The project aimed to develop curricula for 15 physical education (PE) hours that meets >50% MVPA. By this we aimed to contribute to diminishing physical inactivity (PI) of children and teenagers (age 12 to 15) that is urged regularly by important organisations, e.g. World Health Organisation Physical Activity reports (2018). Several organisations accepted a direct guideline to counteract in the field of PE classes (e.g. EU Physical Activity Guidelines, 2008) to increase time spent in moderate to vigorous physical activity intensity (MVPA). Our project developed curricula for PE classes and through local public campaigns encourage target groups to become active members of various local sport clubs in order to reach recommended levels of daily physical activities. After our previous we reported that 45-minute PE class, lasted no more than 36 minutes, with only 9-13 minutes of MVPA and more than 16 minutes of physical inactivity (PI). This clearly demonstrated that during PE class children and young people fails to reach 50% MVPA (=22.5 minutes). Our finding was in line with rare other studies, reported in USA and Netherlands. An Institute for Kinesiology Research at Science and Research Centre Koper (a research coordinator of the project) accepted at the very beginning of the project “Recommendations for achieving medium- and high-intensity physical / sport activity in physical education to improve the health and learning of children and adolescents” to be used as the project message throughout professionals working in this field.Methods being used were of high quality, using objective methods and a valid research design that will allow many scientific reports. Five athletics sport clubs, from 5 countries, were included in the project. Their aim was to organize a demo team of ten 12-15-year old children (their members), with 2 coaches and PE teacher(s) and develop specific curricula of three (per club) PE classes with educational activities from their expertise (athletics). Athletics was used as it represents the base of child motor development. Altogether 15 PE curricula, were developed locally and presented in 3 camps (5 curricula per camp) in front of international council of all partners with physical activity measurements to further develop and optimize the PE class. During the camp several activities were performed to further increase the quality and intensity of a PE class to come out with a final version that was video recorded and evaluated with a means of accelerometers – a valid method to assess physical activity phenotypes (physical inactivity, light, moderate and vigorous intensity of physical activity).At the and we were successful to develop all 15 PE classes with more than 50% MVPA. We have reached 27.4±3.5 minutes of MVPA (21.9% more than recommended = 22.5 minutes) and 107% more than existing reported data of three studies. Furthermore, PI was diminished by 63.1%, being only 7.1±3 minutes. The average heart rate during 15 PE classes was 157±10.5 beats per minute indicating moderate aerobic physical activity. Furthermore the Borg scale of effort was 6.6±0.9 (out of 10), indicating hard (but not very hard) effort.Based on a children opinion, effort assessment, professional evaluations of PE teachers, those PE classes were suitable for majority of 12-15-year old children and could be employed in a primary schools. Our results were so far presented in a BSc and MSc diplomas, scientific conferences, workshops and will be further presented in PhD thesis as well as in scientific journals.