> By working at the building site, for example, you train your body and your mind to respond in constantly changing situations You mean like most competitive s

> By working at the building site, for example, you train your body and your mind to respond in constantly changing situations You mean like most competitive sports in existence? Your comparison is also overlooking the physical and mental aspects that are missing in everyday physical work. What you have to become both mentally and physically to deadlift 600 pounds or snatch 250 pounds cannot be emulated. It's a process that takes years and requires constantly overcoming your own fears and perceived limits. When you step under the bar and walk it out in preparation for a heavy back squat, the weight wants to drive you into the floor and you are struggling to even keep yourself standing. But now you have to squat all the way down and all the way back up, for several repetitions multiplied across several sets. That's one exercise for one day. You now have to do that several times a week, for years.