This month’s issue of our journal features three rather unique articles that I have chosen for highlighting.
A study reported by Rottensteiner et al. employed whole-brain magnetic resonance imaging to show that physically active co-twins had larger striatal and prefrontal cortex gray matter volumes compared to their inactive co-twins. These region-specific differences in brain gray matter volumes among physical activity discordant young adult monozygotic male twin pairs were detected in the global test of brain gray matter volumes. Since these regions are heavily involved in motor control networks, these findings provide novel evidence for structural, region-specific effects of long-term physical activity on the healthy adult brain. As a supplement to this work, I refer you to a highly cited paper by Ferris et al. [The effect of acute exercise on serum brain-derived neurotrophic factor levels and cognitive function. Med Sci Sports Exerc. 2007;39(4):728-734].
In this month’s second highlighted study, Aparicio et al. evaluated the utility of seven physical fitness tests to discriminate between presence/absence of fibromyalgia in women of different ages. They observed that physical fitness in general, and particularly the arm curl, the 30-s chair-stand, and handgrip strength tests, powerfully discriminate the presence/absence of fibromyalgia in women. The authors concluded that quick and inexpensive fitness tests using minimal equipment can be a useful and feasible tool that might supplement the current diagnostic criteria for fibromyalgia in clinical settings. To complement this report, we offer a link to work by Meyer and Lemley [Utilizing exercise to affect the symptomology of fibromyalgia: a pilot study. Med Sci Sports Exerc. 2000;32(10):1691-1697].
Inspiratory muscle fatigue, traditionally associated with intense exercise, has been considered irrelevant in ultraendurance competitions. Nevertheless, despite low ventilation, such events may fatigue respiratory muscles due to prolonged postural requirements and/or inflammation. Indeed, Wuthrich et al. report in this month’s journal that substantial respiratory muscle fatigue developed after a mountain ultramarathon. In combination with severe levels of leg muscle fatigue, this respiratory muscle fatigue may expose athletes to an increased risk of injury. The authors suggest that specific respiratory muscle training could be useful for preventing impairments in postural control as well as to improve performance. Interestingly, only small amounts of central fatigue were detected as opposed to locomotor fatigue, possibly indicating important differences among muscle groups. Fatigue remains an enigmatic circumstance and will be the topic of the World Congress on The Basic Science of Exercise Fatigue in association with the ACSM Annual Meeting in San Diego, California on May 27-28 of this year.
L. Bruce Gladden