By Abhishek Behl (Accredited Exercise Scientist)
Training on unstable surfaces—such as Bosu balls, wobble boards, or Swiss balls—has gained popularity in both athletic and general fitness circles. While this method remains debated in some strength and conditioning settings, growing evidence supports its benefits when applied appropriately.
For athletes and everyday gym-goers alike, unstable surface training can significantly enhance core strength, balance, proprioception, and overall functional fitness. As with all training strategies; the crucial component to gaining a benefit is the how specific you employ exercise technique and strategies whilst using unstable equipment.
Key Benefits of Training on Uneven Surfaces
Improved Balance and Stability
Exercises performed on unstable surfaces require continuous adaptation and stabilisation, thereby improving both static and dynamic balance (Bishop et al., 2017). These adaptations are particularly beneficial for preventing falls, improving posture, and enhancing sport-specific movement.
Core Activation: Why Unstable Training Excels
One of the most significant benefits of unstable training is its profound impact on core muscle activation. When performing exercises on uneven surfaces, such as a Swiss ball or Bosu ball, your body recruits not only the superficial abdominal muscles but also deep stabilisers such as the transverse abdominis, obliques, and multifidus (Behm & Colado, 2012; Paillard & Noé, 2015).
Unstable environments challenge the body’s neuromuscular control systems, which must fire and be utilised rapidly to maintain alignment and posture. This constant micro-adjustment leads to increased muscle recruitment and can be especially beneficial for athletes requiring spinal stability, such as surfers, gymnasts, and skiers. According to Behm and Colado (2012), core activation is significantly higher during exercises on Swiss balls compared to stable surfaces, making these exercises ideal for improving functional strength and spinal control.
Importantly, instability doesn’t replace strength training—it complements it. Excessive instability can reduce overall force output and limit gains in hypertrophy and power (Behm & Colado, 2012). Therefore, unstable training should serve as a tool for enhancing muscle activation, control, and balance, rather than replacing foundational strength work.
Proprioception and Neuromuscular Coordination
Training on uneven surfaces also enhances proprioception—the body’s ability to sense position and movement in space (Lackner & DiZio, 2005). As the nervous system becomes better at processing feedback from joint and muscle receptors, movements become more coordinated and reflexes more efficient. This is essential for athletes responding to unpredictable environments (e.g. surfing or contact sports), and for injury prevention in the general population.
Injury Prevention and Functional Resilience
By strengthening the stabilising muscles around the joints, instability training may help prevent common injuries, especially those of the ankles, knees, hips, and spine (Mayer et al., 2018). For example, enhanced motor control and joint stability gained through Swiss ball training have been shown to support injury rehabilitation and prevent re-injury by improving motor patterning and postural control.
The Importance of Intelligent Programming
Despite its benefits, unstable training is not a one-size-fits-all solution. High levels of instability can actually reduce muscle activation and limit strength development if not applied strategically. A study by Behm and Colado (2012) highlighted that when instability is too great, the prime movers are less able to produce force, and antagonist muscles may overcompensate, reducing exercise effectiveness and potentially increasing injury risk.
Thus, the key lies in progression and intelligent integration. Instability exercises are best used as accessory movements, activation tools, or for building foundational strength and balance. They should not replace heavy compound lifts or plyometrics, particularly when training for explosive power or hypertrophy. Also, barbell exercises should generally be avoided on unstable surfaces, due to the increased risk of injury and being prone for accidents to happen. Dumbbells, kettlebells, cable work or bodyweight training offer far safer and more practical alternatives.
Examples of Effective Exercises
Bosu Ball Squats
Adding a Bosu ball under the feet turns a standard squat into a dynamic, core-intensive movement. The body must work to maintain posture and balance, activating muscles in the hips, knees, and core (Paillard & Noé, 2015).
Dumbbell Single-arm Chest Press on a Swiss Ball
Lying on a Swiss ball adds a demand for full-body stability. The chest, shoulders, and triceps are targeted, while the obliques and transverse abdominis contract to prevent rotation or tipping, making this a dual-purpose strength and core stability exercise (Behm & Colado, 2012). As well as a strong utilisation of the hips, remaining upright ensuring the movement is stabilised.
Swiss Ball Hamstring Curls
This movement strengthens the posterior chain while forcing the core to stabilise the spine. It mimics sport-specific movements that require posterior engagement with core control. Andersen et al. (2014) found that unstable hamstring curls lead to increased activation of both the gluteal muscles and trunk stabilisers, making them ideal for both injury prevention and performance.
Swiss Ball Plate Rotations
Swiss Ball Plate Rotations are a perfect example of controlled instability. Sitting or lying on the ball with a weight plate and rotating side to side requires full engagement of the obliques, erector spinae, and glutes, while resisting rotational force. This simulates real-life movements where strength and control are required simultaneously—for example, surfers holding balance during turns or transitions in choppy conditions. It’s a functional and athletic way to build anti-rotational core strength. When done correctly, this movement also acts as a powerful activation drill, preparing the nervous system and core musculature for more demanding work.
Slider Body Saw (Push-Up Position)
Begin in a forearm plank position with both feet on sliders. Keeping the core braced and body in a straight line, slowly slide your feet backwards, extending your body, then pull them forward to return to the starting position. Movement should come from the shoulders and hips, not the lower back.
Lateral Lunge with Slider (Standing)
Stand with one foot on a slider and the other on the floor. Keeping the stationary leg straight, slide the other foot out laterally while bending the stationary knee into a lunge. Return to the starting position by engaging the inner thigh and glutes. Or if you’re advanced you’re welcome to have a slider under each foot and sliding in and out like a mountain climber exercise but with sliders – controlled tempo.
Use Instability Strategically
Training on unstable surfaces offers a unique and powerful tool for developing balance, core strength, proprioception, and injury resilience. However, its effectiveness depends on intelligent application. It should complement, not replace, traditional strength training.
For athletes, especially those in dynamic sports like surfing or snowboarding, instability training provides direct benefits. But it’s also beneficial for the general population aiming to improve functional movement, injury prevention, and core control.
Best Practices:
- Use moderate instability to avoid reducing muscle activation.
- Avoid barbell training on unstable surfaces—opt for dumbbells or bodyweight.
- Pair instability work with strength, mobility, and power training for a well-rounded program.
- Progress gradually—from stable to unstable, from simple to complex movements.
By integrating movements like Swiss Ball Hamstring Curls, Bosu Ball Squats, and Plate Rotations, you’ll build a resilient, balanced, and highly functional body.
If you’re needing any further guidance with this form of training please enquire with one of our friendly team at Inspire Fitness and we’d be more than happy to help you not only with the exercise but also why it is relevant to you and your training!
References:
Andersen, L.L., Andersen, C.H., Mortensen, O.S. & Zebis, M.K., 2014. Muscle activation and perceived loading during rehabilitation exercises: Comparison of dumbbell and elastic resistance. Physical Therapy, 90(4), pp.538–549. https://doi.org/10.2522/ptj.20090167
Behm, D.G. & Colado, J.C., 2012. The effectiveness of resistance training using unstable surfaces and devices for rehabilitation. International Journal of Sports Physical Therapy, 7(2), pp.226–241.
Bishop, C., Read, P., Chavda, S. & Turner, A., 2017. Asymmetries of the lower limb: The calculation conundrum in strength training and conditioning. Strength and Conditioning Journal, 39(1), pp.30–36. https://doi.org/10.1519/SSC.0000000000000261
Lackner, J.R. & DiZio, P., 2005. Motor control and learning in altered dynamic environments. Current Opinion in Neurobiology, 15(6), pp.653–659. https://doi.org/10.1016/j.conb.2005.10.012
Mayer, J.M., Nuzzo, J.L., Dagenais, S. & Knechtle, B., 2018. Effect of lumbar stabilisation and dynamic core exercises on pain, disability, and muscular endurance in people with chronic low back pain: A systematic review. Physical Therapy Reviews, 23(4-5), pp.231–243. https://doi.org/10.1080/10833196.2018.1500955
Paillard, T. & Noé, F., 2015. Techniques and methods for testing the postural function in healthy and pathological subjects. BioMed Research International, 2015, Article ID 891390. https://doi.org/10.1155/2015/891390