An Inside Look: December 2011 Medicine & Science in Sports & Exercise®

The December issue of Medicine & Science in Sports & Exercise (MSSE) is available online now. ACSM members can access the journal for free – simply log in to the ACSM website and click “My ACSM.”

MSSE Editor-in-Chief Andrew J. Young, Ph.D., FACSM offers his insights into the December issue:

“There is considerable need, especially in sports and military medical communities, in understanding better how to diagnose and treat concussion or mild traumatic brain injury (mTBI). The December MSSE features a study by Len et al. in which cerebrovascular reactivity to altered arterial carbon dioxide levels was measured in uninjured control subjects and compared to changes measured in subjects who had experienced an mTBI within the past four days. Transcranial Doppler ultrasonography was used to measure blood velocity in the middle cerebral artery before and after periods of breath holding or hyperventilation. Although baseline velocities did not differ between groups, changes in middle cerebral artery velocity in response to hyper- and hypocapnia differed between mTBI subjects and uninjured control subjects. The authors suggest, and the reviewers agreed, that these findings may provide a basis for development of methods to monitor cerebrovascular reactivity impairments following mTBI, and potentially to assess recovery status.

“Also featured in this month’s MSSE is an interesting article by Jenkins and Hagberg who investigated the degree to which a six-month endurance exercise training program could, independently from diet changes and/or weight loss, reverse abnormal glucose metabolism in prediabetic individuals sufficiently to enable them to maintain normoglycemia. The authors observed that the prediabetic subjects did experience more pronounced changes in blood glucose regulation than experienced by normoglycemic subjects completing the same training program. However, training did not completely eliminate differences in glucose regulation between the prediabetic and normoglycemic groups, although prediabetes appeared to be completely reversed in some subjects who achieved normoglycemia following endurance training.

“For our sports-performance scientists, MSSE this month features an article by Angus and Waterhouse describing a new modeling method to study pacing strategy during endurance running. The authors believe that their method is easily employed, and use of this approach may provide new insights into fatigue development of athletes under real, competitive conditions.

“Although interest in assessing effects of and recovery from sports-associated mTBI has increased recently, MSSE has published quite a few papers over the years in which effects of sport-related mTBI and their persistence following injury have be documented and discussed. This month, to complement the new paper by Len et al., I am featuring one of the earliest and most cited articles from our archives on this subject, "The effects of closed-head injury on postural sway," by Ingersoll and Armstrong [Med Sci Sports Exerc. 1992; 24(7): 739-743]. In that article, the authors report data consistent with a progressive "dose-response" relationship between severity of mTBI and indices of degraded postural-sway control during a standardized test protocol, but what really caught my attention was that all of the injured were at least one year past the injury, and in many cases several years.”