And if you can improve your muscles' capability deep into your 90s, there's no excuse for slacking off now whether you're 30 -, 50 - or 70-something!

如果你在90多岁的时候还能锻炼身体，改进肌肉的力量，那么，无论你现在是30多，还是50多，甚至是70多，都没有理由懈怠！