The research findings might surprise you! Core chiropractic specialist, Dr. Alexander Jimenez investigates.
In the past ten years large inflatable plastic balls variously called Swiss balls, match balls or stability balls are becoming required gym gear. Ranks of them line the back walls of course studios, a few constantly lurk in the abs and stretch area and, increasingly, they are stored at the free weights area. They'll also be present in almost any self-respecting sports physiotherapy clinic.
Within a very similar period of time, 'core stability' has invaded the world of recreational sport and fitness, altering traditional approaches to training and keep fit at all levels of aspiration. And in the realm of core stability, Swiss balls have become crucial, almost synonymous with the very concept. If you are serious about core conditioning, you work out with a Swiss ball.
But are these cheap, cheerful, outsized space hoppers warrant their popularity concerning effectiveness? Sports science research goes a way towards helping us solve the issue of if Swiss balls are beneficial or just fashionable.
The fitness trainer Paul J Goodman argues that Swiss ball- based exercises are the key to effective improvements in back strength. Since activities done on the ball involve higher stimulation of the body's 'neuromuscular system', users build better balance, co-ordination and proprioception (sense of bodily awareness in distance), Goodman states. All these assertions are not backed up with any research references -- instead, they come from Goodman's experience of working with clients using Swiss balls.
Evidence to support the efficacy of Korean ball exercises comes in a piece of research in the Canadian lab. Kathryn Clark and her research team at Dalhousie University's School of Health and Human Performance compared the electro- myographic (EMG) activity of the upper stomach (rectus abdominis) muscle through various abdominal exercises2. By measuring the level of electrical activity, EMG provides an indication of the amount of muscle activity going on. Elevated levels of EMG are connected with high forces and a larger number of muscle fibers being recruited.
Clark's team studied several abdominal exercises: the curl upward (flooring), Swiss ball pops upward, reverse osmosis, ab roller curl up, Swiss ball roll-out to bridge, and supine leg-lower. The typical level of EMG activity for three repetitions of each exercise has been calculated as a proportion of each area's maximum level of EMG activity.
The most EMG for the upper abdominal muscle was determined by the topic performing a 'maximal voluntary contraction' (strongest muscle power potential) during the ab crunch movement against an immovable resistance created by a trainer pushing down the subject's shoulders.
The researchers discovered that the Swiss ball pops resulted in the highest EMG score out of all the ab exercises, at roughly 90 percent of maximum EMG -- significantly higher; for instance, compared to ab curl on the ground, which listed an EMG amount of approximately 70 percent.
Support for Clark's findings comes from another Canadian writer, Stuart McGill 3. His team also looked at the EMG activity of this Swiss ball ab curl versus the ab curl around the ground. McGill reports that the EMG activity of the upper abdomen and oblique muscles is higher whenever the ab curl has been done on the Swiss ball. Thumbs up for the Swiss ball up to now.
Another piece of research looked at the Swiss ball from a different angle. David Behm and staff, from the Memorial University of Newfoundland, in comparison how much muscle force was used to do exercises under stable (on a bench) versus unstable (on a Swiss ball) conditions. They examined muscle power and EMG of the very front of thigh (quadriceps) muscle during leg extension and calf muscle during plantar-flexion (toe- extending), in stable and unstable modes, also noting that the electrical action of these opposing (antagonist) muscles (hamstrings and dorsiflexors).
This generated some unexpected outcomes. As may be anticipated, the leg extension and plantar-flexion forces were higher where the subject was steady, seated on the seat rather than on the Swiss ball. However, while the front-of-thigh and calf electrical activity was lower throughout the shaky movement, the EMG of the opposing muscles (hamstring and dorsiflexors) improved. This suggests that the amount of activity of the principal muscles (prime movers) is inhibited through shaky exercise, with increased muscular activity happening in the opposing muscles. So Swiss balls are not going to be the ideal way of developing prime-mover muscle strength.
"The Swiss ball changes the task from pure leg extension to leg extension while controlling the body. In other words, stability/ proprioception rather than limb- strengthening."
Basically, the Swiss ball alters the activity from pure leg extension to leg extension while controlling the body. It transforms the movement into a stability/proprioception exercise rather than a limb-strengthening workout.
So while this research doesn't encourage the use of Swiss ball for strength exercises of the leg muscles, it will indirectly support Swiss ball exercises for use in core stability programs.
Together, these research findings will give encouragement to devotees of Swiss ball training as well as the growing number of trainers and therapists that prescribe ball-based exercises most of the time for all muscle groups, in the belief that this may enhance core stability and 'make the workout more operational'.
I regularly see athletes and fitness center users doing many exercises on chunks, such as core power, a selection of dumb-bell upper body exercises such as bench press, and squatting movements. Before we leap in and endorse this kind of approach, a couple observations and questions are in order.
Q: Can The Swiss Ball Automatically Increase Core Muscle Activation?
To do so, look not in the concept, but at what happens in training. Just because a research article indicates an increased core training impact can be obtained does not mean that the ordinary gym user or rehab patient will be able to reap those benefits. This is because it's the quality of the individual's technique, not the gear you use, which overwhelmingly determines how effective the exercise is.Let us take the Swiss ball ab curl, which the investigators have proved includes a superior training impact to the model done lying on the floor. Typically I have observed, the exerciser working out on the Swiss ball does not have sufficiently good technique to be gaining any substantial benefit.
What normally happens is that the exerciser simply pivots their low back around the curvature of the ball, levers their shoulders up and probably uses their hip flexors to help pull their back up. This lever activity significantly lowers the load on the abdominals and side stomach (oblique) muscles.
"In most cases I have seen, the exerciser on the Swiss ball does not have sufficiently good technique to be gaining any significant benefit"
Swiss ball 'roll ups' -- because I predict the bad-technique variant -- are easy and anyone can perform many repetitions without any benefit. Swiss ball curl ups -- adjusting the clitoris with strict technique -- are tough, and sets of 10 reps will be hard for most people.
Using the Swiss ball, then, is no guarantee of increased training achievement. Balls alter exercises -- generally making them more advanced -- and you'll need superior power and strategy to carry out the modified exercises efficiently. Instructors should always put technique and correct muscle recruitment ahead of any 'favorite' piece of equipment. If the exerciser can't utilize the targeted muscle groups efficiently or control the unstable surface satisfactorily, then the exercise will not have the desired effect and the instructor should find an alternative.
Q: Are Swiss Ball Exercises Suitable For People With Low Back Issues?
If Swiss ball curl ups (with good technique) are very capable of challenging the abdominals, McGill's research alerts us to elevated levels of trunk muscle 'co-contraction', which is connected with increased spinal loading. This is important for anyone undertaking injury rehab for their back: you'll need to take great care to not over stress your recovery back once you use a Swiss ball.McGill also challenges another modern instability fashion, for example Swiss chunks or air cushions as convenient sitting surfaces at the office (a Swiss ball and frame is designed to replace your office chair). The rationale is to help the individual strengthen their trunk muscles during daily activity and maintain their spine mobile throughout the day. McGil's study shows that spinal loads are greater on unstable surfaces in contrast to sitting on a chair. He wouldn't recommend this for his patients.
Q: Why Perform Leg & Arm Exercises On The Swiss Ball?
It is very common these days to see people in the gym performing conventional strength exercises on Swiss balls, often using dumb-bells or similar free weights, in the belief that this will make the actions somehow more 'functional' or assist them further enhance their core stability.Yet as we've observed previously, the Newfoundland research discovered that the particular strength-training influence using Swiss balls is reduced, as exercise pressures are dissipated through the entire body.
The amount of weight lifted in a shoulder press exercise on a Swiss ball is significantly less than when sitting on a bench.
There's little additional benefit, in fact. The dumb-bell bench press, for example, already requires co-ordination of elbow and shoulder and stability in the trunk, even when performed on the stable bench. When the exercise is moved to a lying position on the ball, the truth is that the leg muscles are quite active and provide a lot of the stabilizing function to restrain the moving ball below the spine as the dumb-bells are pressed down and up. This is only because the legs would be the natural anchors when lying on your back on a ball.
In general, then, I would argue that it's more efficient to lift heavier weights and gain the entire strength advantage with conventional (and steady) leg and arm exercises, and then compliment these with specific exercises for the back muscles which are guaranteed to target the core. More research is required to establish the complete range of benefits and limitations of using Swiss balls, but in the absence of scientific support, you'd do well to not assume that everything done on a ball adds value to your training regiment. Some of it might perform (if you are already advanced enough in your fitness and strategy to cope with it); other exercises will do you little or no good and in case you have a low back injury you may be impeding the healing process.
References
1. Goodman P, Performance Training Journal of the US National Strength and Conditioning Association, vol2 no6 p9-25
2. Clark et al, Journal of Strength and Conditioning Research 2003 17(3), 475-483
3. McGill S, ‘Low Back Disorders’, Human Kinetics 2002
4. Behm D et al, Journal of Strength and Conditioning Research 2002 16(3), 416-422
The information contained in this publication is believed to be correct at the time of going to press. Whilst care has been taken to ensure that the information is accurate, the publisher can accept no responsibility for the consequences of actions based on the advice contained herein.