for archiving)
Running is a very efficient form of energy expenditure and if you don’t overdo it, you won’t hurt yourself very easily. You can get the same value out of hiking or walking at the cost of increasing time at exercise. So running is just efficient. But it works the same muscle groups and it actually can make you injury prone unless its over uneven terrain. (Spoken as someone who spent a year taping his feet to recover from plantar fascia injuries.)
One of the reasons that the military has always focused on marching twenty miles or more with gear is to build up minor muscles, build cardio, pulmonary, liver, and kidney efficiency, is that it’s makes you exhausted, but exposes you to little risk of injury. Moreover it depletes your brain and combined with surprise commands, teaches you how to function ‘explosively’ on demand even when you are cognitively impaired. If you look at the special forces guys they are athletes not weight lifters. It is far easier to pass endurance stress while retaining mental discipline – which is the test of special forces – if you are able to perform while physically and cognitively depleted.
The problem is fitness vs bulk. The bigger you get the more calories, oxygen, cardio, and pulmonary you need, and you generally lose the most important ‘aryan’ advantages: speed, agility, and endurance (ooda loops).
As far as I know complex motions like ‘rolling that big industrial tire’, chopping wood, crawling across grass or swimming, and climbing trees and ladders, all produce the best overall fitness without damage. (I have only had injuries lifting weights, because it is very easy to ‘overdo’ it on minor muscles with )
However, if you are careful and just lift a few heavy things a few times a week, plus walk a bit, you can achieve almost all of the good. So, weight decreases time.
Unfortunately, those of us with asthma face a constant challenge. Even though I was the fastest sprinter in my class in grade school I have never been able to run distances. I can hike at fairly good pace now that I’m no longer seriously ill, and I can walk pretty much forever. And I can get away with a sprint. But lifting has become almost unbearable. When it was, for most of my life, my favorite way of staying fit. The most fit I have ever been is working an office job, using a simple barbell set at home before work. I naturally walk around a lot, even if writing. The big decline in my fitness was my long struggle with my health. When I tried crossfit while still carrying cancer around, I seriously thought it would die.
It is non trivial to function competitively while deprived of sleep, water, food, while physically and mentally exhausted, hot or cold, and stressed from the possibility of being killed by a bullet at distance.