1. Genetics- if you go them you got them...If you DONT you DONT....I have stepped on stage and I have shitty genetics and I cant even compete with great genetics...
2. Drugs- Slin,HGH,Test- you need it
3. Diet- Also dependent on Genetics...Some people cant eat like shit and still look great
4. training - Again somewhat dependent on genes...Some people respond well to weight and some have to work twice as hard....
Strength and size has always been easy for me...I can put on 10lbs in a few weeks and I can maintain it well but even with a good diet and cardio...lean and mean is always a challenge...