I just got back into riding after a 10 year hiatus. I always wore a kidney belt when I was a kid, but I never really knew what it did. Do people still wear them? I don't see any of the pro SX/MX riders wearing them. Do people wear them under their jerseys now? Are they mainly for lower back support or is there something internal that they protect (kidneys)? If I don't wear one will the only consequence be a sore lower back? I'm starting to get suspicious that they exist to make more money for the apparrel companies.
I keep one in my gearbag and wear it only if my lower back's sore or if the track is extremely rough. I'm more comfortable w/out one. I have heard they don't do diddley for your kidneys, but do help support the back some.
There main function is supposed to be to keep your kidneys supported so they won't get jarred around on all those bumps and jumps. I wear mine mainly to support my lower back. Plenty of pros use them but they wear their pants over them so you only see the top portion of it. Once I wore one, I always wanted to wear it. Everytime I hit the dirt, I'm thankful for every piece of protective equipment I'm wearing, even if it's uncomfortable the rest of the time.
I wear one everytime I ride, but mostly just out of habit. I think they help more when you have a flabby belly. When I started riding again last year I was 50lbs overweight and the kidney belt helped hold my gut from bouncing. I have since lost those 50lbs and do not have a problem with my belly bouncing. I do like the thought of the biofoam padding on my lower spine(not that it protects that much).
I've owned two kidney belts, and everytime I put it on I end up taking it off...to uncomfortable for me. Hey wait a minute, mabey it's my belly that's making it uncomfortable...