Effects of resistance training performed to repetition failure or non-failure on muscular strength and hypertrophy: A systematic review and meta-analysis

Purpose:We aimed to perform a systematic review and meta-analysis of the effects of training to muscle failure or non-failure on muscular strength and hypertrophy.Methods:Meta-analyses of effect sizes(ESs)explored the effects of training to failure vs.non-failure on strength and hypertrophy.Subgroup meta-analyses explored potential moderating effects of variables such as training status(trained vs.untrained),training volume(volume equated vs.volume non-equated),body region(upper vs.lower),exercise selection(multi-vs.single-joint exercises(only for strength)),and study design(independent vs.dependent groups).Results:Fifteen studies were included in the review.All studies included young adults as participants.Meta-analysis indicated no significant difference between the training conditions for muscular strength(ES=-0.09,95%confidence interval(95%CI):-0.22 to 0.05)and for hypertrophy(ES=0.22,95%CI:-0.11 to 0.55).Subgroup analyses that stratified the studies according to body region,exercise selection,or study design showed no significant differences between training conditions.In studies that did not equate training volume between the groups,the analysis showed significant favoring of non-failure training on strength gains(ES=-0.32,95%CI:-0.57 to-0.07).In the subgroup analysis for resistance-trained individuals,the analysis showed a significant effect of training to failure for muscle hypertrophy(ES=0.15,95%CI:0.03-0.26).Conclusion:Training to muscle failure does not seem to be required for gains in strength and muscle size.However,training in this manner does not seem to have detrimental effects on these adaptations,either.More studies should be conducted among older adults and highly trained individuals to improve the generalizability of these findings.     

Visual guidance during competition performance and run-through training in long jumping

To ensure precise foot placement on the take-off board, long jumpers visually regulate their stride pattern during their run-up. A relationship between how much visual guidance they use and the horizontal distance they jump has not, however, been quantified. Run-up precision is often practiced using run-throughs, which exclude the take-off and, therefore, the high physical stress of the complete long jump. The validity with which this common training method simulates the long jump approach remains, however, to be verified. Four state-standard long jumpers and two heptathletes completed two sessions, each comprising six runthroughs and six competition long jumps. A 50 Hz video camera was manually panned from an elevated platform to film each trial, to enable subsequent gait characteristic evaluations. Linear regression analyses identified that a longer visual regulation phase, measured in time, distance or number of strides, was a key predictor of long jump distance. The number of strides that were visually regulated during the long jump approach was, accordingly, positively correlated with long jump distance (r = 0.67, p = 0.001). The amount of visual regulation used during run-throughs was, however, less than half (p = 0.001) of that observed during long jump approaches. Our results should compel long jump coaches to supplement run-through training with additional visual guidance exercises, to encourage their athletes to visually regulate more of their long jump approach.     

Teacher adaptation of document-based history curricula: results of the Reading Like a Historian curriculum-use survey

Although most teachers adapt curriculum, we know little about teachers’ rationales for modifying materials, how these rationales align with actual modifications, nor whether any patterns exist in the modifications that teachers make. This is especially the case in history/social studies, where research on curriculum is scant and research on teacher adaptation of curriculum is virtually non-existent. This paper addresses that gap. We report the results of a large-scale survey on curriculum use with over 1900 history teachers. The online survey focused on how and why teachers use and adapt lesson materials from a free online history curriculum and prompted teachers to upload examples of curriculum materials they had modified. We found that individual differences among teachers correlated with particular types of modifications. Moreover, we found that teachers were motivated to modify materials to address their students’ needs, and that their modifications rarely affected the core structure – or theory of content – of the lessons. We argue that such alignment between teachers and curricular materials represents an example of curricular fit. We discuss what curricular design features may have contributed to the high level of curricular fit among users as well as the implications of this construct for curriculum implementation efforts across subject areas.     

Students＇ Pursuit of Name Brands

现在很多学生全身上下、从穿到用，全都是“名牌”装备。学生阶层到底该不该去追逐“名牌”？TianDong就此现象咨询了Brad。