The said combat dash may go on for 300 metres (so you may have to do it 30 times if the strategy happens to suck big time). And still with the equipment. We actually did that in a swamp when the instructor ordered us to (yeah, that's non-commissioned officer school for you). Yes, I do recall seeing women dropping quite far behind on these cases. Ditto during the time of snow. The infantry sort of strength requires both, be very quick short term while you should be able to sustain slower speed with heavier load for longer periods. What it comes to combat, physical limits are certainly reached - not intentionally exceeded during training (since that would be bad and stupid for Defence Forces to maim people in peace time), but they do get close. Yes, I know a soldier should consider the sustainability of operations, but that's not always possible when certain factors start to work against you.
Some of my squaddies started to hallucinate little green men waving at them from the forest during a certain lengthier marching exercise. Needless to say, nobody even suggested giving certain heavier stuff for women participating in the exercise, nor did they offer for help. Performance enhancing drugs were used in last war here, and if I recall, also in the beginning of the current Iraqi operations. My question is, have you ever gone three days with 45 minutes of sleep during the whole exercise while participating in a combat exercise all the time? The tiredness adds in to the exhaustion, and I don't remember much about women participating in that exercise - actually, the whole exercise is sort of sketchy dream world like occurrence, like the aforementioned march as well. I sort of recall having been in an APC that crashed into forest when we were returning. Yes, endurance is halfway psychological, but the lack of sleep, heavy stuff and the soft ground tends to get you quicker, all of them dangerous for a well-trained sportsman/women.
Oh, and that 30 km skiing, that's without water to drink or stopping to catch the breath. Intentionally so, since I sort of wanted a challenge.