Aerobic fitness (VO2max) is more than about fitness: it is about health too VO2max is the maximum amount of oxygen that your body can use per minute and is the main measure of aerobic fitness. VO2max is also a very important measure of health, especially cardiorespiratory health or the health of your heart and lungs. VO2max combines into a single number1 the ability of the (i) lungs to bring in fresh air (oxygen), (ii) blood to carry oxygen from the lungs to the muscles via the heart (iron stores, haemoglobin), (iii) heart to pump blood to the muscles (carrying oxygen) and (iv) muscles to transport and use oxygen to produce aerobic energy for exercise.
VO2max is a bit like a chain: it is only as strong as the weakest link. To have a high VO2max, all four links in the chain need to be working well.
So VO2max is a very important measure of health. Low VO2max correlates with high risks of cardiovascular disease and even early death not just from heart disease, but also cancers of the breast and colon.2,3 And improving your fitness (increasing VO2max) reduces the risk of early death from all causes.4
For this reason, itis recommended that all individuals be regularly tested for aerobic fitness (VO2max).3
So how is aerobic fitness (VO2max) measured? Unfortunately the gold standard of expired air collection and analysis requires expensive laboratory equipment, highly trained staff and the need for clients to attend specialised facilities, and so is inaccessible to most people except for elite athletes, or patients with cardiovascular disease, or patients who are being pre-screened for surgery. Fortunately it is possible to estimate VO2max using predictive equations known as algorithms, based on just a few simple measures that can be made in a gym or a studio.
Whilst I acknowledge that these algorithms are not perfectly accurate when compared with the gold standard direct measurement of VO2, they are reliable enough for testing the general population and are perfect for pretraining versus post-training comparisons for individual clients. They are also excellent for measuring the effects of lifestyle changes in your clients.
So why then are so few people being assessed for VO2max?
Surely exercise professionals are in a great position to offer this service using algorithms. Why do so few exercise professionals conduct exercise tests that can estimate VO2max? And the even bigger question is why so many exercise professionals don’t test the fitness of their clients in order to design exercise plans at intended intensities? If exercise professionals aren’t testing the aerobic fitness of their clients, then they are relying on guesswork to design exercise programs that could even be unsafe for the client. The answer is that most exercise professionals are either unaware of the algorithms or don’t use them because they don’t know how to use them.
In this series of articles, I am going to show you how easy it is to use algorithms to not only estimate VO2max with good levels of precision, but also to estimate submaximal levels of VO2 and measure fitness and then link these directly to prescribe exercise scientifically and individually to your clients.
If you are not already doing this, then this will greatly enhance the value of your service to your clients.
1. Opondo MA, Sarma S, Levine BD. The Cardiovascular Physiology of Sports and Exercise. Clin Sports Med. 2015;34(3):391-404.
2. Kaminsky LA, Arena R, Beckie TM, et al. The importance of cardiorespiratory fitness in the United States: the need for a national registry: a policy statement from the American Heart Association. Circulation. 2013;127(5):652-662.
3. Ross R, Blair SN, Arena R, et al. Importance of Assessing Cardiorespiratory Fitness in Clinical Practice: A Case for Fitness as a Clinical Vital Sign: A Scientific Statement From the American Heart Association. Circulation. 2016;134(24):e653-e699.
4. Lee DC, Artero EG, Sui X, Blair SN. Mortality trends in the general population: the importance of cardiorespiratory fitness. J Psychopharmacol. 2010;24(4 Suppl):27-35.
a Exercise professionals includes exercise physiologists, exercise scientists, sports scientists, physiotherapists (physical therapists) and personal trainers.