How Exercise Can Lower Your Risk of Heart Disease
People often ask, "If I start exercising, when I will see results?" The 'results' they are talking about are usually on the outside of the body - weight loss, inch loss, and improved muscle tone. Numerous surveys have shown that appearance is the number one reason why people begin an exercise program.
There is nothing wrong if vanity is your main motivation to work out. Exercise can certainly improve the way your body looks but looking good is just scratching surface of what exercise can really do for you. The real benefits of exercise happen on the inside.
Health doesn't have anything to do with appearance. Being fit and healthy does not mean having the "perfect" body or losing substantial amounts of weight. The benefits I am talking about have to do with internal changes like improved cholesterol and triglyceride levels, blood pressure, bone density, digestion, and a reduction in stress and anxiety levels. These benefits can occur even if you don't lose weight.
In today's column, I will concentrate on how exercise, specifically aerobic exercise, can help to lower your risk of heart disease. Of course, exercise is only part of an over-all program to keep your heart healthy. The other components are diet, stress reduction, and the appropriate medication when necessary.
The word "aerobics" has become synonymous with Jane Fonda who popularized aerobic dancing in the early Eighties. But it was actually Dr. Kenneth Cooper who first used the term in conjunction with exercise. Aerobic exercise is any exercise that uses the large muscles of the body (arms and legs) in a continuous rhythmic fashion for at least fifteen to twenty minutes. Examples are walking, jogging, running, dancing, cycling, etc. Sports like tennis, badminton, soccer, and basketball are usually a combination of aerobic and anaerobic (short spurts of activity) exercise but can be considered as part of the aerobic conditioning component of an exercise program.
To get heart disease prevention benefits, scientists have determined that you need a minimum of thirty minutes of moderate intensity exercise most days of the week. The "exercise" can also be physical activity that uses most of your muscles like gardening and house cleaning. Thirty minutes is a minimum and some scientists say sixty minutes is the goal to shoot for.
Strengthens the heart
Exercise makes the heart stronger and more efficient so it can pump more blood with each beat. This lowers the resting heart rate since the heart does not have to beat as fast anymore.
This may prolong your life because a long-term study involving 34,000 people indicates that a higher than normal resting heart rate is associated with an increased risk of cardiovascular disease and even some cancers.
Makes blood vessels more flexible.
Exercise also helps to make blood vessels more flexible and increases their diameter probably by increasing nitric oxide levels. Nitric oxide is a blood compound that keeps blood vessels clear and helps them to dilate. In one exercise study, nitric oxide levels rose by 28%. Nitric oxide also helps to prevent platelets and other inflammatory substances from sticking to the blood vessel walls.
Scientists are not sure exactly why exercise can lower blood pressure but the latest research shows that a single session of moderate intensity exercise can lower systolic blood pressure (the higher number in your blood pressure reading) by 18 to 20 mmHG and diastolic blood pressure (the lower reading) by 7 to 9 mmHg. These changes remain for 12 to 16 hours after the exercise.
According to endocrinologist Ralph La Forge, there is no pill that will give you the same effect but this doesn't mean you should stop taking hypertensive medication since very few people can exercise every twelve hours. In some cases, exercise and diet alone are enough to keep high blood pressure under control. In other cases, medication is necessary. Only your doctor can tell you for sure. Exercise has the greatest effect on lowering blood pressure after six months of regular workouts.
La Forge explained that there is strong evidence that low intensity exercise is also beneficial at lowering blood pressure and that exercising at high intensity levels does not appear to provide additional benefit to blood pressure reduction.
Improves cholesterol profile
To find out if exercise alone could improve cholesterol readings without weight loss, cardiologist William Kraus of Duke University adjusted the diets of obese subjects so they could maintain their weight while on a three month program of aerobic exercise. The subjects lowered their LDL or "bad" cholesterol from 122 to 104 and raised their HDL or "good" cholesterol from 32 to 37.
The rise in HDL may not seem that dramatic but it has been calculated that for every one-point increase in HDL, the risk of heart disease is lowered in women by 3% and in men by 2%.
Forty-five minutes of moderate to high intensity exercise will do the trick in helping to raise HDL cholesterol levels.
After a large meal high in saturated fat or high in refined carbohydrates, large amounts of triglycerides are released into the bloodstream. If these kinds of meals are part of the daily diet, the high triglyceride levels make the blood "stickier" and the arteries less flexible. High triglycerides also promote the formation of lesions in the artery walls where LDL cholesterol can accumulate and form a hard plaque. To make matters worse, high triglycerides also lower HDL or good cholesterol.
The good news is a single session of thirty to sixty minutes of moderate to high intensity exercise can lower triglyceride levels in the blood by 15 to 40% and the effects last about 36 to 48 hours. Scientists believe that exercise increases an enzyme that breaks down triglycerides so it can be processed by the liver. Of course, exercise should not be an excuse to eat all the saturated fat or refined carbohydrates you want because you will always be able to eat more than you can exercise.
Regular exercise has an anti-clotting effect similar to aspirin therapy. Research indicates that you don't have to do much exercise to achieve this health benefit; you just have to do it regularly. It could be something as simple as walking at a low intensity for fifteen minutes daily. The wonderful news is that this anti-clotting benefit occurs even if you don't lose weight.
However, La Forge warns that if you are on anti-coagulant medication, this doesn't mean you should throw out your pills and do only exercise. Check with your doctor because if your blood is unusually thick, you could be at risk for a heart attack or stroke if you missed even one session of exercise.
Reduces inflammation-related protein
People who have high levels of C-reactive protein (CRP) have a higher risk of cardiovascular disease. CRP is a protein that is an indicator of inflammation in the body. Recent studies have found that inflammation in the blood vessels is twice as likely as high cholesterol to lead to heart attack. This means that you could have normal cholesterol but still be at risk for heart disease if you have high CRP. Exercise helps to lower CRP levels (so do diet, cholesterol-lowering drugs, and aspirin). A 2002 Cooper Institute study found that the fitter the person, the lower the level of CRP.
Reduces visceral fat
Visceral fat is fat that is located deep inside the abdominal cavity surrounding the internal organs. It is not the same as subcutaneous fat or the fat that is directly under the skin, which is locally known as "bilbil". Subcutaneous fat is soft and can easily be felt when you pinch the skin. Visceral fat is located so deep within that even relatively slim people can have an excess and not know it. The only way to find out how much visceral fat you have is with a CAT scan or MRI.
Visceral fat can increase the risk of heart disease, insulin resistance, type-2 diabetes, and strokes in middle age. One possible reason could be that unlike subcutaneous fat cells, visceral fat can release fatty acids even when the body does not need them for energy so the fatty acids are less likely to be burned and remain in the blood. Another possible reason is that visceral fat cells release inflammatory molecules that damage blood vessels.
Whatever the reason, exercise can reduce visceral fat even if you don't lose much weight. In a study of overweight postmenopausal women who exercised regularly (35 to 45 minutes of brisk walking five days a week) for one year, the subjects only lost three pounds (because they were told not to change their diet) but they lost 3.4 to 6.9 percent of their visceral fat. Lead researcher Anne McTiernan said that visceral fat seems to be the first kind of fat that is lost through exercise and may explain why some people who begin an exercise program observe that their pants fit better but they haven't lost any weight.
Interestingly, sumo wrestlers have a lower incidence of type-2 diabetes compared to sedentary obese people. This is because their size is mainly due to subcutaneous fat. They don't have much visceral fat since they do several hours of exercise a day.
Lowers your risk of sudden heart attack
Regular exercise lowers your risk of sudden cardiac death in situations when you have to exert a large amount of physical force like lifting heavy luggage or having to run after a train or bus. A 1998 study presented at a meeting of the American Heart Association found that there was an "inverse relationship" between the risk of dying of exertion-related heart attack and the frequency of regular workout sessions. The men who exercised the most (five times a week) had the least risk while the men who didn't exercise at all had the greatest risk (followed by the men who exercised only once a week). No wonder that the actor James Cagney has been quoted as saying that he tried to dance at least once a day because he didn't want to "take his heart by surprise".