Some people may struggle to do sit-ups without holding their feet because they lack core strength or have tight hip flexors, which can make it difficult to maintain proper form and complete the exercise effectively.
To effectively perform situps without holding your feet, you can anchor your feet under a heavy object or have a partner hold them down. This will help stabilize your lower body and allow you to focus on engaging your core muscles during the situp movement.
He didn't do situps, silly!
Your best bet is to do the situp properly without cheating or trying to get away with sloppy situps. The heavier you are the more calories you should burn with situps but it is very difficult to tell beyond that an exact number.
maybe
situps in a decline position situps towards left and right side leg raises for lower abs
500 situps burn 100 calories so you need to do more than 2,500
Most people think you have to have a gym membership but really simple stuff like pushups, situps, jogging, will work if you keep at it.
Yes, 1cm.
situps
lower body parts
the muscles of the abdomen
The only thing you have to do is situps twice daily and you should see a difference