Tag: exercise

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Physically Active Children Have Higher Scholastic Achievements

In the last column, we discussed how regular exercise benefits adult brain. Today, we will focus on the importance of exercise for school children to boost their brain power.

These days, it is sad to note, when the education system is hit with cutbacks, one of the first programs to suffer is the physical education program. In Canada, we are also at the mercy of the unpredictable weather which hinders children’s outdoor activities.

We can always talk about the good old days. I was brought up in a country where our outdoor activities were not hampered by the vagaries of the weather nor country’s economic situation. Tanzania (then Tanganyika) was under the British rule and life those days was comfortably slow.

We would start the day at school with one hour of physical activity outdoors. After school we would have another hour or two of sporting activities involving different teams. Now the reality is, we can pine for those days but they isn’t coming back. We now live in a different kind of world where economic realities trump all other considerations.

We, as teachers and parents, owe it to our children to provide them with time, facilities and financial support for an hour or two of physical activity on a daily basis. This will not only boost their brain power, it will also act as an antidote for obesity and poor health. Developmental psychologists have suggested that in young children there is a link between physical and mental growth.

An article in the Scientific American Mind (September/October 2010) by Steve Ayan, a psychologist, makes three important points about the academic athletes:

-Students who are fit – based on their high aerobic capacity and low body fat – also tend to perform well in school and on standardized tests.
-In addition to regular exercise, brief periods of movement such as jumping or stretching can help improve children’s concentration.
-Exercise may turbocharge the brain by raising levels of neuronal growth factors, which foster the formation of new connections between brain cells.

Ayan’s conclusions are based on several studies quoted in his article. A review of about dozen articles done by psychologist Charles H. Hillman in 2008 revealed that children and teenagers with higher level of aerobic fitness – but not muscle strength or flexibility – were associated with better performance in school and on standardized tests.

That means, if the young person is more physically fit then more likely he or she will attain higher grades. This connection holds well from elementary school to college. Being fit at age 18 was correlated with a higher level of scholarly achievement in later life, says Ayan.

In a review of 17 studies from 2008, scientists from Universities of Quebec and Toronto concluded that reserving up to an hour a day for physical activity in school curriculums does not detract from academic achievement. “To the contrary, they noted that more exercise often improved school performance, despite the time it took away from reading, writing and arithmetic,” says Ayan.

Teachers and parents should recognize that physical education is about building the brain as well as body. Ayan concludes by saying, “If teachers want their students to pay attention, they should consider letting them jump, stomp and bend their bodies regularly during the school day. Most children have a natural inclination to move, so all the adults have to do is get out of their way.”

A very sensible advice.

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Does exercise make you smart and smarter?

The summer holidays are over. Children are back to school. Parents are back to work and I am back to writing.

Today, we will explore studies which show that people who do regular physical exercise improve their brain power and can improve their chances of avoiding dementia and cognitive impairment. Whatever the age of the person, physical exercise is critical to vigorous mental health.

How do we define cognitive function?

From birth to old age we have a capacity for cognitive function. That means each person is capable of learning or remembering a certain amount of information. During early childhood, most people are best able to absorb and use new information, with most children learning new words, concepts and ways to express themselves. This capacity to learn slows down gradually as we get older.

Cognitive function involves mental process of perception, thinking, reasoning and remembering. Studies done on individuals over the age of 65 have shown that individuals who undergo cognitive training show substantial benefits and these benefits last for many years.

In a study published in the Journal of the American Geriatrics Society (2010), author Dr. Laura E. Middleton suggests that early life physical activity is important to late-life health and in particular in preventing late-life cognitive impairment. The sooner you start being physically active, the better it is.

The study suggest that those who took up regular exercise as young adults were 30 per cent less likely to suffer late-life cognitive impairment compared with women who remained sedentary. This study looked at the physical activity levels of 9,000 women at various ages, from adolescence to senior years.

Physical activity can help the brain build new connections and repair itself, can increase overall brain volume and build enough mental reserves to compensate for the loss of brain power as we age.

An article in the Scientific American Mind (July/August 2009), titled Fit Body, Fit Mind? says your workout makes you smarter and you stay sharp into old age.

“We are used to thinking of intelligence as largely a matter of genetic inheritance, but that is not the whole picture. What you do affects your mental well-being: staying physically and mentally active helps us stay sharp as we age,” says the article.

Although the idea of exercising cognitive machinery by performing mentally demanding activities – popularly termed the “use it or lose it” hypothesis – is better known, a review of dozens of studies shows that maintaining a mental edge requires more than that. Other things you do – including participating in activities that make you think, getting regular exercise, staying socially engaged and even having a positive attitude – have a meaningful influence on how effective your cognitive functioning will be in old age, says the Scientific American Mind article.

As we age, we have an increased desire to be independent in everything we do. If we are able to maintain our cognitive function then we can enhance our quality of life for many years without having to rely on others. For this we have to prepare from a very early age. At an age when we think nothing can ever go wrong in our minds or bodies.

Studies have shown that most active women had a 30 per cent lower risk of cognitive decline. Walking distance was related to cognition but walking speed was not. Even moderate levels of physical activity can serve to limit declines in cognition in older adults. Some studies show aerobic exercise may be the real key to brain fitness and also helps with circulatory system.

The message is clear: if you want to be smart and stay smart into old age then start exercising early in life and make it a lifelong habit.

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What is the role of exercise in a weight loss program?

Did you know that less than 25 per cent of people who attempt weight loss, on their own, incorporate exercise into their weight loss plans? Are you one of them?

If yes, then remember, exercise is more strongly associated with weight loss than any other factor, including diet. Combine exercise and weight loss diet and you will see effective and sustained weight loss. Evidence shows that even if you do not lose weight, you will find exercise improves your cardiovascular system.

Evidence also shows that increased exercise intensity increased the magnitude of weight loss. The question is: besides being on a diet, how much exercise do we need to lose weight?

A study published in the Journal of the American Medical Association found that if you can get people to reduce how much food they eat by about 25 per cent, and you get them to do a least
30 to 40 minutes of exercise five days a week, you can achieve a weight loss of nine per cent. This means a 200-pound person could lose about 20 pounds and successfully maintain it for at least a year (Globe and Mail October 1, 2003).

A study from Duke University, published in 2004, in the Archives of Internal Medicine, showed that study participants who got no exercise during the eight-month study gained an average of almost 2.5 pounds. But 73 per cent of those who briskly walked 17 kilometers a week or about 30 minutes a day were able to maintain their weight or even lose a few pounds. Those who did more vigorous exercise, like jogging 27 km weekly, had the most noticeable weight loss.

Let us look at the study published in 2008, “Effect of Exercise on 24-Month Weight Loss Maintenance in Overweight Women,” in the Archives of Internal Medicine. For two years the authors of the article studied 201 overweight and obese women with body mass index of 27 to 40, with age range of 21 to 45 years.

They found that by the end of the 24-month intervention, the women who managed to lose at least 10 per cent of their starting body weight and managed to keep it off were exercising twice as long as and burning more than twice as many calories through exercise as women who had no change in body weight. More they exercised, more they lost weight. Women who lost the most weight exercised 68 minutes a day, five days a week.

Every day we read about the epidemic of obesity. Is it because we eat too much or we are not exercising enough? Well, you will be surprised to read that our calorie intake over the last 100 years has not increased. What has happened is there has been a sharp drop in caloric expenditure secondary to changes at the workplace and in the home.

The Archives article defines the duration and intensity of physical activity necessary to maintain weight loss. Your happy hour of physical activity should have 68 minutes. The challenge is to sustain intense exercise for 68 minutes per day about five times a week and keep it interesting.

The Archives article suggests that increased daily activity should be encouraged via formal exercise, a modified work and school environment that allows for movement while working and learning. A modified home environment with less television and more movement would go a long way in achieving the happy hour of activity. So, let us keep moving.

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Is exercise beneficial or hazardous to your heart?

In the U.S. an estimated 1.5 million heart attacks occur every year. Of these, 75,000 (about five percent), occur after heavy exertion (shoveling snow, recreational jogging, sexual activity), leading to 25,000 deaths. Similar statistics are reported from Canada and Europe. Some studies report up to 17 per cent deaths after heavy exertion.

There are mainly four risk factors which are associated with complications during exercise: age, presence of heart disease and intensity of exercise.

Normally, if the muscles are deprived of oxygen and energy then they easily fatigue. Delivery of oxygen and energy and removal of carbon dioxide and lactic acid (break down product of metabolism) are essential for sustained exercise. This depends on the health of our lungs and heart.

Glycogen is the principal carbohydrate stored in liver and muscles and it is the immediate source of energy. Safe prolonged exercise depends on the amount of glycogen in the muscles. Although fat stores are a huge reservoir of potential energy, the rate at which fat can be utilized for immediate energy is approximately one quarter of the rate at which glycogen can be utilized.

Increased oxygen and energy demand by the muscles, rapidly increases the heart rate to ensure adequate supply. That means hard work for the heart, at the expense of other organs. The risk of sudden death increases.

Can we reduce the risk of sudden death during or after vigorous exercise?

Yes, we can. A prospective data from a study of U.S. male physicians confirms this. Physical activity clearly benefits cardiovascular health (NEJM November 9, 2000). It has been shown that excess risk of heart attack during strenuous exertion was limited, for the most part, to persons who did not exercise regularly. Among those who exercised at least four or five time per week, there was little or no excess risk (NEJM December 2, 1993).

Although the exact reasons why physical exertion triggers heart attacks are not known, the possible factors are the disruption of atherosclerotic plaques (the deposits which narrows the coronary arteries), and the shearing stress on the heart caused by increased heart rate and blood pressure.

In sedentary people or couch potatoes, the risk of heart attack was seven times higher in a German study and more than 100 times greater in a U.S. study during vigorous exertion than during lighter activity or no activity. If you compare this to among people who exercised regularly, there was almost no increased risk. Another beneficial effect of regular exercise is that it increases the blood level of HDL (good cholesterol). HDL is another line of defense against heart attack.

What are the other hazards of vigorous exercise?

Dehydration. Drink plenty of fluids before, during and after a workout. You should adjust your activity according to the weather and reduce it when fatigued or ill.

Hyperthermia can result in light headedness, nausea, headache, hyperventilation, fatigue and loss of concentration. Heatstroke is the most dangerous complication of hyperthermia.

Avoid injuries to bones and muscles. High-impact exercise can also damage the inner ear, causing dizziness, ringing in the ear, motion sickness or loss of high-frequency hearing.

How can you exercise safely?

Most important thing is to listen to your body’s warning signs during exercise: chest pain, irregular heartbeat, undue fatigue, nausea, unexpected breathlessness or light-headedness. It is estimated that at least 40 percent of young men who die suddenly during a workout have previously experienced and ignored, warning signs. Remember to warm up, cool down and stretch.

For the general public the message is clear – regular exercise has important health benefits over the long term. Sudden vigorous exertion by people who are unaccustomed to it can sometimes end in tragedy (NEJM December 2, 1993). Consult your doctor and fitness expert.

Start reading the preview of my book A Doctor's Journey for free on Amazon. Available on Kindle for $2.99!