Scanning Sports Medicine
THE NATIONAL WEIGHT CONTROL REGISTRY: A STUDY OF "SUCCESSFUL LOSERS"
In the March/April 2011 issue of ACSM's Health & Fitness Journal®, the authors highlight key strategies that National Weight Control Registry (NWCR) members have used to achieve success in losing weight and maintaining their weight loss over time (2). Despite the fact that we live in a society where weight-loss programs abound, very few people are able to succeed in their weight loss efforts. Approximately only one fifth of overweight and obese individuals in the United States have been successful at maintaining weight loss. Therefore, studying a group of "successful losers" can help health care providers offer better advice to the majority of people who struggle to achieve and maintain their weight loss. The NWCR is made up of more than 6,000 individuals who have maintained a weight loss of at least 30 lb for an average of 5 yr or more. A majority of NWCR members (91%) had attempted to lose weight in the past, with their successful attempt usually being linked to either a medical or emotional trigger that forced greater compliance. Almost all NWCR members (89%) used a combination of diet and physical activity to achieve and maintain their weight loss. NWCR members report high levels of physical activity, and the majority watch fewer than 10 h·wk−1 of television. This is compared with the average American who watches approximately 28 h·wk−1. NWCR members also consume a consistent diet of low-calorie, low-fat items, usually prepared at home. They also self-monitor calories and/or fat intake on a daily basis and weigh themselves regularly. One of the most important predictors of weight maintenance for the NWCR group is a sustained high level of physical activity. A limitation of this study is that the NWCR group is composed mainly of white, middle-aged, college-educated women, with some recent increases in male and older participants. Because of this, caution needs to be exercised when trying to generalize findings to other populations. However, efforts are underway to further diversify the NWCR.
Bottom line: The success of the NWCR group sheds light on the fact that continuing high levels of physical activity and monitoring of diet are keys to successful weight-loss maintenance.
CAN A CLINICAL TEST OF REACTION TIME PREDICT A FUNCTIONAL HEAD-PROTECTIVE RESPONSE?
The March 2011 issue of Medicine & Science in Sports & Exercise ® has a study that examined a clinical test of simple visuomotor reaction time and its ability to predict the time taken to raise the hands to protect the head from a rapidly approaching ball (1). The authors of this study recruited 26 healthy subjects to complete two experimental protocols: a manual visuomotor simple reaction time test (RTclin) and a sport-related head-protective response (RTsprt). RTclin measured the time necessary to catch a thin, vertically oriented device upon its release from the tester and was based on the distance the device fell before being arrested. RTsprt measured the time required to raise the hands from waist level to block a foam tennis ball fired at the subject's face from an air cannon. This time was calculated using an optoelectronic camera system. The results demonstrated a strong positive correlation between RTclin and RTsprt, independent of age, gender, height, or weight. Because prolongation of reaction time is a common symptom in those suffering from concussion, the finding that RTclin is a clinical test capable of predicting the ability to protect the head in a simulated sport environment is significant. The authors propose that RTclin be considered in a multifaceted approach to concussion management.
Bottom line: The visuomotor simple reaction time test described by the authors is a clinical test that may offer promise in its ability to predict reaction time in a concussed athlete.
1. Echner JT, Lipps DB, Kim H, et al
. Can a clinical test of reaction time predict a functional head-protective response? Med. Sci. Sports Exerc.
2. Thomas JG, Bond DS, Hill JO, Wing RR. The National Weight Control Registry (NWCR): a study of "successful losers." ACSM's Health & Fitness Journal.