Running is a good simulation for riding up hill, which is why I hate running. If there are no steep climbs in your local area, you can try sprinting up what hills you have. Living for years in South Florida, where there are no hills, let alone mountains, I used to have to make due with bridges and overpasses. Getting up these at as high a speed as I could manage was a good workout, however brief. Now I live in a place with plenty of hills and mountains, and these make me miss riding in South Florida.