Quoting Halley Nicole:" that sounds like a great idea but i cant exercise with him bc i have two toddlers and a newborn and ... [snip!] ... too busy cleaning cooking and chasing kiddos . i dont want to be like start doing sit ups i want him to do something he likes"
Take them to the park. Go on the weekend. There are tons of things you can do to make exercise an important part of your lives. If he sees you guys not doing it and not feeling it's important, then how on Earth can you explain to him that it's important? I mean, it sounds like he's having a hard enough transition, but then to basically single him out and be like "YOU need to go exercise and go out and ride your bike around. We're all too busy for that." Yeah, I don't think I'd really want to do it either.
You don't have to do sit ups. Do a work out video together. My kids (toddlers) and I do a toddler yoga video. We go for a walk every day and play at the slide. Take a ball outside (if you have a yard) and set up an impromptu game of soccer for your guys. There are plenty of ways to get more exercise and activity in, but kids need to see adults doing it or they wont feel it's really that important.