It is one of the great and enduring ironies of sport that while fitness and athletic competition are often perceived as important components to a healthy and enjoyable passage into middle age and beyond, the aging process limits athletic performance as emphatically as any other barrier.
The age-related response to injury must be considered in two ways: how age affects the physical ability of the body to recover from a particular injury, and the impact age has on the mental and psychological capability of an athlete to deal with the stresses of rehabilitation and recovery.
In general terms, aging is a process of often gradual change to the physical structures and organs of the human body. The aging process is unrelated to, but may be accelerated by, disease, traumatic injury, or accident; aging also impacts upon the manner in which the body recovers from an injury. As the body ages, muscle mass will decrease, typically in a more pronounced fashion after age 45, as the muscle protein rebuilding and repair processes become slower and less effective, resulting in decreased physical strength. The power of the heart, and the corresponding ability of the body to transport oxygen by way of the red blood cell system, also begins a slow but perceptible decline in performance at age 40. These general aspects of aging in athletes are each influenced by the specific makeup of each athlete.
Age is of particular importance in the consideration of how athlete injuries are managed and treated. In general terms, a younger person will heal from injury more quickly than an older subject with a similar injury; the recovery rate is directly related to the speed with which the body can grow new cells to repair itself. Various sports science studies have illustrated that an injured athlete of age 45 and over will recover at a rate of between 15% and 18% slower than a similarly injured 30-year-old person. Skin thickness is reduced by as much as 30% by age 50, making the skin more susceptible to cuts and lacerations. Bone density naturally decreases by approximately 10% by age 50; conditions such as osteoporosis (a common disease in persons who do not consume proper amounts of bone-building minerals) will tend to reduce bone density still further, making the skeleton more prone to fractures.
From elite athletes to the recreational competitor, an injury can be as emotionally devastating as the physical limitations that result. The age of the injured athlete will often play a role in how each of these factors is resolved. Such psychological factors associated with injury include:
While as a general proposition, injury has a more pronounced impact on athletes over age 40. Concussions and other blows to the head introduce an additional factor to recovery. Concussion, a bruising of the brain caused by a blow to the head, is a common injury in contact sports such as American football. The incidence and treatment of this potentially serious injury has been the study of intense research. A 16-year-old high school football player will often return to play within two or three days of sustaining a concussion; peer pressure is a common motivator, as opposed to an absence of symptoms. The recovery rate for an injured 16-year-old is as much as 100% longer than that for a 20-year-old college football player who has sustained a similar concussion. The differing rate results from the slower healing process in the 16-year-old athlete, who is not yet fully grown, and whose body's capacity to repair itself is correspondingly less.
In a similar fashion, for young athletes who have not yet reached physical maturation, injury recovery and a return to athletic activities must consider the long-term consequences upon the epiphyseal plate, known as bone growth plates. The plates are developing tissues found at the epiphysis, the ends of long bones (such as the femur, or thigh bone). Both injury and a failure to consider the consequences of damage to a growth plate may have serious long-term consequences to a healthy bone structure.
Injuries are the first component of a cycle that progresses through rehabilitation and recovery, to full participation. This cycle will be repeated throughout the career of any athlete, as injury to some degree is inevitable. In some sports, the mental hurdles associated with recovery are as demanding as physical rehabilitation. For the downhill skier returning from an anterior cruciate ligament tear and a bad fall, or the NASCAR auto racer who was badly injured in a crash, the injury may prompt a retirement, even where the physical rehabilitation is complete.