The Healing Power of Exercise

4
6–12
Leg extension
3
6–12
Leg curl
3
6–12
Because we did not emphasize the importance of not changing his diet to Dave, one of our study subjects, he proceeded to eat much more fat that he did prior to training. When we asked Dave why, he said, “Since exercise will lower my cholesterol, I should be able to eat more ice cream and other desserts, without having my cholesterol increase.” Although Dave’s cholesterol level did decrease, the benefits of exercise were not as dramatic as they could have been.
Do I Still Need to Exercise If I Change My Diet?
Don’t think that changing your diet is all you need. It is not. We base this on our own clinical experience plus volumes of research. In a 1998 study reported in the New England Journal of Medicine, researchers followed nearly 400 men and women who had levels of LDL cholesterol between 125 mg/dL and 210 mg/dL Exercise training was in the form of brisk walking or jogging 10 miles each week. Participants were divided into four groups:
Group 1. Diet without exercise
Group 2. No special diet, but regular exercise
Group 3. Diet plus regular exercise
Group 4. No special diet and no exercise
The diet was very low in cholesterol and saturated fat. Study subjects were observed for one year. What were the results?
All exercisers improved their fitness, whether they dieted or not.
Dieters who lowered fat intake from 30 percent to 22 percent of total calories lost about 7.5 pounds, whether they exercised or not.
Only dieters who exercised lowered their LDL cholesterol levels (by about 11 percent).
Adding exercise to a diet low in saturated fat doubles the diet’s cholesterol-lowering effect.
The authors of this study concluded that lowering fat intake from 30 percent to 22 percent of total calories lowers cholesterol only when you exercise.
However, it is important for us to remember that the typical American diet is so high in fat that when we eat 30 percent of our calories from fat, most of us will dramatically improve our cholesterol and triglyceride levels. Either a diet or exercise alone can improve your blood fat levels. But when exercise and diet are combined, they become a potent antidote for abnormal cholesterol levels.
How Much Exercise Do I Need?
Improving cholesterol and triglyceride levels usually requires a large dose of exercise. For instance, you can lower your blood pressure with 30 minutes of moderate walking, three times each week. However, more exercise is needed for cholesterol manipulation. If you are inactive and want to improve your cholesterol and triglyceride levels, you need to exercise the equivalent of 8 to 10 miles of jogging or brisk walking each week. The more miles you log, the higher your HDL cholesterol level can climb. Also, lowering the amount of fat in your diet will add to these cholesterol and triglyceride benefits. If you want to lower your LDL cholesterol by lifting weights, you need to work out for 45 to 60 minutes, three times each week. The successful programs are shown in Tables 6.5 and 6.6.
How Long Will It Take to See Reduced Cholesterol Levels?
Don’t despair if you fail to see improved cholesterol levels during the first few weeks of training. You will begin to feel better, and your endurance will improve even before you see enzyme and blood chemistry changes. After 12 weeks of aerobic exercise, about 50 percent of

cholesterol was lowered even more, and HDL cholesterol was raised. This was great news. Exercise changed all the major blood fat levels—and all in the right direction.
Cutting Cholesterol with Weight Lifting
By the early 1980s, it was becoming more clear that aerobic training improved cholesterol levels and burned up triglycerides, too. But what about pumping iron? Most scientists thought lifting weights was for those who wanted to look good, rather than be healthy, but they were wrong.
As we described earlier in this chapter, weight lifting, or any kind of resistance exercise using springs, bands, or air pressure, can change cholesterol levels. In several studies, including our own publication in the Journal of the American Medical Association, strength training lowered LDL cholesterol levels and improved the ratio of good (HDL) to total cholesterol levels. We found these benefits occured among both men and women after just 16 weeks of exercise. In our program, participants worked out three times each week, lifting weights for approximately 45 minutes to 1 hour. Our study participants used moderately heavy weights. If they could lift a weight 8 times (upper body) or 12 times (lower body), the amount of weight was increased by about 10 pounds (upper body) or 20 pounds (lower body). Altogether, our subjects used eight different exercises, with a minimum of three or four sets of three to eight repetitions per exercise (Table 6.5).
Why Diet If I Exercise?
Although this book is about exercise, we can’t emphasize enough the importance of your diet. We all splurge and eat foods that are loaded with fats, but this can’t be the rule. You can magnify the benefits of your workouts by making wise food choices. On the other hand, you can ruin all your hard work by poor food selections. For example, rewarding yourself for a workout by eating a typical cheeseburger will add more calories to your body than you would use on a five-mile run. In addition, you will be pummeling your body with high doses of saturated fat from the red meat and cheese.
TABLE 6.5 Weight-Lifting Exercises to Change Cholesterol

Sets
Reps
Upper Body Exercises

Bench press
4
3–8
Latissimus pull
3
3–8
Shoulder press
3
3–8
Arm curl
3
3–8
Rows
3
3–8
Lower Body Exercises

Leg press

If you are eating the typical American diet, which is not a healthy one, you can expect to reduce your cholesterol level by following any one of the diets found in Table 6.4, with the listing of each diet’s major nutrient amounts.
If your total cholesterol level is 240 mg/dL, you will lower it by about 11 mg/dL with the general recommended diet and 20 mg/dL with the higher-risk diet. If your LDL cholesterol is 160 mg/dL, the general recommended diet will drop your LDL level by about 7 mg/dL, while the high-risk diet will drop it by a little more than 12 mg/dL. If you lost weight, your cholesterol and LDL levels will drop even further. The Mediterranean diet is similar to the recommended diet in changing your LDL cholesterol level. However, it has an advantage of not reducing your HDL cholesterol, a problem that can occur when you reduce fat and increase carbohydrates. However, all diets work best when you are at your optimum weight (also see Chapter 7).
Fat is essential to our health. Fat contains vitamins A, D, E, and K. It is part of our cell membranes and is needed to form certain hormones.
Your Fat-Busting Enzymes
Certain types of enzymes control our body’s cholesterol and triglyceride levels. These enzymes can be changed by drugs, your body fat and muscle mass, and whether you exercise.
One enzyme, named lipoprotein lipase, also known as LPL, is located in the walls of our blood vessels and in our heart, fat stores, and muscles. This enzyme breaks down triglycerides. Low levels of LPL are associated with increased cardiovascular disease. So, higher LPL levels are good, and things that stimulate LPL action will help us avoid coronary heart disease.
Another enzyme, hepatic lipase (HL), breaks down HDL cholesterol, but in the process converts some of it to harmful LDL cholesterol. The higher our HL enzyme level, the lower our HDL cholesterol level, which increases the risk of developing heart disease.
A third important enzyme, with the very long name of lecithin cholesterol acyl transferase, is better known as LCAT. Although it sounds to us like a piece of heavy machinery that moves dirt (“Hey, get that LCAT over here to clear this section of land!”), it actually grabs onto cholesterol, cleaning it off of artery walls, in a way that is similar to the powerful sucking of a professional-quality vacuum cleaner.
Enzyme Changes and Exercise
Production of the enzymes that control our blood fat levels can be changed by exercise. LPL, the enzyme that breaks down triglycerides and increases HDL cholesterol levels, has been found in greater quantity among aerobic exercisers. Its effects are increased after just one exercise session. Also, losing body fat will increase the action of LPL.
Hepatic lipase (HL) is the enzyme that clears out our good HDL cholesterol and breaks it down. Endurance exercise tends to increase the amount of HDL cholesterol by reducing the activity of HL. One study found that HL action was lowered among middle-aged men after 15 weeks of exercise, although not all studies have found similar results. Likewise, the amount of LCAT, the enzyme that takes up cholesterol from the artery walls, can be increased by exercise. Not everyone will improve his or her enzyme function with exercise, likely due to individual differences. Similarly, not all drugs affect us in the same way, which is why we have so many different medications for the same medical problem. However, for many people, exercise can generate more enzyme activity and improve our blood fat levels.
Running Down Cholesterol and Triglycerides
In the mid 1970s, researchers at Stanford looked at the blood fat profiles of runners and of inactive men. They found that the amounts of protective HDL cholesterol were higher in the joggers, while triglyceride levels were significantly lower. Over the next few years, 66 studies concerned with the effect of exercise on cholesterol were published by researchers. When these programs were bundled together and analyzed, total cholesterol levels were lowered an average of 10 mg/dL, while triglycerides were reduced by an average of 16 mg/dL. When the researchers looked at the bad (LDL) and good (HDL) cholesterol, they found that LDL