Guest guest Posted July 1, 2010 Report Share Posted July 1, 2010 Members may enjoy reading the below excerpts: Chocolate Milk and Other Strategies for Athletes at the 2010 ACSM Annual Meeting Will G Hopkins Sportscience 14, 22-28, 2010 (sportsci.org/2010/wghACSM.htm) Training with blood-flow restriction is the latest craze, apparently, and it even has a Japanese name: kaatsu. An entire poster session was devoted to it [2757-2767], along with a smattering of abstracts in other sessions. In kaatsu, limb exercise is performed while arterial blood blow is occluded with a cuff. The gains in muscle mass and strength after 2 and 4 wk of such training in 14 untrained subjects (no control group) were correlated with the metabolic changes in the muscle induced by the cuff [2072]. Fine, but performance improvements in best-practice controls are about equal to [2758] or even better than with kaatsu alone or with kaatsu in combination with best practice [2761]. Remain skeptical. In a meta-analysis of nine controlled trials, whole-body vibration for 10 d to 47 wk had small-moderate effects on jump height; larger effects were observed with higher frequencies, higher amplitudes, and longer session durations [1555]. We have to allow something for placebo effects and publication bias, though, so it's reassuring to see an acute effect of whole body vibration on objectively measured post-activation potentiation [1558]. But it didn't seem to work on softball batting speed [1559]. Inspiratory muscle training had varying degrees of failure [847] and success [848] for performance of non-athletes, but of course these outcomes don't necessarily apply to highly trained athletes. Either of two kinds of high-intensity sprint training twice weekly for 4 wk was more effective than continuous running for improvements in aerobic and anaerobic tests in a randomized controlled trial of 26 collegiate male soccer players [1857]. Super-slow resistance training was probably less effective than traditional resistance training for 1-RM strength in 14+13 (+8 control) previously untrained women [2081]. There were some potentially useful differences in outcomes with low vs high speed strength training in a powerful (24+25) study of high-school athletes: " high speed may be preferential when the performance goals reflect agility and upper-body power " [2083]. In a controlled trial with 74 army cadets, repeated sprint training for 7 wk improved 40-m sprint performance by 2.2% compared with a non-training control group, but the added resistance of a parachute led to a much bigger 5.1% improvement [2634]. Five novice tennis players improved the speed of their swing in forehands, backhands and serves after training with resistance in the form of a racket with vanes. Would the gains translate into faster ball speed without loss of technique? Worryingly, outcomes in three skilled players were partly negative [2637]. Six subjects in each of three training groups is such a pity, because the rowers who added high-load low-repetitions resistance exercises to their usual training improved their 2000-m rowing ergometer time by a non-significant but promising 0.7% relative to control training and a suggestive 0.4% relative to low-load high-repetitions group [2887]. You shouldn't do a study with six in each group. Nine in each of two groups would have been better, but still not enough. The magic minimum is 10 per group, and that's only for representativeness. Adequate precision for trivial or small effects on performance requires many more. ===================== Carruthers Wakefield, UK Quote Link to comment Share on other sites More sharing options...
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