Mr Voldore meticulously explained the details of diffusing Mana into the muscles to increased physical capabilities. He instructed them on doing this at a small part first, and when the got the feel for it, they could advance to increase the muscle amount that would carry the Mana.
Grey and Asher stood at their position, they began trying to do as Mr Voldore had instructed.
Grey would have an easier time in this test because of a certain factor, and that was the fact that though summoned beast used Mana, they didn't cast spells, no, they possessed innate abilities that they could cast with Mana. The next thing was that they subconsciously use Mana to increase their strength.
And just as said before, Grey was the first to begin making reasonable progress, he was able to slowly infuse his body with mana. He started with his left fist, after sometime, he could do his whole arm.