The article shows the results of a research on growth and physical development among students of sensitive age, 14–17, studying at boarding schools and gymnasiums, and university students aged 17–19. Also, the article includes a hygienic assessment and comparison of the students’ physical development and its correlation to the adaptive capacity of a human body. The research observed 447 boarding gymnasium students, 505 boarding school students, and 144 university students, their physical development was studied concerning the criteria of adaptation that are expressed as an adaptation capacity. The data gathered indicates that the majority of the students experience balanced physical development, that is natural to a healthy, adequately adaptive human body, and the presence of a strong statistically relevant correlation between physical development and adaptive capacity (r = 0,91; p ≤ 0,001).