TRAINING – A prescription for health

Orienteering –

a prescription for health

Steve Bird

Inactivity is recognised as a major health risk in Australia, and studies have suggested that approximately 20% of the health burden could be reduced if people exercised at the advocated levels. Nationally1, it is estimated that physical activity could prevent:

– 33% CHD (coronary heart disease) – 25% Diabetes – 12% breast cancer – 15% stroke – 10 to 16% hip fractures

In addition to these there is a growing body of evidence to support the efficacy of exercise in reducing the risk of other diseases, including colorectal cancer. So with all this evidence, does a regular dose of Orienteering represent your best buy for health? Well, although there have been relatively few studies, looking at Orienteering in particular, one study2 on male Masters orienteers in Finland showed that their risk of a heart attack was less than one-seventh that of inactive age-matched controls. Of course it could be argued that orienteers are a self-selected group, who may be less prone to heart attacks due to an innately better level of health. So to consider this further we must expand our discussion to consider walking and running activities in general, for which there is a large body of epidemiological evidence.

A weighty argument

Many people are concerned about their weight, and according to national statistics, nearly half of Australian adults are either overweight or obese. However, despite all the marketing and expensive products being sold to help people reduce their weight, in most cases it is simply a matter of calories in (food) vs calories used (metabolism and exercise), virtually everything else is of minor impact. So to reduce weight, or more specifically, to reduce our fat stores, we need to use up more calories than we take in. And one of the ways to increase the use of calories is through exercise. Whilst the exact calorific cost of a bout of exercise will depend upon the individual; an hour’s vigorous exercise, such as Orienteering, will utilise around 600 - 900 Calories (kcal), depending upon how fast you’re running and how hilly the terrain is, etc. This is the calorific equivalent of about 0.08 – 0.12 kg fat. So if you do around 20 events a year, it equates to about 1.5 – 2.5 kg of fat (values estimated from Robergs and Roberts, Exercise Physiology, Pub. McGraw-Hill). Not a bad way to keep the fat off. But even if you’re losing this battle, don’t despair, because in terms of health, fat isn’t the whole story. For example, very large epidemiological studies have shown that whilst being fit and not overweight is the best combination for health, if you are active and relatively fit despite being overweight, your risk of heart disease is the same as someone who is not overweight but inactive (Lee et al3). And of course, being inactive and overweight is the worst combination. So the message is that being active is good for your health even if you are overweight. And, as indicated above, it may help you to lose those excess kgs, or at least stop you from putting on any more.

It’s in the blood

And other studies are beginning to reveal the metabolic and physiological bases of these benefits. Some of these benefits are associated with the acute effects of each bout of exercise, whilst other benefits are accrued through repeating these bouts on a regular basis (chronic benefits). In general terms, for our bodies to remain in good health, numerous factors need to be maintained within specific and permissible ranges, thus maintaining homeostasis. Examples of this include the concentrations of glucose and fats within our blood. If these become too high or fall too low, it will lead to illhealth and, in extreme cases, death. However, whilst we need to regulate these factors in our blood, our supply and use of them is not consistent. For example there will be surges in supply when we eat a meal and then periods of fasting between times. So to prevent their levels becoming too high after eating, our bodies have complex regulatory systems that are designed to rapidly store away the excess for later use. This storage also provides an internal source that can be mobilised when our blood levels drop in the hours between meals or when we increase demand for them, as when exercising. However, some of our most prevalent chronic diseases such as heart disease and diabetes are associated with a failure of these homeostatic responses to work as effectively as they should. And consequently glucose and lipid levels are inclined to rise too high after a meal. This can even be seen in some people who have not yet succumbed to the full-blown disease, but are in a pre-disease state; and probably don’t know it. Fortunately exercise has been shown to restore much of this sensitivity. For example, it has been shown that for about 72 hours after a bout of exercise (the length of time does vary depending upon the individual, their age and the exercise), our systems for controlling blood glucose and blood lipid levels after a meal are more sensitive4. This means that they respond more effectively to the ingested food and prevent the levels of glucose and lipids from rising too high, and reaching the disease associated levels. Unfortunately these benefits wear off after a few days, and therefore in order to restore the benefits, you need to exercise again. Hence, exercise needs to be undertaken regularly to gain the full health benefit. Regular exercise also has chronic health benefits, such as producing a healthier blood lipid profile throughout the day (not just after a meal), with lower levels of the atherogenic Low Density Lipoprotein Cholesterol (LDL-C) and a better ratio of LDL-C with the cardio-protective High Density Lipoprotein Cholesterol (HDL-C).

Mental health

When espousing the health benefits of Orienteering, it is important not to focus solely upon the physiological, and to forget the mental and social aspects. It’s a great sport, with a friendly clientele, and at the end of a hard challenging event, I’m sure many of us feel so much better for having focused on the challenges of our course, whilst forgetting the stresses of other aspects of our lives. And even on the occasions when we didn’t perform at our best, we can probably still coin the phrase that “A bad day’s Orienteering is still better than a good day at work”.

The complete prescription

In truth, whilst Orienteering is certainly good for our cardiovascular fitness and health, it probably doesn’t cater for all our health needs. And some muscular strengthening work is needed, particularly as we get older. Interestingly, there is a growing body of evidence for the benefit of strength training in improving our glucose control, insulin sensitivity, and reducing the risk of developing diabetes. Also we must not forget the other factors that contribute to our health, such as healthy eating, not smoking, and not abusing alcohol.

Negative health impacts

Of course, as with all activities there is a risk of injury. In Orienteering this is usually in the form of sprained ankles5, 6 or the occasional broken bone. In reality, this risk and the long term impacts are relatively low, compared to the consequences of not exercising, which includes a risk of heart disease, diabetes, osteoporosis and many other diseases. A point which was nicely made by the esteemed exercise physiologist P.O. Åstrand, when he said “Those who decline to participate should undergo a medical examination to check whether it is safe for them not to do so”. Furthermore, despite popular mythology, being active in sports such as Orienteering does not significantly increase your risk of arthritis in later life, indeed the paper referred to earlier2 also found that compared with age-matched inactive people “Disability due to hip or knee pain after the same everyday activities tended to be less in the runners” .

Conclusion

Yes, there is overwhelming evidence that regular Orienteering is good for your health, but: • You need to exercise more than once a week, and so need to do more than just your Sunday event. As advocated by all the health messages, try to exercise for at least 30 minutes on at least five and preferably all days of the week. • For a holistic level of health, you’ll need to do some muscle strengthening exercises as well as cardiovascular work. So visiting the gym once or twice a week is recommended. • Whilst being not overweight, but not too lean, is good; health is not all about weight and independent of your weight, your health will improve with regular exercise. • There are always risks when exercising, but these are relatively low, compared to the large risks of being inactive. And whilst the occasional exercise related incident may grab the headlines it is unfortunate that the converse fails to get similar headlines such as “ 30 people died suddenly yesterday – none of them were out jogging’’

References

1. The cost of illness attributable to physical inactivity. - Stephenson et al 2000. Commonwealth Department of Health and Ageing. 2. Kujala UM et al, Heart attacks and lower-limb function in master endurance athletes, Medicine and Science in Sports and Exercise. 1999

Jul;31(7):1041-6. 3. Lee S et al. Cardiorespiratory fitness attenuates metabolic risk independent of abdominal subcutaneous and visceral fat in men,

Diabetes Care. 2005 Apr;28(4):895-901. 4. Gill JM et al. Moderate exercise and post-prandial metabolism: issues of dose-response, J Sports Sci. 2002 Dec;20(12):961-7. 5. Creagh U and Reilly T, Training and injuries amongst elite female orienteers, J Sports Med Phys Fitness. 1998 Mar;38(1):75-9. 6. Linko PE et al. Orienteering competition injuries: injuries incurred in the

Finnish Jukola and Venla relay competitions, Br J Sports Med. 1997

Sep;31(3):205-8.

Professor Steve Bird is at RMIT University, Melbourne. Steve worked with the Great Britain National Orienteering Squad for over 10 years and is now assisting the Victorian Junior Squad.

Orienteering Australia – National Training Centre Tea may help Navigation

New research shows that tea can help you to focus. Had a bad day, fancy a chat with friends or really need to crack that tricky problem? What do you do? Put the kettle on of course. We have always known that tea gives us a certain something that helps us through, but it’s always been hard to define exactly what’s so special about it. Until now... New research carried out by Unilever could help us understand why taking time out for a cup of tea is beneficial and makes such a difference. They have established that a normal cup of tea typically contains 22mg of the amino acid theanine. Tea is virtually the only dietary source of theanine, apart from the edible bayboletes mushroom, which explains why sometimes only tea will do. A study by scientists at Oxford University found that 50mg of theanine stimulated alpha brain waves which are associated with being relaxed yet alert. 50mg of theanine represents the amount typically present in 2-3 cups of tea. Alpha activity is thought to be important for the ability to focus attention. A further study by Unilever found that people who drank two cups of tea were not only faster but also more accurate at performing tests that measured their ability to focus attention. The odds of a correct response on one test of attention were increased by 40%. This research by Unilever has been supported by a number of independent scientists including Louise Dye, a reader of psychology at Leeds University:”There are a number of studies (published and unpublished) which examine the effects of theanine ingestion on psychological outcomes which suggest that regular tea consumption over a period of hours may maintain relaxation, focused attention and accuracy. Theanine may modulate the more acute effects of caffeine such as found in coffee.” Whereas coffee offers a stimulant from caffeine, tea is the only drink that naturally contains both caffeine and the less common theanine. The level of caffeine in tea is also much lower overall than brewed coffee (approximately half in an average sized cup). Kate Hick, Unilever tea Brand Manager says: “We really wanted to understand the unique effects felt by tea drinkers. We have invested a lot of time and energy in really getting to grips with what makes tea so special when it’s really so simple - just tea leaves, water and sometimes milk.” In the test volunteers performed computerised tests that measured their ability to focus attention. This is the ability to ignore distracting information and is synonymous with concentration. In the laboratory, it is measured by presenting more than one piece of information at a time, but with instructions to process and respond to only one. After drinking tea, there were significant improvements in both the speed and accuracy of their performance. So, can the humble cuppa tea help you to concentrate in the terrain? That’s for individual orienteers to find out, but it may be worth a try.