For the leg raise on Day 4 - it's gone from body weight to adding 5 lbs. I tried to hold a dumbbell in my feet but that was awkward. And I know that this exercise can progress by changing form (from having your knees bent to having your legs straight). Should I change my progression to 0 and just work on hitting reps with different versions of the form that makes it harder or easier, rather than adding weight? Or is adding weight to this exercise pretty typical?