And you're definitely not the only one at the gym using a protein supplement.

在健身房使用乳清蛋白的人絕對不止你一個。

In 2017, 9.4 billion dollars was spent on whey protein globally.

2017 年，全球乳清蛋白消費額達 94 億美元。

So is protein powder actually helping you build muscle, or are you turning your money into dust?

那麼，蛋白質粉究竟是在幫你增肌，還是在把你的錢轉化為灰燼？

Let's talk about how your body uses protein to build muscle and whether protein shakes are helping you get the best out of resistance training.

讓我們來談談人體是如何利用蛋白質來增肌的，以及蛋白質奶昔是否能幫助你從阻力訓練中獲得最佳效果。

Welcome to DocUnlock, where we help you make better decisions about your health.

歡迎訪問 DocUnlock，我們將幫助你更好地決定自己的健康。

So how exactly does your body build muscle?

那麼，你的身體究竟是如何鍛鍊肌肉的呢？

When it comes to increasing the size of any organ, the body only has two options:

要想增大任何器官的體積，人體只有兩種選擇：

You can either increase the number of cells, called hyperplasia, or you can make each cell bigger, called hypertrophy.

你可以增加細胞數量，這被稱為細胞增生，或者你可以讓每個細胞變得更大，被稱為肥大。

When it comes to building up new muscle, your body can't build new muscle cells, so your body relies on muscle hypertrophy.

說到鍛鍊新肌肉，你的身體無法制造新的肌肉細胞，所以你的身體依靠肌肉肥大。

So how does muscle hypertrophy work?

那麼，肌肉肥大是如何產生作用的呢？

If you look at a muscle cell under a microscope, what you will see are long tubes of fibres running along the length of the cells.

如果在顯微鏡下觀察肌肉細胞，你會看到長長的纖維管沿著細胞的長度。

These are called myofibrils and are full of protein-based fibres.

這些纖維被稱為肌纖維，充滿了以蛋白質為基礎的纖維。

When a muscle cell builds more of these protein fibres, it gets bigger and stronger.

當肌肉細胞生成更多這種蛋白質纖維時，它就會變得更大更強壯。

To achieve muscle hypertrophy there's a simple rule, Muscle Protein Synthesis (MPS) needs to outweigh Muscle Protein Breakdown (MPB).

要實現肌肉肥大，有一個簡單的規則，即肌肉蛋白質合成（MPS）需要超過肌肉蛋白質分解（MPB）。

And to trigger Muscle Protein Synthesis, you need 2 ingredients: resistance training and protein from your diet.

要觸發肌蛋白合成，你需要兩個成分：阻力訓練和來自飲食的蛋白質。

If your body doesn't get enough protein from your diet, then it can't trigger muscle protein synthesis effectively.

如果你的身體沒有從飲食中攝取足夠的蛋白質，那麼它就無法有效地引發肌蛋白合成。

And this is where the advice comes from to include protein in your diet especially if you're doing a lot of resistance training.

這就是建議在飲食中包含蛋白質的原因，特別是如果你進行大量的阻力訓練。

Most people living in high income countries get enough protein from their diet for normal body function.

生活在高收入國家的大多數人透過飲食攝取足夠的蛋白質來維持正常的身體功能。

But we know that protein needs are higher in those people who are deliberately trying to achieve muscle hypertrophy.

但我們知道那些刻意嘗試達到肌肉肥大的人需要更多的蛋白質。

But does adding protein powder to your diet help you get better results from resistance training?

但將蛋白質粉加入你的飲食是否能幫助你在阻力訓練中獲得更好的結果呢？

Well, there have been so many studies done on the topic!

關於這個問題的研究已經很多了！

If only there was a meta-analysis that put all the results together so that we can get the best answer possible.

如果能有一項總結分析，將所有結果匯總在一起，以便我們能夠得到盡可能最好的答案就好了。

Ah HAH! Found it!

啊哈！找到了！

Published in 2017 in the British Journal of Sports Medicine, this is the largest review so far on whether protein supplementation leads to gains in muscle mass and strength.

這項研究發表在2017年的《英國運動醫學雜誌》上，是迄今為止關於蛋白質補充是否導致肌肉質量和力量增加的最大綜述。

It combined the results of 49 randomised controlled trials.

它綜合了 49 項隨機對照試驗的結果。

In these trials, almost 2000 people were put on a resistance training program.

在這些試驗中，近 2000 人接受了阻力訓練。

In these people, the average protein intake even before supplementation was approximately 1.4 grams of protein per kilogram, per day,

在這些人中，即使在蛋白質補充之前，平均蛋白質攝取量已經是約為每公斤體重每天約 1.4 克，

and this is already above the recommended dietary allowance of 0.8 grams per kilogram, per day.

這經高於每日 0.8 克每公斤體重的建議飲食攝取量。

The experimental group received an additional protein supplement of 36 gram per day on average, with almost half of the trials using whey protein.

實驗組平均每天額外攝取 36 克蛋白質的補充劑，其中幾乎有一半的試驗使用乳清蛋白。

The control group most commonly received a carbohydrate supplement to make sure that the total calories were the same as the experimental group.

對照組最常見地接受碳水化合物補充劑，以確保總卡路里與實驗組相同。

The average resistance program was 13 weeks long, with training sessions 3 times per week.

阻力訓練計劃平均為期 13 周，每週訓練 3 次。

On average, each session had 7 exercises, 4 sets per exercise and 9 reps per set. And the results?

平均每節課有 7 個練習，每個練習 4 組，每組 9 次。結果呢？

Well, protein supplementation improved strength, muscle size and lean body mass.

補充蛋白質可以增強力量、肌肉體積和減少體重。

So you aren't wasting your money after all, protein supplementation does lead to some benefit.

所以說，你的錢並沒有白花，補充蛋白質確實會帶來一些好處。

BUT WAIT – there's a catch.

但是，等等，有一個問題。

First, there is a point where adding more protein doesn't lead to more benefit.

首先，增加蛋白質並不會帶來更多益處。

The researchers found that the benefit of protein supplementation plateaued after a total daily intake of 1.6 grams of protein per kilo, per day.

研究人員發現，蛋白質補充的益處在每天總攝取1.6克蛋白質每公斤體重後趨於穩定。

For someone weighing 70 kilos, that would mean a total protein intake, both from food and supplements, of 112 grams per day.

對於一個體重70公斤的人來說，這意味著每天從食物和補充劑中總共攝取112克蛋白質。

And the second thing: even though protein supplementation did have a benefit, it's not as impressive as you might think.

第二點：儘管補充蛋白質確實有好處，但它的並不像你想象的那樣令人印象深刻。

When it came to improvement in strength, participants who didn't use a protein supplement increased their 1 rep max by an average of 27 kilos just through resistance training alone.

在力量改善方面，未使用蛋白質補充劑的參與者增加了僅通過阻力訓練，他們的最大單次重量就平均增加了 27 公斤。

Those who were given a protein supplement had an additional benefit of 2.49 kilos.

補充蛋白質的人額外獲益 2.49 公斤。

In other words, protein supplementation contributed an additional benefit of only 9%.

換句話說，補充蛋白質帶來的額外益處只有 9%。

What does this mean?

這意味著什麼？

Well, the researchers tell the story best:

研究人員說得最清楚：

"The practice of Resistance Exercise Training is a far more potent stimulus for increasing muscle strength than the addition of dietary protein supplementation."

「進行阻力運動訓練的實踐遠比添加膳食蛋白質補充劑更強烈地刺激增加肌肉力量。」

If you're a professional athlete where every last bit of strength counts, then yes absolutely optimise your protein intake.

如果你是職業運動員，每一點力量都很重要，那麼肯定要優化你的蛋白質攝取。

For serious athletes, this study recommends supplementing protein intake to an upper limit of 2.2 grams per kilo, per day, to get the maximum possible benefit from protein supplementation.

對於認真的運動員，這項研究建議將蛋白質攝取的上限補充到每公斤體重每天2.2克，以獲得蛋白質補充的最大可能好處。

But if you're an average person like me just trying to stay fit, then protein shakes will help you a bit, but not as much as getting to the gym and actually doing the work.

但如果你像我一樣只是想保持身材，那麼蛋白質奶昔會對你有一些幫助，但不如去健身房實際鍛鍊來得有用。

So the next time you see someone at the gym drinking some protein, the real question is: "Hey bro, do you even lift?"

所以下次你在健身房看到有人喝蛋白質，真正的問題是：「嘿，兄弟，你真的有在鍛鍊嗎？」

In this video I've only looked at the effect of protein supplementation on strength training.

在這段影片中，我只介紹了補充蛋白質對力量訓練的影響。

There are some other reasons why people use protein shakes:

人們使用蛋白奶昔還有其他一些原因：

to boost protein intake without eating a lot more calories, to suppress appetite or to aid in recovery after cardio.

增加蛋白質攝入，而不需要攝取更多的卡路里，抑制食慾或在有氧運動後幫助復原。

If you're interested in these topics, drop a comment below.

如果你對這些話題感興趣，請在下面發表評論。

And if you're interested in getting specific advice about your particular situation and protein intake, then I would suggest seeing a sports dietician.

如果你有興趣獲得關於你特定情況和蛋白質攝取的具體建議，我建議諮詢一位運動營養師。

A common concern about a high protein diet is whether there are any negative effects on your health.

對於高蛋白飲食，人們普遍關心的一個問題是，它是否會產生負面影響你的健康。

For example, could a high protein diet cause lead to worse acne, hair loss or even cause kidney damage?

例如，高蛋白飲食會不會導致痤瘡、脫髮加重，甚至導致腎損傷？

In the next episode, I'm going to look at the science behind these questions.

在下一集中，我將探討這些問題背後的科學依據。

So make sure you're subscribed for that and the video will be up there to your right when it's released.

請確保你已訂閱，屆時影片發布時就會出現在右側。

Thanks for watching and I'll see you in the next one.

感謝收看，我們下期再見。