休息间隔可减少增强骨形成所需的负荷次数。
Rest intervals reduce the number of loading bouts required to enhance bone formation.
作者信息
Srinivasan Sundar, Ausk Brandon J, Bain Steven D, Gardiner Edith M, Kwon Ronald Y, Gross Ted S
机构信息
Department of Orthopaedics and Sports Medicine, University of Washington, Seattle, WA.
出版信息
Med Sci Sports Exerc. 2015 May;47(5):1095-103. doi: 10.1249/MSS.0000000000000509.
PURPOSE
As our society becomes increasingly sedentary, compliance with exercise regimens that require numerous high-energy activities each week become less likely. Alternatively, given an osteogenic exercise intervention that required minimal effort, it is reasonable to presume that participation would be enhanced. Insertion of brief rest intervals between each cycle of mechanical loading holds potential to achieve this result because substantial osteoblast function is activated by many fewer loading repetitions within each loading bout. Here, we examined the complementary hypothesis that the number of bouts per week of rest-inserted loading could be reduced from three bouts per week without loss of osteogenic efficacy.
METHODS
We conducted a series of 3-wk in vivo experiments that noninvasively exposed the right tibiae of mice to either cyclic (1 Hz) or rest-inserted loading interventions and quantified osteoblast function via dynamic histomorphometry.
RESULTS
Although reducing loading bouts from three bouts per week (i.e., nine total bouts) to one bout per week (i.e., three total bouts) effectively mitigated the osteogenic benefit of cyclic loading, the same reduction did not significantly reduce periosteal bone formation parameters induced by rest-inserted loading. The osteogenic response was robust to the timing of the rest-inserted loading bouts (three bouts in the first week vs one bout per week for 3 wk). However, elimination of any single bout of the three one-bout-per-week bouts mitigated the osteogenic response to rest-inserted loading. Finally, periosteal osteoblast function assessed after the 3-wk intervention was not sensitive to the timing or number of rest-inserted loading bouts.
CONCLUSIONS
We conclude that rest-inserted loading holds potential to retain the osteogenic benefits of mechanical loading with significantly reduced frequency of bouts of activity while also enabling greater flexibility in the timing of the activity.
目的
随着我们的社会变得越来越久坐不动，每周遵守需要大量高能量活动的锻炼方案的可能性越来越小。另外，鉴于一种只需极少努力的成骨锻炼干预措施，有理由推测参与度会提高。在每个机械加载周期之间插入短暂的休息间隔有可能实现这一结果，因为在每个加载回合中，通过少得多的加载重复次数就能激活大量的成骨细胞功能。在此，我们检验了一个补充性假设，即每周插入休息的加载回合数可以从每周三次减少到每周一次，而成骨功效不会丧失。
方法
我们进行了一系列为期3周的体内实验，将小鼠的右胫骨非侵入性地暴露于周期性（1赫兹）或插入休息的加载干预措施下，并通过动态组织形态计量学对成骨细胞功能进行量化。
结果
尽管将加载回合数从每周三次（即总共九次回合）减少到每周一次（即总共三次回合）有效地减轻了周期性加载的成骨益处，但同样的减少并没有显著降低插入休息的加载所诱导的骨膜骨形成参数。成骨反应对插入休息的加载回合的时间安排具有很强的耐受性（第一周三次回合与每周一次回合，共3周）。然而，消除每周一次回合的三次回合中的任何一次都会减轻对插入休息的加载的成骨反应。最后，在3周干预后评估的骨膜成骨细胞功能对插入休息的加载回合的时间或次数不敏感。
结论
我们得出结论，插入休息的加载有可能在显著降低活动回合频率的同时保留机械加载的成骨益处，同时还能在活动时间安排上提供更大的灵活性。
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