不能久坐，我站着还不行么？

在办公室或教室坐一整天，难免浑身僵硬，肩颈腰背酸痛。即使下班或下课后拼命运动，也很难抵消久坐带来的不舒服。

除了难受，长时间的静坐还会使人容易长胖，患2型糖尿病、肿瘤及心血管疾病的风险也升高[1]。知道久坐有害后，越来越多的人开始尝试别的姿势，甚至随之出现了专供站立办公的设备，比如可升降桌子、笔记本支架、可调高度的屏幕支架等。

用了这些设备，人们可以做到每天坐着的时间平均缩短1.3小时，站立时间增加1.4小时[1]。看似成效显著，但别忘了减少久坐只是手段，大家改变姿势目的是减少久坐带来的健康危害、缓解身体的僵硬酸痛、预防打瞌睡或通过增加消耗来减肥。由坐到站，能不能实现这些目标？

站得那么累，怎么还算“久坐”

想知道站立是否有利，还得先看久坐为什么有害。实际上，久坐行为的危害不在于“坐”，而在于很低的能量消耗。

其实不管你是坐、靠、躺还是站，无论在工作、玩游戏或者坐车，只要清醒状态下能量消耗低于静坐的1.5~2倍，都属于久坐行为[1]。

对于多数人来说，仅仅站起来不能使能量消耗超出久坐范围，也不能增加运动量[3, 4]。既然脱离不了久坐行为，站立的好处也存在疑问。

腰痛可能有效，其他不一定

为了健康站起来的人可能对下面的消息很失望：多数研究中，坚持间断站立办公数月时间，并不能明显改善健康人的血压、血糖及血脂水平，仅肥胖者的血糖水平可能有所好转[1, 5]。

有人听了会说“我站来又不是为了防病，只是因为一直坐着太难受”。对于缓解身体僵硬酸痛，坐站交替可能优于久坐，特别是对于慢性腰痛的人[6, 7]。绝大多数人会都在一生中某个阶段经历腰痛，长时间静坐可能加重症状[8]。在久坐办公间歇适当站立，会使部分人的腰痛症状明显减轻。

虽然站立可能缓解腰痛，但对肩颈、上肢不适及酸痛的作用有限[4, 9-11]，还要亲身尝试才能知道对个人是否有效。对于下肢，站立姿势反而比坐位更容易引起酸痛。

站立缓解酸痛的效果不一致，也与大家姿势不同有关。颈部、躯干及下肢正确排列才能减轻疲劳，如果过度低头、弯腰或始终将重心放在某一条腿上反而不舒服。

站立使我清醒？

除了身体僵硬酸痛，上班时的困倦也让人难以抵抗。很多人看到支架上标注的“提高效率，活力加倍”，而期望站立如咖啡一般提神醒脑。

其实多数研究中，人们坐着与站着时的困倦程度及情绪并没有明显区别[12, 13]。少数人站立后感觉更有活力并且心情更好，另一些人站起来反而比持续坐着更疲劳[14, 15]。

既然不能提神醒脑，对于多数人来说，站与坐时的工作效率也没有明显区别 [16, 17]。当然了，上课犯困时被拎起来罚站听讲，是个例外。

减肥，还是别指望了

除了提高工作效率，站立办公设备的宣传里还常有“消除赘肉”。确实一般人站着比坐着消耗能量稍多，但两者差异并不大[18]。相对于坐着，站立1小时能量消耗只多出4.2~10千卡[1]，即使每天站立累计4小时，多消耗的热量还抵不上两小块巧克力。

另外还有少数人非常擅长站，静止站立时能量消耗甚至低于坐着。因此，尝试用站代替坐来减肥的研究，都没有得出站立瘦身的结果 [19-21]。

站久了还不如坐着

站着的获益不是很确定，但久站的危害人们早就体会到了。早年间，很多工人都需要整日站着工作，不能坐下或来回走动。他们不仅饱受腰痛、脚痛、下肢静脉曲张、腿脚水肿的折磨，女性还会因长时间站立增加早产及流产的风险[1]。

对于多数人，舒适的持续站立时间不超过15~30分钟[22, 23]。如果为了减轻背部不适而站立，每次15分钟就足够了，持续站立时间过长反而难受[24]。

当静止站立达到30分钟时，小腿及足部的血流增多，疲劳、不适及疼痛的感觉开始出现[25]。已经存在外周血管疾病的人，应尽量避免连续站立30分钟以上。如果工作需要连续站立2小时以上，可利用压缩袜、地垫、鞋垫及坐站两用凳子来缓解疲劳[25]。

多换姿势，多活动

无论坐着还是站着，长时间的静态姿势都对健康不利并且导致身体酸痛不适。

想要改善身体僵硬及肌肉疲劳，关键在于经常变换姿势，而不是长时间的持续站立[1]。对于减轻体重或久坐健康危害，进行比站立强度更大的活动，才有肯定的效果。

常年久坐不动的人，可以从工作中坐站交替及轻度体力活动开始，逐渐增加时间及活动强度。添置桌子或支架是途径之一，多走动比静静站着更为有效[26]。

参考文献

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作者：代天医

编辑：odette