我们都知道运动的好处：减肥、减压、提⾼代谢、增强免疫⼒、保持大脑灵活、冻龄，等等，但为什么我们总是运动不够？经常听到的原因：我没有时间。

We all know the benefits of exercising: weight management, stress reduction, metabolic health,  immune health, sharper brain, anti-aging, etc., etc. but why are we not all doing sufficient  exercise to better our lives? One of the biggest reasons you often hear: I don’t have time. 

那是因为， 提到完美的腹肌，我们总是想到在健身房⻓时间的挥汗如⾬。如果这不是真的呢？如果你可以⽤最少的时间和精⼒却能获得最⼤的效果呢？你要不要试⼀试？ 

That’s because we often associate a perfect six-pack with long hours of sweating in the gym.  What if that’s all a myth? What if you can achieve maximum health benefit with minimum time and effort? Would you want to give it a try? 

很多⼈都熟悉HIIT：High Intensity Interval Training: 高强度间歇训练。但我们今天说的⽐这个还要再进⼀步。 

Many people are familiar with HIIT: High Intensity Interval Training. But what we are talking about today are even one step beyond that. 

那我们先说说HIIT，看看它是什么样的运动，以及做HIIT的正确的⽅法。

For now let’s stay with HIIT and understand what it is and how to do it the right way. 

HIIT在过去⼗年左右变得⾮常流行，因为它的高效。它其实就是短时间的爆发式的高强度运动，一般持续几十秒到⼏分钟，紧接着是低强度的活动或休息进⾏恢复。然后重复⼏轮。通常，锻炼总长是10到30分钟。尽管时间很短，但⼀项⼜⼀项的研究发现，它对身体的好处与那些持续时间更⻓的中等强度运动相当，尤其是⼼⾎管健康。 

HIIT has become extremely popular in the last decade or so, because of its efficiency, It involves short burst of high intensity exercise followed by recovery period of very low intensity  activity or resting.  Usually the short burst lasts from 20 seconds to several minutes. You repeat this for several rounds. Typically the exercise time is 10 to 30 minutes in total.  However, in spite of its short time duration, study after study have found that it can achieve the same health benefits, especially cardiovascular health, as moderate exercise of much longer  duration. 

这是为什么？

Why is that？

当你以⾮常快的速度提⾼运动强度并增加能量需求时，你的肌⾁就不能只使⽤通常的燃料来源：⾎液中的脂肪和糖分。它必须求助于储存在肌⾁中的糖分：肌糖原，这其实是我们身体在紧急情况下（被老虎追赶比如）的紧急能量储备。所以，当肌⾁开始利⽤这种紧急储备时，它会触发⼀系列的身体的反应和信号，也就是说告诉身体变得更为强壮。 

When you ramp up exercise intensity and increase energy demand in a very rapid rate, your  muscle cannot just use the usual fuel source: fat and sugar it can get from the blood stream.  Instead, it has to turn to the sugar stored in the muscle: muscular glycogen, which is our  body’s energy emergency reserve for situations such as when you are chased by a tiger. So  when the muscle taps into this emergency reserve, it triggers a cascade of molecular reactions  and signaling, which basically tells the body to be stronger and fitter. 

所谓“⾼强度”是指那些让的⼼脏达到最大心率⾄少80%的运动。你可以拿220 中减去你的年龄来估算你的最大心率。⽐如，如果你50岁，你的最大心率约为 220 -50 = 170，80% 也就是136。这就是你高强度运动的心率⽬标。 

What counts as “high intensity” are those activities that make your heart reach at least 80% of  its maximum capacity. You can estimate your maximum heart capacity by subtracting your  age from 220. For example, if you are 50, your maximum heart rate would be around 220 -50 =  170, and 80% of that would be 136. So this is the heart rate you should aim for when starting  your intense burst. 

恢复期取决于运动的强度和持续时间，但通常在3到5分钟之间。如果你做1分钟⾼强度训练， 然后休息1分钟，那就做错了。不断给你的身体施加太多压力，但没有⾜够的恢复时间，你可能会因此分泌过多的⽪质醇，反而伤害到自己。

The recovery period depends on how intense your burst is and how long it lasted, but usually it  is between 3 to 5 minutes. If you are doing 1 minute of high intensity, and then 1 minute of  resting, you are doing it wrong. By constantly giving your body too much stress, but not  enough recovery, you could end up pumping out too much cortisol and end up hurting yourself  instead. 

在2013年的⼀项荟萃分析中，研究⼈员对18项HIIT研究进⾏了综合分析后发现，更剧烈的运动和更⻓的恢复期⽐那些不太强烈的运动和较短的时间间隔要有着更好的效果。

In a 2013 meta-analysis where researchers looked at 18 studies all together, they found that  less intense bursts and short intervals produce less benefits than those that have more intense exercises and longer recovery periods. 

如果运动强度越高越好，那最小的运动量是多少呢？

If more intense is better than less intense, what is the the minimum dose of exercise? 

研究⼈员发现，触发身体变得更强壮的信号就像是按下开关⼀样。它要么是打开，要么是关闭。试图非常用力把它打开没有任何意义，只要打开了就行。而两次20 秒的最大强度的运动就可以把开关打开。 

What researchers have found out is that triggering the molecular signaling that tells the body to  get stronger is just like flipping on a switch. It is basically either on or off. Switching it harder  does not make any difference as long as it is switched on. A two 20-second maximum  capacity exercise is all that is required to flip the switch.

我最近听了 Ulrich Dempfle 的采访。他是健身车公司“Carol”的创始⼈。他们的自行车正是基于这些理论发现之上。他将这种类型的运动称为 REHIT：Reduced Exertion High Intensity Interval  Training: 低运动量高强度间歇训练。 

I recently listened to an interview by Ulrich Dempfle, the founder of exercise bike company  “Carol”.  Their bike is exactly based on these findings. He calls this type of exercise REHIT:  Reduced Exertion High Intensity Interval Training. 

“Carol” 是⼀款⼈工智能驱动的⾃动⾃⾏⻋，可以帮助你达到你个⼈的最⼤运动量，并且维持20秒。你⼀共做两轮。整个练习只有8分40秒。⽽且你每周只需要做 3 次。 

“Carol” is automated and AI powered, helping you reach your individual maximum exercise capacity and stay there for 20 seconds. You do a total of two rounds. The complete exercise  is only 8 minutes and 40 seconds. And you are supposed to do it only three times a week. 

每周26分钟，坚持8周，⼤约共3个半⼩时，研究发现，你就可以将你的最大摄氧量提高12%（最大摄氧量是衡量身体强健状况的指标），并将患糖尿病的⻛险降低 60%。我们⼀般是⼗年内健康指标会降低10%。这种锻炼在 8 周内让你将时间倒流10年。挺值得的，不是吗？ 

So basically, 26 minutes a week, about 3 and half hours for eight weeks, according to studies,  you can increase your VO2 max by 12% （VO2 is an indicator of your fitness level), and drop  your diabetes risk by 60%.  Considering we lose about 10% of our fitness over a decade, with  this type of exercise, you turn the clock back by 10 years within 8 weeks.  Worth it, isn’t it? 

当然，不是每个⼈都会⽤ Carol 自行车。他们好像不送货到中国，说实在的，即使他们可以送货，我也不确定我会去买⼀辆2000多美元的自行车。⽬前我在国内还没有看到到类似的东西。但是，我们都可以⽤⼀样的原则来设计我们自己的 REHIT 练习：

Of course not everybody is going to use a Carol bike. I don’t think they ship it to China, and  even if they do, I’m not sure I’m ready to pay for more than 2000 USD for a bike yet. And I haven’t found something similar here. But we can all use the same principles to design our  own REHIT exercise:

• 最⼤强度是关键。使⽤上⾯提供的公式，以最⼤心率的 90% 到 100% 为⽬标，并保持大约20到30秒。当然，这也是⾃动自行车的优势：当你在用力达到最大心率时，⽆需去搞旋钮或者是看你的运动⼿表。但是我们可以做到⾮常接近。

• Maximum capacity is key. Using the formula provided above, aim for 90% to 100% of your  maximum heart rate and maintain it for about 20 to 30 seconds. Of course, this is why an  automated bike has its advantages. It takes out the need to mess with the knob and check your watch when you are trying to reach the maximum heart rate. But we can get pretty  close.

• 给自己足够的时间来恢复。可能是 3 到 5 分钟，也可能更⻓。⽐这少的话可能就不够了。你需要在下⼀次冲刺之前将身体恢复到位。

• Give yourself sufficient time to recover. It may be to 3 to 5 minutes, it may be longer.  Anything less than that is probably not enough. You want your body to recover well before  another sprint.

• 两轮之后，如果你觉得还可以再做⼀轮，那很可能你做的不对。因为从理论上讲，你的身体是 不可能以最大强度进行超过两次40秒的运动的。

• After the two rounds, if you feel you still can do another round, that’s probably because you  were not doing it right. Because, theoretically, it is not physically possible to do more than two rounds at maximum capacity. 

如果这对你来说过于剧烈，可以尝试从常规的HIIT 做起。记住给自己足够的恢复时间。

If this is way too intense for you, starting with regular HIIT is a good idea. Just remember to  have sufficient recovery time. 

⼀次不超过10分钟，每周 3 次。没有太多的借口了，对吧？

Less than 10 minutes at a time, three times a week. Not easy for more excuses, right?