Going off your history, I would hazard a guess that you could stay away from the gym altogether. You are into longer distance road riding, so I will assume you're not aiming at being a sprinter. Points and scratch style racing sounds like where you'd be aiming. I would just incorporate jumps into your regular road riding and some other stuff that others would know better to tell you. I don't know any points style racers that hit the gym. It's more about the endurance and the ability to jump multiple times in a race.