It is already well established that smoking damages our lungs, but a new study indicates that the habit also directly damages our muscles.

According to international researchers, smoking affects a person's ability to exercise because it makes their muscles weaker. Until now, it was thought that this weakness was due to the lungs becoming inflamed and eventually destroyed by smoking, therefore limiting a person's activity levels.

However, this latest study suggests that smoking causes direct damage by reducing the number of small blood vessels that bring oxygen and nutrients to the muscles of the legs.

This can have a negative impact on metabolism and physical activity levels.

The study involving mice was not able to identify which of the 4,000 chemicals in cigarette smoke were responsible for this damage, however the researchers are hoping to investigate this further.

"It is vitally important that we show people that the use of tobacco cigarettes has harmful consequences throughout the body, including large muscle groups needed for daily living, and develop strategies to stop the damage triggered by the detrimental components of cigarette smoke," the researchers said.

Details of these findings are published in The Journal of Physiology.