I like three hard and one easy week. I examined my journals (all the way back to 1971) and found that I naturally do it with illness, injury or crappy efforts. So, I decided to just learn to plan it. It is really a hard thing to teach young athletes, but the same holds true….
Compared to things like football or wrestling or boot camp or war, three days a week full body is not too stressful. I think the human body can handle a ton of load and make progress, especially in strength gain. The secret is to find the least amount of work that will provide the most….
“Great weightlifters would readily (one year) make elite/champion kettlebellers and not vice versa” I can only address this with my experiences, but I have only found two things in life that “carried over” into other sports: high school wrestling and the O lifts. Wrestling in high school is one of the rare times in life….