Leg, knee and ankle overuse injuries are the single biggest threat to Soldier health and readiness, according to Bruce Jones, M.D., who manages the Injury Prevention Program at the U.S. Army Center for Health Promotion and Preventive Medicine.
In other words, these injuries sideline Soldiers more frequently than any other type of injury, disease or chronic physical condition, or even any battle injury.
Jones and other CHPPM epidemiologists have shown that relatively minor injuries such as sprained ankles can be costly in terms of lost training time and reduced combat readiness. It follows then, that leaders and Soldiers need to be conscious of the signs of overtraining to prevent unnecessary injuries.
A decrease in performance of individuals or groups, substantial increases in fatigue, decreases in morale among Soldiers training or playing sports as a unit and higher incidence of injuries each may signal too much training, Jones said.
What Soldiers should know
Jones and his colleagues have spent years studying injuries in basic training populations, as well as specialized occupations such as parachutists.
Their studies of injuries show the factors below increase a
Soldier’s likelihood of experiencing a training-related injury:

Not being physically active Lower aerobic fitness level Smoking cigarettes Running in older/worn or worn-out shoes High-mileage training Being too lean or overfat Being older than 25 Soldiers, especially those who have any of the risk factors above, can decrease their chance of injury by staying active and by starting slowly before vigorous physical training or other physically demanding activities.
Soldiers should gradually increase the intensity and length of workouts as they become more fit.
Workouts should be cut back in intensity and length if soreness or fatigue persist or increases after a good night’s sleep, according to Jones.
“It is better to do too little than too much,” he advised. “If you feel good today, then repeat it the next day. If you continue to feel good, then keep it at that level. If it feels good for a week or two, then increase,” he said.This approach is the key to getting in shape and staying injury free, according to Jones.
There are many myths concerning training injuries.
For example, stretching — alleged to reduce injury — has little effect on injury rates. Insoles for shoes have not been proven to prevent injures, according to studies conducted and reviewed by Jones.
Another finding that may be important to Soldiers is that if they smoke, their injury rates are higher, and the more they smoke the higher their risk of injury is, Jones said. For smokers who quit, risk of injury returns to normal.
A new ground-breaking study on military training footwear and musculoskeletal injuries was published this year by a senior CHPPM scientist who works with Jones. This study determined that there is no advantage in having Soldiers wear shoes prescribed on the basis of foot arch height.
However, it is important to wear good, supportive shoes that have good cushioning, adequate stabilization and fit well and that are not worn out.
What women should know
Women in Army basic training have twice as many overuse injuries as men, according to Jones.
He attributes this to women entering the service with lower physical fitness level than men and to women’s hormonal fluctuations.
Jones explained that when certain hormone levels are high, ligaments become very relaxed and flexible (for example, during early pregnancy or certain parts of the menstrual cycle); bones are affected by hormones as well. This may put women at greater risk for injuries, he said, but staying physically fit and in shape can help women prevent injuries.
Jones’ studies show that women and men of equal fitness levels have similar risks of injury during Army training. Women and men of the same fitness level can be expected to complete identical physical tasks and to experience the same amount of injuries, he said.
What leaders should know
The best way for leaders to protect their Soldiers is by preventing overtraining — avoiding thresholds of training above which injury rates increase but fitness does not. Leaders also should be aware that Soldiers who are subject to high amounts of mileage while training are at an increased risk of injury. High-mileage companies have 50 to 60 percent more lower-extremity injuries than units running lower mileage, according to Jones. Having Soldiers participate in lower mileage training is an excellent way to prevent injury and to reduce the number of Soldiers recycled or discharged during basic combat training, he said.
“Training in ability groups eliminates the problem of having the slower guys getting injured and the faster guys getting less fit when running as a whole group,” Jones explained.
The less fit group can run for the same amount of time at a slower pace. While they’ll run fewer miles, CHPPM studies have shown they will increase fitness while reducing their risk of injury.
This approach makes it possible to avoid exceeding the training-injury threshold for the least fit while not undertraining the most fit.
New and controversial research also has been done on the relationship between flexibility, stretching and injury risks.
“The traditional sports medicine literature suggests that the more flexible you are, the fewer injuries you will have,” said Jones. CHPPM scientists have shown that this is not true.
“We found that both extremes of flexibility were bad,” Jones said. Individuals who were very inflexible and those who were very flexible were at double the risk of injury during Army basic training compared to those of average flexibility.
“So strive to be average,” was Jones’s ironic advice. “The strongest and most consistent risk factor that we’ve seen is, the less fit you are coming into the Army, the more injuries you are likely to get,” said Jones.
Words to the wise, then: increase fitness training gradually but steadily, and sustain fitness continuously — even if it means working out while on Rest and Relaxation — to prevent injuries and decreased individual and unit readiness.