General and physical benefits of exercise

“Those who think they have not time for bodily exercise will sooner or later have to find time for illness” ~Edward Stanley.

There is no shortage of evidence that regular physical activity is good for us. Flick through the pages of any health report and there’s sure to be a section outlining the benefits of exercise on our physical wellbeing. And many of us have experienced ourselves just how satisfying it can be to climb into bed, pleasantly tired after a day of strenuous activity.

According to government studies, physical activity reduces the risk of death or ill health from many diseases and conditions, especially:

• heart diseases and strokes
• some cancers
• type 2 diabetes
• osteoarthritis and osteoporosis
• falls in older people
• obesity
• depression and anxiety
• high blood pressure.

There's a whole range of other health benefits, including help with digestion and poor posture. Perhaps more significantly, exercise can promote regular sleep and a healthy body weight, avoiding the poor health effects associated with insomnia and obesity.

Don't be a statistic

Every January, gym memberships rocket as people act on their New Year’s resolution to improve their fitness.
The sad truth is that many of those memberships are barely used as we soon return to our old routines and find excuses to skip a work out. But if you are looking for a good reason to get moving again, consider the following:

• Cardiovascular disease (including strokes) is the leading cause of death in New Zealand, responsible for 40% of deaths annually – that’s 11,300 people.
• Obesity is a risk factor for a number of diseases including diabetes, high blood pressure, coronary heart disease, osteoarthritis and some cancers.
• It has been estimated that by 2011, around 29% of the adult population may be obese.
• Approximately 80,000 New Zealanders are known to have type 2 diabetes. By 2011 this number could increase to 145,000. At least one third of this increase is driven by increasing numbers of overweight and obese people.

Physical activity has been shown to have an important role to play in reducing the risk of death or ill health in all of the conditions mentioned above.

Regular exercise achieves health benefits by:

• Increasing ‘stamina’ or cardio respiratory endurance – making your heart and lungs deliver oxygen-rich blood to your muscle cells. Your heart rate will not rise as high with equivalent exertion, and will return to normal more quickly following exercise. You will also have increased your stamina for the everyday activities of life, not just for exercise.
• Increased muscular endurance – your muscles will be able to work longer and harder before they lose strength or feel exhausted (‘fatigued’). This effect can also see you feeling more able to cope with everyday physical tasks.
• Lowering blood pressure.
• Increasing good cholesterol levels.
•  Improving bone health.
• Providing social benefits - whether you walk with a friend, play tennis with workmates, or form a social cycling team.
• Weight control - low intensities of aerobic exercise have the potential use up the body’s fat stores. Interestingly, short bursts of high intensity muscular activity are more likely to use the body’s stores of glucose rather than its stores of fat as a source of energy for the exercise. Regular sessions of 30 to 60 minutes of low to moderate intensity aerobic exercise (at around 55 to 70% of maximum heart rate) can be an important part of a weight loss or weight management programme.

The battle against cancer

The New Zealand Cancer Society’s position statement also makes sobering reading. It states that improved nutrition and increased physical activity could help prevent many of the 7,600 cancer deaths in New Zealand each year. The society believes nutrition and physical activity may have a role in around a third of all cancers - that makes them second only to tobacco as a potentially preventable cause of cancer.

Body weight and physical inactivity together are estimated to account for approximately one-quarter to one-third of several of the most common cancers, specifically:

• cancers of the breast (postmenopausal)
• colon
• endometrium
• kidney
• adenocarcinoma of the oesophagus.

Poor nutrition and lack of regular physical activity have also been most closely linked to colorectal cancer, where New Zealand mortality rates are the highest in the world. There is also a growing body of evidence to suggest that physical activity alone is associated with a reduced risk of some cancers, eg, colon cancer and breast cancer in premonopausal women and those just hitting menopause.

The Cancer Society recommends: “Be physically active for at least 30 minutes on most days, preferably more, including some vigorous activity.”

How much exercise is needed to reduce risk?

The Ministry of Health has published a useful table outlining how exercise can help with various conditions and diseases. It also describes what type of exercise we should be concentrating on. Moderate exercise is beneficial in most cases and it needn’t be hard to slot into our usual routine. The New Zealand guidelines for promoting physical activity define moderate-intensity activity as anything causing a slight but noticeable increase in breathing and heart rate. So get walking or swimming and you could be exercising your way to a long and, more importantly, healthy life.

Key
* Small effect ** Moderate effect *** Large effect 
1.  Moderate activity is important in stroke prevention; strength exercise is important in the rehabilitation post-stroke.

Source: Ministry of Health, NZ. 

Aerobic exercise precautions

If you're over 40, have existing health problems or muscle, bone or joint injuries, or you have not exercised regularly in the recent past, check with your doctor before undertaking an aerobic exercise programme. As with any form of exercise, be aware of over-exercising, either by doing aerobic exercise too hard, for too long or too often. This approach can lead to injury, and abandoning of your fitness programme.

Remember to build up gradually from your current activity level, and not to progress too rapidly. 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.