Dear Dr. Roach: I learned from the American Heart Association’s website that when exercising, one should stay between 50 percent and 85 percent of his or her maximum heart rate. But my cardiologist just shrugged off this warning and said that as long as one is not out of breath, he or she doesn’t have to worry about this “less than 85 percent” formula. It also intrigues me that sometimes we see people in their 70s or even 80s running marathon races. In that case these “reckless people” certainly will exceed their 85 percent MHR. Doesn’t that sound like they are sent on a suicide mission? What’s your take on this? I’m a 75-year-old, always exceeding my 85 percent MHR.
Dear F.R.W.: Guidelines, like the one you mention to keep your heart rate at a percent of maximum, are useful rules of thumb. But, they can’t take into account the large variation from person to person, or even the differences between men and women. I tend to agree with your cardiologist that your own physiology is a better guide: If you are able to speak in full sentences, that’s a safe level of exercise.
It’s also worth noting that the usual formula for estimating MHR (220 minus your age) is very rough, and trained older athletes may be much higher. A better formula for women is subtracting your age multiplied by 0.88 from 206, but even this may underestimate female endurance athletes. A treadmill test is the best way to determine true MHR, but most people don’t need it if they follow the physiology rule of backing off exercise intensity when unable to speak in full sentences.
As far as racing goes, high-intensity endurance exercise probably does increase the short-term risk for heart attack, at least in middle-aged men. However, proper training certainly reduces heart disease risk, so I would advise high-risk individuals to avoid super-high-intensity workouts or racing. Some are willing to take the risk.
Dear Dr. Roach: My 4-year-old grandson enjoys eating raw onions, jalapeno pepper slices and all kinds of hot, spicy foods. Is this normal? I worry that this is going to harm the lining of his stomach in some way. He eats other normal foods, but at such a young age, I don’t think it’s good for him.
Dear W.G.: A normal diet for a 4-year-old depends on culture. Raw onions and peppers are not harmful. Too much hot pepper can be unpleasant, especially for someone not used to them, but it won’t cause damage to the stomach or the rest of the gastrointestinal tract. If he is enjoying them, I think any raw vegetable is healthier than the sugar-laden sodas I see some 4-year-olds drinking.
Dr. Roach Writes: In a recent column, I gave the range of INR (a type of test for coagulation) for people treated with warfarin as 2.5 to 3.5. That is the dose for people with mechanical heart valves. For almost all other indications for warfarin, the usual range is 2.0 to 3.0. My thanks to Alan Kelley, Pharm.D.
Email questions to ToYourGoodHealth@med.cornell.edu.