Understood, but the parent I responded to was talking about efficiency so I thought that was the context. In my experience I'm not so sure about that either.

Understood, but the parent I responded to was talking about efficiency so I thought that was the context. In my experience I'm not so sure about that either. I can't repeat centuries day after day when I am out of shape and need to lose weight. If one can, it's very unlikely he/she needs to lose weight.