Density hangs are primarily a beginner routine. Beginners can start on a large hold, one they can hold comfortably (but not a jug), and hang as long as they can. Once you can hang for 60 seconds, you can progress to a smaller hold.
Using one hand on a 20mm edge, pull down for 10 seconds. Using one hand will preclude the possibility of lifting off the ground for most people, but if you can lift your body in this way, add weight until that's no longer possible. The idea is to let your body and feel regulate effort. This is good for rehab and/or prehab of finger injuries, and can be done more frequently than other routines.
Repeaters are focused on endurance by doing multiple hangs in quick succession. Using a 7-on, 3-off timing for 7 reps is common.
I don't like adding weight to repeaters, for a few reasons:
- With density hangs or max hangs, if you mess up a hang, you can just rest a bit and try for time or weight again. However, because timing is more important for repeaters, this doesn't work for repeaters. Faffing about with adding weights increases the chances of having some swaying, mis-timing, or just bad setup that messes up a hang.
- Hanging on different holds has benefits for repeaters because volume is high for repeaters. This high volume lends itself to repetitive stress injuries, so varying the holds helps with this.
To keep things simple, I find it easiest to follow a guided routine: the Beastmaker app works well for this. It's not perfect, but none of the problems really make it hard to use.
I prefer to do repeaters after a session: this can make my measurment of progress less accurate, but it doesn't detract from the endurance benefits.
Max hangs simply hanging with as much added weight as possible, to 3-5 hangs, each 5-10 seconds long. Longer rests are ideal here: 5 minutes is a very reasonable minimum. A 20mm edge is fairly standard.
I primarily train half crimp and three finger drag. Half crimp translates well to full crimp and avoids some of the injury potential of full crimp. But half crimp translates poorly to three finger drag for me.
I find it's not a bad idea to do these before a climbing session. It's unusual for a climbing session to work my hands as much as the max hangs, so it doesn't often interfere with my climbing, and usually leaves me well-warmed up. I can hangboard after max climbing if the max climbing was on slopers, since these barely work my fingers.
I don't like training primarily on edges less than 20mm, because the hangs become more condition dependent. It's worth training smaller edges occasionally to ensure that the strength gained from heavier hangs on larger holds does translate to the smaller holds, but in general I find that this doesn't have to be done often for the strength to translate.
What follows is a rant.
There's no evidence whatsoever that hangboarding has a higher potential for injury than climbing itself. Hangboarding is far more controlled than climbing.
Yes, you can hangboard with poor form and get injured: it's much easier to climb with poor form and get injured because climbing form is far more complex and hard to assess, and involves a lot more ballistic and harder-to-control movements.
Yes, you can hangboard too much or too hard and get injured: it's much easier to climb too much or too hard and get injured because you can't easily put numbers on how hard you're climbing (no, grades don't help with this).
There's a strong argument that beginners shouldn't hangboard, but that has nothing to do with injury. The fact is that beginners will likely see the fastest gains in climbing ability from climbing, and learning climbing movement.
However, there are a lot of cases where climbing isn't an option, and hangboarding is an option. I have a hangboard in my home: I can hangboard at home but I can't climb at home. Similarly, early in my climbing career, I injured my ankle, and was unable to climb, but I was able to hangboard. In such situations, hangboarding may make it possible to continue to progress your climbing when it's not actually possible to climb.
And further, the adaptations caused by static loads such as hangboarding actually prevent injury. Hangboarding is literally one of the most effective ways to rehabilitate an injured finger.
I get hate for this opinion, and invariably that hatemail is a litany of anecdotes which don't have any information about what form the people were hangboarding with, how often, or at what intensity, which just goes to show that people didn't read what is written above. Literally the entire point of hangboarding is that you can measure it to ensure progress and avoid injurty, so if you aren't measuring it, then yes, you should not be hangboarding.
There's one special case of the above, which is the person who did measure and then ignored the measurements, went too hard, and got injured. This should not be seen as a refutation of the idea that the entire point of hangboarding is that you can measure it to ensure progress and avoid injury. If you've done nothing to avoid the avoidable, that doesn't change the fact that it was avoidable.
End of rant.