Standing to pedal is extremely tiring - should it be this difficult? I've gotten back into riding fairly recently. I used to ride a bicycle a lot when I was younger - the single-speed, steel-frame deal with coaster brakes. I'm now riding a Fuji hybrid.

When I was younger, standing to pedal was the thing to do. However, now when I do it, I can't really sustain it for more than four seconds, literally; my quads ache and I feel as though I have absolutely no endurance for this. This happens not only on hills, but on flat as well.

Sitting to pedal has been alright for the most part. I'm able to climb hills in low gear (even though I'm really not good at it yet) and I can pedal well on flat ground. Standing is just a different story, as it takes it out of me so incredibly quickly that it's an almost useless technique.

Am I doing something wrong? Might I need to adjust my handlebars to be higher or something? (My saddle is at a correct height, but perhaps when I stand, I'm having to lean too far forward to keep my hands on the bars?) Or is this common and it's something I'll just need to get over with practice? Don't get me wrong - I know that these things do come with time - but it doesn't seem to make sense that I get tired standing to pedal even on flat ground...

Thank you.
Standing up on a bike, especially when you lack fitness, is a good way to go "anaerobic." Put simply, that means your body is working so hard, it can't get enough oxygen. You can only do that for a short amount of time, which for most people is in the range of 10-30 seconds. Then the lactic acid build up in your muscles becomes too painful and you are forced to ease up.

The solution is simple. You need more strength and fitness. If you like to ride fast and/or climb hills, you can't avoid the anaerobic zone completely, but you can move it a little farther away by getting good fitness. Keep riding, and keep riding hills.