> a time-box of one month or less during which a "Done", useable, and potentially releasable product Increment is created. Sprints have consistent durations throughout a development effort. A new Sprint starts immediately after the conclusion of the previous Sprint.
(http://www.scrumguides.org/scrum-guide.html#events-sprint)
There's nothing that says you need to "sprint" through your sprints, quite the contrary it's supposed to be a way of measuring your team's steady-state output by making the feedback loop short.
If people are really hearing the word "sprint" and thinking "ah, Scum is telling me to work at 110% all the time without stopping", then I put forth that no methodology or change of terminology is going to save them from themselves. However, I suspect there's something about the timebox structure that makes short-term thinking the default unless discipline is applied, and discipline is hard.