Every Spring, as track season gets under way and as millions of Americans take to the streets to get back in shape or to shift from indoor to outdoor fitness activities, overuse injuries abound. Overuse injuries are a result of repetitive mechanical stresses that exceed the body’s normal capacity to repair and accommodate to minor injuries. They occur because someone has tried to do too much too soon. When we work out and feel a little sore the next day it’s because we actually caused a small amount of injury to occur in certain muscle groups. In response to these minor injuries and tensile loads, our bodies recover quickly by repairing the areas of injury and building up more muscle mass in order to tolerate the increased work it needs to do. By physically stressing our muscles and bones over time, we develop strength. Unfortunately, it takes time for our muscles and bones to respond and accommodate to increased activities.

Some of the most common overuse injuries are associated with running. With each running step, one’s legs and feet can receive up to 5 times their body weight, and it takes a lot of steps to run a mile. Even someone who has been playing basketball all winter and is in good shape aerobically needs to train gradually to work up to running distances or races. A good general rule for running is ‘the 10% rule’– increase your mileage and/or duration by no more than 10% per week. Students who are expected to run daily at the beginning of track and field season should start training on their own before the season begins. People running just for general fitness should start out running only 2-3 days per week and cross-train on the alternate days by cycling, swimming, aqua-jogging, or rowing, allowing their muscles to recover between runs. Those who are out of shape, overweight, or who haven’t run for a long time should avoid hills and consider starting out running only for ten minute intervals either on a treadmill or at a track while maintaining aerobic fitness by doing some other activity. Runners wishing to add hill-training or speed-work to their routines should do so only after they have been running their desired weekly mileage at a slow pace for a few weeks.

While training errors (doing too much too soon) account for the majority of running injuries, there are a lot of other factors that cause or contribute to the development of overuse injuries. Hard surfaces, banked surfaces such as cambered roads and tracks, and improper shoe wear can add to the impact and shear forces our limbs are subjected to. Basketball shoes, tennis shoes, even many aerobic shoes do not provide the right amount of cushioning and support needed for running. Running shoes should generally be replaced after 500 miles. Even shoes that haven’t been worn much but are a year or two old will have undergone some stiffening and loss of cushioning. Since some people require more stability and others require more cushioning from their shoes, it’s best to consult with an expert shoe salesperson at a respected running shoe store to find the right shoe. Even with the best shoes, there are many individual factors that can predispose a person to injuries. People with flat feet are prone to certain types of injuries and those with high, rigid arches can be prone to others. Females may be more prone to develop knee problems, most likely because of their hip-to-knee angle. Age plays a role in the process of injury and repair. As we age, our muscle and tendon fibers take longer to heal and our elastic fibers become stiffer and less stretchy. The same stress that causes a pulled calf muscle in a younger person is more likely to cause an achilles tendon rupture in someone over 40. A young person whose long bones are growing rapidly may develop pain at sites where the muscles attach such as on the uppermost part of the shin just below the knee. Both young and old alike need to include stretching in their training program not only to prevent injuries but also to prevent them from getting worse. Muscles become tighter as their bulk increases and minor injuries cause muscle and tendon fibers to shorten even more. Other activities such as cycling or weight-lifting can increase calf bulk so much that running without adequate stretching may result in a calf or achilles tear or achilles tendonitis. Significantly injured tissue is not replaced by healthy tissue but by scar tissue, which tightens even more over time and tears much more easily. Many overuse injuries can progress to this stage if they aren't allowed adequate time for recovery and repair. While physical therapy, appropriate exercises, and correcting biomechanical and training errors can help treat the earlier stages of overuse injuries, over time, if a tendon suffers enough sustained damage, its strong, elastic parallel fibers become replaced by jumbled, haphazard scar tissue that only surgery can repair. While most overuse injuries are soft tissue injuries that involve muscles or tendons (the end of the muscle where it attaches to a bone), one of the more devastating types is a stress fracture. These can be difficult to detect initially and difficult to heal. If ignored or missed, continued running can cause even further damage, even a complete fracture of the bone.

Remember that in the process of attaining and maintaining fitness and health, it is important to listen to your body, to be kind to yourself, and seek consultation if what you’re doing isn't working.