DEAR DR. ROACH: I usually walk 45 minutes daily for a cardio workout. However, the Florida summer heat can be brutal, so instead of walking, I swim and walk one hour in the pool. Is that as good a cardio workout as walking? — R.G.
ANSWER: I think that having several different ways to exercise is a good idea, since the muscles used will always be at least somewhat different and it can keep you from being bored when doing the same thing day after day. In your situation, I think that it makes a great deal of sense to avoid the heat by getting in the pool.
The intensity of a cardiovascular workout can be measured simply by your pulse rate. A rough but commonly used guide is that moderate cardiovascular exercise is 50 percent to 70 percent of your agepredicted maximum of 220 minus your age. So for age 50, your maximum is 170, and moderate exercise is a pulse of 85 to 119. You can check your pulse at the wrist with a clock, or wear a heart monitor.
Swimming almost always is a more-intense workout than walking (race walkers certainly can get a very fast pulse rate), and walking in the pool is a good exercise for your heart and many muscles.
If the pool is outdoors, as is usual in warm, sunny places, you need to wear and reapply plenty of sunscreen to protect your skin.
DEAR DR. ROACH: In 1978, I was diagnosed with a benign brain tumor. It was on the pituitary gland and pushing on the optic nerve. I had surgery, but only half was removed because of the optic nerve. The other half was shrunk with chemo and radiation. I am concerned about the long-term effects of radiation, because I had a stroke in 2012 and the doctors said this stroke might have been a link to long-term effects of radiation. But 36 years later? Can you confirm or deny that the long-term effects of radiation cause stroke? — B.R.
ANSWER: I can’t tell you whether your stroke was caused by the radiation you received; however, I can confirm that high-dose radiation (from radiation therapy for your tumor, not from a diagnostic CT scan) increases the overall risk of transient ischemic attack and stroke. A welldone study from Australia in 2011 showed that radiation treatment approximately doubles the risk of TIA and stroke.
This does not mean that the treatment you had in 1978 was inappropriate.
Treatment of a brain tumor, even a noncancerous one, is critical, because there is very little room in your head for a tumor in that position. The medical treatment we have now for these kinds of tumors was not available in 1978.
What this means for people with a history of radiation treatment to the head is that they should do everything to reduce their risk of stroke, which means no smoking, careful control of blood pressure and cholesterol, careful diet including low sodium and low sugar, and discussion with a doctor about aspirin therapy.