The truth is, almost none of us "do enough". We have bodies evolved to survive in the paleolithic. Take a few minutes to envision what life in the paleolithic entailed, and how much physical exertion was required. Even the women, though they didn't typically go out and hunt/forage/fight with the men, had to carry their kit and supplies for miles and miles during the days they were migrating (which was probably half the year). They had to erect the shelters, etc. The human female is technically evolved to march a solid ten to fifteen miles per day bearing a substantial load. This is a level of physical exertion that we today would associate with an all-male infantry, carrying 100lbs plus on marches across difficult terrain for ten miles or more, at a fast step.
Even in the medieval period, if you look at old engravings and illustrations of common life, women were out in the fields working all day long. The men had to work the landlord's fields. The women worked the fields set aside for the peasants to produce their own food.
It's not personal. Probably none of us on this forum work that hard, and many of us have psychological governors in our brains telling us we hit some kind of limit in physical effort that is an extremely low threshold.