In veg you can bend them and secure them with some string, a stake, or something similar... or, you can simply snip the top of the plant at the last node, which will halt so much vertical growth and produce two new shoots at the site of the cut. With bending or "training", the plants seem to get a bit bushier. You still will have a main cola, and you'll also have all the side shoots at the same level and receiving the same amount of light. Essentially, you'll end up with several top colas.

Hope that helps.