How stretching actually changes your muscles - Malachy McHugh

譯者: Lilian Chiu 審譯者: Helen Chang

Here we have an athlete preparing for a game.

這是運動員在為比賽做準備。

They’ve put on their gear and done their warmup,

他們完成了著裝，也做了暖身。

and now it’s time for one more routine— stretching.

現在還有一項例行事項 要做——伸展。

Typically, athletes stretch before physical activity to avoid injuries

通常，運動員會在進行 身體活動之前做伸展，

以避免受傷，如肌肉拉傷或撕裂傷。

like muscle strains and tears.

But does stretching actually prevent these issues?

但伸展真的能預防這些狀況嗎？

And if so, how long do the benefits of stretching last?

如果能，伸展的效益能維持多久？

To answer these questions,

若要解答這些問題，

we need to know what's actually happening in the body when we stretch.

我們得要知道伸展時 體內會發生什麼現象。

There are two kinds of stretching our athlete might be doing.

運動員可能會做的伸展可分為兩種：

Dynamic stretches, which are controlled movements

動態伸展，

也就是有控制的動作， 動作過程會用到一系列的肌肉；

that engage a range of muscles throughout the motion.

And static stretches, where the stretcher holds a position

還有靜態伸展，

伸展者會維持一個姿勢， 讓特定的肌肉保持

to keep specific muscles at a fixed length and tension.

固定的長度和張力。

Our athlete is currently doing a static hamstring stretch—

這位運動員正在做靜態的 大腿後側膕繩肌伸展——

a 30 second interval where he pulls his hamstring

他會把膕繩肌拉到 超過一般的動作範圍，

beyond its usual range of motion.

每次拉三十秒。

However, while we often think of stretching a muscle

然而，雖然我們通常認為 伸展肌肉就如同伸展橡皮筋，

like stretching a rubber band,

muscles are actually comprised of various tissue types,

但肌肉其實是由多種 類型的組織所構成，

which interact to make a complex material.

它們彼此作用，形成複雜的物質。

Rubber is elastic, meaning it resists being stretched

橡膠是有彈性的，意即 它會抵抗拉伸的力量，

and then returns to its original shape.

拉伸結束後會回到原狀。

But muscle is viscoelastic.

肌肉的則是黏彈性，

This means that, in addition to those elastic qualities,

意即除了具有 彈性相關的特質之外，

muscle changes under the stress of being stretched.

在承受被拉伸的壓力時， 肌肉會發生改變。

Let’s see this in action.

咱們來實際展示一下。

At the large scale, this hamstring stretch is pulling on layers of protective tissue

宏觀來說，這個膕繩肌的伸展動作

會拉扯肌肉纖維周圍的保護組織層，

surrounding the muscle fibers,

as well as the tendons that connect this muscle to nearby bones.

及將此肌肉和附近骨頭連結的肌腱。

These tissues contain elastic proteins like collagen and elastin,

這些組織含有彈性蛋白質， 如膠原蛋白和彈力蛋白，

which allow them to slightly elongate over the duration of the stretch.

能讓它們在伸展過程中稍稍延長。

At the smaller scale, these skeletal muscle fibers are comprised

微觀來說，

這些骨骼肌纖維是由 數百萬個肌節構成——

of millions of sarcomeres—

the smallest contracting unit of muscle tissue.

肌節是肌肉組織中最小的收縮單位。

Sarcomere’s long, fibrous proteins can relax to elongate muscle fibers

肌節的長纖維蛋白質

可以放鬆，讓肌肉纖維能夠延長；

or they can contract to shorten them—

也可以收縮，讓肌肉纖維變短——

pulling on tendons and protective tissue

拉扯肌腱和保護組織，

to create the force propelling our athlete’s body.

以產生力量，推動運動員的身體。

And when those tissues have been stretched out,

當這些組織被拉伸後，

they retain their strength at longer lengths,

它們在更長的長度上保持其強度，

allowing our athlete to take full advantage of his improved range of motion.

讓運動員能夠充份利用

改善後的動作範圍。

Unlike a rubber band, this muscle’s resistance to stretching decreases

和橡皮筋不同，

此肌肉對於伸展的抵抗力

每經過三十秒的伸展， 就會再下降一些，

with each 30 second stretch,

allowing our athlete to continually elongate his hamstring.

讓運動員能夠持續拉長他的膕繩肌。

And this improved flexibility likely decreases the chance

柔軟度改善之後，

有可能可以減少 某些肌肉受傷的機會。

of incurring certain muscle injuries.

But due to muscle’s elastic properties,

但，因為肌肉的彈性特性，

this effect will be gone in just 10 minutes without further activity.

若十分鐘沒有做進一步的 活動，此效應就會消失。

The exercise from his match should elevate his muscle’s temperature

他在比賽時的運動，

應該可以讓肌肉的溫度升高， 並持續延長肌肉，

and continue elongating the muscle,

maintaining his increased flexibility throughout the game.

在比賽過程中一直維持 提升後的柔軟度，

But once he gives his hamstrings a break,

但，一旦讓膕繩肌休息了，

they’ll retract back to their previous state.

膕繩肌就會收縮回到先前的狀態。

So if all this is just temporary,

如果這一切都是暫時的，

how can you permanently improve your flexibility?

你要如何永久地改善你的柔軟度？

For skeletal muscles, improved flexibility comes from additional sarcomeres,

就骨骼肌來說，柔軟度改善 來自於額外的肌節，

which allow you to maintain strength at even greater lengths.

它們讓你在更長的長度下 還能維持力量。

Sarcomeres are added and subtracted to muscles

根據被使用的頻率，

depending on how frequently they’re used,

肌肉的肌節會增加會減少，

so improving overall flexibility requires a comprehensive stretching regimen.

因此，改善整體柔軟度

需要的是全面的伸展計畫，

Plus, you need to stretch often— very often.

此外，你得常伸展——很常伸展。

Current research suggests at least 10 minutes a day for roughly two months.

目前的研究建議， 每天至少伸展十分鐘，

持續約兩個月。

And since it's unsafe to hold any stretch for too long,

因為任何伸展姿勢 持續太久就不安全，

it's recommended that you break up your stretching within any given session.

建議你每次伸展時， 都把它拆開分散進行。

Frequent stretching also makes lasting changes to your brain.

經常伸展也會對你的大腦 產生持久的改變。

The more you stretch a muscle, the higher your pain threshold becomes,

你越常伸展肌肉，

你的疼痛閾值就會越高，

allowing you to stretch further and further.

讓你可以伸展更多更多。

Long-term improvements to your flexibility can provide

柔軟度的長期改善，能讓 關節有更佳的活動度，

a better range of motion for your joints,

potentially reducing your risk of muscle injury in the short and long-term.

可能可以短期和長期地 減少肌肉受傷的風險。

But it’s also possible to stretch too much,

但也有可能會伸展過頭，

as flexible people can move their joints in potentially dangerous ways.

柔軟度好的人，有可能會用 危險的方式去動他們的關節。

Stretching also isn't helpful for every kind of movement,

伸展並不對每種動作都有助益，

especially those where muscle injuries aren't very common.

特別是肌肉不容易受傷的動作。

For example, long distance running only involves a small range of motion

以長跑為例，

相關的關節只需要做小範圍的動作，

for the joints involved,

so stretching is unlikely to prevent that sport’s most common injuries.

因此伸展不太能預防 長跑最常見的傷害。

When it comes down to it,

就這點來說，

different lifestyles require different kinds of mobility.

不同的生活方式會需要 不同類型的活動度。

And no single stretching regimen is flexible enough to fit every situation.

沒有單一種伸展有足夠的彈性 可以適用於所有情況。