What exactly is the definition of being "healthy"? Everyone around me seems to care quite a bit about their health, but somehow I the sense that people also seem to obsess about some aspects of health over others.
Traditional Chinese culture tends to assume that everyone has a weak organ, usually either the liver or the kidneys, and needs nutritional + herbal supplements to strengthen these organs. Some people will go as far as not bothering with exercising or watching their diet, and attempt to cultivate health entirely from Chinese medicine and health food supplements, sometimes to the point of overloading the liver and kidney.
On the other extreme, some people equate the term "health" with "fitness level". To be healthy means being the fittest person one can be. Some people erroneously think that by running ultramarathons, winning Ironman triathlon and/or Strongman competitions, their superhuman fitness will make them invincible to all diseases. It does seem like some people's bodies are built to be able to comfortably run insanely long distances or lift super heavy weights, but I hope these people realize that what they achieve are celebrations of human performance capability, rather than a pursuit of ultimate health. Sometimes people overestimate the body's ability to regenerate. When we're younger (20s and younger), our body can handle a lot of abuse and we seem to be able to recover in no time. But we can learn from observing retired Olympic athletes that they seem to age faster than people who exercise in moderation. It seems like they have used up their youth prematurely in achieving those superhuman feats during competitions and training.
Now let's take a look at yoga. The general impression of yoga is that it is a relatively mild form of activity that will exercise the body, increase flexibility, and lowers stress levels. This makes it especially popular for people who dislikes gyms and not very sporty. It also makes ultra-athletic and competitive people look down on yoga. Now the extremeness of yoga comes when people see the advanced yoga poses that requires extreme flexibilities, for example the feet behind the head poses, or the crazy backbends (kapotasana or Tirieng Mukha Uttanasana.. ouch!!!). Just looking at these pictures can make people feel pain (especially for people who are particularly not that flexible). I was fortunately born quite flexible and could touch my toes to my head when I was 5 years old (though I lost that ability as I grew older). I have avoided yoga for the longest time because I felt these poses acted to showcase these yogi's contortionist capabilities and were not a sign of health. My belief for health has been "everything in moderation".
Now that I'm completely hooked on Ashtanga, and worship the ground my teacher walks on, seems like my belief system is slowly morphing. In the beginning I was careful to take things easy and not push the poses to the extreme, but my teacher has been quite enthusiastic in helping me into a lot of the poses while taking care not to use too much force on me. So now that my knees have stopped aching when doing Ardha Baddha Padma Paschimotanasana (I was quite concerned for awhile there) and my feet can come off the floor in supta kurmasana (uh, off the ground but not over my head, yet), it just seems like every pose will be possible with enough practice (at least it feels this way in my first year of Ashtanga practice. We'll see when I hit a bottleneck). Soooooo, am I working towards the extreme poses for my ego, like the marathon runner going for that extra mile, or the strongman looking to break his personal weightlifting record? Is the Ashtanaga practice actually healthy for me, phyically?
I am certain that mentally it's doing me wonders. When I started coming to yoga, my teacher told me that I looked like I carried a lot of tension. I didn't talk to anyone for months. I went for the corner spot of the room every class and pretended I was invisible. Now I actually smile at people who look my way instead of averting anyone who makes eye contact with me. Every practice makes me happy, no matter how exhausted I may feel when the class is over. I don't really understand why I need to twist and fold myself into a human origami in order to nurse my mental health back to life. I suppose yoga is not the only way to cultivate, but the yoga community happens to be the most supportive community I have encountered yet in my life. I'm guess that it's the shared sensations and experiences in the journey of Ashtanga that brings people close together (Teacher: I know exactly how you feel; my ankle would hurt too if I didn't flex them during Mari B, D, and padmasana).
To bring it back to my question in the beginning: while Ashtanga is a very physically demanding practice, especially in terms of pushing one's limits in flexibility, I appear to be pursuing this path more for the sake of my mental health more than physical health. I happen to be the type of person who requires something this extreme to save my mind, a mind with a tendency to over-worry, over-analyze and over-criticize. Actually I have available to me opportunities to pursue alternative activities that are more physically demanding than Ashtanga, in terms of strength, power, agility and coordination. By choosing Ashtanga, I am actively choosing to not strive to be the fittest person I can be physically, and instead go down this path of deepening my mind-body connection. Who knows where this path will take me?