Sitter~ma! I was pretty lucky in that regard. I took the kids to work with me which provided lots of distractions and activity. We also had a family friend who was in his mid-20s that was my go to sitter for date nights. What nature didn't give him intellectually it made up for with common sense and I could trust his decision making completely. He also could play indoor and outdoor games non-stop and had the energy to keep up with the boys. He'll be going to Bobby's wedding too. After they were 2 their grandmother was always willing to keep them for weekends as often as I would let her.
You have to have time off! When they are in elementary school the social schedule and sports and thing keep you running non-stop and the time off is even more essential.