PHYSICAL ACTIVITY PATTERNS AMONG HIGH SCHOOL AND UNIVERSITY STUDENTS IN THE V4 COUNTRIES: A COMPARATIVE STUDY - Pongrác Ács; Ewelina Niźnikowska; Marian Stelmach; Marcin Weiner; Alexandra Makai; Viktória Prémusz; Ján Junger; Ferdinand Salonna; Iva Šafaříková; Věra Kuchařová; Joanna Baj-Korpak (Health Problems of Civilization)