I think women tend to be afraid of really weightlifting (ie heavy weights that make you struggle), either because it is so weirdly testerone-ish or because they are afraid of "bulking up". However, if you don't lift heavy weights nothing happens (women and five pound barbells are a pet-peeve of mine), and bulking up is really, really hard, for both men and women -- if you work out 3 days a week and stay away from the protein drinks (and steroids), you won't see any bulk at all, just tone and reshaping.
I think Pilates and Yoga are cool, too, but there is a little bit of the Oprah's book club thing going on ...
Having a good core is one of the easiest ways to maintain your health as you get older too and if you're active you will feel a great benefit having that balance and strength. Until I tried Snowboarding I had no idea my core was as weak as it was.
The test I always like to give myself is being able to put my socks on in the morning whilst standing up, without wobbling all over the place or leaning on anything :)
Since I don't have access to a gym with weights and only a small set of dumbbells I'm not sure how much of the weight training side of this I can do, but I might try the running thing and perhaps some simpler weights that I can do with dumbbells. Maybe pick up a yoga class again too :)
Being able to perform each of these lifts properly would make you more knowledgeable than MOST people at your average ballys or 24 hour fitness, and that should give you plenty of confidence to start busting your ass at the gym.
edit, here's the link [cosgrove evil 8]:
http://www.tmuscle.com/free_online_article/sports_body_train...
One of the reasons compound lifts moving heavy weight are so important is the effect they have on your entire body. Doing heavy squats recruits nearly every muscle in your body. But it doesn't just stimulate those muscles, it also stimulates your central nervous system.
Doing something hard enough to get the attention of the CNS is important to making progress, since, for example, the CNS will respond by releasing more hormones such as growth hormone.
Doing full squats with your bodyweight on the barbell 15 times (3 sets of 5) is like screaming at your body to get in shape and it will respond. Doing yoga might be like gently asking.
This isn't to say yoga isn't beneficial, it's just not the most efficient way to get in shape.
Particularly squats. Nothing better to wreck your knees or back than squats done with too much weight and/or poor technique.
Excercise causes muscle damage which rest heals up (and results in stronger muscles). Aside from the obvious over- or understimulation, you do have some control over the type of stimulation…the two archetypes are the high-rep/low-weight and low-rep/high-weight with slightly different results.
> Doing full squats with your bodyweight on the barbell 15 times (3 sets of 5) is like screaming at your body to get in shape and it will respond.
I do not think (very-)high-resistance training is a good approach for people wanting to be "in shape" but, then, I make a distinction between that and bodybuilding.
(Of course, "in shape" means different things to different people. I prefer endurance/cardio, many others think more in terms of strength/musculature.)
As a gross oversimplification of the body types attained, yoga == Bruce Lee, weights == Arnold Schwarzenegger.
Edit: IIRC, Lee described running as the best exercise.
Also, as someone else mentioned, don't be afraid of doing weights. The only way to gain weight and thus more muscle is by eating a surplus. So many women shy away from weights because they don't want to get 'bulky', when it's the food that makes you bulky not the training.