I'm not Kyomu. But I'd like to chime in here if you don't mind. I'm natural, and my work outs normally are 2 - 2.5 hours. Somedays 3 hours, and a few times I've done 4 hours!
Everyone is different, I've seen naturals who do 40 mins and are freaky huge, and some that can't respond to such a short work out such as HIT. I fall in that category, Volume has always worked for me!
If Kyomu trains 3 hours, then thats probably what works for him since he looks great!
Would be interesting to hear his take on this as well as other naturals!