Magal, M, Smith, RT, Dyer, JJ, and Hoffman, JR. Seasonal variation in physical performance-related variables in male NCAA division III soccer players. J Strength Cond Res 23(9): 2555-2559, 2009-The purpose of this study was to examine changes in various aerobic and anaerobic physical performance measures in male National Collegiate Athletic Association (NCAA) Division III soccer players during the competitive soccer season. Twelve starters of the men's soccer team (mean ± SD; age = 20.0 ± 0.9 years, height = 175.7 ± 8.1 cm, body mass = 73.9 ± 11.00 kg, body mass index [BMI] 24.0 ± 3.0 kg·m2, and percent body fat = 10.6 ± 5.4%) were tested at the beginning (PRS) and the end (POS) of the collegiate soccer season. Each experimental trial included a maximal aerobic capacity test (V̇O2max); 10-, 30-, and 40-m sprints; pro-agility test; and the Wingate anaerobic power test (WAnT). From PRS to POS, V̇O2max significantly increased (51.05 ± 5.97 vs. 54.64 ± 4.90 ml·kg−1·min−1), and the 10- and 30-m sprint were significantly lower (2.03 ± 0.15 vs. 1.96 ± 0.11 seconds and 4.72 ± 0.26 vs. 4.51 ± 0.24 seconds, respectively). Anthropometric measures, 40-m sprint, pro-agility test, and WAnT were not significantly different between PRS and POS. The results of this study indicate that NCAA Division III male soccer players appear to improve aerobic and anaerobic performance measures during the competitive soccer season. It is arguable that these performance improvements may represent a poor preseason conditioning level that may result in a competitive disadvantage during the early stages of the season. An ongoing process of recruiting better-quality players that may closely follow the off-season training regimen may partially remedy this problem.