This group will begin coming to the Clinical Research Center (near the undergraduate campus of Wake Forest University) for exercise classes 2-3 days per week for about an hour each day. The investigators also have a site on High Point University's campus. The class will consist of a 10-minute warm-up, a 20-minute strength training period, 15-minutes of neuromuscular (balance/coordination) training, and a 15-minute cool down. These regular exercise classes at Wake Forest and High Point University will go on for 9 months, followed by another 9 months of option to continue at facility, plus follow-up via email and 2 group meetings/runs at Fleet Feet (at around months 12 and 15).

This group will be observed as they follow their usual run-training routine over the course of 18 months. Emails will be sent biweekly for 18 months to update the research team on injury/training status. The group will attend 5 group meetings/runs at Fleet Feet (at around months 1, 3, 6, 12, and 15). After the 18 months, the participants will be offered a free 8-week strength training program at the Clinical Research Center or High Point University.

To compare the effects of a 9-month strength training program to a control group on the incidence of overuse, lower extremity, running injuries in female adult recreational and competitive runners during and 9 months subsequent to the training period.

To compare the effects of 9-months of strength training to a control group on lower extremity muscular strength at the conclusion and 9 months subsequent to completion of the intervention.