He stated this fact on his twitter account back in 2014
"AdamB
@Adambloor1984
7 Dec 2014
@Dorian_Yates
had you incorporated your HIT style of training at that stage? Or did you use the more traditional volume style?
Dorian Yates
@Dorian_Yates
7 Dec 2014
@Adambloor1984
traditional"
There you go.