I would like to buy some DVD's from Yoga because I need to exercice my body as well as my mind.
I am not fat but I am not toned and I get problems because of stress and lack of muscles.
Which one of those types of yoga would be the most appropriate for me?
I'm definitely a yoga novice, but from what I understand Ashtanga yoga is "power yoga" and Hatha yoga is "regular/classic yoga". If you want to relax and destress and stretch, do Hatha. If you want to build strength and sweat, do Ashtanga. If you've never done yoga before, I would start with Hatha. That's what my gym recommends, and I agree.
And honestly, I find talking to yoga-experts can be really intimidating! I like to do yoga as a form of exercise sometimes....and I think it's fine to use yoga as that, without getting into all the spiritual stuff, and ancient history, and fancy words for things, etc.
"I don't know! I don't know why I did it, I don't know why I enjoyed it, and I don't know why I'll do it again!" -BART SIMPSON
We have room for but one flag, the American flag. We have room for but one language here and that is the English language ….and we have room for but one sole loyalty, and that is a loyalty to the American people. —Theodore Roosevelt
Ashtanga is good if you don't mind repetitive motion since the postures never change. It's not like Hatha styles where every tape can be a totally different set of postures. Generally speaking, Ashtanga is very physically demanding, should really be done under supervision, and can easily lead to injuries if you are not aware of how to properly protect yourself and modify postures for your skill level. Also, the pace of an Ashtanga class may be faster than what you are used to with a regular hatha class.
I have not seen any beginer Ashtanga tapes, so I do not know how good they are. A full primary series Ashtang tape can be a bit overwhelming and intimidating.
Regarding some misinformation:
Ashtanga yoga is not power yoga but is a subset of the umbrella Hatha. Power yoga (or Vinyassa Yoga) is a faster, flow-ey type of yoga, but does not use the strict posture sequence of Ashtanga.
I personally find Ashtanga much more relaxing than hatha, becasue it suits my personality. Iyengar drives me crazy You may find that Ashtanga stresses you out. There are so many flavors of hatha, I'm sure you can find one that works for you.
I would add that it's hard to learn yoga from a video. There are so many things that you just can't figure out, but a live instructor can show you a little adjustment in your pose that makes a huge difference. I'd really recommend trying to find a live class -- at a Y, a school, a community center if you can't find or don't want to go to a yoga studio. Once you have the basics, you can continue to practice at home with videos. (But I bet you will still want to go to a class, they are a very different experience from home practice.)
As Webby said, there are many, many styles of yoga, so if the first one you try doesn't grab you, don't give up entirely.
As a beginner who has not been doing much exercising, you might look for a "Gentle Yoga" class to start with.
If your only option is to use a video, I recommend these for beginners:
Unlike many beginner videos, these do not assume you already know the poses. The Patricia Walden is especially good in terms of explaining the poses. After you have been practicing a while, you will outgrow this one. The Yoga Zone one is another favorite for beginners, and will probably keep your interest longer.