We all know exercise is good: But how much is good for you?

By Flavia Nassaka

Exercise is recommended for everyone opting to stay healthy and in shape but more so for the hypertensive.Usually, when you are first diagnosed with hypertension, your doctor will recommend doing plenty of exercise. And so you have decided to heed expert advice and startedexercising but are wondering how much exercise is enough?

Dr Charles Mondo, a cardiologist at Mulago hospital says at least 30 minutes of daily physical activity is required to reduce the risk of chronic diseases in adulthood.  For some, that’s only the beginning as Dr Roland Mukana, a Senior Sports Tutor at KyambogoUniversity says an ideal physical exercise should last 90 minutes. But, he adds, that duration could also be determined by what one intends to achieve from the exercise.

“30 minutes are recommended for those with normal weight but want to enjoy the benefits of being active, 60 if you want to control your weight and 90 if you want to cut and sustain your weight,” he says.

To Mondo, it does not require a lot of exercise to be fit or to fight disease as long as one balances the energy and manages weight.

You do not need to go to the gym or go running but whatever activity that makes your heart go pumping. Anything that makes you breath harder and faster is good. Such kinds of exercise that require consumption of substantially more oxygen than at rest are referred to as aerobic.  They may be of light to moderate intensity, and can be undertaken for a prolonged duration without excessive fatigue. Examples of aerobic exercise include walking, jogging, swimming, and dancing.

“The effects of exercise are cumulative,” says Mukana, “It doesn’t have to be done all at once. It can be done in bits and pieces until it all adds up and meet the target.”

What are the best exercises for you?

Doctors recommend two types of physical activities to be done every week to improve your health; aerobic and stretch.   Stretch exercises enable all the muscle groups of the body to work for instance the back, chest, shoulders and arms.

To gain health benefits, Peninah Kabenge, a Makerere University based Sports Scientist says muscle-strengthening activities need to be done to the point where it’s hard for you to do another repetition without help.

“A repetition is one complete movement of an activity, like lifting a weight or doing a sit-up. Try to do at least 1 set of muscle-strengthening activities, but to gain even more benefits, do 2 or 3 sets,” she says.

But Mukana worries that only people with very mobile shoulder joints can keep their spines straight enough to do some stretching exercises properly.  If not done well, some activities like holding bars can lead to shoulder impingement. This can be more dangerous if the bar is held from behind and hits the back of the neck, it could injure cervical vertebrae.

Dr Mondo talks of running as one of the best types of exercise for it provides a great cardiovascular workout, and it also strengthens muscles. To him, regular jogging not only improves cardiovascular fitness, it has also been shown to have other health benefits, including mental health benefits such as helping to manage depression and anxiety.

The cardiovascular improvements that jogging provides include making the heart stronger and more efficient, thus reducing the risk of heart disease and heart failure. This is becausejogging improves blood circulation and respiratory health.

Kabenge says lifting weights, jogging, and walking alone can speed up the digestive system and can help to relieve digestive problems. Many people who live a sedentary lifestyle develop digestive problems because lack of exercise inhibits contraction of the layer of the muscle that moves food through the system.

Precautions

As with any form of exercise, be aware of over-exercising, either by doing aerobic exercise too hard, for too long, or too often. All these can lead to injury.

It is recommended that one builds up gradually from the initial activity levels.  If you are new to regular aerobic exercise, several weeks of low to moderate intensity aerobic exercise are usually advised before introducing more vigorous aerobic exercise sessions.   If you have existing health problems, are at high risk of cardiovascular disease, or have muscle, bone or joint injuries, the cardiologist recommends to check with your doctor before undertaking an aerobic exercise. Also, men aged over 40 years and women aged over 50 years who do not regularly exerciseshould check with a doctor before undertaking a programme of vigorous physical activity.

For a 70 year old person, any sport is okay as long as it is adopted but he advises that persons above 30 years toalways engage in activity at least thrice a month because of their vulnerability to cardiac diseases. They should, however, avoid exercises of high intensity.

He recommends weight lifting for cardiac patients for these keep the cardiac muscle at rest. Heavy exercises could, however,precipitate a cardiac arrest.

For any physical activity, Kabenge warns, one has to begin with a warm up to awaken the muscles which may involve stretching to avoid pains associated with working out.

Working out destroys muscle cells meaning that these must be rebuilt. In the process lactic acid is produced which causes the pain, especially for those who only exercise once in a while. But with regular exercise, these acids are recalled and turned into an energy source.  For asthma patients, exercise is even more important according to Dr Mondo. He says it strengthens lung muscles, which improves lung function by strengthening the heart and makes one less winded with exertion.  Over time, the more you exercise the more tolerant your heart and lungs become to the effects of exertion.

He however recommends stretch exercises in order to avoid scenarios of exercise induced attacks.

Taking a lot of fluids is also recommended when exercising to avoid dehydration since in the process, body temperature raise leading to loss of energy, heat, and water.