Like so many things in life, finding the perfect balancing point between focused hard work and breaks is the key to success. There will always be situations that require a hard push to a deadline or an all-in team effort, and there will always be those that require careful consideration and deep thought. Just as we need periods of rest after strenuous exercise when trying to strengthen our muscles, we also need breaks - moments of quiet reflection to best utilize the high-energy work we do.
Aside from lending us the space to think and the time to recuperate, these periods also allow us to detach from the matter at hand. The longer we spend surrounded by a particular issue, the more likely we are to approach exhaustion; many times we get caught up on our own method of approach to a problem and our mind begins to close to other points of view. It is only after disconnecting completely and resting that we are finally able to confront the problem with a fresh perspective when we pick it back up.
Taking a deep breath and pushing through will lead us to completion regardless most of the time, but with breaks, the quality of work improves. At times stepping out can be it's own challenge, especially when the team approaches a deadline or the project completion date approaches. Indeed, a brief break can be most crucial during these times when stress is at its peak. That break, whether it's 15 minutes or just 5, can be just what you need to make it the last stretch of the way.