[Sheila53]

I started a new program on the balance discs. I take a stride stance with a foot on each disc, then do a bicep curl with alternating dumbells. I've noticed that 1) I can only lift 15 lbs. (and on a barbell, I can lift 35 lbs.), and 2) the arm associated with the leg that's in front goes to failure first (and after only 4 reps or so).

I'm just curious as to why I can't lift that much, and why one arm (and it changes with whichever foot is in front) goes to failure first??

[Mel]

I don't know why the arm associated with the leading leg goes into failure first, but you will always be able to lift more in any type of exercise if you are ground based rather than "wobble based". If you are standing on the gound, the rigidity of your legs transfers energy to the rest of your body, and you don't have to put much energy into simple standing up- let me go find a better worded explanation of this--- can't find it quickly...sorry.

Additionally, the stride position torques your core muscles as you do the curl. If you were standing on the ground with your feet in the same plane, ideally, the only muscle that you would be using is your bicep (we'll ignore the antogonist muscles for this discusion!) Standing in a stride position on the balance discs, you are using all the muscles in your feet, your calves, your quads and hamstrings, your abdominus rectus and obliques, as well as your biceps. Getting tired quicker ?

Sheila- balance training is fantastic, but in other posts you've mentioned that you have osteoporisis and osteopenia. You also need to do a lot of standing, ground based weight work to improve your bone density. Studies has shown that although there are lots of other benefits, balance work even with fairly heavy weight, doesn't do anything for increasing bone density.

Mel

[Meg]

Also, most people can lift more with a BB than with two DBs combined. Bet you can bench more with a BB than with two DBs, right? Or row?

[Sheila53]

Thanks for the explanation, Mel --you're such a font of information! And I didn't realize that the ground-based weight work was more important for people with osteoporisis/osteopenia. I thought just the act of lifting weights would help (although my bone density has gone down even after a year of medication and weight lifting--it's discouraging!). When I see my trainer again in two weeks, I'll have to talk with her about that because she has me do the majority of weight training on discs now.

And, yeah, I get danged exhausted after disc work, and I sweat like a woman in labor--and sound like one, too.

[sportmom]

15 lb dumbbells are all that I can curl too, on the ground even! I keep thinking that will go up as the others have, but my left arm is holding me back. Still those last 3-4 reps require extra inhalations, a momentary break, and alot of effort to not lift with my back by arching. Maybe after the new year!