Single Leg vs Double Leg is a much debated topic in the strength and conditioning world. I see it as the “Which came first, the chicken or the egg” of our field. If you ask 10 different “experts” you may have 5 on one side, 5 on the other, and all can see the reasoning behind either choice. It’s very similar to political debates (sarcasm).
This summer, myself and another intern were having a conversation with Bob Alejo on just this topic. Bob believes in a ground-based approach i.e. working from the floor up on both feet (deadlifts, squats, pulls from the floor). Obviously you can lift more weight on both legs opposed to one, which leads to a greater power output. Training an athlete is, after all, about making them more powerful. He also explained to us he thought it was better to start with the bilateral lifts, even if it was leg press, to build a base level of strength before moving to unilateral exercises. He followed this by saying he could see the argument it is more advantageous to start on one leg and progress to two, and includes single leg work in all of his programs. When he asked me and the other intern our opinion, I landed on the side of unilateral and the other intern voted in favor of bilateral training.
Bob is friends with Mike Boyle, who believes single leg training is superior to bilateral training. Mike Robertson has a DVD called Single Leg Solution, and writes an article HERE about the benefits of bilateral training.
UTTER MADNESS!
I assure you none of these guys are trying to be politicians and appease both sides. Unlike politicians, your success in this field is based directly on the results you actually get, not the results you say you will get. Each of the men listed have become well known and worked with athletes of the highest level because they get results.
Now that I have thoroughly confused you on the best way to go, I’ll throw in my two cents.
As I stated previously, I tend to favor unilateral exercises.
Here’s why:
It can fix many asymmetries. Your dominate leg can compensate for your weaker leg during bilateral exercises. These minor weaknesses become much more obvious when the weaker leg is forced to function on its own.
One leg is less stable than two. I know that just blew your mind, but this causes the stabilizers to be recruited more during the exercise to keep us from not falling over. The best way to increase stability, which is important in any sport, is to strength the stabilizers. As a broad generalization, I believe it is easier for people to train their prime movers (bigger muscles), so to keep necessary balance in the body, the stabilizers must be trained equally.
You run/walk/live on one leg. I’ve stressed training in a way that imitates the movements of your sport, and every sport requires running (or skating for you Canadians).
They are safer. I would feel much more comfortable telling an athlete who I have never seen lift before to do a lunge over a squat or deadlift. Bilateral exercises are usually more technical and can be difficult for a younger athlete who does not have the body control an older, more experienced athlete would.
Conclusion
Am I slightly biased because I am a baseball guy and it’s easy to see the carryover to a pitcher? I don’t believe this is the case. I would recommend it to older adults and younger kids that are just trying to improve their health. Don’t get me wrong, I believe bilateral exercises definitely have their place in any workout. I will go into detail about the benefits of double leg training at another time. From what I’ve read and experienced, unilateral training can be overlooked and undervalued. What lower body training methods have you found to be most successful? What unilateral exercises are staples of your program?