Because muscle memory doesn't last.

因?yàn)榧∪庥洃洸粫?huì)持續(xù)。

Taking a month or two off of regular exercise may not be so benign. A new small study shows that when muscles take a break, they maintain very little muscle memory from the prior exercise.

把平常的規(guī)律性運(yùn)動(dòng)暫停1到2個(gè)月可不是個(gè)好習(xí)慣。一個(gè)新的小研究顯示,當(dāng)肌肉放松時(shí),它只能保持很少之前運(yùn)動(dòng)時(shí)的記憶。

The goal of the new study, published Thursday in the journal PLOS Genetics, was to gain a better understanding of how exercise influences the body on a genetic level. As TIME recently reported, exercise carries a whole host of benefits for the body, from aging to brain health to a stronger ability to fight infections. But how that exercise translates to changes in genetic activity is more unknown.

現(xiàn)有一項(xiàng)于星期四在科學(xué)公共圖書(shū)館基因雜志板塊發(fā)布的新研究,它的目標(biāo)是:更好地理解鍛煉怎樣在基因?qū)用嫔嫌绊懮眢w�！稌r(shí)代》雜志最近報(bào)道,鍛煉完對(duì)身體大有益處,好處的范圍包括延緩衰老、大腦健康、增強(qiáng)抵抗力。不過(guò),這些鍛煉究竟是如何影響基因活動(dòng)的,依舊在很大程度上不為人知。

In the report, 23 people trained one of their legs for three months by kicking and pulling a bike-like contraption 60 times a minute for 45 minutes. They did this training four times a week for three months.

報(bào)告顯示,23個(gè)人通過(guò)堅(jiān)持3個(gè)月,每天45分鐘,每分鐘騎60圈動(dòng)感單車(chē),來(lái)鍛煉一條腿。每周鍛煉4次。

After that, the people in the study took nine months off.

之后,他們休息了九個(gè)月。

The study authors took skeletal muscle biopsies from both legs before and after and found that the cells in the muscles expressed over 3,000 genes in different ways after a person exercised. However, after the fitness hiatuses, the scientists couldn’t detect any exercised-related genetic changes between the people’s trained and un-trained legs.

文章的作者前后分別對(duì)雙腿做了骨肌活組織檢查,并指出,鍛煉之后肌肉細(xì)胞中的三千多基因發(fā)生了表達(dá)方式的變化。然而,健身活動(dòng)停息后,科學(xué)家在鍛煉過(guò)的和沒(méi)鍛煉過(guò)的兩條腿之間,無(wú)法發(fā)現(xiàn)任何和鍛煉有關(guān)的基因變化。

“We couldn’t see any differences at the gene activity level,” says study author MaléneLindholm of the KarolinskaInstitutet in Sweden. “Most effects are lost by a month or two of no training.”

“我們看不出基因活動(dòng)層面有任何區(qū)別”來(lái)自瑞典卡洛琳斯卡學(xué)院的研究主導(dǎo)者馬爾?林霍爾姆說(shuō)。“一到兩個(gè)月不運(yùn)動(dòng)大部分的效果就消失了”

After that, 12 of the people in the study started training both of their legs. When the researchers compared biopsies of the two trained legs, they once again saw changes in genetic activity, but the leg that had undergone training nine months early looked virtually the same as the newly trained leg. “We did see some differences in the response but not substantial enough to claim some type of memory,” says Lindholm.

此后,研究中的12人開(kāi)始鍛煉他們的雙腿。當(dāng)研究者對(duì)比了雙腿的活組織性檢查結(jié)果時(shí),他們?cè)俅慰吹搅嘶�因活性的改�?但是9個(gè)月之前鍛煉過(guò)的那條腿和最近鍛煉的這條腿看起來(lái)一樣。“在結(jié)果中我們的確看到了些不同,但是不同的程度還不夠去說(shuō)明它是某種肌肉記憶”

Lindholm says the study could be interpreted in a couple ways. It underlines fact that exercise can spur healthy biological changes, and that keeping up the practice is important to ensure those healthy changes are sustained. On the other hand, she says that the results can be encouraging to people who are sedentary. It suggests they can achieve the same benefits from exercise as anyone else. “The study could be used as positive encouragement,” says Lindholm. “It’s never too late to start training from a muscle perspective.”

林霍爾姆說(shuō)這個(gè)研究可以通過(guò)許多方式去闡釋。它強(qiáng)調(diào)了運(yùn)動(dòng)可以刺激健康的生理變化這一事實(shí),而且堅(jiān)持鍛煉對(duì)于確保這些健康的變化能夠保持是很重要的一點(diǎn)。另一方面,她說(shuō)結(jié)果可以鼓勵(lì)那些久坐的人。它說(shuō)明他們可以和其他人一樣從鍛煉中獲益。“這個(gè)研究可以算是一種積極的鼓勵(lì),”林霍爾姆說(shuō)。“從肌肉的角度來(lái)說(shuō)什么時(shí)候開(kāi)始鍛煉都不晚。”