Lst stands for low stress training it is basically like topping but instead of pinching off your top node you will be tieing that top node downward. So the rest of the nodes below the top are now open to more light and they all want to be the top. The art of lst is to try to grow your plants wide with lots of tops rather then growing tall with a few main colas. When you lst a plant you want to fill in the space your working with. Your light coverage. Here is a pineapple chunk i lst last night and you can see the top is allready trying to go towards the light again.