Relationships Between Injuries, re-injuries, Body Weight Change, and Time of Practice

Introduction: Collegiate football is a stressful combat sport. Over the length of the season there are expectations for injuries to occur. Training camps are designed to lessen this risk but still present inherent risk factors to student athletes. Studying training camp metrics will lead to better ways to train athletes while maximizing the prevention of injuries. Purpose: The purpose of this study is to investigate the relationships between injuries, reinjuries, body weight change, and time of practice over two different years of pre-season training camps of division I football athletes. Methods: Collegiate football players (body weight mean=100.3±SD 20.8 kg. n=53) were tracked over two pre-season training camps for injuries, reinjuries, body weight change, and time of practice over two years of pre-season training camps. All injuries were recorded requiring the absence of one practice or game, as defined by NCAA standards, along with date, practice number, time in, type of injury, and reinjuries. Reinjuries were classified as a player who had previously been had an NCAA defined injury to a body area and has had a second NCAA defined injury to the same body area. Body weight changes were monitored by weighing each athlete before and after each practice session and recorded as both body weight in kilograms and percent change in body weight. Time of practice was recorded as 10:00, 11:20, 13:00, 18:00, or 19:30. Results: There were significant inverse correlation between team body weight change and cumulative stress (r=-.563, p=.045, n=13). Change in team body weight during the testing period was mean=2.447±SD .978, n=28. Team bodyweight percent change was mean=.989±SD .004%, n=28, and cumulative stress mean=2.056±SD 1.474, n=18. There is also a significant relationship between football injuries and reinjuries (r=.412, p=.011). Football injuries during testing period was mean=1.054±SD 1.545, n=37 and reinjuries mean=.216±SD .417, n=37. There was a moderate relationship between soft tissue injuries and the camp year (r=.360, p=.031, n=36). Soft tissue injuries mean=1.694±SD 2.424, n=37. However, there were no significant correlations between injuries and time of day, number of practices, and/or cumulative stress. Discussion: This study shows that as athletes gain weight, the cumulative stress on them decreases. This is most likely due to muscle gain during training, causing a decreased total work load to the body. These results can be useful to strength coaches seeking to add muscle to their athletes, but concerned about cumulative stress. One section of the study that does show likelihood of injury is reinjuries. Strength and conditioning staff can use this information to be aware that an athlete that has had a reinjury before has a likelihood of another injury and an athlete that has had an injury has a likelihood of a reinjury to the same body area. The results of this study also show that how many practices an athlete attends, the time of day of the practices, and the cumulative stress do not correlate to whether an athlete will have an injury. Using this information, coaches can provide more freedom in when they will plan practices without concern to increased risk of injury. Conclusion: Further research must be performed analyzing the relationship between injuries and total workload over the course of preseason camp training, and more variables must be tracked to show more significant relationship to injury