Smoking is one of the leading risk factors for death in the world and the primary risk factor for developing chronic obstructive pulmonary disease (COPD).
Patients with smoking induced COPD have lower physical fitness, as well as locomotor, respiratory and cardiac muscle dysfunction. However, whether this is due to the COPD lung dysfunction and the inactivity that often follows, or a direct consequence of the cigarette smoke itself, is not known. In a recent study, we attempted to answer this question. We exposed mice to cigarette smoke and compared muscle function as well as cardiorespiratory fitness (VO2max) with a non-smoke exposed control group before they developed COPD. In addition we had a smoke exposed group that exercised after the smoke exposure. We found impairments in both the heart and the diaphragm in smoke exposed mice, without any evidence of COPD having developed, as well as a reduced VO2max, indicating that these changes negatively affected performance at the whole body level. Luckily, interval training prevented much of the cigarette smoke associated decline in muscle function, and VO2max was normalized.
The message of the paper is that exercise restores the decreased physical fitness caused by smoke exposure. So if you have just abandoned your smoking habit, perhaps taking up physical activity is a good idea.
Fredrik Hjulstad Bækkerud, PhD Candidate at CERG