Strength Cardio

Tried strength/toning cardio. Man, that stuff hurts. Is it just me? It hurts worse while doing it than later, when one would think you’d be sore afterwards. If it hurts “that” much while doing it, I fear over-doing it because I don’t know if I can handle if it gets much worse afterwards. (sigh) What to do? I found a play list of Pahla B’s seated workouts, and thought hey, I should go through the whole list so I can see which ones I like. But I’ve already had to to modify or drop the strengthening part on multiple times because I can’t stand how much it hurts. How is that possibly normal? One would think you might get too fatigued; tuckered out, and drop the weights, or switch to smaller ones, during the workout. But is it normal to hurt this much? And the hurt not being because I’m sore from previous exercise?