enough hours in the day to schedule what Kristen considered to be a worthwhile amount of exercise. Her idea of worthwhile exercise was to drive fifteen minutes to the gym, participate in a forty-five-minute high-intensity aerobic-dance class, stretch, shower, and then drive home. This ideal exercise program would have taken almost two hours out of her day. No wonder she had no time for exercise.
The first step, when it came to incorporating some exercise (the first E in SENSE) into her daily routine, was to get her to think about exercise in a different way. Over the next several weeks, Kristen began to sprinkle small amounts of exercise throughout the day—taking the stairs whenever possible at work, pushing her baby in his stroller when the weather was nice, and parking her car at the back of the parking lot and walking the hundred yards to the front door of the grocery store. Kristen even took her sprinkling of exercise to the extreme by performing a set of deep knee bends while her baby was swallowing between each spoonful of baby food. Suffice it to say, Kristen embraced the concept of sneaking exercise into her day—and even though she would have preferred to be out running five miles or sweating at the gym, she accepted the fact that this was as good as it was going to get at this point in her life.
In terms of nutrition, Kristen’s greatest challenge was her constant snacking. Because she had difficulty planning the balanced meals she knew she should be eating, she was in a constant state of "grab and go"—and there didn’t appear to be any solution for changing that pattern. Instead, the most practical strategy for Kristen was to make each of the "grab and go" meals a more balanced blend of carbohydrates, proteins, fats, fiber, vitamins, and minerals. A logical way to do this was to incorporate meal replacements; that is, shakes and energy bars. For Kristen, grabbing a shake for breakfast or a bar for the drive to work offered just the right amount of structure. Doing so enabled her to get the fuel she needed to keep her metabolism humming, it helped her control her blood sugar and banished her late-afternoon cravings for sweets, and it gave her the willpower she needed to resist sneaking to the fridge for a late-night snack after putting the baby to bed.
Perhaps the aspect of SENSE that made the most significant impact on Kristen’s stress and cortisol levels was her incorporation of dietary supplements into her daily schedule. During her pregnancy she had already become accustomed to taking a daily multivitamin, so it was easy for her to continue this positive habit. In addition to her multi, Kristen also added a twice-daily theanine supplement (50 mg with breakfast and 100 mg before bed) and a midday dose of Cordyceps sinensis and American ginseng. The combination of cordyceps and ginseng provided the dual benefits of blood-sugar regulation (and added appetite control) plus an energy boost, without the side effects of stimulants. Theanine helped Kristen to stay calm and focused during the day (without drowsiness), while also helping her to sleep soundly during the night and fall back to sleep after getting up with the baby. The higher quality of sleep combined with heightened energy and mental focus during the day helped Kristen to regain her sense of relaxation and emotional balance.
In addition to these mental aspects of cortisol control, the exercise, nutrition, and supplements in Kristen’s personalized SENSE plan helped her modulate her blood-sugar levels, control her appetite, accelerate her fat metabolism, and lose the weight she had gained during pregnancy. In short, SENSE provided a simple and easy-to-follow framework for Kristen to use in getting her life back under control—and back to the place where she felt it should be.