Two readers have asked about continuing to take exercise once the weather grows colder. One from Kent enjoys swimming even if the rain is pouring down and a cold east wind is blowing, but wonders if it is good for her health. The other reader, Susie, has e-mailed asking whether, because it is accepted that exposure to cold increases the basic metabolic rate, exercising in winter is more beneficial than in the summer.
For someone in good health, exercising every day in classic British winter weather won’t do any harm. Exercise doesn’t have to be excessive: half an hour to 40 minutes a day is enough. But it must be regular, winter and summer. In whatever form the exercise is taken, it should be brisk but not violent. Brisk walking is the best exercise with brisk being interpreted as vigorous enough to make talking difficult but not impossible. Anyone, especially those who are older when starting an exercise programme, should build up to any objectives gradually. Those people who know that they have any form of cardiovascular or respiratory problem should consult their own doctor about the exercise they should take. On the other hand, those who are well, but who have an increased risk of developing heart disease because they suffer from, for example, diabetes, high blood pressure, raised cholesterol levels or are overweight, should double the amount of daily brisk walking to a minimum of an hour a day rather than half an hour.
The over-65s, and younger people who are known to have cardiovascular disease or its risk factors, should not take brisk exercise in extremes of temperature. Extreme heat is as bad for the circulation as cold. Cold weather is especially dangerous for those with a vulnerable cardiovascular system if it is associated with an icy wind, and heat is more lethal when it is accompanied by high humidity.
Cold is more likely to cause trouble if someone is overtired, stressed or dehydrated, and is either very young or elderly. Cold is also more dangerous for those who drink heavily. Every year there are news stories of revellers who set off home along a windswept lane in an icy wind. Unfortunately, before they can totter back to the warmth of their own house they are overcome by the weather.
The recent television reconstruction in the Antarctic of Scott’s last journey demonstrated that more than twice as many calories are needed to pull sledges in sub-zero temperatures than are burnt up by a miner working at the coalface. There is no change in the basic metabolic rate in the winter for those living in a centrally heated environment. However, if they are exercising in cold weather the same tasks will burn up more calories. If more food is not eaten to compensate and Susie’s calorie intake remains the same, her usual daily exercise regime will help her to lose more weight than in summer. To this extent winter exercise is better for her.
The health benefits of swimming for our correspondent who swims in cold weather will depend on her cardiovascular system. Swimming is excellent exercise for people whose heart is in good order. If there is any doubt about this they shouldn’t swim in cold water and even in the summer should ease their way slowly into the sea or pool. Emulating the Russians and cutting a hole in the ice before swimming may not be as bad as falling unexpectedly into icy water, but it puts a strain on the cardiovascular system and may even lead to neurological problems.
A LONDON READER asks why it is that when she first goes out into bright sunshine she sneezes repeatedly. Bob has e-mailed us about a different form of sneezing bout. His wife has attacks of sneezing when they dine out. For all of the 60 years of their marriage she has sneezed from 12 to 20 times as the meal is drawing to an end. After the sneezing she can eat no more.
An ordinary sneeze is the reflex response to an irritant in the nasal spaces. The membranes in the nose may be irritated by factors ranging from cold air to dust or a dried nasal secretion. Inflamed eyes and allergic rhinitis (a runny nose) are often associated with asthma or eczema. Rhinitis may be triggered by dust mites, pollens, moulds or the skin flakes and spit of some animals. Rhinitis, whether as the result of an allergy or a cold, also causes sneezing.
There are two conditions that cause attacks of sneezing. The London reader is suffering from the photic sneeze reflex; Bob’s wife has gustatory sneezing attacks.
Sneezing in the sun, the photic sneeze reflex, is a relatively common problem. My elder brother did this all his life but, as is usual, it was less obvious when he was 60 than 6. It is a condition inherited as an autosomal dominant characteristic. One of a photic reflex sneezer’s parents is likely to have suffered similarly and each child of a sun sneezer has a 50 per cent chance of having the same symptom. The cause of the photic sneezing reflex is a minor abnormality of the reflex response to light by the eye and brain. Usually a pupil contracts in bright light, but in sun-sneezers the reflex response to sun is greater and not only do the pupils contract quickly but victims sneeze repeatedly. It can be an embarrassing nuisance but no more than that. Wearing dark glasses when going into bright sunlight helps.
The gustatory sneezing response is much rarer and doctors have no all-embracing explanation for it. Classically, Bob’s wife sneezes repeatedly only when eating in certain circumstances, in her case when dining out. Other people may sneeze repeatedly only when eating at home. There is a suggestion that there may be an allergic component to the gustatory sneezing response. Possible triggers for it include certain wines (especially old wine), spiced foods including pepper, mustard — more commonly an allergen than realised — and peppers and other herbs. Possibly, domestic tensions may provide a stronger emotional component to other triggers.
ASK DR STUTTAFORD: TOPIC OF THE WEEK
Read about attention deficit hyperactivity disorder (ADHD) in times2 tomorrow, and send any queries about ADHD to Dr Stuttaford at www.timesonline.co.uk/talkingpoint. His answers will appear online at 1pm next Wednesday.
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