What are they up to?

Would like to know what some of the guys at my gym are up to when I see them doing the following:

Start of set
Heavy weight - 3 reps
stop
decrease weight and increase reps - 6 reps
stop
decrease weight and increase reps - 12 reps
stop
decrease weight and increase reps - 15 reps

What does this do?

Is this ripping? Cutting?

I ask cause im un sure and would like to know

Drop sets, basic training principle, pushing the muscle to failure with decreasing weight. U can do something similar with increasing weight if u are more experienced.

Leg press 3 plates a side for 6 reps. Add a plate. 6 reps. Add a plate. 6 reps. Add a plate 10 reps. Then rest for 30 seconds then another 6 reps, take a plate off, 6 reps, take a plate off 6 reps. Then go till u can't do any more. U will need 2 people to add weight each set for u and do not rack the weight when adding plates. It's another way of increasing volume and intensity of your training so can be for building lean muscle,and burning fat.

If you are used to doing 3 or 4 sets of 8 - 12 reps... Any of these types of superset or dropsets will probably make you cry like a baby girl...lol...

You can use this principle (drop sets, pyramids or supersets) on pretty much any exercise. I find using the machines is easier for this type of thing as you don't need to hog a whole bunch of weights.

Remember kids... pain is just weakness leaving the body...