The problem, as you might expect, is that many lifters don't know how tightly to wrap to restrict the veins and not arteries. This is no good. But our study addressed the problem directly, and we found a simple approach to make sure you're on the right track.
Simply put, wrapping at a pressure that lifters perceived to be a 7 on a scale of 10 on the legs, and 5-6 on the arms, reliably occluded the veins but not the arteries. This is as tight as you should go, and no tighter.
You may have to do some tinkering to find your 7, but you should never wrap as tight as possible, which would be a 10.
As for weight, all the research indicates that there's no benefit to be gained from going heavy. Select a weight that is 20-40 percent of your 1RM—seriously! Trust me, it will feel much heavier by the end.
Our recommendation for the ideal BFR workout to optimizing growth is 4 sets with reps of 30, 15, 15, and 15, with only 30 seconds rest between sets. Perform this workout 2-3 times per week.
It is essential that you wrap directly around in a circular manner on a narrow area, such as the narrowest part of the upper arm. Wrapping in a wider area puts you at risk for occluding the arteries.[SUP]4[/SUP]