Do you lose points on crunches if you stop with your back on floor and then start again? Obviously, with a 2 minute limit, it is crucial not to waste time. However, I have a fitness guide geared toward Marines and it says it is acceptable to stop during crunches as long as you are on your back (shoulders touching ground). Does anyone know about this? I can do about 70 but then have to rest my muscles for a few seconds.