Capacity is the ability of a person to do something – both as an activity and as an amount. To find his own capacity, one balances between laziness and overload. Both extremes are equally exhausting.
Always check if what you do makes you tired. If you get tired, then you tend to either one or other of the two extremes. If you’re overloaded, see what you can leave. If you are lazy, check what you would like to do.
Kids are very good at finding balance. They are able to play and jump all day long without getting tired.