Adolescent swimmers (N = 231) from Greece, Japan, Sweden, and the U.S. completed questionnaires on training practices, mood state, staleness prevalence, and symptoms. Contrasts were made across countries and between stale and healthy groups. Of the total sample, 34.6% reported having been stale, ranging from 20.5% to 45.1% across countries. The mean length of staleness episodes was 3.6 weeks. Stale swimmers had faster (p < .01) personal best times in the 100-m freestyle compared with healthy swimmers. Mood disturbance was elevated (p < .05) during peak training for all countries except Japan. Stale swimmers reported greater (p < .05) mood disturbance at all assessments compared with healthy swimmers. The pattern of staleness symptoms was similar across all countries, with perception of training effort being the most affected.