Renals, L, Lake, J, Keogh, J, and Austin, K. Strongman log push press: The effect log diameter has on force-time characteristics. J Strength Cond Res 32(10): 2693-2700, 2018-Strongman training is becoming more common in strength and conditioning practices, particularly the log press. The existing literature analyzes force characteristics of the log clean and jerk or press compared with the weightlifting clean and jerk exercise. This investigation aims to explore the braking and propulsive phase performance characteristics of the push press with a barbell and strongman logs of different sizes. Ten experienced athletes volunteered to perform the push press exercise using 65% of their 1 repetition maximum using a small-diameter log, a large-diameter log, and a barbell. Analysis of variance showed a significant difference in all mean braking and propulsive characteristics (force, velocity, power, impulse, and displacement) between the barbell and both logs but there was no difference in lift duration. Comparison between both logs showed that the small log had significantly greater power (6%, p = 0.01), velocity (2%, p = 0.01), impulse (5%, p = 0.03), and force (3%, p = 0.01) but no difference in center of mass displacement or lift duration. In addition, propulsive phase when using the barbell was 4.4 times greater in force, 2.2 times in impulse, 1.8 times in velocity, and 2.3 times in power, and this was greater when compared with the larger diameter log. The athletes achieved larger propulsive outputs with a barbell over a log in the push press exercise in addition to showing a higher mechanical demand with a log that increases the larger log diameter, which may mean that the athlete needs to adapt loads when looking to optimize training parameters.