Dear Dr. Roach: I learned from the American Heart Association鈥檚 website that when exercising, one should stay between 50 per cent and 85 per cent of one鈥檚 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鈥檛 have to worry about this 鈥渓ess than 85 per cent鈥� formula. It also intrigues me that sometimes we see people in their 70s or even 80s running marathon races. In that case these 鈥渞eckless people鈥� certainly will exceed their 85 per cent MHR. Doesn鈥檛 that sound like they are sent on a suicide mission? What鈥檚 your take on this? I鈥檓 a 75-year-old, always exceeding my 85 per cent MHR.
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鈥檛 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鈥檚 a safe level of exercise.
It鈥檚 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鈥檛 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 four-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鈥檛 think it鈥檚 good for him.
W.G.
A normal diet for a four-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鈥檛 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 four-year-olds drinking.
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Dear Dr. Roach: I鈥檓 wondering about what I have read regarding blue-light emissions from flat-screen TVs, smartphones, computers and other devices. Blue light, so I have read, is deleterious to one鈥檚 eyesight in the long run, including contributing to insomniac or 鈥渘ight bird鈥� behaviour and possibly eye strain. I bought blue-blocking glasses, which, at the least, sharpen vision. Have you seen any evidence about the effect of blue light?
E.L.
Blue light penetrates more deeply into the retina, so it is suspected that blue light might be more likely to damage the retina, increasing the risk for age-related macular degeneration. Blue light also has more powerful effects on the sleep-wake cycle, so blocking blue light at nighttime may reduce the adverse effects of light on sleep cycles. Some authorities have suggested that blue light is more likely to cause eye strain. An alternative to blue-blocking lenses is to reduce the colour temperature of the monitor to reduce blue light.
Dear Dr. Roach: I have severe halitosis. I have had my sinuses, teeth and gums checked to see if they are the cause of the odor, but the dentist and ENT found nothing. I was referred by my primary doctor to a G.I. specialist, who found I had a sliding hiatal hernia, which was causing acid reflux. He recommended surgery to push the stomach back into its normal position below the diaphragm. I decided to pass on the surgery. He recommended taking over-the-counter medications such as Nexium, but after several days my lower back started to hurt, so I stopped taking them. I am reconsidering the surgery and was wondering if this is a good idea. Is it possible that the hernia has nothing to do with the halitosis?
E.H.
Experts believe that 90 per cent of the time, halitosis comes from the mouth. What your gastroenterologist is suggesting as the cause of the halitosis is plausible. I found several anecdotal cases where surgery cured the halitosis. However, it鈥檚 not only possible that the hiatal hernia has nothing to do with the halitosis, I think it is unlikely that it does. Since surgery would not otherwise be recommended for a sliding hiatal hernia, I can鈥檛 recommend surgery.
Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to [email protected].
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