To move they need help from the muscle is they did not have any help from them they would be like a bunch of sticks
Cells do not require oxygen to perform anaerobic activity
Answer:
When you don't have proper body alignment, then the curl ups could be too easy or too hard.
This could also cause injury, due to improper stretching of the muscles.
Some tips would be: (<em><u>You may choose any two of them</u></em>)
1.) keep your feet about 12 inches/1 foot aways from your bottom.
2.) Stretch properly before doing curl ups to prevent injury.
3.) Lay on something soft to prevent spine aching/injury.
4.) Instead of putting your hands behind your head, put them in an X shape across your chest. This can prevent neck injury or aching.
5.) Don't let your feet lift off the ground, have a friend hold them down. Never put gym weights on them, as that can cause injury to your feet.
Which followings above ??
