Physical Fitness and Body Composition as Predictors of Anxiety, Depression, and Stress in University Students

University students experience high levels of psychological distress, including anxiety, depression, and stress. Physical fitness and body composition have been proposed as potential protective factors against these conditions. This study aimed to examine the relationship between indicators of physical fitness and body composition with symptoms of anxiety, depression, and stress in Chilean university students, primarily enrolled in sport-related programs. A cross-sectional design was conducted with 281 participants (85.7% male; age = 20.85 ± 2.24 years). Assessments included muscle strength tests, body composition via bioimpedance, and estimated cardiorespiratory fitness (VO 2 max). Psychological symptoms were evaluated using the DASS-21 scale. After applying uniform Benjamini–Hochberg false discovery rate correction across 15 predictor–outcome tests (q = 0.05), no significant associations were found between physical fitness or body-composition indicators and anxiety, depression, or stress (all q ≥ 0.45). Descriptively, an inverse association between estimated VO 2 max and anxiety was observed, consistent with prior literature, but it did not remain significant after correction. These findings should be interpreted cautiously due to the cross-sectional design, indirect VO 2 max estimation, sex imbalance, and sport-enriched sample. Results are exploratory and hypothesis-generating, requiring confirmation in larger, more representative, and pre-registered studies.