IF ANYTHING,THINK ABOUT THIS: AT 20 YOU STILL MIGHT ACTUALLY HAVE A BIT MORE TIME TO GROW.YOUR BONES AREN'T COMPLETELY FUSED YET.DO A CYCLE,AND U END ANY CHANCE FOR MORE NATURAL GROWTH.EVENTUALLY YOU'LL ENCOUNTER SOMEONE WHO STARTED WHEN HE WAS 14-15 AND PAYED THE PRICE FOR IT.