Eat a bunch of fruit, take a good multi (only one I like is New Chapter) but...
Do a real warmup (no stretching). You can walk for a while, swing your leg back and forth,
do some exercises like jumping jacks, planks, all that sort of thing.
Then when you start riding, go easy. It takes a while to get everything fully warmed up and ready.
One thing to consider is resistance exercises. Cycling is wonderful exercise. But if you think of your
body as being like a suspension bridge, there are places it doesn't help, and ways in which it doesn't promote resilience.
Cycling is front of the leg, exercises for the back of the leg create a needed balance. Back exercises add strength and