DEAR DR. ROACH: With all the misinformation flying around, can you comment on whether it’s a good idea to wear N95 masks if you have them on hand? — F.C.
ANSWER: N95 masks are the standard for personal protective equipment for most health care providers in the hospital. Ideally, health care workers would have enough N95 masks to use them with every patient suspected of having COVID-19, but unfortunately, there remain shortages in many areas of the country. Many hospital workers still reuse the masks, or reserve them for the highest risk situations, such as a procedure on a person known to have COVID-19 lung disease.
Because of the nationwide shortage, it is difficult to get the certified N95 masks. Many hospitals have obtained KN95 masks, but recent studies have shown that up to 70% of KN95 masks are inadequate. This makes it particularly important that N95 masks are reserved for when they are really necessary. If you have any unopened N95 masks, your local hospital will be delighted to give them to frontline workers. You may help save lives. However, if you have an already used N95 mask, you may certainly continue to use it as long as it provides a tight fit.
A well-made cotton mask, whether store-bought or homemade, provides good protection in combination with adequate physical distancing. Masks have made a big difference on slowing the growth of the COVID-19 pandemic in the world. Two or more layers provide protection as good as you can get without a certified N95 mask.
DEAR DR. ROACH: I have always wondered about the best amount of time spent and the speed of walking on a treadmill at the gym for the optimal health. Is it better to walk slow but perhaps for an hour, or walk much faster but for only a half an hour? Does one use the heart pulse as a guide to answer this question? Pulse is always displayed on the treadmill. — R.I.
ANSWER: In general, higher intensity exercise leads to better cardiovascular fitness. For weight loss, there is probably not a lot of difference between walking 3 miles in an hour versus jogging 3 miles in half an hour: The distance is the more important number. The pulse rate will certainly be higher in those who run or jog compared with walk, and even in those who walk briskly compared with walking at a leisurely pace. As long as the pulse is not dangerously high (generally only a concern for people at risk for heart disease), the pulse is not so important to monitor. Serious athletes measure heart rate carefully to be sure they are staying in their appropriate training zone.
Although intensive exercise provides more cardiac benefits than leisurely exercise, it is important to remember is that any exercise — even a 10-minute pleasant stroll — is better than no exercise. The best exercise is the exercise you will continue to do and enjoy. If walking fast doesn’t let you enjoy the exercise, walk at a comfortable speed. Many people will build up their speed and distance as their stamina improves with regular exercise.
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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 ToYourGoodHealth@med.cornell.edu or send mail to 628 Virginia Dr., Orlando, FL 32803.
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