[TobyD]

So what is a measurement of good core muscles?
Curious as someone commented the other day that I had good core strength, but I've always thought mine was average / pretty poor.

I would have said that it is practically impossible to measure, as it relies on totally different muscles, or sequences of muscles for each different phase / movement / position. Many of the things that we think of as 'core' involve far more hip flexor activity than anything else, unless your form is perfect, and you concentrate ridiculously hard to enagage TA and other core muscles. The extent that this distinction matters is pretty limited, as if you are doing a specific exercise, you'll probably kick in the hip flexors on the crux as well.
Relative performance in reps / load / form in a single exercise is the only way i can see that you would gauge it, Paul's 'walk downs' on a board would be a good one of climbing specific core, i'd suggest; but even then only really worthwhile with one individual between sessions, as it is obviously extremely height dependent how far away you can keep your feet on.

[saltbeef]

probably semantics but I would suggest "core" strength is probably exemplified by a one arm front lever. however "tension" is probably best exemplified by keeping your feet on when doing hard steep climbing eg look at macleod in that vid of him on conquistadores.

for the original poster. i don't see there being anything wrong with floor exercises, and neither does the champ. for example if one is doing a fingerboard session you need to rest between reps on the hangs. if you start doing some l sits or hanging leg raises you are going to detract from your ability to complete your deadhangs, max hangs whatever. your core muscles are massive you can do fucking loads of reps as Tom Randall does. there is really no exuse for a weak core, its just lack of application. your tendons will limit your doigts but i've rarely seen someone "pop" an ab. (Jim might be able to - he only has one though so could be catastrophic)

as rodma states elsewhere is the ability to do a front lever a good example of a strong core? dunno it might demonstrate  a strong core  but maybe not tension which is what you want. climb on steep stuff and don't let your feet come off.

(conflict of interest - i do none of this really - i fuck about at the wall and gossip)

[Fultonius]

...and don't forget, the most overlooked area of core strength and the one that is probably in abundance in the strong lads and lasses you see effortlessly bearing down on tiny footholds on steep walls.

POSTERIOR CHAIN

The lower back, hamstrings and glutes do a lot of the work to keep your feet on, not the abs/hipflexors etc.  If you think about the mechanics of it - the hip flexors would do the work if your waist was anchored and you were trying to "lift" your legs. (I.e. the same motion as leg raises etc.) - great for getting your feet back on when they swing off, not so good for keeping them on in the first place  Don't get me wrong, they are required to assist with twisting, getting to high steps etc. just don't focus too hard on the front and forget the back...


[/Sermon ends]

One of my favourite abdominal exercises is a bit like the dish, but also like a sit-up. Basically lie on your back and close up like a clam, raising your legs and torso off the ground and balancing on your hips/bum. Ankle weights can be added to increase the resistance.

[TobyD]

One of my favourite abdominal exercises is a bit like the dish, but also like a sit-up. Basically lie on your back and close up like a clam, raising your legs and torso off the ground and balancing on your hips/bum. Ankle weights can be added to increase the resistance.

So, pretty much navasana then:
http://www.yogajournal.com/poses/489
(to continue my ongoing rant about how good ashtanga yoga is...)
fairly key to avoid tipping backwards a bit to compensate / cheat, and to avoid bowing your back out, which is probably a good method of attaining little core training and getting low back pain instead. Which would be rubbish.

[SA Chris]

Don't be daft. Everyone knows yoga makes you weak.