Stronglifts 5x5 Too much? (Stormbitch)

I am able to swim breast stroke for 20 minutes with no stopping around 3 times maybe 4 a week without DOMS. Noted 5x5 on here, but last week I did 1 workout and was F UPPPP for a week (legs) I did 15 min walk 1x8 1x10 1x10 squats no weight. And B..