高強(qiáng)度運(yùn)動(dòng)或可減緩肌肉衰老

The toll that aging takes on a body extends all the way down to the cellular level. But the damage accrued by cells in older muscles is especially severe, because they do not regenerate easily and they become weaker as their mitochondria, which produce energy, diminish in vigor and number.

衰老對(duì)身體造成的損害一直延伸到細(xì)胞層面。但在衰老的肌肉中，細(xì)胞累積的損傷尤為嚴(yán)重，因?yàn)樗鼈儾灰自偕?。而?dāng)細(xì)胞內(nèi)產(chǎn)生能量的線粒體活力和數(shù)量減少，這些細(xì)胞會(huì)更加衰弱。

A study published this month in Cell Metabolism, however, suggests that certain sorts of workouts may undo some of what the years can do to our mitochondria.

《細(xì)胞-代謝》(Cell Metabolism)雜志本月發(fā)表的一項(xiàng)研究卻表明，某些類型的鍛煉或許能消除歲月對(duì)我們的線粒體造成的影響。

Exercise is good for people, as everyone knows. But scientists have surprisingly little understanding of its cellular impacts and how those might vary by activity and the age of the exerciser.

眾所周知，鍛煉對(duì)人有益。但關(guān)于運(yùn)動(dòng)對(duì)細(xì)胞的影響，以及這些影響因活動(dòng)和鍛煉者的年紀(jì)不同會(huì)如何變化，科學(xué)家的了解出奇地少。

So researchers at the Mayo Clinic in Rochester, Minn., recently conducted an experiment on the cells of 72 healthy but sedentary men and women who were 30 or younger or older than 64. After baseline measures were established for their aerobic fitness, their blood-sugar levels and the gene activity and mitochondrial health in their muscle cells, the volunteers were randomly assigned to a particular exercise regimen.

因此，明尼蘇達(dá)州羅切斯特梅奧診所(Mayo Clinic)的研究人員近期對(duì)72名30歲及以下或64歲以上、身體健康但習(xí)慣久坐不動(dòng)的男性和女性進(jìn)行了實(shí)驗(yàn)。在確立志愿者的有氧體能、血糖指數(shù)以及肌肉細(xì)胞中基因活性和線粒體健康的基準(zhǔn)后，他們會(huì)被隨機(jī)分配到一個(gè)特定的鍛煉方案。

Some of them did vigorous weight training several times a week; some did brief interval training three times a week on stationary bicycles (pedaling hard for four minutes, resting for three and then repeating that sequence three more times); some rode stationary bikes at a moderate pace for 30 minutes a few times a week and lifted weights lightly on other days. A fourth group, the control, did not exercise.

志愿者中的一部分人每周需進(jìn)行多次高強(qiáng)度的舉重訓(xùn)練;一部分每周需進(jìn)行三次短時(shí)間的健身腳踏車間歇訓(xùn)練(用力蹬車4分鐘，休息3分鐘，再如此重復(fù)3次);還有一部分人每周以適中的速度蹬車數(shù)次，每次30分鐘，并在其他時(shí)候做低強(qiáng)度舉重訓(xùn)練。第四組為對(duì)照組，不做運(yùn)動(dòng)。

After 12 weeks, the lab tests were repeated. In general, everyone experienced improvements in fitness and an ability to regulate blood sugar.

實(shí)驗(yàn)室測(cè)驗(yàn)在12周以后再次重復(fù)。總的來(lái)說(shuō)，每個(gè)人的健康狀況和血糖調(diào)節(jié)能力都有所改善。

There were some unsurprising differences: The gains in muscle mass and strength were greater for those who exercised only with weights, while interval training had the strongest influence on endurance.

有些差別是預(yù)料之中的：僅做了舉重訓(xùn)練的志愿者在肌肉量和力量方面有更顯著的增加，而間歇訓(xùn)練對(duì)耐力的作用最大。

But more unexpected results were found in the biopsied muscle cells. Among the younger subjects who went through interval training, the activity levels had changed in 274 genes, compared with 170 genes for those who exercised more moderately and 74 for the weight lifters. Among the older cohort, almost 400 genes were working differently now, compared with 33 for the weight lifters and only 19 for the moderate exercisers.

但在肌肉細(xì)胞活檢中出現(xiàn)了更多出人意料的結(jié)果。在較年輕的試驗(yàn)對(duì)象中，進(jìn)行了間歇訓(xùn)練的志愿者有274個(gè)基因出現(xiàn)了活性水平變化，相比之下，運(yùn)動(dòng)適中的志愿者出現(xiàn)變化的基因有170個(gè)，做舉重運(yùn)動(dòng)的有74個(gè)。在年紀(jì)較大的組別內(nèi)，有將近400個(gè)基因現(xiàn)已有活性的改變，相比之下，舉重運(yùn)動(dòng)者有33個(gè)，運(yùn)動(dòng)適中者僅有19個(gè)。

Many of these affected genes, especially in the cells of the interval trainers, are believed to influence the ability of mitochondria to produce energy for muscle cells; the subjects who did the interval workouts showed increases in the number and health of their mitochondria — an impact that was particularly pronounced among the older cyclists.

大多數(shù)受到影響的基因——尤其是進(jìn)行間歇訓(xùn)練的志愿者細(xì)胞中的基因——都被認(rèn)為影響了線粒體為肌肉細(xì)胞制造能量的能力;進(jìn)行了間歇運(yùn)動(dòng)的實(shí)驗(yàn)對(duì)象表現(xiàn)出了線粒體數(shù)量和健康狀況的提高——這個(gè)影響在年紀(jì)較大的腳踏車運(yùn)動(dòng)者中尤其顯著。

It seems as if the decline in the cellular health of muscles associated with aging was “corrected” with exercise, especially if it was intense, says Dr. Sreekumaran Nair, a professor of medicine and an endocrinologist at the Mayo Clinic and the study’s senior author. In fact, older people’s cells responded in some ways more robustly to intense exercise than the cells of the young did — suggesting, he says, that it is never too late to benefit from exercise.

該項(xiàng)研究的資深作者、梅奧診所醫(yī)學(xué)教授、內(nèi)分泌學(xué)家斯利庫(kù)馬蘭·奈爾博士(Dr. Sreekumaran Nair)說(shuō)，與衰老有關(guān)的肌肉細(xì)胞健康程度下降似乎可以通過運(yùn)動(dòng)來(lái)“修正”，尤其是高強(qiáng)度的運(yùn)動(dòng)。事實(shí)上，年長(zhǎng)者的細(xì)胞對(duì)高強(qiáng)度運(yùn)動(dòng)的反應(yīng)比年輕人的更加強(qiáng)烈——他表示，意思就是，從運(yùn)動(dòng)中受益是不存在“太晚”這一說(shuō)的。