In western countries we have a huge problem with people doing less exercise than they should and with that some major problems occur. As we all know. Getting your children to like exercising almost always comes naturally if YOU like exerising. And the tip of the day is to do it together.
Today most people living the normal 9-5/school/job-life doesn't have the time to really be able to take care of themselves. you pick up your kids from school, go grocery shopping with cranky kids and then making dinner ar home before it's time to go get some sleep. It doesn't really inspire you to do much else. Most people seem to take their kids to an activity, but very rarely I see parents participate. They'd rather stare into their iphone.
We try to lead by doing ourselves what we want our children to do. I want them to eat healthy food so we talk about it A LOT. Why we eat, what's good/bad for our boddies, what happens inside etc etc. They watch us cook food from scratch and they participate as well.
Same with exercise. I run, so the kids want to do the same. We go rockclimbing together. We go to the gym together. They watch us and then they want to do the same.
If we do this and like it for real, then it shows and rub off on them. Simple as that. Also, the key to it all is that we have the time to do all of this during the day when they're not tired. By homeschooling our children we can do this at what ever time suits them best on that particular day. That's the most valuable part of it all. Freedom to chose!