The individualisation of sports training is often seen as the holy grail of sports performance, the ability to perfectly match the characteristics of a player with how they train is often proposed as the key to maximising performance. In one way, it is quite easy to recognise what type of athlete you are, do you like to run fast or slow? Lift heavy for a few reps or a moderate load for a number of reps, on the 5 a side pitch are you great and making short fast bursts or can you plod along for the whole game seemingly never to fatigue? We are all born with a specific amount of muscle fibre types, either fast or slow twitch. The percentage of each essentially dictates our ability to excel in different sporting activities. The 100 metre sprinter will be predominately fast twitch and the marathon runner of course we would expect to be predominately slow twitch. In team sports such as Gaelic, rugby and soccer, it may be harder to identify the motor type or characteristics of many players as a combination of speed and endurance qualities will exist. So how can we identify or classify the type of athlete we are?
Historically this was done by the invasive method of muscle biopsy, where a sample of muscle tissue was taken directly from the individual, the muscle tissue was then examined under a microscope and the percentage of fast and slow twitch fibres was estimated. Many studies have reported the relationship between a higher proportion of fast twitch fibres in strength and power athletes compared to non-athletes, and the higher proportion of type I muscle fibres in endurance athletes. Following on from this, other investigators reported the validity of using squat jump and countermovement jump test to predict muscle fibre composition compared to muscle biopsy, thus reducing the need for invasive and expensive biopsies. Numerous researchers have reported significant correlations between jump height variables, reactive strength index, Isokinetic force maximal strength, and sprint speed. Those who can jump higher, lift heavier and create more force, tend to run faster. From these studies it is clear that while muscle fibre composition cannot be identified directly from these tests, it may be possible to identify the “motor type” of the athlete, i.e. do they display fast or slow biomotor abilities as determined by jump, force or sprint tests.
While the research suggests that numerous field tests can give an indication of an athlete’s physical capabilities, limited studies have deliberately sought to characterise athletes as either slow, intermediate or fast motor type, indeed using the end point or outcome of these tests may not fully identify the athletes characteristics. Technique, skill level and training history all play a part in the outcome of these tests. Recent research from UL by Robin Healy, shows that individuals with similar sprint times may use different mechanisms to achieve these times, this is something that can also be seen in analysing the force time characteristics of various jump and isokinetic force tests. While many of these tests can be carried out reasonably easily and cheaply, often with apps on your iphone or laptop, more recent developments include the use of genetic testing to identify an athletes genetic composition and as a result their dominant physiological attributes. Genetic testing is now commercially available, with home testing kits available from approximately €50 up to in excess of €500. These kits test for common genomes such as ACTN, IL-6, and ACE which have been associated with sports performance. Over 200 genetic variations are potentially associated with physical performance phenotypes or training responsiveness and to date approximately 20 polymorphisms have been found to be specifically associated with elite athlete performance. In a recent study, graduate of UL, John Kiely, indicated that by matching the individual’s genotype with the appropriate training modality leads to more effective resistance training and greater improvement in performance. While this is a relatively new area of research, it is possible that genetic testing may become the most preferred way of identifying athletic potential and directing training interventions. Through my own research in UL, I hope to establish more clarity in objectively identifying the motor types of athletes using non invasive methods, with the aim of maximising training interventions.
Ciaran Keogh is a postgraduate student in the Physical Education and Sport Sciences Department. Contact Ciaran at ciaran.keogh@ul.ie, Twitter: @cgkeogh
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