Thanks for the extra input. I’ll edit the post to try and draw more attention to it.

Flexibility is about passive ROM, mobility is about active ROM (see for example http://laurensfitness.com/2008/01/31/mobility-vs-flexibility-do-you-understand-them/ ).

But I think more salient here is the strength vs stability distinction. Being stronger, cetus paribus, will make you more stable, but you can have strength without a lot of stability, and vice versa.

For example, if you train on machines you may or may not be used to relying on your prime movers rather than your stabilizers.

The important bit I would say is that you need to be stable first (and at least in the off-season symmetric L/R) in your lunges before you go about making them stronger.

Walking lunges are a good start for strength, but I like Dusty’s suggestion to add medballs (rather than weighted bars or dbells) as you have less leverage on a medball than a bar or dbell.

I might suggest a progression like this. First, check your deep squat, don’t train the lunge until your deep squat is actually deep (butt below knees). Next, check your in-line lunge to weed out any strong L/R asymmetries or bad movement patterns.

After that, have someone spot your barefoot-grass lunge for mobility / stability / strength issues. If that’s fine, you could progress to a farmer’s walk (adapted to a farmer’s lunge) with dbells, backpacks, or water jugs. Next, do weighted lunges with ‘bells in the racked (1-handed) clean position. Finally you can do the lunge demonstrated in the crossfit vid you posted with ‘bells overhead.

After you have that dialed in you could progress to weighted backpacks / jugs / medballs in the same progression, building up to kettlebells. Why I would suggest medballs or kettlebells is that you have less leverage on them, unlike dbells or barbells where you have close to perfect leverage. Given the same weight, you will be less efficient with medballs or k’bells, especially as the balls + bells go above shoulder height.

CrossFit strength is fine, but as Ulty players, you want stability first–just being strong without knowing how to use your stabilizers is not going to help as much.

Today I actually tested on this progression this morning, with 8kg (1-sided, as it’s in season not pre-season for college Ulty) kettlebell Farmer’s lunges L/R, then 8kg racked clean lunges, and finally 8kg pressed overhead a la Turkish get-up lunges.

(Another take on kbell lunges: http://hockeydl.blogspot.com/2007/12/kettlebell-is-traditional-russian-cast.html)

After this blog comment break I’m going to go back and practice my actual lunges with a disc, as strength/mobility gains are useless without SAID–specific adaptation to imposed demands–in other words, you have to practice the sport skills after you get strong/mobile.

There are lots of way to train your lunge, but medball in a backpack or kbells give you a way to incorporate strength practice at every Ulty practice with minimal fuss. Due to the decreased leverage, you won’t need as heavy a weight (vs dbell/barbell) and the increased kbell portability will just let you bring it in your car to practice (what I do), where you can practice your mobility/stability/strength on a field itself, in cleats if you like. (balance training, after all, is said to be very specific/specialized… I don’t know enough about it to make recommendations, but it seems to make sense to have strength practice be cleated on grass from time to time).

For example: Side lunges w/ medball. Start with feet shoulder-width and medball held over your head (arms straight).

Step out to the right while simultaneously bringing the medball down past your right foot. (Goal: lightly tough the medball to the ground just outside of your R foot.)

Now, as soon as you touch the ball to the ground, stand back up (medball over head). Pauses are for… losers.

I use a 12lb medball and tend to do various ~Tabata intervals. Not easy work.

Var: Step and twist w/ a medball in hand.

If you have a partner, throw the disc to them (lefty from the left, righty from the right) and alternate double taps. For bonus fun, add penalties for incomplete passes.