I first saw an example of the butterfly kip (BFK) about a year ago while perusing some videos of AFT. At first I was incredulous about the movements’ legitimacy. The problem was, I could not DO the BFK so I had an opinion but no real experience on the matter. Said another way, I was full of shit. This was similar to what I see from the folks who CAN NOT DO or COACH the Olympic lifts…for these folks the OL’s are dangerous, in-effective and slow to implement. Yea, ok.
Well, I finally got around to learning the BFK and it is both fun and dramatically more efficient than the standard kip which I feel like I’ve refined pretty well given I’ve done 62 pull ups this way. My BFK is not near this yet but I think it has potential due to the ability to store elastic energy in the movement. In essence one never really comes to a stop position…you never have a full change of direction and one can thus string movements together in a very efficient, flowing way. Here is an interesting thing however: the BFK will not work for someone who is relatively weak or with a significant load. For this I suspect the default will be the gymnastics style mini-glide kip. This is a fairly easy experiment to run. Can you BFK with a 20lb vest on? 40lb? What do you do for a 1RM weighted pull-up? It’s not going to be the BFK, but that’s not a problem, different movement for a different situation. I see a similar situation with movements like the push press (PP) and push jerk (PJ). The standard 1RM approach to the PP & PJ is to keep a perfectly upright torso and drive through the heels and this is without a doubt the most efficient way to produce maximum force…but if the load is relatively low one can (in my opinion) improve total work output but driving off the balls of the feet…due to stored elastic energy. This is how we box-jump, double under, triple jump and a host of other athletic moves which benefit from stored elastic energy.
I’ve been thinking about some way to look at movements and how to determine which derivative is the best. I REALLY like rang of movement as a criteria. This places the sumo-deadlift and squat in pretty questionable terms. Some thought of dimensionality or path dependence is helpful I think. A solid athletic style squatter (ass to ankles) can do a sumo squat with little to no preparation, whereas the opposite is rarely if ever the case. The kipped pull up is a similar case whatever variety you use…get that and you can still dead hang, but it’s a skill which needs to be learned & practiced. Beyond this I think movements might be sub divided into max-effort formats and high repetition formats, the high rep formats benefiting from some kind of stored elastic energy.