Cycling is primarily an aerobic sport. That’s cardiovascular / metabolic fitness. Sprinting is primarily an anaerobic activity. That leans much more towards muscular fitness. There’s a little bit of overlap, but not a ton. It’s pretty common to be good at one, but not the other.
Generally, if you want to improve your fitness for a particular type of riding, you train for that. So if there’s a race/event you’re interested in, you can focus your training around that. If you just like riding, find the type of riding you want to do, and train as if there was an event of that type.