I don’t know what you mean?
I was just thinking that at 85% of 1RM, basically all motor units would be activated, so I just don’t see how Poliquin thinks that a test of 5 reps, give or take, says anything about being “slow twitch dominant.” My thoughts were that it could say just as much about how resistant to fatigue the FT fibres were, among other things.
As for types of training that might affect it, well obviously FOG (IIa) fibres are more resistant to fatigue than FG (IIx) fibres, and I think it has been shown that certain training tends to make IIx fibres behave more like IIa fibres… (not exactly sure if the fibres literally change, or just take on metabolic characteristics of the different type), and so my thoughts were that with the right training, the muscle fibres could become much more resistant to fatigue without necessarily changing the maximum amount of force that they can generate, therefore changing the results on the test but still saying nothing about whether one is “slow twitch dominant” or “fast twitch dominant.”