Watching that video reminds me of what a fucked up activity drug bodybuilding is. Most bodybuilders who are nationally known who claim they are natural are liars. Drug bodybuilders also lie to them self that it's impossible to be muscular by training natural.
No, a natural will never be able to stand on an Olympia stage but there are hard working guys who look impressive due to their genetics and work ethic. I've been around the game a long time. I have seen guys that look like nothing change drastically in 6 to 8 weeks doing a cycle. I've also known guys who will never be able to win a any drug bodybuilding contest but look amazing for decades, month in and month out training natural.
The tale tell signs of steroid use is how quickly they lose their physique when they give their body a complete break from the drugs. Another indicator is how quickly they gain with their body changing from week to week. Back in the day guys would go on for 2 to 3 months then take months off. Now from what I heard guys are juicing for a really long time before going off. Their endocrine system at a minimum must be really compromised.
