Look at yourself in the mirror. How are you doing? Do you see a happy and healthy person who takes everything out of life? Or do you see a person burdened with stress, who is often tired, has a lot of chronic afflictions and mostly lives on automatic pilot? Complaining won't help you much, but confronting the issues will. In the 'ring', you'll learn how to beat your biggest opponent: yourself! A mindboxer deals with limiting thoughts and takes responsibility for their own freedom and happiness. Mindboxing® is the battle in your mind. Not through fighting symptoms, but trough getting to work 100 days with the tried Three Batteries® method: Battery of Body, Battery of Heart and Battery of Mind. These batteries symbolize physical, social and mental resources to keep you balanced. With countless real-life examples, tests, practical exercises, 1+75 extensive charging tips and exclusive instructional videos on the website, you'll be equipped with the right language and tools to become the best version of yourself.
Jan Sleijfer is the owner of KEIKO® Health & Performance Center and founder of the Dutch national network NLsportpsycholoog®. He graduated in 1991 from the Academy for Physical Education with an additional specialization ‘Teacher Self Defense’. Then he graduated cum laude as a social psychologist at the University of Amsterdam where he also obtained the basic endorsement sports psychology. Since 2006 Jan has been listed in the register of the ‘Vereniging voor Sportpsychologie in Nederland’ (VSPN) as a sports psychology teacher and SPORTPSYCHOLOOG VSPN®. In addition to Western training, Jan immersed himself in Eastern medicine. In 2013 he successfully completed a three-year training as a naturopathic therapist Traditional Chinese Medicine and in 2017 the college training as a therapist Complementary Additive Medicine. Within the Educational Institute Custodial Institutions Agency (OI DJI), Jan has been training the physical and mental resilience of justice personnel in the areas of crisis communication, aggression management, hostage taking and trauma management since 1993, from individual employees to special stand-by teams and management. From 2011-2016 he taught both sports psychology and martial arts at the Hogeschool van Amsterdam (International Sports, Management and Business). As KNVB exercise master III he has coached soccer teams for years and from 2010-2014 he has been a teacher of Judo in Care and a practice assessor of teachers within the Judo Association Netherlands. In addition, he has been providing training and workshops on Mindboxing® for over ten years within all kinds of organizations, including trade unions, large IT companies, educational institutions and sports clubs. All his life Jan has been practicing martial arts. The most important of these are: judo, (kick) boxing, jiu jitsu, tai jitsu, taiji- quan, taikiken and yiquan. With his sober Western scientific knowledge as a (sports) psychologist and his Eastern wisdom as a naturopathic thera- peut (TCM), Jan teaches people to get the best out of themselves. For example, Jan guided Olympic athletes to the games of London (2012), Rio (2016) and Tokyo (2020-2021).