March 2012 Issue of MSSE Is Now Available

The March 2012 issue of Medicine & Science in Sports & Exercise is now available online. ACSM members should log in to the ACSM website and click on “Access My Journals” to navigate to the journal section.

Editor-in-Chief Andrew J. Young, Ph.D., FACSM, offers the following notes on the current issue:

Many athletes and regular exercisers experience exercise-induced bronchoconstriction (EIB), and about half of persons experiencing EIB also exhibit a 1- to 4-hour refractory period, during which vigorous exercise does not elicit EIB or elicits EIB less severe than initially experienced. Thus, athletes afflicted with EIB might be able to use precompetition warm-up exercise to elicit EIB and the subsequent refractory period, but no standardized warm-up protocol exists for this purpose, perhaps because the mechanisms for the refractory period remain undefined. The March MSSE features a systematic review by Stickland et al., the results of which suggest that optimally effective warm-up protocols include intervals of high-intensity exercise, at near maximal levels.

Also featured in the March issue of MSSE are two investigations of skeletal muscle responses to ischemic exercise. Laurentino et al. report that the amplified muscle hypertrophy and strength gains observed in response to low-intensity ischemic resistance training are attributable to adaptations in expression of genes regulating myostatin signaling, which mimic gene expression responses to higher intensity, nonischemic resistance training. Takada et al. report that endurance runners exhibit more pronounced decreases in muscle pH and phosphocreatine during ischemic exercise than sprinters, and that restricting blood flow during low-intensity ischemic exercise produced equivalent decreases in muscle pH and phosphocreatine as during higher intensity, nonischemic exercise in the endurance runners but not sprinters, suggesting that endurance runners may be more responsive to ischemic exercise training than sprinters.

The effects of restricting muscle blood flow during resistance exercise have received considerable attention over the past decade, by both researchers exploring mechanisms of muscle hypertrophy and strength gain as well as those seeking practical applications of this approach to exercise training. One of MSSE’s most cited previous articles on this topic was by Takarada et al. [Applications of vascular occlusion diminish disuse atrophy of knee extensor muscles. Med Sci Sports Exerc. 2000; 32(12): 2035–9], and we are featuring that article as this month’s selection from our archives.