How to have a safe marathon: heart- wise?
It is common knowledge that physical exercise promotes
health and prevents heart disease and heart attacks. However, we also sometimes
see young, healthy looking people having heart attacks or dying suddenly during
training or during marathon running.
Why is this paradox? And what can we do about it?
Well, the difference is between moderate regular exercise
which has all the benefits of exercise minus its risks, versus intense, vigorous
exercise, which has slight additional benefit but with increased risk,
especially if unaccustomed.
The risk of vigorous exercise like running or training for a
marathon comes from interplay of two factors:
1.
Underlying heart disease (most commonly fatty
plaques in coronary arteries) which may or may not be detected by routine tests
such as blood tests, ECG, or a stress test.
2.
Surge of chemicals like adrenaline and increased
shear stress on coronary arteries which may cause rupture of these fatty
deposits (plaques) as well as disturbance in heart rhythm. Also, with vigorous exercise, especially if
unaccustomed there is ACTIVATION OF A TYPE OF BLOOD CELLS CALLED PLATELETS.
When activated, these can clump together and initiate clot formation at the
site of the ruptured plaque in the coronary artery. This clot along with the
fatty deposit and with possible spasm of the artery can suddenly block the
blood flow in the coronary artery which leads to heart attack or sudden death.
(A third factor recently found in marathon
runners has nothing to do with heart disease, but with excessive heat and
dehydration causing heat stroke).
Hence, to prevent a cardiac catastrophe on vigorous exercise
we need to do the following:
- If you
are above 30 years of age or younger than that but with risk factors such as
smoking, hypertension, diabetes, lipid (cholesterol) abnormalities, or have
a family member who has had heart disease, or have unhealthy lifestyle
(frequent and regular intake of sugar, trans- fats or processed very high
fat food and total lack of physical activity) and mental stress, you
should undergo PROPER CHECK UP
BEFORE JOINING the exercise program. This consists of clinical examination by a cardiologist, ECG,
blood tests and a treadmill stress test. Even while you are
regular on an exercise program, it is advisable to undergo these checkups
once a year if you are above 30 years of age or have one or more of the
risk factors listed above.
- In
many people, these routine tests do not reveal an underlying abnormality, despite
having fatty plaques and being susceptible to heart attacks during
vigorous exercise. Hence additional tests such as a coronary artery calcium score (CACS) may be advisable. CACS is
a ‘score’ which tells the amount of calcium in one’s coronary arteries and
a direct evidence of amount of calcified fatty plaques . Higher the number
of these plaques (CAC score) higher the severity of coronary disease and
chances of a cardiac event in future, whereas a score of zero implies
absence of calcium containing plaques (doesn’t rule out soft plaques) .
CACS does not require injection of any liquid but has the disadvantages of
cost as well as slight but definite exposure to radiation (equivalent to
about 10 chest X rays) which could be ‘potentially’ carcinogenic.
A still better test to reveal all
kinds of fatty plaques in the coronary arteries is a CT coronary angiogram which has still higher risk of radiation (equivalent
to about 30 to 60 chest xrays) and potential effect on the kidneys due to the
liquid contrast injected.
It should be clearly understood
that both these above mentioned tests are as yet not recommended as mandatory
or routine in people without symptoms before joining a vigorous exercise
program.
However, looking at the higher incidence of heart attacks in young
Indians (3 to 4 times that in westerners), and inability of routine tests like
an ECG or a stress test to pick up disease in many, these tests may be worth a consideration- but
only after talking to one’s cardiologist, and after fully understanding the
risks versus benefits of such tests.
- A 2 D Echo is advisable in people who
have had heart attacks, angioplasty or bypass surgery in the past or have
some abnormality detected during clinical examination by the doctor or an
abnormal ECG. 2 D Echo is a safe procedure for everyone but adds to the
cost. It can reveal structural or functional abnormalities of the heart
which may not be picked up on routine clinical exam. It does not reveal the state of coronary arteries.
4. Proper
control of risk factors like hypertension,
diabetes and abnormal cholesterol with healthy lifestyle and addition of
medications if required.
5. Use
of preventive medications such as
statins and low dose aspirin, on the basis of your risk defined by clinical
evaluation, routine tests and your coronary
artery calcium score (if done) and after medical consultation. Statins have
been proven to shrink and stabilize fatty plaques and prevent them from
rupture. Aspirin prevents clumping of platelets. Extension of same benefits during vigorous
exercise may prevent a heart attack.
- Starting
slow -when starting afresh. For initial week or so exercise at very
low intensity and pick up in intensity and duration after a few weeks of
lighter exercise. Same precautions should be observed when RESTARTING
after a break of more than a week. Warming
up and cooling down at every session, each for about 5 to 10
minutes.
- BEING REGULAR. Out of all the
characteristics of an exercise program, this is the most important.
Regular means at least five times a week, round the year. IF THERE IS A
GAP OF MORE THAN EVEN A FEW WEEKS, START ALL OVER AGAIN WITH LOW INTENSITY
EXERCISE AS ABOVE.
- Avoiding prolonged sitting in
front of TV, computer or work desk or if possible, have frequent
“standing” breaks.
- Listening
to your body : STOP exercising and go to your doctor or hospital if
you have any of the following feelings at any time before, during or after
exercise: tightness or heaviness in chest, unusual breathlessness,
fainting or dizziness, nausea or vomiting sensation, pain the back, arm,
jaw or throat or unusual gas or indigestion. It could be a warning sign of
an impending heart attack.
- Ensuring
proper rest or sleep for 7 to 8 hours daily. If your sleep has been
less the previous day or night, or if you have not rested well the
previous day, skip the next exercise session or make it very light.
- Finally
one must remember, regular moderate exercise is no guarantee against heart
disease if you also indulge in unhealthy eating habits or smoking or
heavy alcohol consumption. So these have to go if you want be “heart-safe.”
In summary if you have been ‘screened’ properly
(including a CACS, if deemed appropriate), if you make a gradual entry into an
exercise program, building up your stamina and endurance slowly and safely,
noting any unusual symptoms at any time, are leading a healthy lifestyle with
diet, regular exercise and sufficient sleep,
using protective medications if advised and enough fluids, you are sure
to minimize your chances of a heart attack and are on the road to success without tears.