I’d also want a mix of Wanda’s Chaos Magic and Steve’s Super Soldier physiology. Magic is a gateway to pretty much any kind of superpower you can think of, and Super Soldier durability and regeneration are always nice to have.
BTW, I’m fairly certain Steve does actually need to work out to stay in shape — that’s why he does his morning run at the start of Winter Soldier — but he doesn’t need to work as hard as a normal human would to maintain his superhero bod. That’s my assumption, anyway.