Catapult European Manager and Sport Scientist Steve Oosterhof sat down with Mladen Jovanovic, Head Physical Preparation Coach at Hammarby IF in Sweden, to discuss their sport science program and how they apply the Catapult system.

Mladen has previously worked in a variety of roles in Serbia and Turkey and has been using Catapult with Hammarby in 2013, and was generous with his time in discussing his use of the technology.

Catapult: How did you start working in Sweden?

Mladen Jovanovic: Gregg Berhalter, the former Hammarby Head Coach, upon arriving at the club in January 2012, needed the Strength and Conditioning Coach to help him with the physical preparation of the squad and load monitoring. We had a common friend, Darcy Norman from Athletes Performance, who recommended me for the position. I am lucky enough to know a person such as Darcy. Cannot thank him enough, not only for introducing me to Gregg, but for providing the expert support all the time for both of us.

Catapult: When did you first hear about Catapult?

Mladen Jovanovic: I think I’ve heard the Catapult name from time-motion studies I have read couple of years ago. I believe the author was Tim Gabbett or some other high-level sport scientist from Australia. I remember being jealous of those guys for being able to collect such data and take an empiric approach to training and decision making.

Catapult: How do you think Catapult helps improve performance of your athletes?

Mladen Jovanovic: In multiple ways. First one, and the most basic, involves creating the exercise database for the coaches to select from and to suit planned loading and training objectives, at least from a physical standpoint. Second one involves individualised tracking of external work being done by the player. Before GPS this could be done only using notational system, which is time consuming. With Catapult one could do this in real time. Besides having the objective quantification of work being performed by the players, this creates certain accountability in them since they know they are being monitored. The future of GPS monitoring involves creating individualised predictive models to optimise training, competition, recovery and injury prevention together with other data.

Catapult: In your opinion what is the most valuable aspect of football that needs quantifying?

Mladen Jovanovic: That depends on the goal of such task along with signal/noise of the estimate and its pragmatic value. Research is still inconclusive in this regard and I am not sure if someone has it figured out. That is also very motivating since there is still a lot of work to be done to figure out what is the best estimate for a given monitoring task. The recent papers by Chris Carling and Martin Buccheit have put more oil on the fire regarding this very important task.

Catapult: Without revealing any data, has the system shown anything you wouldn’t have been able to detect otherwise?

Mladen Jovanovic: Not sure if the system is the one that “detects” anything. The system provides valid and reliable estimates that one needs to put into a certain model to get insights. The model building is up to the client still and that sometimes leaves the users paralysed – which estimate to follow and how to interpret it. Talking more pragmatically, it seems that the repeat sprints sequences (as usually defined with velocity bands and rest times) doesn’t happen that often in the small sided games, nor games, which might make repeat sprint training a bit overrated, at least from game-demand perspective. Again, we still lack the data to make any conclusive remark on RSS and RSA.

Catapult: Can you name one metric you find most important?

Mladen Jovanovic: The new metabolic power data might be something that merges acceleration data and velocity data and provides better external work estimates. Yet as a practitioner, I believe we need validity and reliability studies to confirm its usability in practical settings. PlayerLoad is also a very interesting metric, especially because it is done with high frequency (100Hz) and also accumulates non-running activities, which could provide a useful measure of total load applied to a player. Besides it could be done indoor as well.

Catapult: You have dabbled with using the devices in boxing/martial arts as well. Did you discover anything interesting?

Mladen Jovanovic: It is hard to quantify external workload in martial arts. The load monitoring in martial arts usually involves internal load (HR, bLA) and subjective indicators (like sRPE). One interesting idea I tried to play with was estimating external workload using PlayerLoad metric and Catapult devices bandaged on the wrists to take into account punches as a source of external work. Additional Catapult devices could be put on the ankles, between the shoulder blades, as it is common with team sports and possibly on the headgear to take into account head punches. Wrapping these might be impractical for daily monitoring, but it might help with the drill classification and database building from physical demand point of view. Being able to estimate external load might provide info such as if a given athlete is able to generate more work on the heavy bag or in sparring after a given training program and thus have the higher potential to be used in a match. External work rate measuring might also help with the design of sport and training specific tests. As of now a lot of boxers and martial artists perform running based tests, such as VO2max testing on the treadmill, which is not really sport nor training specific. For sure, running around the ring is not a sign of a great boxer.

Catapult: For someone visiting Stockholm for the first time, what is the one thing you must see/experience?

Mladen Jovanovic: Definitely Vasa Museum. It is the museum build around Vasa ship that sank just outside of the Stockholm harbor in 1628. After just 1300m of sailing. She was found in the 1950s and salvages in 1961. And eventually moved to current museum in 1987. Besides that, the nature in Stockholm is nothing short of amazing. If you are interested in nightlife make sure to visit Stureplan area in Stockholm downtown.

Catapult: Thank you for your time Mladen and best of luck for the remainder of the season at Hammarby IF.

Mladen Jovanovic: Thank you for the opportunity to do this interview, Steve, and thanks for the professional support.


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