如果您认为实际上在健身房时会出现所有进展，那么您实际上会在健身房中进行。事实证明，当您给身体剩下的需要时，您就会获得收益。
Here, experts break down what happens in your body when you take a recovery day — and how taking days off from the grind ultimately helps you become a fitter, stronger individual.
It probably comes as no surprise yourmuscles have lots of recoverywork to do when you take a day off from training.
物理治疗师解释说：“您的肌肉一直处于崩溃或建立的状态。”威廉·凯利（William Kelley）DPT，运动培训师和认证的力量和条件专家。当您在锻炼过程中推动身体时，基本上是在肌肉纤维中创建微尖。在里面24–48小时that follow, your muscles repair — and grow larger and stronger — through a process called muscle protein synthesis. (Your body uses the你吃的蛋白质to make this happen.)
肌肉蛋白合成只能在休息期间发生。凯利说：“如果您没有康复，那么您总是在努力回到基线。”
Even if you don’t感到酸痛经过挑战性的锻炼后，您的肌肉组织仍然遭受损害，需要愈合，并补充说Max Castrogaleas MA，认证的力量和调理专家，并在运动生理学家AT纽约市特殊手术医院.
In addition to physically rebuilding your muscle fibers, rest also allows the cells in your muscles to restock the fuel they need for you to perform during your next workout. First, there’s glycogen, a form of stored糖凯利说，这是“何时需要长时间执行的持续能源”。然后是肌酸磷酸盐，我们从红肉中获得的一种化合物，我们的肌肉用来快速，爆炸性动作。
Just as your muscles take a hit during exercise — and need to do some renovating on rest days — so do your connective tissues, such as tendons.
凯利说，想想这些组织 - 将肌肉产生的力传递到骨骼上，以便您可以像绳索一样移动四肢。“在恢复过程中，这些绳索变厚和加强，因此您可以更努力地将它们拉动，而不必担心它们会磨损或撕裂。”
与肌肉不同，肌腱主要由蛋白质制成collagen（您从诸如食物来源获得的骨汤) and shuttle that protein in to repair damaged tissue and increase overall strength.
Castrogaleas说，尽管您可能不会在这些组织中感到酸痛，但他们在剧烈运动中承受的微创伤可能会导致您看不到肿胀，这可能会使您的关节感到紧绷和柔软。
Your nervous system, the electrical network that connects your brain to the rest of your body, plays a bigger role in fitness than many people realize. After all, it’s your nervous system that signals your muscles to contract when needed.
When you exercise, “you stimulate your nerves to move a muscle or perform a task or do something coordinated,” explains Kelley. Then, when you rest, your body strengthens the pathway between that signal and movement (called a ‘motor connection’) so you can do it more efficiently next time.
“If, however, you jump from stimulus to stimulus, your body never quite forms that pathway properly,” he says. The result: You don’t improve at a certain move as quickly as you could.
尽管您可能看不到练习和同事的令人讨厌的电子邮件之间的任何相似之处，但您的身体都认为压力源.
实际上，艰苦的锻炼可以提高我们的生产压力激素皮质醇, as well as the other adrenal (or ‘fight or flight’) hormones epinephrine and norepinephrine, explains Castrogaleas. “These hormones increase our heart rate and blood pressure so we feel a surge of energy when we need it.”
尽管这些激素在HIIT会议上派上用场，但您当然不希望它们一直升起。
当太高太高时，这些激素（尤其是皮质醇）可以affect our sleep, make us hungrier and contribute to weight gain, says Kelley. (They can also contribute to athletes feeling stale or ‘overtrained.’)
That’s where rest days come in: “Recovery days give your cortisol the opportunity to settle back down to baseline,” Kelley says.
REST还可以使您的身体天然的“类固醇”（又称胰岛素样生长因子）和生长激素可以介入并从事工作。凯利解释说：“当您经历肌肉崩溃时，您的身体会产生这些激素来帮助修复并变得更强壮。”
在里面long run, supporting balance between your stress and growth hormones helps your body adapt and perform more efficiently.
淋巴系统实质上是您人体下水道系统的作用，可从整个人体中收集废物，因此可以消除它们。锻炼会产生很多此类废物，因此您的淋巴系统在恢复过程中会升高。
凯利说：“当您休息一天时，您会给淋巴管有机会向后流向淋巴结，该淋巴结将淋巴液分散到您的循环系统中，由肾脏处理并踢出体内。”
Your heart’s ability to make small heart rate adjustments in response to different stimuli, known asheart rate variability (HRV)has become a buzzy indicator of recovery recently.
In a perfect world, your ticker would quickly pick up its pace to meet the demands of different intensities of exercise — and then settle back down fast. Go hard day after day, though, and “it takes more and more of a stimulus to get your heart rate up,” explains Kelley. Essentially, your heart, too, fatigues.
According to Kelley, recovery days allow the electrical wiring and chemical balance that makes your heart beat to reset. This then re-sensitizes your HRV, making you better-prepared to tackle whatever challenges you push your body through in the days ahead.
撇开生理适应，休息也使您的灵魂善良.“The constant grind can feel never-ending and monotonous,” Kelley says. “If you walk into the gym and groan instead of feeling motivated and excited, that’s a clear indicator that you need to rest.”
当您经常休息一下训练时，您可以抵御精神疲劳，让自己有机会享受更多悠闲活动（例如邻里散步或皮卡篮球），并在下一次艰苦地上健身房时最终会更有动力。
