1. When sitting up, should I keep my back straight or does it curl into the finish of each repetition?
2. At the top of each sit-up rep, my back felt quite a bit of stress which surprised me because I would've thought it would just mainly be my abdominals and hip flexors getting worked. Was this due to me not keeping my back straight?
3. How far do you go, RoM-wise? Do you stop once you are sitting up at a 90 degree angle to the floor or do you keep going until you feel like your abdominals are as contracted as possible?