Regarding training combats

Ive noticed I really struggle at the moment to train properly. I go through an entire inventory of sole in like no time. I'm currently training necro to 50, or trying to, on Ankous. They are also my slayer task at this time. All my combat skills apart from range and necro are base 50. So is it normal to be bodied by these red, bone things?

The same thing happened when I went to the abyss with my melee stats and a halberd, rune that is.