I do this for biceps conditioning

[seiyafan]

Stand directly under a door in your room, then take one step back, put both of your straight arms to the side wall (like an inverted V) to support the body then lean through the door until the tendon that connects your biceps to the elbow start to feel sore. You can alter the degree of lean to change the pressure on your tendon.

I found this myself a couple of years ago, but only recently started adding it to my routine for fun. Does anyone else do this? Do you think it is useful?

[Brian Li]

I think these would be good for beginners. It's like a supported back lever lean right? I would recommend planche leans, rings support, and bicep curls for beginners. I think if you can bicep curl a lot in relation to your bodyweight (like 70%+ of bodyweight in a barbell curl) and have decent biceps mass then your biceps are strong enough for palms facing down back lever and palms facing back planche at least. Of course you should test it out with lesser straight arm exercises first once you can curl a lot.