Unstable Surface Training (UST) has long been heralded as a transformative approach in fitness, capturing the imagination of gym-goers and trainers alike with promises of enhanced stability, core strength, and athletic performance. From balance boards to stability balls, the allure of exercising on unstable surfaces has gained popularity in the fitness industry, fueled by endorsements from trainers, influencers, and even celebrities. Yet, as the dust settles on this trend, questions arise about its efficacy and relevance for the everyday fitness enthusiast. Despite its prevalence, there’s a growing scepticism surrounding the true benefits of UST, particularly when applied to the general population. We’ll explore the reasons why, despite its popularity, UST may fall short of delivering substantial advantages, especially for those seeking practical and sustainable fitness improvements.
What Exactly is Unstable Surface Training?
Unstable Surface Training (UST), or Instability Resistance Training (IRT) as it’s commonly referred to in academic literature, encompasses a variety of exercises performed on surfaces that lack stability or firmness, such as balance boards, stability balls, or foam pads. The fundamental principle behind UST is to challenge the body’s proprioception and stability by introducing an element of instability during exercises. Advocates of UST often claim that this instability forces the body to engage smaller stabilising muscles, thereby improving overall balance, core strength, and neuromuscular coordination. Proponents suggest that these benefits translate into enhanced athletic performance and reduced risk of injury in real-world scenarios, making UST an attractive option for both fitness enthusiasts and athletes looking to elevate their training regimen.
The History of Unstable Surface Training
The history of UST can be traced back to the mid-20th century, with the emergence of pioneering studies exploring the role of balance and stability in human movement. Early research in the fields of physical therapy and rehabilitation highlighted the importance of proprioception—the body’s ability to sense its position and movement in space—in maintaining balance and preventing injury. These foundational concepts laid the groundwork for the development of novel training techniques aimed at enhancing proprioceptive abilities through destabilisation exercises.
In the 1970s and 1980s, Swiss ball training gained traction within the fitness community as a versatile tool for improving core stability and balance. Initially used in rehabilitation settings to facilitate recovery from musculoskeletal injuries, Swiss balls soon found popularity among athletes and fitness enthusiasts seeking to enhance their performance and strength. The inherently unstable nature of Swiss balls necessitated greater engagement of stabilising muscles, prompting interest in exploring similar training modalities.
Throughout the 1990s and early 2000s, researchers and fitness professionals began experimenting with a diverse array of unstable surfaces and equipment, including balance boards, foam pads, and BOSU balls. These tools were incorporated into exercise routines to challenge balance, coordination, and core stability, with the belief that training in unstable environments could confer benefits beyond traditional resistance training methods.
The popularity of UST surged in the late 2000s and early 2010s, driven by a convergence of factors including advancements in exercise science, growing interest in functional fitness, and the proliferation of social media influencers advocating for novel training modalities. Fitness enthusiasts were drawn to the perceived novelty and effectiveness of UST, with many attributing improved athletic performance and injury prevention to their incorporation of unstable surface exercises into their training regimens.
However, as UST gained mainstream attention, so too did scrutiny surrounding its efficacy and safety. Critics raised concerns about the lack of empirical evidence supporting the proposed benefits of UST, as well as the potential for increased injury risk associated with training on unstable surfaces. This scepticism prompted a reevaluation of UST within the scientific community, leading to a more nuanced understanding of its limitations and appropriate applications.
What is Unstable Surface Training Good For?
Despite the ongoing debate surrounding the true benefits of Unstable Surface Training (UST), it can’t be denied that it holds significant importance in rehabilitation programs designed to restore function and prevent reinjury in individuals recovering from musculoskeletal injuries. UST originated in this context, where its potential benefits are most evident. By offering a controlled yet challenging environment, UST facilitates muscle retraining, improves joint stability, and restores functional movement patterns. Engaging in exercises on unstable surfaces prompts the activation of a wider range of stabilising muscles throughout the body, including those in the core, hips, and ankles. These muscles work together to maintain stability and control in response to the unpredictable surface, leading to neuromuscular adaptations and functional improvements over time. A literature review on UST revealed a significant increase of 47.3% in trunk muscle activation during exercises performed under unstable conditions (Behm & Colado, 2013), suggesting the potential benefits of UST in rehabilitation.
It’s important to also keep in mind that early in the rehabilitation process, factors such as inflammation, pain, and stiffness may play a part in reducing force and power production. Therefore, a balance-only training program (without specific resistance exercises) can serve as an effective initial training phase to improve an individual’s strength and power. This balance-training program can provide a safe and effective starting point in the rehabilitation plan, which can then progress to incorporate resistance on unstable surfaces or with unstable devices (Behm & Colado, 2013).
Limitations of Unstable Surface Training
While UST may be beneficial in certain contexts and for certain individuals (as explored above), the issue with this training style is when it is prescribed for the broader fitness industry and glorified as a ‘one-stop-shop’ for a range of fitness and athletic outcomes. Here is where things get messy. Let’s unpack this in two specific contexts, general population training and athletic development.
General Population Training
There has been a lot of recent controversy on the prescription of UST for the general population or the general fitness enthusiast. The question we need to ask ourselves here is “What’s the primary training outcome being sought after?” For the average gym-goer, it’s usually weight loss, muscle gain, increased cardiovascular fitness and/or strength improvements. This is where UST gets put on the chopping block. The issue is that UST is not an appropriate training method to induce adaptations that effectively progress individuals toward these training goals.
For individuals seeking muscular hypertrophy, local muscular endurance, or strength improvements, traditional resistance training is the primary training mode that is effective in eliciting these adaptations. As summarised by Schoenfeld et al (2021):
- A low repetition scheme with heavy loads (from 1 to 5 repetitions per set with 80% to 100% of 1-repetition maximum (1RM)) optimises strength increases.
- A moderate repetition scheme with moderate loads (from 8 to 12 repetitions per set with 60% to 80% of 1RM) optimises hypertrophic gains.
- A high repetition scheme with light loads (15+ repetitions per set with loads below 60% of 1RM) optimises local muscular endurance improvements.
But surely UST combined with resistance training would elicit even greater benefit, right? This is where confusion is created. The academic literature demonstrates that UST results in significant decreases in muscular force and power output (Behm & Colado, 2013). So essentially when performing exercises on unstable surfaces, our larger muscle groups can’t exert the same force they could if they were on stable surfaces, such as a flat ground. Since muscular hypertrophy, strength, and power adaptations are highly dependent on progressive overload through increases in loading, this is where UST doesn’t provide the ‘bang for your buck’ that resistance training does on stable surfaces.
So in summary, if you’re an average gym-goer wanting to lose weight, gain muscle or increase your strength, ditch the free weights on bosu balls, and stick to the ‘tried and tested’ method of resistance training on flat ground to optimise your results.
Athletic Development
As explored above, resistance training on unstable surfaces has been shown to reduce force or power actions in athletes by approximately 30%, compared to traditional ground-based free weights (e.g. squats, deadlifts, Olympic lifts) on stable ground (Behm & Colado, 2013). Because of this, athletes benefit from stable surface training in the same way the general population does to maximise force production and reap the most training benefits. However, when talking about athletic development, the conversation now shifts to training specificity.
The principle of training specificity emphasises that training should be specific to the particular demands of the activity or goal a person wants to achieve. In other words, to improve in a certain skill or activity, the training should closely mimic the movements, energy systems, and conditions of that activity. For example, if someone wants to improve their running performance, they should primarily engage in running rather than solely focusing on unrelated activities like swimming. This principle helps optimise training efficiency and effectiveness by targeting the specific adaptations needed for desired outcomes. So in simple terms, to get better at something, you have to train in a way that’s similar to actually doing that thing. It’s about training to closely match what you want to improve.
Following this principle, it’s ineffective for athletes to train on unstable surfaces because such conditions differ from those encountered in most sports. Consider sports like football, netball, volleyball, or track and field; these activities predominantly occur on stable ground. Athletes exert force and perform movements on solid surfaces during competitions. Therefore, athletes generally benefit more from strength and power training on stable surfaces to optimise force production and ensure a seamless transfer of skills to competitive settings.
So in conclusion, while UST holds value in rehabilitation and physical therapy settings, its broader application should be approached with caution. Recognising its limitations and considering the principles of training specificity can help guide the appropriate use of UST in fitness and athletic training programs. In the end, while UST can be valuable in specific situations, its widespread adoption as a “cure-all” for fitness and athletic improvement requires careful assessment and alignment with individual training objectives and requirements.
REFERENCES
- Behm, D. G., and Colado, J. C. (2013). Instability resistance training across the exercise continuum. Sports health, 5(6), 500–503. https://doi.org/10.1177/1941738113477815
- Schoenfeld, B. J., Grgic, J., Van Every, D. W., & Plotkin, D. L. (2021). Loading Recommendations for Muscle Strength, Hypertrophy, and Local Endurance: A Re-Examination of the Repetition Continuum. Sports (Basel, Switzerland), 9(2), 32. https://doi.org/10.3390/sports9020032
- Zemková E. (2021). Stable to unstable differences in force-velocity-power profiling during chest presses and squats. Journal of biomechanics, 122, 110463. https://doi.org/10.1016/j.jbiomech.2021.110463
- Schilling, B. K., Falvo, M. J., Karlage, R. E., Weiss, L. W., Lohnes, C. A., & Chiu, L. Z. (2009). Effects of unstable surface training on measures of balance in older adults. Journal of strength and conditioning research, 23(4), 1211–1216. https://doi.org/10.1519/JSC.0b013e3181918a83
- Cressey, E. M., West, C. A., Tiberio, D. P., Kraemer, W. J., & Maresh, C. M. (2007). The effects of ten weeks of lower-body unstable surface training on markers of athletic performance. Journal of strength and conditioning research, 21(2), 561–567. https://doi.org/10.1519/R-19845.1
