Because they still believe the pinnacle of healthcare is drinking warm water and walking backwards.

Also because this is still a generation of mostly ex-farmers/peasants, a profession in which people obviously don't age well.

Some of the girls I work with act like old ladies in a lot of ways.  They're all in their early to late twenties and the prime of their lives, but seem to think their bodies are weak, feeble, sickly.... old in other words.They even say things like Chinese bodies are different, and weaker than other races.

They obsess about things like open windows and catching a chill even on a warm day. If they have a runny nose it's like they're convinced they could die from it and have to go to the hospital. If they eat or drink something cold they're convinced they're sick because of it. Walk a few blocks on a hot day and they will whine about being tired, and the heat and whatever else they imagine is attacking their frail bodies.

I don't know if it's the traditional Chinese medicine brainwashing, or wanting to be the victim / invalid so they are cared for and pampered by others, or both but from what I've seen Chinese talk themselves into being sick and weak all the time. It's no surprise they act like they're 90 when they hit 40. It's the culture I think.

Having said that, I see a lot of people who actually are old with a lot of piss and vinegar still in them. They go to my gym and work out, swim, lift weights.They go to the park everyday and practice tai chi, martial arts,dancing. I see them stretching and they're more flexible than I will ever hope to be. I suppose they come from the generation where life was brutal and only the strong ones made it through the famines and cultural revolution etc.

They were all probably malnourished growing up during Mao's time, and the aging process just made them look that much worse. 

I think most Chinese just follow social pressure. I see a few older Chinese women that dress like they are in their young twenties (with caps, bright colored sports clothes) and it looks kind of cute but you can tell the other Chinese people think they are freaks. Hard to express yourself freely in a country full of close minded people... if you mean by dress...

If you mean by appearance... just malnourished and followed foolish traditional beliefs.

Chinese are also known to age pretty quickly once they hit around 40-45 years old.

I compare age to some of the bands I like for eg

The Rolling Stones-Mick Jagger is 72 and he prances around on stage for 2 hours

Then I look at Steven Tyler and Joe Perry both is there 60s still Rocken

Angus Young I think he just turned 60 years old

Then you have got Iggy Pop the Godfather of punk he still stage dives and he is in his 60s.

I have shown people some of these bands and they cringe at the fact why would you do that when you are that age.

I hope to still be working out when I am in my 70s 80s exercise keeps you younger.

It seems to me that most Chinese begin to age very badly once they reach 35-40 years old. Perhaps it is just my personal observation. But, they seem to rapidly look older and older, despite their age.

amazing perceptive powers ......  they all look the same to me