5 minute read
TRAINING
Orienteering,
Ageing and Health
OUR physical fitness tends to peak when we are in our mid-twenties to mid-thirties. Exactly when this occurs varies between individuals and is influenced by how much regular exercise we undertake, what sort of training we do and other lifestyle factors. Then inevitably our physical capacity begins to decline as a consequence of ageing processes. This can be seen clearly in the ranks of top orienteers, where even the best veterans are eventually usurped, as they don’t have the fitness of younger elites who are in their prime.
However, that is not to say that we should give up training after we reach our peak or that there is no point in trying to stay fit. Indeed, not only are there well established health benefits from continuing exercise such as Orienteering, but by continuing to train, the declines in physical capacity can be minimised. In fact in sedentary older people a substantial amount of their loss of physical function is attributable to inactivity and other lifestyle factors rather than ageing per se. Within our sport, the benefits of staying fit are illustrated weekly by fit older orienteers who regularly beat their unfit competitors, even though they may be are 20 – 30 years younger. This is, of course, ignoring factors such navigational skills. What is also encouraging is that if you’re not already training regularly and at your peak of fitness for your age, you can still improve, and studies have demonstrated increases in the fitness of people aged over 70. So it is never too late to try and get fit, or to at least restore some of what you may have lost. Of course the amount of improvement you’re liable to experience depends upon how unfit you are to start with and how much training you are capable of doing.
An analysis of the Orienteering speed of top national orienteers1 shows that having attained a near peak of performance in their early twenties some men and women orienteers are still at this level when aged around 40. But despite their best of intentions and dedicated commitment to their sport there then appears to be an inevitable slowing in Orienteering speed that starts at around the age of 40 – 45 years. This slowing in speed equates to about 10 – 15% per decade, with a suggestion of an even steeper decline after the age of 70 years (Figure 1). This overall pattern is also evident in club level orienteers. So why do we slow down as we age and is there anything we can do about it? maximum heart rate, which reduces maximum oxygen delivery and hence VO2 max. Orienteers certainly manifest these age linked declines in maximum heart rate with average declines of around 3 – 6 beats per decade3,4. In this context it should be noted that the commonly referred to algorithms for estimating a person’s maximum heart rate of:
“HRmax = 220 – age” or “HRmax = 200 – 0.65 age” are rough guides based upon population averages and it’s not uncommon for an individual’s true maximum heart rate to vary from these predictions by more than 20 beats per minute, so don’t rely on them too heavily.
Other reasons for declines in running speed mooted by some researchers are an age-linked decline in muscle mass, which may become very significant in the older age groups. Particularly in Orienteering when good leg strength and power are needed for running up hills and over rough ground. However running economy as measured by the oxygen cost of running at specified speeds does not appear to be affected by ageing, although more research is needed in this area. Nor, it would appear, is the ability to produce lactic acid affected by ageing, as we found some of the older women in our studies5 to have similar levels of lactic acid to that of the young men. So even though an older person’s lactate threshold may occur at a slower running speed, it is at a similar % of their maximum speed and % of their VO2max. Practically this means that even though they may not run as fast, older orienteers certainly try as hard and experience similar levels of fatigue as their younger counterparts.
Age related declines in Orienteering performance
Research on age-related changes in all endurance running events and data based on the world best times for distances on the track and road suggest a decline in running race speed of 6 - 10% per decade in both men and women after the third decade of life2 . Investigations into the underlying physiological changes behind the observed performance declines in endurance events have linked them to reductions in maximum oxygen uptake (VO2 max). In general VO2 max in endurance athletes appears to decline by 5 - 7% per decade3,4 and this is primarily attributed to a decline in
So what can we do about it?
It must be appreciated that the underlying causes of age-linked changes in performance are likely to be a combination of social, physiological, psychological and biomechanical factors. Not all of which will be a direct result of ‘pure-ageing’. As, for example, would be the effects of lifestyle changes, such as having children or the demands of a career. We all go through life phases during which these exert a greater or lesser influence on our athletic activities and our Orienteering becomes higher or lower in our priorities. Other factors affecting performance can be as simple as poorer eyesight and greater difficulty in reading the fine details on the map.
As we age it is important to adjust our training loads to suit our needs and priorities. Although our aims may be to be as fit as we can, the amount we do may need to be adjusted in accordance with what our bodies can cope with. Almost all sportsmen and women eventually have to accept this as recurrent injuries indicate that their training loads are exceeding their capacity. Those of us who have trained hard in our youth and prime, tend to find facing such truths unpalatable, but the adjustment is essential. So finding the optimal volume, intensity and type of training is a key requirement for successful competitive Orienteering in the veteran ranks. Unfortunately there is no formula that suits everyone and we each have to find what suits us through trial and error. However, regardless of our competitive aspirations we should always aim to reach the minimum threshold of physical activity for good health which is to undertake at least 30 minutes of moderate activity on most, and preferably all, days of the week. It is also of particular note that strength training is being more widely recognised by the health and medical professions as an important activity that to some extent can counteract the age linked losses of muscle mass. It is therefore prescribed to help older people maintain their functional abilities. Although I’m not aware of any related study to date, it would be interesting to know whether high intensity strength training could benefit our oldest orienteers and I would speculate that it might.
