Runups rhymes with:
cleanups, grownups, lineups, backups, buildups, buttercups, checkups, cleanups, coverups, eggcups, grownups, hangups, holdups, hookups, lineups, linkups, markups, pickups, push-ups, pushups, setups, shakeups, startups
Runups sounds like:
rainbows, ramaphosa, rampage, rampages, ramps, reemphasize, reimpose, removes, rempac, rombach, rumbaugh