Functional vs Structural changes through training

This blog is about making athletes think about their training, why do certain things and what happens when we try to adapt training programmes to our physiology instead of following the normal cookie cutter approach of just doing. Understanding what functional and structural changes are helps with this understanding of why we see certain changes through training. There is no official definition and these ideas come from FaCT so I have made my own version of the definition here plus given a few examples so you can get a idea of what functional and structural training is.

Don't confuse the definitions of functional training (or functional strength training) which Wiki writes it as, training the body for activities of daily life, which in short is transferring the strengths from one movement with resistance to a sport or activity.

Functional change definition: This is normally a short term result of training and is where the initial changes in the body is seen. Functional changes are often temporary and is gained and lost quickly.

Structural change definition: This is a long term change in the body that results from starting as a functional change and through months and sometimes years of specific training to develop that specific system may see the development of a structural change which supports the human body.

So when the two definition are combined then functional and structural training implies to the development of the human body through specific training which will normally start with functional change, and through specific stresses and adaptions lead to a structural change which will improve athletic performance. The development of the structure of the body which broadly speaking will include the respiratory system, cardiac system, muscular system, hormones, blood system etc.

Here are some simple examples: A professional cyclist who has been cycling for years, has a higher amount of mitochondria growth and capillarization compared to a amateur. Using the same trained cyclist, his muscles have developed from being a amateur cyclist being functionally good to adjusting the muscle fibres structurally so that they can better perform the required activity.

Athletes thus in general have a higher ability to utilise oxygen and pump a higher volume of blood which is developed through training.

You say so what, this is obvious. Here are some more examples to think through: A novice cross country skier will have problems initially learning to ski and use a huge amount of energy learning to balance, after a few days he has learned to balance and found the needed coordination and he will be skiing faster simply by having made a functional change. Now you did some tests as he started skiing and a few weeks later the skier has shown an improvement and you think, great he is fitter, but most likely due to the improved balance and coordination the skier is able to use more muscle to ski faster, which may show a higher VO2, instead of using muscle to balance. The Skier will initially very quickly develop the utilisation ability through capillarization and mitochondria density and the before mentioned improved balance and co-ordination. This is often the big improvements seen in research studies which last only a few weeks versus trained athletes where changes are small as there is very little room for functional changes. To make structural changes which will strengthen the athletes respiratory system, improve cardiac output and stroke volume may take months or even years.

Another type of example: A athlete goes to altitude or sleeps in a altitude tent and is able to raise his blood values, now he goes back to a lower altitude to compete and if he is a responder to altitude, he/her body is simply utilising the extra oxygen available to the body. To make a real altitude adaption takes many years of IHT and altitude training where the body learns to adapt, and to better utilize and deliver.

Some individuals can improve Stroke Volume (SV) through certain training protocols or even exercise which can be due to a plasma volume increase. This again is a very functional change which is temporary. Repeating this functional training over several weeks, sometimes months should (if the correct stimulus is used with the correct timing to stress the limitation) see a structural change in End Diastolic Volume (EDV) as a change in heart size, thus a higher volume ability to pump blood (stroke volume) and a lower heart rate (CO=SVxHR).

So in any system that you are training you need to think, is it development or just utilisation, i.e. capillarization or capillary utilisation, SV through plasma expansion or SV through EDV improvement,   mitochondria density or mitochondria enzyme reaction. Is the sudden improvement weather related, (hot=warmer tarmac=different reactions on bicycle/skate wheels resistance.) or is it true structural adaptation. Another improvement which has not even been mentioned is on the mental side. Once you have done lets say a performance test, you know how it feels, so next time in most cases without any physical improvement you know how to pace it better. Changes in nutrition can make functional changes to blood (e.g. beet root) certain supplements which may buffer H+. Respiratory training with specific devices will initially show great improvements as coordination and general conditioning improves (similar to the idea with the skier) but long term diaphragm strength and transfer of training to sport specific activity may take months.

The key to train structure, you need to find what is the limitation which is creating the weak link in athletic performance.

Further and more in depth reading on functional and structural training go to http://fact-canada.blogspot.de/2008/02/functional-and-structural-training-by.html and the here.