Not necessarily, it's just putting you in the next weight category. It has a weight of 10.0 which is pretty high and makes it a little difficult to stay under 25% or 50% of your weight capacity for either fast or mid-rolling speed. If the extra weight puts you over 50% you are going to be quite slow. I usually strip off most of my armor and use Havel's Ring to stay under the 25% threshold. If you account for the added weight, your movement speed won't be affected.