Strength is contextual. In movement, force (strength) can be produce at all speeds. For example, high-speed strength means being able to produce large amounts of force at a high velocity. Slow speed strength simply means being able to produce high amounts of force at low velocities. At all times, when talking about strength, we need to make sure that the context is clarified. However, just because they are contextually different, does not mean they are not related. For example, increasing slow speed strength (one rep maxes) can help facilitate high speed strength (vertical jump height).
Slow Speed Strength
Slow speed strength training is typically synonymous with heavy weight training, ranging from loads between 75-100% of an athlete’s 1rm. Unlike fast speed strength, slow speed strength is often referred to as the “strength base”. The reason for this is that in untrained athletes, increases in maximal strength (slow speed strength) are often associated with increases in strength at faster speeds, such as the vertical jump (1). In large part, these adaptations are considered “general”, meaning that these adaptations are not just specific to one sport. Increases in slow speed strength will carry over to sport, but only for an extended period of time. Once the athlete has built a large enough base, and slow speed strength no longer progresses at an effective rate, more specific methods might be needed (2).
Physiological Reasons For Slow Speed Strength
Slow speed strength training is associated with many improvements in the physiological capabilities of an individual. It is because of these adaptations that slow speed strength is often considered the “base” for sporting performance.
Increase in muscular hypertrophy (cross sectional area)
Increase in motor unit recruitment
Increase in rate coding
Increase in pennation angle
Increase in tendon strength
Increase in bone density
Increase in motor unit synchronization
Possible increases in central drive
Increase in hormonal response
For greater detail on the influences of these adaptations on power development, please refer to these two links below
Slow speed strength training can lead to many positive, non-specific adaptations. These adaptations are what are often considered as the “strength base”. However, it is important to note that all of these adaptations are facilitating qualities. For example, during the early stages of training, these adaptations have the ability to improve strength at both low and high velocities. The issue with slow speed strength is that as the athlete increases in training age, improvements in slow speed strength become harder to come by and may even lead to detrimental adaptations (too much body mass and increased muscle slack). As a coach, the importance of slow speed strength training should not be ignored, while at the same time, the reason why slow speed strength training is being performed should not be forgotten. The goal of slow speed strength training is to facilitate the development of higher speed movements. Once the facilitations begins to stop, then training may need to become more specific.
(1) Augustsson, S. R. (2013). Maximum Strength in Squats Determines Jumping Height in Young Female Volleyball Players. The Open Sports Sciences Journal, 6(1), 41–46. http://doi.org/10.2174/1875399X01306010041
(2) Cormie, P., Mcguigan, M. R., & Newton, R. U. (2011). Developing Maximal Neuromuscular. Sports Medicine, 41(1), 17–39. http://doi.org/0112-1642/11/0001-0017