Ivan,
currently using farmers walks and crawls after S&S as a "finisher". not particularly heavy, I use what ive got which is a 32kg bell in one hand and a 40kg bell in the other, I walk about 15 meters, stop switch hands and walk 15 meters back. I do them between 5 and 7x per week. its not much, but the daily practice, just like with S&S, gets me energized and keeps me progressing towards my personal goals