The phrase is supposed to imply that one is a counter weight to another and the usual interpretation goes something like this - to keep work and life in balance, workload should be controlled so that life does not get adversely impacted.
Let me attempt a different take on it - to keep the balance, as our workload starts increasing, we can start to increase our life load as well..... maintaining the balance... of course, if the balance itself should be strong enough not to break...
