Originally Posted by
cyccommute
Many people will tell you to shift up when you stand but I'm not one of them. I find that shifting up leaves me in the wrong gear when I eventually have to sit back down. Shifting up on a climb naturally slows you down as does climbing out of the saddle. When you sit back down in a higher gear, you've lost momentum and you are in the wrong gear to gain it back. You've also expended a lot of energy climbing and increased heart rate. You often need to sit to recover and trying to mash a taller gear slows that recovery. Frankly, when I get out of the saddle to climb, I just increase my cadence rather than increase the gear I'm using. This is a short burst effort for the most part and not really something you do for a sustained amount of time.
On flat ground, shifting up provides some comforting resistance when standing up since one naturally pedals a bit slower when standing than seated. On totally flat rides, I'll stand just to get some pressure off my butt and work some different muscles a bit.
On the typical rolling hills that I ride, I have plenty of excuses to stand, whether to avoid shifting down to my granny ring on a particularly steep pitch or to keep momentum at the start of a climb or use some different muscles on a longer climb or even accelerate mid-climb. For the last two reasons in particular, I will shift up a gear or two to compensate for the change in cadence. If I need to sit back down, I just shift back to where I was as I'm sitting down.