The first mile sucks.

[Nanci]

Just start out slowly! After about a mile or two, things should be loosened up to switch to your regular speed. It's nice to slow down and cool off for the last couple miles, too.

I notice on longer rides, that if I stop for anything more than a few minutes, I stiffen up, but it goes away pretty quickly once I start riding again.

Nanci

[Bad JuJu]

That sounds like the way I used to feel in the first mile of jogging (which I don't do any more). My problem then was just what everyone has already said about your cycling--I didn't take the time to warm up properly but just went all out from the start. Not a good idea--that's not how bodies are designed to work.

In addition to taking time to warm up, are you spinning? When I learned about spinning instead of trying to push big gears all the time, that's when I really started to love cycling. Try to keep a relatively high pedal cadence with easy gears, at least while you're new at this, and always when you're warming up. I've read somewhere that even racers do a lot of spinning when they're in training.

[mimitabby]

another thought. Does your bike have multiple gears?
make sure it's in the easiest gear before you get on the bike. easiest,
wheels spin with the least amount of work.
another thought:
pick up the front of your bike. Spin your wheel with your hand. Does it
spin freely?
pick up the back of your bike. do the same thing.
if the wheel doesn't just keep spinning,, something is wrong.

when i got my cross, the first day i rode it, a brake pedal was stuck.
I got on that bike and rode 10 miles (VERY SLOWLY) my husband getting irritated, scolding me even..
i finally threw myself down on the ground and panted, my legs were screaming.
needless to say it took a while to figure out what was wrong.
I always check first now

[btchance]

I feel almost the exact same as you described it, and it happens for me both on the bike, spin bike, and when running. I just take it easy until it goes away, spinning and trying to avoid hills until I'm warmed up. After that, I feel fine.