Tobacco Use Affects Sporting Performance and Physical Fitness

It is well-known that tobacco kills. In fact it kills half its long-term users. What is less well-known, however, is the effect that smoking can have on people's ability to live their daily lives to the full – especially when it comes to taking part in sport or other kinds of physical activity. In addition to its long-term effects on health, tobacco use can have short-term effects, especially on lung function, but also on muscular strength and sleep patterns. Many studies have shown that smokers are less able than non-smokers to take part in sport at all levels, from the international elite to the weekend amateur, and these effects also make it more difficult to live a normal active daily life, when activities such as climbing the stairs or running for a bus become more difficult.

Numerous studies have shown that smokers are simply less fit than non-smokers. For example, in a large study of young army recruits, smokers were twice as likely to fail to complete basic training compared with non-smokers. In studies of endurance exercise, smokers reach exhaustion earlier than non-smokers and derive less benefit from training. In one study of 6,500 19-year old army conscripts, smokers ran a significantly shorter distance in 12 minutes compared with non-smokers, and the more cigarettes smoked per day and the longer the duration of smoking, the shorter the distance run. The same non-smoking recruits ran an 80 meter sprint in a significantly shorter time than smokers. In the same study, of 4,100 regular joggers who took part in a yearly 16km race, smokers were consistently slower. It was estimated that for every cigarette smoked per day, the time to complete the run was increased by 40 seconds. The authors suggested that smoking 20 cigarettes a day increased the time taken to run the 16km race by the equivalent of 12 age-years (i.e. a 30 year-old smoker took, on average, the same time to complete the race as a 42 year-old non-smoker) or destroys the endurance enhancing effect of running 20km per week.

Other studies have shown that short-term exercise is also affected by smoking. Regular smokers are twice as likely to discontinue exercise treadmill tests because of symptoms of exhaustion, fatigue, breathlessness, and leg pain than non-smokers. These disadvantages are directly related to the duration of smoking and the number of cigarettes smoked.

In addition to the effects of tobacco use on lung function, studies have also found other effects on the ability to perform well at sport. For instance, a 1998 study showed that young adult smokers (age 19-30) had less muscular strength and flexibility than non-smokers. Another study in 1982 found that sportspeople who smoked also had disturbed sleep patterns, and other complaints of ill-health.

Not only does smoking affect short-term fitness, but studies have shown that smoking also exerts a long-term consequence on physical
performance. A study of 1,393 middle-aged Norwegian men examined the association between smoking and decline in physical fitness over a period of seven years. It found that the decline in physical fitness and lung function among healthy middle aged men was considerably greater among smokers than among non-smokers and could not be explained by differences in age and physical activity.

For the lungs and heart to work efficiently they require oxygen-rich blood. Carbon monoxide in tobacco smoke binds with haemoglobin, the oxygen-carrying molecule in the blood, to form carboxyhaemoglobin. This means that there is less haemoglobin to carry and deliver oxygen to the body's cells and less oxygen reaches the heart and lungs.

Smoking also reduces the lungs' ability to absorb oxygen. Smoking destroys the alveoli, the tiny air sacs where the air exchange takes place, making the lungs less elastic and less able to exchange oxygen. Smokers' lungs also have decreased surface area and fewer capillaries, resulting in less blood flow. Consequently, the lungs receive fewer nutrients and oxygen needed to make them healthy and function normally. Every inhalation of smoke causes the airways to constrict. Over time, more prolonged airway narrowing occurs and lung damage may be irreversible.

In addition, all tobacco use, including smokeless tobacco (chewing tobacco, snuff, snuss, etc) as well as cigarettes, increases the speed of smokers' resting heart rate, which reduces endurance.