Mladen Opačić is a specialist in the field of physical preparation and rehabilitation. He holds a degree of Bachelor of Sports Science, which he obtained at the Faculty of Sport and Physical Education, University of Belgrade.

Having stopped playing handball professionally, in 2007 he starts working as a strength and conditioning coach in the handball club “S.K. Beo-grad“.

In 2008 Mladen starts working as a personal trainer at the Academy of Healthy Life Profex with professor Duško Ilić, as one of his best students. For the next two years he works with numerous clients of various profiles (reduction of body weight, rehabilitation, recreation, athletes).

Yet, in 2010 he changes his job and starts working in the fitness studio MVP-GYM with Vlado Kaplarević (strength and conditioning coach of Nenad Zimonjić) and Ivan Dimitrijević (strength and conditioning coach of Bojana Jovanovski). For the next three years he works with a great success in this fitness studio and contributes to the strength and condition of junior tennis players and many other clients of different profiles. While workig here, Mladen achieves a successful cooperation with tennis coaches Branislav Jevremović and Ivan Gaža.
At the same time, during the season 2011/2012 Mladen works as a strength and conditioning coach in the volleyball club “Stara Pazova“, where he works with top-class athletes.

At the end of 2012 he founds Top Gym Fitness and Rehabilitation Center with a colleague of his, Bojan Avramović.

Since 2014 Mladen has been responsible for physical preparation of all teams in water polo club “Partizan“, junior categories and the first team players.

In 2015 he becomes the strength and conditioning coach of Serbian national water polo team U17.
In the season 2015/2016 Mladen works as the strength and conditioning coach of the handball club “Al Najma“, Bahrain (the state champion).  

In the season 2016/2017 he works as a strength and conditioning coach of water polo club “Partizan“.


His successes as a strength and conditioning coach:
- Serbian championship in the season 2014/2015 - water polo club “Partizan“, Belgrade
- the gold medal in Baku 2015, European Championship - Serbian water polo national team U17
- the silver medal at Asian Champions League in Doha 2016 - “Al Najma“, Bahrain
- the gold medal at European Championship in Holland 2016 - water polo national team U19
- The Cup of Serbia in the season 2016/2017 - water pola club “Partizan“