The key thing here is, try not to watch the breath, but try feeling it go in and out, so you feel one with the breath. Just see if from the beginning you can minimize that sense of heavy-duty watching it, and just feel the breath going in and out. …. Then start to emphasize the outwardness and the space that the breath goes into, and emphasize that more and more. And then just see if you can let that sense of outwardness and space begin to pervade the whole practice more and more.
Chögyam Trungpa Rinpoche
Unless we train it the mind does the minimum necessary to fulfill a function. In that way it is like the body. For example, our muscles and bones are strong enough for us to walk – but not to run, unless we condition them…..The difference between the mind and the body is that no one is surprised to get winded while running to catch the bus. Nobody get’s mad at themselves, saying “I can’t believe I can’t run 26.2 miles!” However, when we get overwhelmed by longer hours at work, more emails or more parenting duties, we become irritable, moody and unhappy. It does not occur to us that our mind is out of shape. We put more stress on ourselves because we assume we should be able to handle it all. 
Mindfulbalance 