I'm a big fan of More Kettlebell Muscle by Geoff Neupert. It has 20 complex/chain programs that you can do. Currently as we are entering summer for us north of the equator folk, I wanted to get leaner so I've picked the 2nd nastiest program of them all The Long Haul. 9 week complex program 3 x a week. Heavy day is doing work for 2:30. Medium day 2:00. Easy day 1:30 Work:rest ratio for 1st 3 weeks is 1:2, second 3, 1:1.5, third, 1:1 . You also progress in number of rounds every 3 weeks ranging from 4-6. Heavy day is a mental test. For me, because you're doing cleans, snatches and swings each round, at about round 3 or 4 first the grip starts going and then the rear deltoids because you're squatting before presses. I have found the perfect "hack" for the program, that allows finishing in the same amount of time, even less but with less fatigue and chance of injury. I started this in week 6 and really liked the results. For example, I'm in week 7, I did medium day earlier this week. which is 4 rounds, 2 minutes of work, 2 minutes of rest. Double Snatch x 30 seconds, Double Press x 30 seconds, Double Squat x 30 seconds and Double Swing x 30 seconds. So, you have 8 minutes of work (4 rounds) . 6 minutes of rest (Between 1 and 2, 2 and 3, 3 and 4) It's a 14 minutes workout. In those 4 rounds, you're doing 4 sets (Snatch, Press, Squat and Swing) 4x4 is 16. Now there are 840 seconds in 14 minutes. Divide 840 seconds/16 sets. 52.5 . So, instead of gutting out the complex, I do a new set every 52 seconds. Double Snatch 30 seconds (about 8-9 reps). Put 45's down for 22 seconds, pick up do 8-9 military press, put down bells for 22 seconds, pick up bells and do 9 squats for 30, put down bells for 22, finish with double swings, and start the next round after 22 seconds. No extended rest. Much crisper higher quality reps, less chance for injury The heart still pumps over 170 beats per minute. It's like Rest/Pause training meets Escalated Density Training.