Umm...do keep in mind that he is lift up HIS own weight. At the rate he is going he will keep being able to lift himself up even when he gets to my age or you're age.
The boy lifting himself(35lbs) You lifting yourself(ex: 160lbs)
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The boy lifting himself(35lbs) You lifting yourself(ex: 160lbs)
I guess what I am getting at is. What would be light for you, shouldn't be light for someone who weighs that much.
Also keep in mind that doing that requires tremendous core strength and phenomenal balance.
Thats pretty sweet though, He could be a pretty sweet break dancer if his dad were to get him into it.