What was the kids' show on either PBS or Nick, Jr. aired in the mid to late 90s with a guest spot by either Jonathan Winters or Willard Scott? It had various segments, one being a guy doing exercises with the kids. It was geared towards pre-schoolers. It wasn't on the air for long.

Maybe Slim Goodbody?

Thanks, but that's not it. I remember the guy always said, "Wowee Kazowee".