Paz-Franco, A, Rey, E, and Barcala-Furelos, R. Effects of three different resistance training frequencies on jump, sprint, and repeated sprint ability performances in professional futsal players. J Strength Cond Res 31(12): 3343-3350, 2017-The aim of this study was to examine the effect of 3 different resistance training (RT) frequencies (1 strength training session per week [1W], 2 strength training sessions per week [2W], or 1 strength training session every second week [0.5W]) on jump, sprint, and repeated sprint ability (RSA) performances in professional futsal players. Thirty-five futsal players were randomized into 1 of 3 groups, the 1W group (n = 12), 2W group (n = 12), or the 0.5W group (n = 11). The players performed the same RT during 6 weeks, and only training frequency differed between the groups. Within-group analysis showed significant improvements in jump (p ≤ 0.001, effect size [ES] = 0.13-0.35), sprint (p ≤ 0.001, ES = 0.48-0.71), and RSA (p ≤ 0.01, ES = 0.22-0.63) from pretest to posttest in 1W and 2W groups. However, no significant (p > 0.05) pre-post changes were observed for the 0.5W group in any variable. In the between-groups analysis, significant better results were found in jump (p ≤ 0.01), sprint (p ≤ 0.01), and RSA performances (p ≤ 0.01) in the 1W and 2W groups in comparison with 0.5W group. Also, jump (p ≤ 0.05) and 5-m sprint (p ≤ 0.05) performances were significantly better in the 2W group in comparison with 1W group. In conclusion, the current study showed that 6 weeks of RT 1 or 2 times per week in addition to typical futsal training produced significant improvements in jump, sprint, and RSA performances. Additionally, RT once every second week may be sufficient to maintain physical fitness in professional futsal players. This information may be useful for coaches when planning training contents during congested fixture schedules or in periods where the emphasis needs to be put on other qualities and to spend as little time as possible on maintaining or increasing physical performance.