molecule. 1  Chemistry, Physics. the smallest physical unit of an element or compound, consisting of one or more like atoms in an element and two or more different atoms in a compound. 2  Chemistry. a quantity of a substance, the weight of which, measured in any chosen unit, is numerically equal to the molecular weight; gram molecule.
When I do crunches my neck starts to tighten up and it makes me have to rest before doing another set of crunches.
You certainly can do crunches, and other abdominal work, to improve core strength and posture, but doing abs will not get rid of the fat. 4. WEAK BELLY: Your abdominal muscles are weak. If you find itâs work to suck your tummy in or to do a crunch, most likely you need to strengthen those muscles.By strengthening your abs, you are able to support your core and hold your stomach in with ease. The stronger and tighter your stomach muscles are, the smaller and flatter your tummy will look.. WEAK BELLY: Your abdominal muscles are weak. If you find itâs work to suck your tummy in or to do a crunch, most likely you need to strengthen those muscles. By strengthening your abs, you are able to support your core and hold your stomach in with ease.