mercredi 10 avril 2013

Self allocation of resources by the financial monopoly?

"Much more significant is the fact that the bulk of incremental financial activity is trading, and trading, while it may provide a little useful public information about market opinion, is largely a way to transfer wealth from those with inferior information and calculation ability to those with more.There is no enhancement of economic efficiency to speak of."

mardi 9 avril 2013

Is it the end of stretching before running?

1/  2013 Apr;27(4):973-7. doi: 10.1519/JSC.0b013e318260b7ce.

Acute effect of passive static stretching on lower-body strength in moderately trained men.


Department of Kinesiology and Health Science, Human Performance Laboratory, Stephen F. Austin State University, Nacogdoches, Texas.


Gergley, JC. Acute effect of passive static stretching on lower-body strength in moderately trained men. J Strength Cond Res 27(4): 973-977, 2013-The purpose of this investigation was conducted to determine the acute effect of passive static stretching (PSS) of the lower-body musculature on lower-body strength in a 1 repetition maximum (1RM) squat exercise in young (18-24 years.) moderately trained men (n = 17). Two supervised warm-up treatments were applied before each performance testing session using a counterbalanced design on nonconsecutive days. The first treatment consisted of an active dynamic warm-up (AD) with resistance machines (i.e., leg extension/leg flexion) and free weights (i.e., barbell squat), whereas the second treatment added PSS of the lower body plus the AD treatment. One repetition maximum was determined using the maximum barbell squat following a progressive loading protocol. Subjects were also asked to subjectively evaluate their lower-body stability during 1RM testing sessions for both the AD and PSS treatments. A significant decrease in 1RM (8.36%) and lower-body stability (22.68%) was observed after the PSS treatment. Plausible explanations for this observation may be related to a more compliant muscle tendon unit and/or altered or impaired neurologic function in the active musculature. It is also possible that strength was impaired by the PSS because of joint instability. The findings of this study suggest that intensive stretching such as lower-body PSS should be avoided before training the lower body or performing the 1RM in the squat exercise in favor of an AD dynamic warm-up using resistance training equipment in the lower-body musculature.
2/  2013 Mar;23(2):131-48. doi: 10.1111/j.1600-0838.2012.01444.x. Epub 2012 Feb 8.

Does pre-exercise static stretching inhibit maximal muscular performance? A meta-analytical review.


Motor Control and Human Performance Laboratory, School of Kinesiology, University of Zagreb, Zagreb, Croatia.


We applied a meta-analytical approach to derive a robust estimate of the acute effects of pre-exercise static stretching (SS) on strength, power, and explosive muscular performance. A computerized search of articles published between 1966 and December 2010 was performed using PubMed, SCOPUS, and Web of Science databases. A total of 104 studies yielding 61 data points for strength, 12 data points for power, and 57 data points for explosive performance met our inclusion criteria. The pooled estimate of the acute effects of SS on strength, power, and explosive performance, expressed in standardized units as well as in percentages, were -0.10 [95% confidence interval (CI): -0.15 to -0.04], -0.04 (95% CI: -0.16 to 0.08), and -0.03 (95% CI: -0.07 to 0.01), or -5.4% (95% CI: -6.6% to -4.2%), -1.9% (95% CI: -4.0% to 0.2%), and -2.0% (95% CI: -2.8% to -1.3%). These effects were not related to subject's age, gender, or fitness level; however, they were more pronounced in isometric vs dynamic tests, and were related to the total duration of stretch, with the smallest negative acute effects being observed with stretch duration of ≤45 s. We conclude that the usage of SS as the sole activity during warm-up routine should generally be avoided.