高強度間歇訓練幫長者保住肌肉
As we get older, losing weight can be a double-edged sword: along with the fat, we often lose valuable muscle. Now a study from Australia suggests that the type of exercise you choose can make a real difference.
Researchers at the University of the Sunshine Coast recruited 123 healthy adults with an average age of 72. The volunteers were divided into three groups and spent six months doing supervised gym sessions three times a week. One group did high-intensity interval training, known as HIIT, which involves short bursts of hard effort followed by rest. A second group did moderate exercise, and a third group did gentle, low-intensity workouts.
All three groups lost a modest amount of body fat. But there was one important difference. People in the moderate group also lost a small amount of lean muscle, while those doing HIIT held on to theirs.
The researchers believe this is because intense exercise puts more stress on the muscles, which signals the body to keep them. Muscle is vital for strength, balance and independence in later life.
The team cautioned that the differences were small, and other recent studies have produced mixed results. Still, they say the findings show that healthy ageing is about more than the number on the scales.
上了年紀以後，減重常常是一把雙面刃：脂肪少了，寶貴的肌肉也跟著流失。澳洲一項新研究發現，選哪一種運動，結果可能差很多。
陽光海岸大學的研究人員招募了 123 位健康的長者，平均年齡 72 歲。受試者分成三組，在教練指導下每週上健身房三次，持續六個月。第一組做高強度間歇訓練（HIIT），也就是短時間全力運動、再休息，反覆進行；第二組做中等強度運動；第三組做輕鬆的低強度運動。
三組都減掉了一些脂肪，但有一個重要的差別：中等強度組同時流失了少量肌肉，做 HIIT 的人則把肌肉保住了。
研究人員認為，這是因為高強度運動對肌肉的刺激比較大，身體就會把肌肉留下來。對長者來說，肌肉關係到力氣、平衡感，以及能不能自理生活。
研究團隊也提醒，各組的差距不大，近期其他研究的結果也不太一致。不過他們表示，這些結果說明，健康老化看的不只是體重計上的數字。