Changes in pre-competition state anxiety of junior and senior high school football and basketball players were studied as a function of trait anxiety of these athletes and three experimental athletic environments characterized by stressful and non-stressful conditions. In response to the psychological stress associated with athletic competition, state anxiety significantly increased in all subjects. These rises in state anxiety were occurring between practice and regular season and playoffs. High Trait subjects exhibited significantly higher elevations in state anxiety than Low Trait subjects which was in agreement with Spielberger's Trait-State Anxiety Theory. Stressful athletic environments (regular season and playoffs) did not, as has generally been believed, differentially affect the state anxiety of both groups of subjects. Spielberger's State Anxiety Inventory successfully discriminated between practice and competitive athletic environments and was successfully used in assessing the presence and strength of state anxiety levels of athletes in these environments. (Author)