Actually he's really not trying to 'outspeed' someone with superior leg speed. Stepping forward (with forward momentum) is simply a much easier task than lifting ones entire body up and then forcing ones self backwards far enough to completely escape Sigurd's stride, which is considerable as a 6ft 4" man. 

Despite which, no matter what you argue your character's armour is inherently weighty. Armour dense enough to stop longsword strikes in the fashion yours has must be at least comparable to steel plate.

Like I said though, go ahead and take no damage. Some say that T1 Eden is designed for people to accept when they're in a disadvantaged situation, such as crouching on the floor, and take damage accordingly, but I wouldn't want you to feel burdened by the forces of fair play. 

For the record, I'm aware that thirty pounds is not exceedingly heavy, but fourteen kg's of extra weight is still significant in terms of split second mobility, and it would be encumbering if you intend to hold it while rising and moving.