The idea that stability ball training is important has recently gained a wide acceptance as a methodology for the prevention of injury and permeated the training practice of many strength and conditioning professionals. Central to this type of training is the importance of “core stability,” as it has been termed, and its relationship to the muscles that provide stability to the spine. The initiation of this type of training is an offshoot of rehabilitation practices for individuals with lower back injuries and falsely assumes that the “core” or trunk muscles are not properly engaged in healthy individuals when undertaking traditional resistance training practices. It is very clear that stability ball exercises are effective rehabilitation tools when appropriately applied with individuals who are injured, unhealthy, or extremely detrained (5). Proponents of the use of these exercises often cite numerous studies looking at individuals with pre-existing injuries, untrained weaker individuals, such as untrained older adults, and athletes who are unhealthy because these exercises may be effective in these populations (5). The vast majority of these studies use low loads, long tension times, and isometric muscle actions, which are not capable of developing the core stability necessary for sports performance gains in healthy athletes (5).
Conceptually, the degree of effectiveness of “core stability” exercises is related to the threshold for adaptive response stimulus. Clearly, when one is injured, lower loading levels are necessary to achieve an adaptive response. Conversely, when an injury is not present, the threshold necessary to stimulate adaptive responses is elevated and as such stability ball training fails to achieve a level of activation that is effective at inducing strength gains (5). Support for this contention can be found in the recent work from Lederman (1), where it is suggested that individuals who do not have pre-existing injuries to their trunk musculature are unable to achieve a high enough training stimulus necessary to achieve adaptive responses with these muscles when using stability ball or core stability–based training modalities. Similarly, Nuzzo et al. (3) clearly demonstrated that traditional strength training exercises, such as the deadlift and back squat, especially when loaded with resistances typically used to target muscular strength gains, create more trunk musculature activation when compared with “core” stability exercises. Similarly, Marshall and Desai (2) report that only the bridge exercise results in a training stimulus high enough to result in training-induced adaptations, whereas most of the other core exercises tested (hold & crunch, hip extension, and rolls) do not create an overload stimulus high enough to induce strength gains in the trunk musculature.
Another issue related to “stability ball” training is related to its inability to apply a transfer of training effect to the athlete's chosen sport. Stanton et al. (4) clearly demonstrate that using a “stability ball” training regime with endurance athletes, a traditionally weaker population, results in improvements in core stability. At first glance, this may seem like a study that lends support to the use of “stability ball” training methods, but careful inspection reveals that the test of core stability was in fact performed on a stability ball, which biases the results because only one treatment group practiced the testing protocol. Additionally, it was clearly noted that the “stability ball” training methods did not result in any enhancement in running economy or any other markers of actual sports performance. As such, Stanton et al. (4) suggest that there is no scientific evidence to support the use of stability ball–based training, and the methods used with this type of training do not result in athletic performance enhancement in healthy athletes. In fact, much stronger evidence is present for the use of traditional resistance training exercises, such as squats, power cleans, Romanian deadlifts, deadlifts, pulls etc., which target the development of strength and power as a method for the enhancement of athletic performance (1,3-5) and supplying a stimulus high enough to maximally develop the musculature of the trunk (3).
With the limited amount of time that is often allotted for strength and conditioning at the collegiate level, it is very clear that strength and conditioning professionals should prioritize their training activities. To maximize the effectiveness of the allotted training times, coaches should eliminate or severely limit the use of “stability ball” or “core stability” training in favor of traditional resistance training exercises that offer a greater training stimulus and a higher transfer of training effect to actual markers of sports performance (3). Clearly, strength training with traditional exercises offers a much greater efficiency of training and maximizes the adaptive responses necessary for enhanced sports performance.
1. Lederman E. The myth of core stability. J Bodyw Mov Ther
14: 84–98, 2010.
2. Marshall PW and Desai I. Electromyographic analysis of upper body, lower body, and abdominal muscles during advanced Swiss ball exercises. J Strength Cond Res
24: 1537–1545, 2010.
3. Nuzzo JL, Mccaulley GO, Cormie P, Cavill MJ, and Mcbride JM. Trunk muscle activity during stability ball and free weight exercises. J Strength Cond Res
22: 95–102, 2008.
4. Stanton R, Reaburn PR, and Humphries B. The effect of short-term Swiss ball training on core stability and running economy. J Strength Cond Res
18: 522–528, 2004.
5. Willardson JM. Core stability training: Applications to sports conditioning programs. J Strength Cond Res
21: 979–985, 2007.