I knew a guy who spent his career as a farm hand on a state university agriculture campus farm. Even with all his right fingers clipped off by a lawn mower we called them the nubs of death, that dude is 25 years older than me and still strong as an ox.

I never liked doing hours long gym sets, I saw good results doing high weights, low descending reps. Even when I was too busy for the gym, I always did pull ups/chin ups/push ups, all of which can be tailored for a lot of muscles. Always surprised my bigger musclehead friends when grappling, boxing, etc.