A 2011 study [1] conducted at the Shiraz University of Medical Sciences compared the muscle strength, endurance, speed, agility and flexibility of otherwise comparable smokers and non-smokers from a group of college students not actively engaging in any sport.

Summarizing the research findings, the smokers participating in the study performed worse for the measures in question compared to the non-smokers. There where statistically relevant results for muscle strength, agility and speed. Non-smokers in the study could jump further, run faster and could perform nearly double as many pull-ups.

The authors of the study conclude that

“(…) smoking will cause a gradual loss of physical strength and active personal and social power.”

Why Smoking Harms Fitness

In sports science there is a measure for cardiovascular fitness called VO₂-max. It measured the Oxygen consumption reached while going to the limit in an incremental exercise. This can be measured from the inhaled and exhaled air while training on a treadmill or stationary bicycle. The idea is that converting energy in the muscles takes oxygen and therefore a large usage of oxygen corresponds to a lot of available power.

For a good (high) VO₂-max several factors play a role:

• the lung performance,
• the efficiency with which oxygen can be transported through the blood vessels and
• the muscle mass in which energy can be converted.

All three of those factors are impacted by smoking. Lung capacity is probably the most obvious case with all the cases of reported lung disease in smoking populations. Already in 1959 a study showed lower lung capacities in smokers compared to non-smokers [2].

Oxygen is transported by hemoglobin in the blood. One effect hindering that is if that hemoglobin is instead bound to carbon monoxide. With people who smoke one pack of cigarettes per day this effect reduces the oxygen transportation capacity in the blood by 10% [3, 6].

The strength of the muscle itself as the final factor has also been examined thoroughly. For example a recent longitudinal study found several percent of difference in the knee muscle strength, even after correcting for things like physical fitness and body fat percentage [4].

Quitting Helps!

Now the next question is, if the damage done by smoking is permanent or reversible. Here a growing body of research shows, that at least part of the damage done is reversible. To drive this message home let’s look at two studies.

The first study [5] looks at young males who during basic military training are forced to abstain from smoking and to partake in a “uniform physical conditioning regime”. They compared the improvement in run speeds of the subjects between start of the training and it’s end. The authors found a stronger increase in the run speeds of former smokers thereby extracting the effect of the smoking cessation and conclude:

“Smoking cessation in this cohort of young men resulted in improved physical aerobic performance, independent of other behavioral health characteristics.”

The second study [6] looked at women undergoing a 12 week training program where they had to do 30 to 40 minutes of training (plus warmup and cooldown) three times weekly. They compared two groups. One continued smoking and the other ceased smoking from week three. The authors of the study come to conclude:

“(…) women who undergo a vigorous exercise training program and quit smoking demonstrate improved exercise performance over those who continue to smoke.”

And the effect here was huge. While the increase in the (fat-free weight based, calculated) VO₂-max for those training was 10%, it was 19% for those training and stopping to smoke.

Return to campaign home.

Sources:

1. Comparison of Physical Fitness among Smoker and Non-Smoker Men, Farzaneh Moslemi-Haghighi, Iman Rezaei, Farahnaz Ghaffarinejad, Reza Lari and Fatemeh Pouya, Addict & Health 201, vol. 3(1-2), pp. 15-19, March 2011. link
2. Tobacco Smoking, Respiratory Symptoms, and Ventilatory Capacity, I. T. T. Higgins, British Medical Journal, Vol. 1, Iss. 5118, pp. 325–329, February 1959. link
3. Exercise and the cigarette smoker, A. Weltman and B. Stamford, Physician and Sports Medicine, vol 10, p. 53,1982.
4. The Longitudinal Relation between Smoking and Muscle Strength in Healthy Adults, M. O. Kok, T. Hoekstra and J. W. R. Twisk, European Addiction Research, Vol. 18, Iss. 2, pp. 70-75, February 2012. link
5. Smoking Cessation and Improvement in Physical Performance Among Young Men, Jeffrey H. Feinberg, Margaret A. K. Ryan, Michael Johns, Blake A. Marvin, James E. Reading and Martin R. White, Military Medicine, vol 180, iss. 3, pp. 343-349, March 2015. link
6. Effect of Smoking Cessation on Exercise Performance in Female Smokers Participating in Exercise Training, Anna E. Albrecht, Bess H. Marcus, Mary Roberts, Daniel E. Forman and Alfred F. Parisi, American Journal of Cardiology, vol. 19, iss. 2, pp. 126-127, Apr. 1999. link