Exercise & the Heart

Happening Issue 62 Jul, 2010

We are often advised by our doctors to do some form of physical exercise. Did you know that exercise has both risks and benefits? Screening is mandatory under guidelines that minimize risks and maximize benefits. The three important risk factors for exercise are age, presence of heart disease and the intensity of exercise. SCD (sudden cardiac death) under the age of thirty-five years is attributed to congenital heart disease, whereas CAD (coronary heart disease) is the more likely cause for those above the age of thirty-five. However, all research studies indicate that among the general population, risk of sudden cardiac death during rigorous exercise is very low and the benefits of exercise exceeds the risks and thus individuals should be encouraged to exercise prudently.

So, how exactly does exercise benefit us?

  1. Improves lipid profile (cholesterol parameters).
  2. Decreases blood pressure.
  3. Improves glucose (sugar) tolerance by increasing insulin sensitivity and lessening the risk of diabetes onset.
  4. Exercise is largely responsible for obesity reduction.
  5. Psychological benefits by reducing depression and anxiety.

Thus, habitual exercise eliminates the risk factors associated with coronary heart disease, whereas sedentary lifestyle is a major coronary risk factor.

How much should we exercise?
The old dictum of 30 minutes of daily exercise or five times a week is still frequently advised. AHA (American Heart Association) and WHO proclaim mortality and morbidity from heart attack is directly related to the lack of exercise. Remember, exercise need not be of high intensity to be beneficial, it’s the total amount of activity that is more important for the heart than high intensity exercise. High intensity exercise also induces more orthopedic injuries resulting in higher drop out rates.

Gender is another important factor in determining the amount of exercise required. However, more research is needed to define the exercise needs of women. Moreover, most studies on prevention of heart disease have focused on men because of the higher incidence of coronary heart disease in them. At present, women require approximately the same intensity, frequency and duration of exercise as men.

Occupation is another parameter that has a bearing on one’s exercise requirement. People involved in occupational activity requiring continual stair climbing or load   lifting require less exercise compared to individuals with leisurely occupations.

As stated earlier, exercise requirement is based on age, presence of heart disease and intensity of exercise. Mild exercise is achieved with golf, walking, playing musical instruments and billiards among others. Moderate exercise is achieved with calisthenics (without weights), swimming (breast stroke), and brisk walking among others. Vigorous exercise is achieved with badminton, tennis, climbing, cycling, aerobics, skiing, surfing, skipping, crawl-swimming, etc.

The important factor is sorting out different exercises according to the individual’s requirement. In other words, a person should not be playing squash after a bypass surgery because this sport has the highest rate of sudden cardiac death within sporting activities, simply because the oxygen demand by the heart is more than the supply. Group sports like badminton and tennis have added benefits over solo exercise like walking or jogging where the mind is totally on the shuttle or ball and one’s mind is not stressing over the day’s problems.
Diet factor is also very important:Never exercise on a full stomach. Eating increases the blood requirement of the intestines. During exercise, the blood circulation cannot meet the blood requirement of the muscles as it also has to supply the bowels, and due to the inadequate supply of blood, the muscles begin to cramp, besides causing nausea and fainting episodes. There has to be a two-hour gap at least between meals and exercise. Finally, there are minor points to be taken into account, like weather acclimatization – to take fluids during hot weather to maintain hydration. Appropriate clothing is another important aspect. Wear loose-fitting clothes made of porous material; use sweat shirts only for warmth. Do not use non-porous rubberized clothing. Last but not least, know your limitations and select an appropriate exercise. Remember to include cardiovascular/aerobic routine as a major component in your exercise program.
The bottom line is that an active, healthy lifestyle has lower heart attack and death rates compared to a more sedentary way of living. Life after the age of thirty without exercise is like going downhill in a car without brakes. The choice is yours.

Dr. Baral is the consultant cardiologist at Ganga Lal Heart Institute & NORVIC Hospital. Ph: 4436612/4437610, Mobile: 98510-53577