I've done these for 2 weeks now and I'm really impressed with how well this hits the Bicep.
The idea behind this movement is that the starting point is a few inches below a horizontal forearm position and is exactly the point or sweet spot where you'd overload if you were doing cheat curls and concentrates souly on the contraction of the Bicep.
You could do this out of a Rack and rest the bar on your legs after each rep but I find the parallels of a rack useful for moving the bar towards or away from the body which can be used to fine tune how the weight effects the lift.
If you have the time and equipment then I'd say it's a worthy addition for targetting peak.
