Nicotine can act both as a relaxant and stimulant: it relaxes skeletal muscles and increases tension in other muscles.
Carbon monoxide replaces some of the oxygen in your blood and makes it harder for oxygen to transfer into muscle cells. As there is less oxygen available for your muscles they tire more quickly.
Smoking appears to change the distribution of fat in women to a more male "apple" pattern. Women who smoke tend to put on more fat around their waist compared to women who do not smoke. Fat in this area is associated with health risks such as stroke, heart disease, type 2 diabetes and a general increased death rate. When women quit smoking, any weight gain that occurs is put on in the normal and safer female pattern with a preference to the hips.
Smoking gradually decreases your bone density over the course of your life. This leads to low bone density, especially for older women.
Smoking increases the risk of hip fractures in both men and women. It is one of the major preventable causes of fracture in older pe ople . Quitting as early in life as possible reduces these risks compared to continued smoking.