”…disregarding the potential improvements that science can bring is quite foolish to me.”
Today, we will speak about the testing of physical abilities in professional soccer. I’m posting an interview with Dr. Vedran Hadžić who is a member of the chair of sport medicine, member of the Kinesiology section and associate at the sport-medicine diagnostic and nutrition laboratory at the University of Ljubljana, Slovenia.
1. Doctor, what is the aim of testing the physical capacities in Soccer? What tests bring to coaches?
We have many different testing methods and of course, they deliver different types of information. For example, I’m specialized in Isocinetic testing of the muscular function. When a player goes through the testing process, we can 1) determine the level of his capacities in comparison with what we would expect in professional soccer players and 2) determine if there are any imbalance in agonistic-antagonistic muscles. In less scientific words, this means that we often see players with strong quadriceps, but poor hamstrings which evidently increases the risk of injury. By doing the test, we can then orient the athlete or the coach in order for them to plan a training program that will correct this problem (strengthen the hamstring in this case). Then, in a same aspect, we can help an injured player recover his capacities by controlling the progression and see when he has reached the level he had before the injury. That of course implies that we have a consistent testing program that gives us references throughout the season. My other area of expertise is balance. We have now very precise measurement that can tell us if a player has balance problems. Here again, we will sort out in a team players that present lack of ability in this area and help them get better.
Now I have talked a lot about injury risk but of course, the aim of a test is also to give coaches objective data and tell them where particular players can improve. By implementing specific drills or practice sessions in their standard training program, we will be able to make them better. It’s about knowing where the player starts from and control where he is going. I have seen many coaches (especially in Ex-Yugoslavia countries) unwilling to use scientific testing in their training process but, as far as I can tell, the human eye is quite a subjective tool to determine specific physical abilities. Of course, science doesn’t help you much when you want to determine the soccer specific quality of the player (is he a good player?) but when you have a team of well trained athletes and you are engaged in a top level competition, disregarding the potential improvements that science can bring is quite foolish to me. At the top level, it’s a matter of fine tuning, a 2 or 3% percent improvement on speed is enormous for example. Why not take the advantage that our work can provide?
Nowadays, coaches have at their disposal many equipment that they can bring on the field so they don’t need to send their players to the lab. Determining strength parameters, aerobic/anaerobic capacity, balance,…There is a wide choice of testing methods, which you must choose wisely because they must be close to the physical demands of soccer. Do not forget that players prefer to be tested on the field, where they feel comfortable.
2. Talking about players, do you feel that involving them in the process is important ?
It’s essential. If we do some kind of testing here at the university and we keep it for ourselves without explaining it to the player, what’s the point? We want to have players that understand what we are doing, why we are doing it and what they can get from it in term of improvement. By involving them in the process, you get maximal motivation, which is also an important factor. We must also understand that modern players have more knowledge than before, they get a lot of information from internet and they want to be a part of it, not only a subject in a research.
3. Clubs have the possibility to buy high technology equipment like Polar Team system that allows coaching staff to have a look at the hear rates of all the players. Is this kind of live testing meaningful in term of training intensity analysis?
It is, but only at a consistent basis and within a full testing process. That means that you’ve got to test the maximal capacities of the players at the beginning of the pre-season training because you need references. Without references, it has little meaning. You’ve got to know his Vo2max, his maximal heart rate, the heart rate at the anaerobic threshold,… When you have all the data, then you are able to control the intensity of the training with the live heart rate measurement and tell if the aim of your training was achieved. I repeat, testing one time has little meaning, you want to do it consistently in order to get results that will help.
3. Does the university cooperate with professional soccer teams?
Recently, we organized a large scale isocinetic knee testing program for all the youth national teams of Slovenia (from U16 to U21). We also tested some professional teams in our professional league. From all the collected data, there is one evidence: hamstring muscles are under developed for a huge majority of players. In the meantime, they have normally developed quadriceps strength (at the level we expect when comparing to international data). Therefore, we have an imbalance that is a problem not only from the point of injury risk, but also from the point of speed production.
But I must say that the level of cooperation with clubs is still unsatisfying.
Find out more about the University of Ljubljana, faculty of sport.

