Most of this has already been said.
The question reflects attitudes that are late twentieth and early twenty-first century, very Western, and when put into the
perspective of broader history kind of foolish.
As one comedian put it: “It seems like it only counts as exercise if it doesn’t accomplish anything else. I bike five miles across town, it doesn’t count. I have to ride a stationary bike for it to be real exercise. I climb five flights of stairs to get to my gym so I can use the stair climber machine.” He went on to say that the TaiBo craze was a new level of this, “a ‘martial art’ that isn’t actually good for self defense”.
[quote=“gearform, post:1, topic:18292, full:true”] To do this, player should go to gym or build some sports apparatus.
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The reason we have gyms and exercise machines is that we work at desks in offices where we sit all day. Back when we hunted wooly mammoths with sticks and ran away from saber toothed tigers, we didn’t need Bowflex or eliptical machines. Even when we spent the day plowing fields with a pair of mules we were getting plenty of exercise. Even now, plenty of people work jobs that give them adequate exercise.
You can’t tell me that running from zombies, hunting game with a spear, chopping up and reassembling vehicles, climbing through windows, fighting hand to hand, spending a fair amount of your time wearing heavy armor, chopping down trees, farming fields, managing livestock, and various construction projects isn’t viable as exercise.
With that said, a doctor who knows what he’s talking about (most MDs actually have very little training in diet and nutrition, and there is substantial evidence that much of what is taught as established scientific fact on the subject is dead wrong) said that no amount of exercise will fix your weight problems if you are eating the wrong things, that diet is a couple of orders of magnitude more significant as a factor in weight control than exercise is.
As @Litppunk said, there are medical conditions, genetic traits, hormonal imbalances, and so forth that can also affect this. But they’re the rare exceptions, not the general rule.
For most of human history, getting enough exercise hasn’t been a significant problem and getting enough food to survive has been a frequent problem. Apocalyptic events generally send you back to those defaults.
(Edit: Man that’s long. This is what the public education system has done to me, what it continues to do to us and our kids. It trains us to write three page papers to explain what could be adequately expressed in just a few sentences.)