Ross, RE, Ratamess, NA, Hoffman, JR, Faigenbaum, AD, Kang, J, and Chilakos, A. The effects of treadmill sprint training and resistance training on maximal running velocity and power. J Strength Cond Res 23(2): 385-394, 2009-The purpose of the present study was to examine the independent and combined effects of resistance and treadmill sprint training on maximal sprint velocity and power. Twenty-five male athletes (age = 19.8 ± 1.5 years, height = 181.2 ± 7.9 cm, body mass = 88.9 ± 10.9 kg) were matched for 30-m sprint times and assigned to 1 of 3 training groups: 1) sprint training only (ST), 2) resistance training only (RT), or 3) combined sprint and resistance training (SRT) for 7 weeks. Periodized resistance training was performed 4 d·wk−1 (3-4 sets of 6-10 repetitions). The treadmill sprint training program was performed 2 d·wk−1 and consisted of 8-12 sets of maximal sprints for 40-60 m at 0-25% of each athlete's body mass, with rest intervals of 2-3 minutes on a treadmill that was user driven and that enabled loading via a magnetic braking system. Peak 30-m sprint times, power and average velocity attained during maximal sprint trials on the treadmill, and 1-repetition maximum (1RM) squat were determined pre and post training. The 30-m sprint times improved significantly only in the SRT group, and a trend for improvement (p = 0.06) was observed in the ST group. All groups significantly increased treadmill sprint velocity. However, the SRT and ST groups increased significantly more than RT. Only the SRT group increased treadmill sprint peak power. All training groups increased 1RM squat strength significantly by 6.6-8.4 kg, with no differences observed between groups. The results of this study showed that 7 weeks of sprint training on a newly designed treadmill resulted in significant kinematic and kinetic improvements in sprint performance. Of practical significance, treadmill sprint training enhanced land-based sprint performance.