If we accept the model as a realistic representation of the real system, the inevitable conclusion is that the bilateral deficit in jumping is primarily caused by the force-velocity relationship rather than by a reduction of neural drive. This conclusion is different from that drawn by Challis, but his findings were basically the same and he would have come to the same conclusion as we have, had he not focused on the vertical displacement in the airborne phase but on the total work produced. (research attached in discussion)
During the BSMPG conference the concept of bilateral deficit came up and many attendees were left with more questions than answers with regards to the rear leg elevated single leg squat (RFESS) and regular bilateral squats. The truth is that decreased neural drive is just bad science to market a philosophy that is absolute and founded on poor reasoning. So what are we to believe about single leg exercises and conventional exercises such as squats, olympic lifts, and deadlifts? What is the truth on the matter?
Coaches are now asking the same questions. How can we safely prepare athletes to get more explosive and help reduce injuries effectively. Many coaches (complained in the hallways) were not buying the RFESS presentation as they heard the back to back hip dominant and knee dominant days with back to back speed days (lateral and straight ahead work) before and wondering is this another experiment that was ready to fail. Here are my conclusions:
- A complete program will likely use multiple exercises, rendering one exercise vs another debate moot. Having a discussion on what exercise is better is great for forums but not real life. Many coaches use both single leg exercises and double leg exercises.
- The overhead squat (read bilateral) is a screen used in the FMS as an indicator of potential injury yet a loaded squat done with great technique and intelligent loading is bad for athletes?
- Using youtubes of bad technique with bad program design is not evidence period. Like Dr. Fleck said years ago at a seminar, do not fall in love with an exercise – removing a squat is ok if it allows temporary pain relief and ability to load the legs. Giving up on the exercise is a direct decision not to have vertical loading of the spine when ground reactions are vertical is a decision not to fully address the mechanical problem with spine dysfunction. If you can squat pain free it’s a good sign that your back is healthy as running based sports have vertical forces interacting up the kinetic chain.
- It’s ok to have back strength and endurance, so long as it doesn’t cause problems. The transducer theory is nice on paper but shouldn’t a good core program address a weak spine? My coaches felt discouraged that the cook chops couldn’t address this spinal deficit.
- The fast twitch fiber theory doesn’t hold weight (pun not intended) as olympic lifters are increasing their type II composition with bilateral lifts. The research is available on google scholar.
- Where are all of the freaks jumping out of the gym and hang cleaning freaky loads? Where are the piles of mass being put on the freshman? No before and after photos? Surely the increased neural drive and RFESS loading would show up in the other indicators of general leg power.
- One coach pointed out that 18 years of experience in general is not 18 years of experience with the RFESS used in D1 football programs, rendering the wisdom angle to be void of long term development.
- Many people were confused with have a split stance and having spinal loading regardless of poundage. Biomechanics of the spine with such an exercise is cloudy. What does Stu say about loading the spine with a split stance with lighter loads? Is it truly safer?
- Mike Boyle said that the exercise had to be dropped from in-season training because of groin issues? What were they? Nobody asked. I was disappointed with the lack of participation, even with myself for not asking that question.
At the end of the day you must give credit to Mike Boyle for having some valid justifications to the aging athlete and how single leg exercises are valid tools. He has improved the understanding of such modalities and has made training a little more holistic and complete. His presentation was entertaining, clear, and had great points. My decision to keep submaximal squats and focus on technique/bar speed on the olympic lifts didn’t change, but his RFESS presentation made me think that the exercise had too much cons to be worth adding into a program as I already do 8 single leg exercises.