We tend to think of olympic athletes as being "fringe" physical specimens. This is true in a number of ways, but it is not true as a matter of standard benchmarks of physical fitness. Consider, for example, aerobic fitness. One standard measure of aerobic fitness is VO2max (basically, a measure of maximum oxygen uptake). Elite olympic athletes tend to have VO2max scores of around 60 ml/kg/min (see, e.g., Lauresen & Jenkins, "The scientific basis for high-intensity interval training," Sports Medicine, 2002). In contrast, the average value for Americans as a whole is about 37.2 ml/kg/min. The question, however, is who represents the fringe fitness group here?
Well, if you look at modern hunter-gatherers, you will find that their VO2max is about 57.2 ml/kg/min (Boyd Eaton & Stanley Eaton, "An evolutionary perspective on human physical activity," Comparative Biochemistry and Physiology, 2003). So hunter-gatherers have aerobic fitness values that are comparable to modern Olympic athletes. But, of course, hunter-gatherers approximate the evolutionary context in which human beings evolved. Put simply, your genes expect you to be an Olympian, not Homer Simpson.
But make no mistake, hunter-gatherers ain't marathoners. Overall, they are more powerful than your average American as well, about 20% more powerful (Cordain, Gotshall & Eaton, "Physical activity, engergy expenditure, and and fitness: An evolutionary perspective," International Journal of Sports Medicine, 1998). Your average marathoner would be less powerful than your average American for the simple reason that their training regimen changes the relative percentages of slow twitch, fast twitch and intermediate muscle fibers. Marathoners have slow twitch muscles, but it is fast twitch muscles which provide you with power/strength. And it is worth noting that a 20% increase in strength is considerable. For instance, my 1 rep max for a barbell curl is 135 lbs. A 20% increase would take that up to 162 lbs. That is a LOT of additional weight.
So despite the fact that hunter-gatherers have a very high level of aerobic conditioning, they are also physically powerful.
Now how does this sort of information relate to issues in the philosophy of hunting? Well, part of the answer is straightforward. If your fitness levels are more like the fitness levels of hunter-gatherers than like those of Homer Simpson, then you will be able to hunt more like hunter-gatherers; that is, off the trail without reliance on modern mechanical labor saving devices and other space-age crutches. (It will also just make you a better hunter.) But there are also less tangible effects. If you have ever taken up, say, a running program for long enough to gain some significant health benefits you will know that the experience of running changes from one of misery to one of enjoyment over time. The same thing applies in hunting: the experience of wilderness of a physically fit hunter is very different from (and more pleasant than) the experience of one who is not fit.
So the bottom line is this: physical fitness affects how the hunter "interfaces" with the natural environment. (So, incidentally, does a knowledge of natural history.) Seeing the wilderness as formidable, imposing, difficult to navigate through, and adversarial is NOT a natural way of relating to the environment.