Exercise will benefit your health provided you use the right duration, intensity and frequency. Find out how.
By Lim Wey Wen, The Star 5 March 2009
All of us have heard it hundreds and thousands of times. What is the secret to the fountain of youth, a healthier heart or a trimmer waistline?
The answer is almost always: Exercise! A fit body and a healthy heart is something you can work on, but it must be maintained by consistent, regular workouts.
Still, if you have seriously considered starting an exercise regimen before, these questions may sound familiar. What kind of exercise can I do? Would jogging or walking one hour a day keep me fit? Can a daily jog help me lose weight? How long should I exercise? Is this exercise too much for me? Should I be exercising at the age of 60?
It all depends on your motivation to exercise, says professor of physiology Prof Dr Harbindar Jeet Singh.
The exercise regimen for a marathon runner may be a lot more intense and complex, but if you are just looking forward to maintaining good health and a healthy heart, Dr Harbinder says it is quite straightforward.
To maintain good health, he says an individual needs to undertake a minimum of 500-600 METs worth of exercise per week, spread over no less than three sessions per week. (One MET, or metabolic equivalent, is the amount of oxygen consumed when sitting quietly, approximately 3.5ml of oxygen consumption per kilogram of body weight per minute).
So, if you exercise at a moderate intensity ie walking briskly at a speed of five to six km/h (which approximates to about four to five METs per minute), then you will need to do at least five 30-minute sessions per week to achieve the required METs for the week.
If you exercise at a vigorous intensity, like jogging at speeds of eight km/h or greater (more than nine METs per min), then you could do it in less time (20 minutes). You could also choose to have 30-minute workouts and fewer sessions (but no fewer than three times per week).
Intensity, duration, frequency
Can you avoid doing five sessions and have a single two-and-a-half hour session on weekends? Dr Harbindar says no.
It doesn’t matter whether you are exercising to maintain your health, lose weight or compete in the Olympics: you need to have all three components for it to be beneficial, says Dr Harbindar.
“When we talk about fitness, we talk about our body’s response and adjustment to the strain that is placed on it. The way our body responds and adjusts to that strain - that is fitness.?
It is only when exercise is of adequate intensity, duration and frequency that the body will get the message to change its physiology so it can accommodate and sustain a higher level activity over longer periods.
The heart muscles will grow thicker for it to pump more blood to the muscles and the lungs will expand more efficiently to get more oxygen into the blood that passes through. To be considered physically fit, you need to be able to sustain a moderately intense physical activity for 20 minutes or more.
But what constitutes a moderate intensity workout?
One of the simplest ways to find out is to try and have a conversation or sing when you work out. If you can still manage a full sentence without much trouble but have a hard time singing, it’s a moderate intensity workout. If you can hardly talk, it’s vigorous.
If you happen to be walking or jogging on a treadmill, a speed of three to six km/h is moderate. More than that is considered vigorous.
Otherwise, one of the best ways to monitor your level of activity is by checking your pulse. If your pulse rate is about 50-70 per cent the maximum heart rate for your age (subtract your age from 220), the exercise is moderate. If it is about 70-85 per cent, it’s vigorous.
So if you are 30 years old, your maximum heart rate is approximately 190 beats per minute (bpm) and you should be exercising at a pulse rate of about 95 bpm to 135 bpm during a moderate intensity exercise.
You can measure your pulse rate manually or with the help of a heart rate monitor that now comes in the form of a wrist watch.
[Go to page 2]Starting an exercise programme
We often take comfort in our little efforts to increase our physical activity, be it taking the stairs or parking the car further away. However, there’s no shortcut to fitness except making time to exercise, says Dr Harbindar. Still, it is always prudent to start slow.
The easiest, and the most economical exercise to start with is a brisk walk or a regular jog.
“Exercise has no age limit. It is for all ages and you can start at any age; the earlier the better. Make exercise as important as your daily meals,” Dr Harbindar says.
But before you start, the general advice is if you have risk factors for a heart attack, it is best to consult a doctor and get the appropriate advice and treatment, he says. This is more important if you are above 40.
Otherwise, if you are above 40 but do not have any risk factors, it is not necessary to see a doctor.
However, in both instances, start with light intensity exercises and gradually build the intensity up to a moderate or vigorous intensity as you go along over a period of 10 to 12 weeks.
The idea is don’t rush.
If at first you find your heart rate spiking up to 50-70 per cent your maximum heart rate with only a brisk walk, do not worry.
As you get fitter, you may find yourself exercising longer and at a higher intensity with the same amount of effort. After a few weeks or months, you may find yourself comfortable jogging at the same heart rate.
Even for those who survive heart attacks, exercise is beneficial to strengthen the heart and lower the likelihood of subsequent heart attacks.
The exercise component in a cardiac rehabilitation programme (CRP) helps heart attack survivors regain their fitness by putting them on supervised light intensity exercises up to minimally supervised moderate intensity exercises over four to six months.
“If you have a history of heart disease, it is always advisable to exercise under supervision at first, until your doctor says it is OK for you to exercise on your own. Even then, try and exercise in a group,” Dr Harbindar says.
“Should you experience any discomfort or pain in your chest, stop your exercise immediately and take a rest. Always carry your medication like glyceryl trinitrate (GTN) with you so that you can place it under your tongue should the need arise.”
Little things matter
While exercise brings health benefits, doing it incorrectly can hurt your body.
Although more is better, overdoing it is more likely to cause harm. Fatal heart attacks during football or even badminton games have become quite common of late.
Dr Harbindar says the best way to tell if a particular exercise is too strenuous is by monitoring the heart rate, although the body will let you know in due course.
“Any heart rate above 80per cent of the maximum heart rate can be considered as strenuous,” he says.
A simple way to tell is to do the “talk test”, the same way you tell a moderate intensity and vigorous exercise apart. If you are unable to say a simple sentence during your exercise, then it might be too strenuous for you.
Besides that, Dr Harbindar shares a few important considerations to take note of during exercise.
- Mix your exercises. Once you have attained a sufficient level of fitness, mix your exercises. In addition to the aerobic component, the exercise must also contain sessions for the maintenance of muscle strength and endurance (at least two sessions per week).
Calisthenics is one of the simplest forms of exercise that we can do for this. It uses the weight of one’s own body for the required resistance. Exercises like sit-ups, crunches, push-ups, pull-ups and squats are some examples of this.
Alternatively, you could also do some light weightlifting if you have access to such facilities either at home or in a gym.
- Always warm up before exercise and cool down following the completion of your exercise with stretching exercises.
- Make sure you are adequately hydrated before, during and after exercise. You can drink one to two glasses of water before you start, and another three to five within two hours after exercising, but these are not absolute.
If you sweat a lot, you could increase the amount of fluid. A rule of thumb is to drink about 25-30ml of water for every minute of exercise you perform. There is no harm if you drink a little more. Plain water is adequate for the usual 30-40-minute session.
- Wear clothes made out of material that allows your body heat to dissipate easily (e.g. cotton).
- Wear proper, well-cushioned footwear to prevent long-term injury to your ankles, knees and your back.
- Ensure your safety at all times. If possible, exercise in small groups and in visible and well-lighted places.
- For people on medications, ensure that the timing of the medications is adhered to and the timing of exercise does not interfere with their ingestion and absorption from the gut.
And perhaps most importantly, know when to stop exercising and space your exercise sessions with adequate rest.
- It is very important that you get adequate rest in between the exercise sessions, as this is necessary for recuperation and the adaptation of your body to the exercise,” he explains.
But don’t rest for too long, as the body adapts again to the sedentary pace. You can lose your fitness and the whole process has to be repeated again.
“Exercise sessions should not be more than four days apart, and fitness levels generally start to fall significantly within 10-14 days of cessation of exercise. The older you get it becomes that bit more difficult to regain the fitness levels,” Dr Harbindar says.
The take home message is this: a fit body and a healthy heart is something you can work on, but it must be maintained by consistent, regular workouts ‘ done correctly and adequately.
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Work it out
Exercise will benefit your health provided you use the right duration, intensity and frequency. Find out how.
By Lim Wey Wen, The Star
5 March 2009
All of us have heard it hundreds and thousands of times. What is the secret to the fountain of youth, a healthier heart or a trimmer waistline?
The answer is almost always: Exercise!
A fit body and a healthy heart is something you can work on, but it must be maintained by consistent, regular workouts.
Still, if you have seriously considered starting an exercise regimen before, these questions may sound familiar. What kind of exercise can I do? Would jogging or walking one hour a day keep me fit? Can a daily jog help me lose weight? How long should I exercise? Is this exercise too much for me? Should I be exercising at the age of 60?
It all depends on your motivation to exercise, says professor of physiology Prof Dr Harbindar Jeet Singh.
The exercise regimen for a marathon runner may be a lot more intense and complex, but if you are just looking forward to maintaining good health and a healthy heart, Dr Harbinder says it is quite straightforward.
To maintain good health, he says an individual needs to undertake a minimum of 500-600 METs worth of exercise per week, spread over no less than three sessions per week. (One MET, or metabolic equivalent, is the amount of oxygen consumed when sitting quietly, approximately 3.5ml of oxygen consumption per kilogram of body weight per minute).
So, if you exercise at a moderate intensity ie walking briskly at a speed of five to six km/h (which approximates to about four to five METs per minute), then you will need to do at least five 30-minute sessions per week to achieve the required METs for the week.
If you exercise at a vigorous intensity, like jogging at speeds of eight km/h or greater (more than nine METs per min), then you could do it in less time (20 minutes). You could also choose to have 30-minute workouts and fewer sessions (but no fewer than three times per week).
Intensity, duration, frequency
Can you avoid doing five sessions and have a single two-and-a-half hour session on weekends? Dr Harbindar says no.
It doesn’t matter whether you are exercising to maintain your health, lose weight or compete in the Olympics: you need to have all three components for it to be beneficial, says Dr Harbindar.
“When we talk about fitness, we talk about our body’s response and adjustment to the strain that is placed on it. The way our body responds and adjusts to that strain - that is fitness.?
It is only when exercise is of adequate intensity, duration and frequency that the body will get the message to change its physiology so it can accommodate and sustain a higher level activity over longer periods.
The heart muscles will grow thicker for it to pump more blood to the muscles and the lungs will expand more efficiently to get more oxygen into the blood that passes through. To be considered physically fit, you need to be able to sustain a moderately intense physical activity for 20 minutes or more.
But what constitutes a moderate intensity workout?
One of the simplest ways to find out is to try and have a conversation or sing when you work out. If you can still manage a full sentence without much trouble but have a hard time singing, it’s a moderate intensity workout. If you can hardly talk, it’s vigorous.
If you happen to be walking or jogging on a treadmill, a speed of three to six km/h is moderate. More than that is considered vigorous.
Otherwise, one of the best ways to monitor your level of activity is by checking your pulse. If your pulse rate is about 50-70 per cent the maximum heart rate for your age (subtract your age from 220), the exercise is moderate. If it is about 70-85 per cent, it’s vigorous.
So if you are 30 years old, your maximum heart rate is approximately 190 beats per minute (bpm) and you should be exercising at a pulse rate of about 95 bpm to 135 bpm during a moderate intensity exercise.
You can measure your pulse rate manually or with the help of a heart rate monitor that now comes in the form of a wrist watch.
[Go to page 2]Starting an exercise programme
We often take comfort in our little efforts to increase our physical activity, be it taking the stairs or parking the car further away. However, there’s no shortcut to fitness except making time to exercise, says Dr Harbindar. Still, it is always prudent to start slow.
The easiest, and the most economical exercise to start with is a brisk walk or a regular jog.
“Exercise has no age limit. It is for all ages and you can start at any age; the earlier the better. Make exercise as important as your daily meals,” Dr Harbindar says.
But before you start, the general advice is if you have risk factors for a heart attack, it is best to consult a doctor and get the appropriate advice and treatment, he says. This is more important if you are above 40.
Otherwise, if you are above 40 but do not have any risk factors, it is not necessary to see a doctor.
However, in both instances, start with light intensity exercises and gradually build the intensity up to a moderate or vigorous intensity as you go along over a period of 10 to 12 weeks.
The idea is don’t rush.
If at first you find your heart rate spiking up to 50-70 per cent your maximum heart rate with only a brisk walk, do not worry.
As you get fitter, you may find yourself exercising longer and at a higher intensity with the same amount of effort. After a few weeks or months, you may find yourself comfortable jogging at the same heart rate.
Even for those who survive heart attacks, exercise is beneficial to strengthen the heart and lower the likelihood of subsequent heart attacks.
The exercise component in a cardiac rehabilitation programme (CRP) helps heart attack survivors regain their fitness by putting them on supervised light intensity exercises up to minimally supervised moderate intensity exercises over four to six months.
“If you have a history of heart disease, it is always advisable to exercise under supervision at first, until your doctor says it is OK for you to exercise on your own. Even then, try and exercise in a group,” Dr Harbindar says.
“Should you experience any discomfort or pain in your chest, stop your exercise immediately and take a rest. Always carry your medication like glyceryl trinitrate (GTN) with you so that you can place it under your tongue should the need arise.”
Little things matter
While exercise brings health benefits, doing it incorrectly can hurt your body.
Although more is better, overdoing it is more likely to cause harm. Fatal heart attacks during football or even badminton games have become quite common of late.
Dr Harbindar says the best way to tell if a particular exercise is too strenuous is by monitoring the heart rate, although the body will let you know in due course.
“Any heart rate above 80per cent of the maximum heart rate can be considered as strenuous,” he says.
A simple way to tell is to do the “talk test”, the same way you tell a moderate intensity and vigorous exercise apart. If you are unable to say a simple sentence during your exercise, then it might be too strenuous for you.
Besides that, Dr Harbindar shares a few important considerations to take note of during exercise.
- Mix your exercises. Once you have attained a sufficient level of fitness, mix your exercises. In addition to the aerobic component, the exercise must also contain sessions for the maintenance of muscle strength and endurance (at least two sessions per week).
Calisthenics is one of the simplest forms of exercise that we can do for this. It uses the weight of one’s own body for the required resistance. Exercises like sit-ups, crunches, push-ups, pull-ups and squats are some examples of this.
Alternatively, you could also do some light weightlifting if you have access to such facilities either at home or in a gym.
- Always warm up before exercise and cool down following the completion of your exercise with stretching exercises.
- Make sure you are adequately hydrated before, during and after exercise. You can drink one to two glasses of water before you start, and another three to five within two hours after exercising, but these are not absolute.
If you sweat a lot, you could increase the amount of fluid. A rule of thumb is to drink about 25-30ml of water for every minute of exercise you perform. There is no harm if you drink a little more. Plain water is adequate for the usual 30-40-minute session.
- Wear clothes made out of material that allows your body heat to dissipate easily (e.g. cotton).
- Wear proper, well-cushioned footwear to prevent long-term injury to your ankles, knees and your back.
- Ensure your safety at all times. If possible, exercise in small groups and in visible and well-lighted places.
- For people on medications, ensure that the timing of the medications is adhered to and the timing of exercise does not interfere with their ingestion and absorption from the gut.
And perhaps most importantly, know when to stop exercising and space your exercise sessions with adequate rest.
- It is very important that you get adequate rest in between the exercise sessions, as this is necessary for recuperation and the adaptation of your body to the exercise,” he explains.
But don’t rest for too long, as the body adapts again to the sedentary pace. You can lose your fitness and the whole process has to be repeated again.
“Exercise sessions should not be more than four days apart, and fitness levels generally start to fall significantly within 10-14 days of cessation of exercise. The older you get it becomes that bit more difficult to regain the fitness levels,” Dr Harbindar says.
The take home message is this: a fit body and a healthy heart is something you can work on, but it must be maintained by consistent, regular workouts ‘ done correctly and adequately.
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