Those of us who do any strength training for running performance can put the exercises we perform into two large categories. Bilateral exercises where we are on two legs, or using both arms and aiming to use both limbs in equal amounts. These exercises such as squats and deadlifts allow us to lift large amounts of weight and can really help us to get strong overall. The other group of movements is Unilateral (single limb) training. Being on one leg is familiar to us, as all running happens on one leg!
The biggest upside to unilateral training is reducing asymmetries - where one limb is stronger than it's counterpart. This is shown to be a higher risk factor for injury but also has implications on your running performance.
Unilateral suggests being entirely on one leg (or working only one arm) but in reality we can use a variety of positions and stances to EMPHASISE the training of one limb at a time without always having to fully balance on one limb. Balance training can be useful too but it limits what we can lift so is a little different in nature to true strength training.
Pro’s of Unilateral exercises:
reduce injury risk
get stronger (especially in weaker limbs)
get more work done with less external load
variety of exercise selection
can give the weaker side more focus/attention
can be used if an injury prevents bilateral training
Con’s of Unilateral exercises:
less maximal strength than from bigger bilateral compound exercises
can take more time as you’ve got to do both sides
balance can sometimes be the hardest part of the exercises
Unilateral lower body training options:
Split stance work - split squats*, Bulgarian split squats, lunges^
Where there is a long distance between feet and the focus is on the front knee bending/extending.
B-stance work - good mornings, Romanian deadlifts, swings (mostly posterior chain exercises).
Where the feet are only slightly offset and the focus is on the hip hinge pattern to give the front leg hamstring and glutes a training effect.
Purely single leg work - step ups**, pistol squats, calf raises, hops
A little more reliant on balance but can be assisted if required. Only one leg performs all the work.
How to perform unilateral exercises:
The key thing to keep in mind during training each limb separately is that it nearly doubles the training time. Sets can take a long time so we are working very hard. This makes it great for a metabolic/conditioning workout as well as for strength training.
Focus on your weaker limb first. Always do the weaker side before the stronger side so that if you were to reach failure earlier than planned, you’re not increasing the gap between strong and weak sides.
Use perfect form. This should go without saying but the point is that both sides should do the same movements in the same way. No cheating on the weak side or being sloppy/lazy with the strong side.
Adjust rest periods. Be sure to account for things like how long you have to hold a weight as you’ll be doing longer working sets to train both sides. You may need a short break between sides so that the grip or core doesn’t become the limiting factor to performance.
If you don’t already, we highly recommend using some form of unilateral exercises in your training. There are far too many reasons not to! We use them in addition to bilateral strength exercises rather than in place of them. A little single limb work can go a long way to being a stronger, faster and more robust runner.
By Alex Adams
* Split squats have several options: front foot elevated (FFE), rear foot elevated (RFE)*
^ Lunges could be alternating, walking, reverse, lateral, drop…^
** Step ups can be performed a variety of ways; side, front, crossover…**