Everyone may have different motivations to exercise. For Soldiers, the exercise motivation may be to pass a PT test or because the mission requires it.
One of the pitfalls of preparing Soldiers to meet the physical rigors of completing the mission may be overtraining, also known as overuse. Overtraining occurs when the amount of exercise is out of balance with recovery or rest. When this happens, it can predispose a Soldier to injury. Sometimes, a leader’s sincere desire to show that his or her unit exceeds the standards may be one of the reasons we have an epidemic of injuries today.
The Joint Services Physical Training Injury Prevention Work Group thoroughly reviewed proven injury-prevention strategies in the military. The work group found that too much running was the primary contributor to overuse, and that those who are at the greatest risk for injury are those who are least fit.
A large amount of both military and civilian research shows that running volume (amount of running) significantly increases the risk of lower-extremity injuries (injuries to the legs). During initial military training, about 25 percent of men and about 50 percent of women incur one or more PT-related injuries. About 80 percent of these injuries are in the lower extremities and are of the overuse type – a condition brought about by excessive running relative to the fitness level of the individual.
The work group found ample evidence that running mileage was an injury risk factor. An obvious intervention (change) would be to reduce the amount of running performed by military members. In fact, this intervention has been proven to reduce injuries without affecting physical performance. Marine recruits in a 12-week boot camp had a 54 percent reduction in stress fractures of the legs with essentially no change in aerobic fitness when they reduced their running mileage 40 percent (from 55 miles down to 33 miles). A group of Soldiers in Basic Combat Training who ran 56 miles was compared to BCT Soldiers who ran 130 miles in 12 weeks. The Soldiers who ran fewer miles during 12 weeks of BCT training not only decreased their injuries by 24 percent but scored just as high on the two-mile run part of the Army Physical Fitness Test. It is important to note the group that ran less miles increased their marching mileage (117 miles versus 68 miles for the group that ran the higher mileage). Increased marching is probably more realistic a scenario in wartime.
Another study compared male Navy recruits assigned to basic training divisions that ran either 12 to 18 miles or 26 to 44 miles. The lower-mileage division had lower injury rates, with 1.5-mile run time improvements that were the same as the higher-mileage divisions. In other words, a reduction of 20 miles of running during this Navy recruit training reduced injuries by 20 percent without negatively affecting physical fitness!
There are thresholds of running above which injuries increase dramatically without any significant gains in fitness. Running frequency of five times a week versus three times a week for 30 minutes increases the injury incidence (percent of subjects injured) by 225 percent without significantly improving fitness level. Running durations of 45 minutes versus 30 minutes three times a week increases the injury incidence by 125 percent without any significant change in fitness.
The bottom line: If Army leaders are serious about taking care of Soldiers and reducing PT-related profiles, there is plenty of hard evidence that proves less is more.