Spectrum is a word that has come to be closely associated with Autism over the last several years. People are described as being ‘on the spectrum’. But the word spectrum just means a range. It is a concept used to classify something in terms of its position between two extreme points, and we’d like to look at the spectrum of VO2max.
VO2max is a measure of the body’s use of oxygen, most often in relation to sport and exercise. But as we shall see later it also has relevance to daily life. A VO2max test tries to establish the highest amount of oxygen that can be taken in to the body and used by someone, usually over a period of one minute. Equipment is used to measure how much of the oxygen breathed in is absorbed into the blood to be used by the muscles and other internal organs. The higher the VO2max score, the greater the level of what is described as cardiovascular fitness. To you and me that is just fitness.
There are two measurements describing VO2max, absolute and relative. Absolute VO2max is the total amount of oxygen that is taken in and used in one minute, and is measured in litres per minute (L/min). But the more usual, and useful, measure is Relative VO2max, which is the amount of oxygen taken in and used per Kg of bodyweight per minute. Bigger people will be able to use more oxygen due to their size, so using the Relative VO2max measure means that oxygen use can be usefully compared across people of different sizes. Relative VO2max is measured in millilitres of oxygen per kilogramme of bodyweight per minute (mL/kg/min).
A VO2 max test will involve, say, running on a treadmill while the speed gradually increases. As the treadmill speeds up physical exertion rises to keep up with it and the measuring equipment will then see a corresponding rise in the amount of oxygen being taken in and used. At a certain point, even though the treadmill continues to get faster and the exertion continues to rise, the rate of oxygen absorption will peak. No more oxygen can be absorbed by the subject and they will become more and more out of breath. This point, at which their maximum rate of oxygen use has been reached, is their VO2max. The higher the VO2max measurement, the fitter they are.
These measurements are most often used in relation to elite athletes, and elite athletes have put in a great deal of training to increase their VO2max. Most people don’t have access to the kind of equipment needed to measure it so won’t know their own score but as an example male elite athletes might have a relative VO2max of 85 mL/kg/min and in female athletes the measurement might be 77 mL/kg/min. The highest recorded VO2max score was by Norwegian cyclist Oskar Svendsen who is thought to have recorded a VO2 max of 97.5 mL/kg/min, when aged 18.
However, most people are not elite athletes, even if many Silver Grey athletes are elite in their age groups, so what is the relevance with regard to everyone else? The relevance is twofold. Firstly, within the medical and sporting communities age is regarded as a significant limiting factor in VO2max - VO2max is generally something that declines with age. Correspondingly one’s ability to perform physically, in sport and exercise or in daily life, also declines. Secondly, as described above VO2max is a strong indicator of cardiovascular fitness, and increased cardiovascular fitness is regarded as a strong indicator of a decreased risk of disease. The fitter you are the less likely you are to fall victim to one or other of the modern diseases, heart disease, diabetes, stroke and cancer. Additionally, as aerobic activity has been established as a good way of maintaining brain health, better fitness will also have benefits there.
So as you become older higher VO2max means better health, as well as a better ability to perform any of the physical activities of daily life. This last is an important factor as we shall now see.
From the top end of the spectrum we’ll look at the other end, the lowest values of VO2max. VO2min, one might say! The reason that this is important is that scientists have established that there is a VO2max score below which it is thought that you can no longer live an independent life. You have such a low capacity to absorb oxygen into your system that you no longer have the physical resources to autonomously complete activities of daily living. Scientists put this value at about 18mL/kg/min for men and 15mL/kg/min for women. If your VO2max falls below this level scientists believe you can no longer look after yourself!
So, this one spectrum of VO2max extends from elite athletes at one end all the way down to people who no longer have the physical capability to look after themselves and live independently. The most able and the least able can both be assessed across the same spectrum. And you can see that there is a relationship between the ability to perform athletically and the ability to live independently.
When you think about the elite athletes it is no surprise that in order to reach the level of fitness required to perform at their level a lot of training is required, and over a long period. But what about those at the other end of the spectrum? Can they do anything to help themselves? The answer, according to a paper published by Roy J Shephard Ph D in 2008 in the British Journal of Sports Medicine, (Shephard, R. J. (2008). Maximal oxygen intake and independence in old age. British Journal of Sports Medicine, published online April 10, 2008, Doi:10.1136/bjsm.2007.044800) is definitely yes! VO2max is an aspect of health and fitness that does, in most cases, respond to effort put in to improve it!
For people who have reached or are approaching what we have called somewhat flippantly VO2min, training is very effective, and can raise the VO2max level significantly. Shepherd’s analysis of previous research showed that VO2max can be increased by almost 13% over an 8-10 week period of training and by almost 17% over a 24-52 week period. To illustrate what this means, “from review of the data, Shephard suggests that gradually increasing aerobic training can boost the aerobic power of the elderly by at least 10 ml/kg/min, potentially delaying the loss of independence by as much as 20 years. Shephard continues that higher intensities with seniors lead to even greater gains. An increase of 25% in VO2 max (about 6 ml/kg/min) is equivalent to gaining back an estimated 12 years of vigor to one's lifestyle.”
That’s to say that this loss of physical capability can be reversed. You can restore your energy levels with training and get back to how you were a decade or two previously! In practical terms, of course, it is far better to start training before you reach the point of dependence, but this research shows that there is never a time when it is too late to make a difference to your life! Certainly, our Silver Grey athletes are nowhere near a VO2min value. Some of them will be classed as elite, particularly those competing in age-group sporting events. However, the important thing to take away from this is to realise once again just how transformative exercise can be and how effective it is at countering so-called age-related decline, whatever your situation.
Take control of your life and define your own future.