Good form, an HH or HH style bow, and a consistent practice routine will make moderately heavy weights comfortable for archers of any physical size.
I think one of the biggest myths in Trad shooting is it takes a ton of physical strength or size to shoot heavier weight bows.
The HH grip and the lack of bow mass, plus the length of time at full draw (generally less with HH shooters) allows a shooter to use 10-15 more than with a heavy weight/target style recurve.
Just another factor that is often overlooked in the bow speed comparison...add in an additional 10-15 pounds to an HH draw weight when comparing the style to the "high performance" styles and the gap closes quite a bit.
I also notice he isn't using ANY string silencers...