We live in a reward system, right? You do something well, you get a reward. This is why we should pay for grades, give candy to our kids when they eat their whole dinner, give our toddler a toy when she goes potty on the toilet, and take ourselves on a cruise if we lose 20 pounds.
Does this feel completely wrong to anyone else? This "if... then" reward system places all the emphasis on the receiving of a reward and makes the action taken to get the reward simply a means. Not only that but the action is a means to an unnatural reward, one that does not follow naturally from the action. If we read we become educated and intelligent, if we exercise and eat good foods we become healthy, if we save money we become self-reliant, if we treat people kindly we become a friend and a good member of society. The WSJ has an article on why boys don't read some disappointed parent even tried "bribing him with video games" to get him to read. As Daniel Pink suggest in his interview on EconTalk , "What you've done is say reading is like working at a fast-food restaurant; only a chump would do it for free."
So for yourself and for you kids try using the natural reward of an action as a motivator. Say things like, "Eat your food so you will be healthy and strong and have energy to play" or "Isn't working hard fun, I always feel good when I try my best and work hard" or "Let's clean up our toys so we can keep them all together and also so we will have more room to play in".