A former marine created Marine Style Fitness, a site that offers workouts and training for physical education. It's not created for children, and it has a few "premium" workouts on the site, but after registering (free) and looking through the site, I think it definitely has enough value to highlight the site here on Freely Educate.
If you're looking for a great physical education program, or a good workout for yourself, check out Marine Style Fitness:
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