When i work out, lets say my back, i do about 3 sets 10 reps, and about 4 different exercises, if i set the weight too high, i have trouble finishing all 10 reps because i get too tired, so i set it at about 50 lbs, and i can finish fine, but i dont seem to be struggling on the 10th rep, should i increase the reps? also im not getting sore really, so im not sure what technique will work for me. i could do heavy weight but then i would need to rest longer before i could lift again. plz help i dont want to be wasting my time at the gym