爲什麼身體走形之後想還原這麼難？
Why Getting Back in Shape is So Hard？
爲什麼身體走形之後想還原這麼難？
Because muscle memory doesn't last.
因爲肌肉記憶不會持續。
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.
把平常的規律性運動暫停1到2個月可不是個好習慣。一個新的小研究顯示，當肌肉放鬆時，它只能保持很少之前運動時的記憶。
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.
現有一項於星期四在科學公共圖書館基因雜誌板塊發佈的新研究，它的目標是：更好地理解鍛鍊怎樣在基因層面上影響身體。《時代》雜誌最近報道，鍛鍊完對身體大有益處，好處的範圍包括延緩衰老、大腦健康、增強抵抗力。不過，這些鍛鍊究竟是如何影響基因活動的，依舊在很大程度上不爲人知。
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.
報告顯示，23個人通過堅持3個月，每天45分鐘，每分鐘騎60圈動感單車，來鍛鍊一條腿。每週鍛鍊4次。
After that, the people in the study took nine months off.
之後，他們休息了九個月。
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.
文章的作者前後分別對雙腿做了骨肌活組織檢查，並指出，鍛鍊之後肌肉細胞中的三千多基因發生了表達方式的變化。然而，健身活動停息後，科學家在鍛鍊過的和沒鍛鍊過的兩條腿之間，無法發現任何和鍛鍊有關的基因變化。
“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層面有任何區別”來自瑞典卡洛琳斯卡學院的研究主導者馬爾ž林霍爾姆說。“一到兩個月不運動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.
此後，研究中的12人開始鍛鍊他們的雙腿。當研究者對比了雙腿的活組織性檢查結果時，他們再次看到了基因活性的改變，但是9個月之前鍛鍊過的那條腿和最近鍛鍊的這條腿看起來一樣。“在結果中我們的確看到了些不同，但是不同的程度還不夠去說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.”
林霍爾姆說這個研究可以通過許多方式去闡釋。它強調了運動可以刺激健康的生理變化這一事實，而且堅持鍛鍊對於確保這些健康的變化能夠保持是很重要的一點。另一方面，她說結果可以鼓勵那些久坐的人。它說明他們可以和其他人一樣從鍛鍊中獲益。“這個研究可以算是一種積極的鼓勵，”林霍爾姆說。“從肌肉的角度來說什麼時候開始鍛鍊都不晚。”
