Muscle sprains and joint strains are the commonest ill-effects of exercise, particularly competitive sports.
Activity versus inactivity
Physically active adults experience a higher incidence of leisure-time and sport related injuries than their less active counterparts. However, healthy adults who meet the usual governmental activity recommendations have an overall musculoskeletal injury rate that is not much different to inactive adults. Active men and women have a higher injury rate during sport and leisure-time activity, while inactive adults report more injuries during non-sport and non-leisure time. A possible reason for this lower injury incidence during non-leisure time is the increased fitness levels (endurance, strength, balance) of the more active adults.
Inevitably more vigorous exercise with its greater benefits does bring a higher risk of musculoskeletal injuries as the intensity and amount of the activity increases. I would suggest to you that the benefits of a vigorous exercise regime greatly outweigh the temporary inconvenience and discomfort of these minor injuries. It is probably true, however, that excessive exercise such as that taken by ultra- marathon runners and the like may bring a less acceptable level of injury.
Studies on injuries in adults aged 65 and over are scarce. The rate of injuries occurring during physical activity in advanced age, based on existing data, is very low compared to other ages. Based on current available research, there is no substantial evidence to justify the fear of getting injured in purposeful physical activity or in sports in advanced age. Indeed, by strengthening bones and improving balance, the risk of injurious falls in the elderly is reduced by exercise training programmes.
The common belief that it is exercise that causes chronic joint problems and osteoarthritis is bunkum – regular physical activity may even reduce the risk of developing painful osteoarthritis by improving cartilage resilience and by increasing the strength of the muscles which support the joints. High levels of walking are associated with reduced need for hip replacement surgery. Bicycling is an effective way of delaying hip surgery. Activities such as jogging that place greater strain on joints appear to be more protective than lower impact activities and it is a myth that recreational running leads to osteoarthritis of the knees.
Some sports which involve either violent contact or much twisting (think football or rugby) carry a considerable risk of more serious joint injury such a ligament tears, particularly of the knees. Ex-footballers are particularly prone to osteo-arthritis of the knees later in life.
These are small cracks in the bone usually in the foot or lower leg, brought on by overuse and repetitive activity. High impact or prolonged exercise are most often involved – running, football and basketball in particular. Sudden increase in activity or change in exercise pattern are causes. Other possible sites include pelvis and vertebrae. The symptoms include pain and tenderness at the site of the injury. An Xray may not initially show the fracture but within a week the repair mechanisms can be seen. Treatment is rest and avoidance of further impact until healing has taken place – usually about eight weeks.
Exercise and trauma
Some sports like cycling carry an increased risk of trauma, mainly at the hands (or machines) of other road users. Despite this the cyclists are the ultimate winners. A study of 230,390 commuters identified 5,704 who travelled to work by bicycle. The cyclists were 3.4 times as likely to sustain transport related injuries as the other travellers – but the overall mortality over the period of study was still lower in the cyclists.
Contact sports often result in head injuries. Boxing is the obvious example but football, rugby and American football can all involve repetitive head impacts which can eventually result in “chronic traumatic encephalopathy”. This causes brain damage and accounts for up to 15% of cases of dementia. Another outcome is lowered testosterone production with resultant erectile dysfunction. Wisely the government has banned primary school children in the UK from heading the ball in football training – but not yet in matches.
Extreme endurance exercise
Excessive physical activity does have complications. A number of cardiac indicators are worse in those undertaking very high levels of exercise including enzymes released by heart muscle damage and calcification of the coronary arteries. Nonetheless high levels of physical activity and cardiorespiratory fitness and extremely protective against cardiovascular disease and cardiac mortality.
Other ill effects, found in sports students training for five to seven hours per week, include increased bodily pain, sleep disorder and anxiety.
People with exercise addiction experience loss of control such that exercise becomes obligatory and excessive. This is very similar to the obsession with exercise seen in some eating disorders when the excessive exercise is part of the strategy to maintain weight control. Exercise addiction is not common, occurring in about 0.3% of the general population and about 2% of regular exercisers. In some sports it is much more common – up to about 25% in runners. It seen about equally in men and women though in women it is more often associated with eating disorders. Some of the characteristics include continuing to exercise despite injury and illness and giving up social, occupational and family interests which might interfere with the exercise programme. Sufferers may report withdrawal effects when their exercise schedule is disrupted. The most effective treatment is probably cognitive behavioural therapy (CBT) with the aim not of stopping the subject from exercising but of helping them to recognise the addictive behaviour and reduce exercise routine rigidity.