PURPOSE: To assess the training load, energy expenditure, dietary intake, and sleep quality and quantity of junior tennis players during a tennis training camp. METHODS: Ten junior academy tennis players (14  y) completed a 6-day camp with daily morning and afternoon training. Players wore accelerometer watches to measure activity energy expenditure and sleep. Global positioning system units were worn to monitor external training load (distance covered, maximum velocity, and PlayerLoad™). Dietary intake was obtained from a food diary and supplementary food photography. RESULTS: Players covered significantly more distance and had higher PlayerLoad™ during morning sessions than afternoon sessions (5370  m vs 4726  m, P < .005, d = 3.2; 725  a.u. vs 588  a.u., P < .005, d = 4.0). Players also ran further (5624  m vs 4933  m, P < .05, d = 1.0) and reached higher maximum velocities (5.17 [0.44] m·s-1 vs 4.94 [0.39] m·s-1, P < .05, d = 0.3) during simulated match play compared with drill sessions. Mean daily energy expenditure was 3959 (630) kcal. Mean energy intake was 2526 (183) kcal, resulting in mean energy deficits of 1433 (683) kcal. Players obtained an average of 6.9 (0.8) hours of sleep and recorded 28 (7) nightly awakenings. CONCLUSIONS: Junior academy tennis players failed to achieve energy balance and recorded suboptimal sleep quantity and quality throughout the training camp.