On Aspirin and running

By Dr. Jon Hooper

Does an aspirin on race day keep the doctor away?

There are a lot of things to think of when preparing to run a 10K or longer race, and one concern that nobody wants to think about is the possibility of suffering a heart attack or cardiac arrest.

Unfortunately these catastrophic events do occur, but fortunately not too frequently.

Heart attacks, cardiac arrests and deaths from cardiac events occur more commonly in men over the age of 40 and in the marathon distance (although they have occurred in women, those under the age of 40 and in shorter races as well). The cause of these cardiac issues is usually atherosclerosis (hardening of the arteries).

Aspirin has been used with great success for many years to treat and prevent these events in patients with risk factors for atherosclerosis.

Many race doctors wonder if an aspirin on race day would also decrease the chance of a bad cardiac event in those competing in a running race.

There has never been a study done to test this hypothesis but it has received enough support that a group of race doctors (the International Marathon Medical Directors Association) have released a statement that says:

“Long distance runners, especially men over the age of 40, are advised in the absence of specific contraindications to take pre-race aspirin if approved by their personal physician after discussion of its risks and benefits”

They are suggesting that all men over the age of 40 take a baby aspirin (81 mg) on the day of the race (10 km or more) if you do not have any contraindications (i.e. a specific situation when you shouldn’t use a drug).

What are the contraindications?

  • An allergy to aspirin
  • A bleeding disorder (aspirin very slightly increases your chances of bleeding)
  • If you are taking other blood thinners (see above)
  • A history of stomach ulcers or gastro-intestinal bleeding
  • In theory, aspirin could possible aggravate kidney injuries brought on by heat exhaustion and dehydration

Their statement has been a bit controversial with some interesting debates in running forums and in the medical literature.

So what to do?

If you are already taking aspirin for cardiovascular reasons – continue taking it.

If you have risk factors (hypertension, diabetes, smoker) for atherosclerosis then strongly consider taking a baby aspirin before you race (talk with your doctor).

If you are an over 40-year-old male without significant risk factors and running 10K or longer then weigh the risks. The risks of side effects from one baby aspirin are pretty small, and the chances of a bad cardiac event are also pretty small.