Board Thread:Warhammer 40k General Discussion/@comment-3580035-20130420010932/@comment-6078851-20130424170703

the power armour worn by the sisters is normal human sized, so is far lighter than astartes armour, and while the page on power armour doesn't say outright that it provides a strength boost for sisters' armour, it does imply a strength boost - "doesn't provide a strength enhancement to match astartes".

i would also think that power armour worn by actual humans, not superhumans, would need a strength boost for humans to be in any way effective while wearing it, regardless of musculature, and while sisters would definitely have a muscular physique, as all soldiers do, i doubt they are grotesquely big (mr and mrs universe big). to add to what kadjah said, "how else can they lug around those bolters and plasma guns", but also how else can they lug around those heavy bolters and heavy flamers? when the biggest guys of the imperial guard struggle to use a heavy bolter on their own i don't see how sisters can hold them without a power boost, let alone hold them underhand without a boost.