Author: noorali

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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.

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How can you improve your fitness?

This is the fourth column in the series about health and exercise.

First column discussed Darwin’s theory of “survival of the fittest”. Research supporting the concept of survival of the fittest is strong and compelling. There is plenty of evidence showing relation of fitness, physical activity and exercise to reduced mortality overall and from cardiovascular causes.

Second column was on the fundamentals of exercise. We need to exercise regularly to maintain tone in our muscles. If you do not use certain muscles on a regular basis then the muscles start to waste, become thin and weak. Our cardiac and skeletal muscles need regular exercise to keep them toned and strong.

Third column was on the importance of having a good exercise plan. An exercise plan should have three components – aerobic exercise, resistance training (weight lifting) and stretching. The plan should have two aims – to prevent disease and reduce mortality. A good exercise plan should prevent cardiovascular disease and prevent weakness of muscles, bones and joints .

Today, we will discuss the concept of physical fitness. A fitness program should train you to build strength, power, stamina, endurance, flexibility and balance.

To build strength, power and stamina, the best exercises are: swimming, basketball, bicycling, climbing stairs, dancing, hiking, and jogging.

To build flexibility, the best exercises are: swimming, basketball, dancing, tennis and yoga.

Except for swimming, none of the other exercises cater to all aspects of fitness. Therefore, you should combine more than one type of activity in your schedule to maximize your fitness.

To prevent boredom and monotony, you should change the exercise regime and goals every six to eight weeks. This keeps your mind and body working towards a new goal. A professional qualified trainer can help you achieve this. They know more about strength, power, stamina, endurance, flexibility and balance. This article is just an introduction to what you need to do to be fit and healthy.

Review of literature suggests swimming is excellent for all aspects of fitness. It probably fits the definition of a perfect or best exercise. When swimming, you can burn 12 calories per minute. Compare this to jogging 9.6 km. (six miles) an hour, cross-country skiing, squash and handball where you can burn 10 to 11 calories per minute.

Those people who are calorie conscious and want to shed some weight off their girth, thighs and gluteal areas would like to know what kind of exercise would do that. Here is some information on how to melt that unwanted fat.

You can lose two calories per minute by just standing or sitting at one place. You can lose up to four calories a minute by walking 3.2 km (two miles) an hour or bicycling eight km. (five miles) an hour.

You can lose up to seven calories a minute by indulging in sexual activity, shoveling dirt, skating or bicycling 16 km. (10 miles) and hour. Anyway, who would like to shovel dirt when you can burn calories by getting involved in a romantic activity?

Other examples are: housework burns five calories/minute; raking leaves burns six calories/minute; tennis, shoveling snow, downhill skiing, and water-skiing burn eight calories/minute; and basketball burns eight to 10 calories/minute.

What about golf? Golf is not a good activity to build stamina. It is good for flexibility. And has small effect on building strength. You can lose 250 calories per hour when you golf riding a cart.

A study done by Golf Digest showed a golfer who walks 18 holes while carrying his bag travels an average of 9.4 km. (5.9 miles) and burns 1811 calories. A rider with no cart path restrictions, surprisingly, walks an average of 3.7 km. (2.3 miles) and burns 859 calories.

So, keep moving. Remember, more is better and less is better than being a couch potato.

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An Exercise Plan Should Have Three Components

For a happy retirement, you need a good financial plan. For a healthy retirement, you need an exercise plan.

An exercise plan should have three components – aerobic exercise, resistance training (weight lifting) and stretching. The plan should have two aims – to prevent disease and reduce mortality. A good exercise plan should prevent cardiovascular disease and prevent weakness of muscles, bones and joints.

There is much evidence to show that a regular combination of moderate intensity aerobic and resistance exercises can help us achieve these goals. “…..simple, long walks are not the way to health, nor are six-pack abs and marathon running,” says Dr. Khursheed Jeejeebhoy, professor of medicine at the University of Toronto, in an article in the Medical Post. What we need is moderately intense physical exercise.

How do you define moderately intense physical exercise?

“Moderately intense physical exercise is that which results in mild shortness of breath and involves oxygen uptake that is approximately 50 per cent of the maximal level; an example of such exercise is brisk walking,” says an editorial in the New England Journal of Medicine.

Aerobic exercise involves continuous activity. It exercises your heart. It increases endurance and helps body use oxygen more effectively. It makes the lungs, heart and muscles strong. It is good for cardiovascular fitness. Examples of aerobic exercises are – swimming, brisk walking, running, bicycling, climbing stairs, cross country skiing, using stationary bike, elliptical machines, dance-based classes and similar exercises that significantly increase your heart rate.

Aerobic exercises train your lungs and cardiovascular system to process oxygen more efficiently. There is efficient delivery of blood and oxygen to distant parts of the body. Aerobic exercises burn calories and melt fat, reduce blood pressure, increase body metabolism and increase lung capacity.

Aerobic exercises reduce the risk of heart attack, diabetes, improve our immune system and provide relaxation and reduction of stress level. Aerobic exercises should be done three to five times a week for 20 to 60 minutes.

Resistance training involves exercises to increasing muscle strength. This is done by weight lifting or any physical or sporting activity that makes you flex muscles repetitively.

Resistance exercises help burn more calories even while at rest. These exercises make our bones strong, reduces incidence of osteoporosis and injury, joints are supported and protected by strong muscles, reduces arthritic pain, improves muscle mass and delays muscles wasting, reduces body fat, increases metabolism and improves glucose tolerance and insulin sensitivity, thus reducing the risk of diabetes.

Start with a weight that allows you to do eight repetitions. Once you can completer 12 reps increase the weight by five per cent and try to do eight reps and then 12 reps. You should do weight training at least once a week for strength maintenance. You can do it two to three times a week to increase strength and power. There are countless alternate approaches, depending on your focus – is it strength, endurance and/or power. You should consult a trainer to figure out how much and how often you should do resistance exercise.

A study involving Harvard runners showed that men who trained with weights for 30 minutes or more per week cut their risk of heart disease by 23 percent. In a study of nursing home residents, researchers found 45 minutes of resistance exercise three times a week over a 10-week period resulted in 35 to 40 per cent of previously chair-bound people gaining the strength to be able to climb stairs.

Stretching and warm-up are important part of an exercise and fitness program. You should warm-up before you exercise. There is no particular method to warm-ups. Every individual has his or her plan. Professional athletes spend a lot of time on stretching and warm-ups. There is a theory that muscles contract better after they have already been contracting. The idea is to get the muscles warmed and get them ready of action. Does it improve performance? There is a dearth of good research on whether it actually does.

There are low-intensity and high intensity warm-ups. One review paper concluded that warm-up was shown to improve performance in 79 per cent of the criterions examined. But most of the studies were poorly conducted. An exception is a study found that a seven-and-a-half-minute warm-up involving cardiovascular exercise, stretching and air swings – swinging a golf club without hitting a ball – can significantly improve a golfer’s performance. There you go. Some good news for struggling golfers.

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