What You Don't Know About BOSU Balls

Are They Pointless or Practical?

BOSU balls were all the rage a decade ago, promising core strength, balance, and improved athleticism. Today they're considered to be a gym gadget used mainly by people who don't know what they're doing. So what's the real story?

Before the BOSU came around in 1999, trainers and therapists would use a full stability ball (Swiss ball, physio ball, etc.) to challenge balance by having clients sit on it, roll around on it, and occasionally stand on it. Some people squatted on it and Darwinism weeded out those that deserved to live and those that deserved a concussion. This new half-ball, the BOSU, was slightly more stable and more applicable to the masses.

Many saw the BOSU as the greatest thing ever, even venturing so far as to turn it over to stand on the flat side, despite numerous warnings from the manufacturer to not do so. Trainers started having clients focus on balance, core strength, and more "functional" exercises such as standing on one foot, pressing an elastic band, and curling a dumbbell on the half-ball. Yep, things got out of hand.

In some cases, yes. In most cases, no. It depends on what you're measuring.

If it's the ability to squat a brick house on your shoulders, then no. If it's to improve the tolerance of your spine to deformative forces, again no. If it's to control your body position in space and improve vestibular response, then yes. It doesn't make anyone faster, stronger, or any more stable than any other tool in the gym, nor does it make them any more swole, but it does improve balance which benefits aspects of both strength and conditioning. The downside is this type of training usually has a ceiling.

BOSU ball research found that it didn't improve strength in common movements compared to performing the exact same exercises on solid ground. This makes sense since having a solid foundation allows for more ground reaction forces to be applied and thus more force generated up into a weight you're trying to move. If more energy is spent trying to maintain balance, less is being applied into the weight. A more stable foundation – a bench or the ground – allows for a greater force and velocity of loading compared to an unstable foundation.

Kinda, but so does doing big compound exercises that have additional benefits.

The BOSU does provide higher EMG activity in the rectus abdominis compared to performing the same exercise on a stable surface with a similar shape. More peak and average EMG activity in the rectus abdominis means more shredded abs, right? Well, maybe. When comparing peak and average EMG activity as a percentage of maximal voluntary contraction to similar studies with EMG set ups, common strength movements like heavy deadlifts and front squats would actually yield a higher percentage of maximal contraction compared to the crunch on a BOSU.

It works pretty well for athletes rehabbing lower body injuries to the knees and ankles, but can make certain foot problems worse.

Unstable work helps people who've suffered lower limb injuries. People who've rolled their ankles and those who've had ACL or MCL injuries in their knees seem to benefit significantly from the increased muscle firing rate needed to manage unstable surfaces. But if you haven't had these injuries, the benefits seem to be minimal after the initial adaptive phase where you learn to not fall on your face. Unstable surface training can actually make some conditions like plantar fasciitis or patellar tendinitis worse. The overused tissues have to work much harder to stay upright, so it tends to cause more flare ups.

Not in most athletes. It might help a little with balance and reaction, but there are much better methods.

Coaches who work with downhill skiers use BOSU balls for their dry-land strength training. They believe that using unstable surfaces mimics the unstable environment of skiing. That sounds good in theory... but that theory has holes.

First, the ground contact in many sports is very short, meaning the athlete contacts the ground, creates deformation in the surface, and then moves on to do it again at another position on the field/course. For a BOSU to replicate this, athletes would need to step on it and then move on to another surface or contact point. That means prolonged exposure to the unstable surface would be non-specific and provide minimal benefits unless they're looking to compete in the BOSU Olympics.

Second, the contact area skiers contend with is rarely dome-shaped, meaning the surface they're using is more convenient than specific. Impact still deforms the surface in a meaningful way, but is dependent on where on the ball they hit. Also, to be truly specific, they would have to do their training in ski boots, which would be hilarious to watch.

For athletes in sports like basketball, hockey, soccer, and football, they'd never come into contact with any surface remotely like a BOSU. That means they'd rarely see any specific benefit to it, unless you count the development of general fitness qualities like balance and reaction, which could be trained on any surface, including solid ground, and with reactive force applications like an opponent trying to move them. An athlete has to deal with unstable loading from changes of direction, contact with opponents, and varying speed more than he does adjusting to changing surfaces.

Using unstable loads like a slosh pipe or partner grappling, or hanging weights from bands on the bars would provide more than ample instability. One study has shown that using unstable loads totaling the same as stable loads at approximately 60% 1RM had greater activation of the rectus and obliques and resulted in statistically significant reduction in ground force application (3.9%). That means you work harder to control the weight and don't apply as much force into the ground.

The BOSU does actually have some uses. Biceps curls while standing on the half-ball is not one of them. Here are some practical uses:

  • The BOSU can be a benefit as a part of a warm up or even a cool down as it can alter neural activity following massive strength work.
  • Using a single-leg stance works the leg in 360 degrees, meaning you have to control anteroposterior, lateral, and rotational movement while on the ball. This can be beneficial for anyone who trains in purely sagittal plane movements like powerlifting, Olympic lifting, and many aspects of bodybuilding. It takes them out of their usual plane-specific movements and provides a different stimulus.
  • The shoulders could benefit from the BOSU. Try working on maintaining a push-up position while rotating the pressure on the hands from under the thumb to under the little finger, to the heel of the hand and up to the fingertips, and then progressing to the same thing with only one hand on the ball.
  • If you're looking for some direct ab work, doing partial curl ups on the ball gave higher EMG activity compared to doing them on the ground, so get your crunch on.
  • For athletes looking to simulate impact on variable terrains, doing a movement like a lateral jump onto the ball, gaining a stable position, and then jumping off would be a good option, as would jumping and immediately driving off the ball. This could be done forward to lateral (change of direction with rotation), lateral to lateral, along with other movements and directions necessary for their sport.