Is Two Really Better Than One: Bilateral vs. Unilateral Training
The argument around which type of training is superior when matching up unilateral and bilateral training has been a longstanding debate. The history on the debate dates back to Mike Boyle when he was guided to the topic by Gambetta and Gray back in the day. These S&C gurus indicated that sagital plane dominance, as with bilateral training, could be developing lifters instead of athletes. Their point being that as a human strides, we are performing a single leg action – or as they referred to it, “a series of bounds”. So the reason for this article is to answer a couple of questions regarding this debate and to explain how we would use both modalities.
When looking plainly at the two modalities, bilateral training allows us to put more plates on the bar and lift heavier weights, thus increasing the stress on the body and allows for adaptation. Unilateral training on the other hand uses less weight, more dynamic stabilization and might be a novel activity which places more load on accessory muscles. From a developmental point of view, we prefer getting a youth athlete activated and started by using unilateral exercises. The purpose in this phase is to not overload the athlete, but purely to teach several movements and equalize any asymmetrical deficits which come with the territory. When the athlete is strong, confident and stable in the unilateral phase, we prefer to then start using bilateral lifts, pushes and pulls and start adding plates. Paraphrasing Mark Rippetoe, “your muscles aren’t firing because you’re weak” – obviously youth/ beginner athletes are going to be weak, so let us utilize unilateral lifts to get them confident and able to control their movement.
A following point which was argued by both Boyle and Rippetoe in their blog was the term “training specificity”. What they referred to here, is the purpose of your sport or the outcomes that are measured– Rippetoe believed in “one body, one bar”, which is lovely for powerlifters, but why stop there if you can measure yourself with a bar and box (step down). The power lifts (squat, bench and deadlift) are frequently used and advocated by coaches as a method of seeing if a program is working and I completely agree – use these tools to measure your conditioning program. So if bilateral lifts can be used, then why not also use unilateral lifts to look at any asymmetrical deficiencies or to screen for injury risks.
It might come as no surprise that S&C coaches rely heavily on bilateral lifts to see progression in athletes and evaluate their own programs. S&C coaches are the first to criticize each other on their methods and judge training programs. We might also not be the most humble species, showing off our athletes’ numbers for instant gratification. As strength and conditioning coaches, our job is firstly to keep athletes injury free and secondly to get them as strong as possible to perform optimally – And yes we know the stronger they are the less injury prone they will be. So why get caught up on one idea and totally exclude the other?
In general coaches use an overhead squat to evaluate strength and mobility – which I completely agree with. But why have only one test – why not expand the testing battery to a single-leg step-down test, which has been effective in evaluating trunk and hip strength as well as screening players with ACL injuries. The inclusion of another test might take some time away from our programs and I agree - time is not always our greatest ally. However that’s where we can be creative and even insert these screening tools as “activations” during a warm up.
When considering these two tests, I do understand that the overhead squat is a complex movement and screens for numerous factors. What if, when repeating the test 4 times the athlete falls over twice and performs two unstable reps? Is this still a true reflection of an athletes’ strength and stability, or when is it time to consider a unilateral test? Couldn’t we isolate and identify the problem area when testing one limb at a time?
We believe that if we incorporate unilateral and bilateral tests we can comprehensively get an indication of where our athletes are in terms of their sport-specific strength and stability. Great powerlifting numbers can indicate that our athletes are strong, but a good powerlifter doesn’t necessarily make a good runner. Unilateral and bilateral are all just tools in the arsenal, let’s use them at the right time and place for our athletes to be successful.
Mike Boyle (2007) - The case for single leg training, available: https://www.t-nation.com/training/case-for-single-limb-training
Mark Rippetoe (2013) – Rippetoe goes off, available: https://www.t-nation.com/training/rippetoe-goes-off
Burnham, J.M., Yonz, C., Patel, A., Robertson, K., Ireland, M.L., Noehren, B. What does single leg step down measure? Contributions of core and hip strength. American College of Sports Medicine. Conference poster. May 2014.