I am a 29 year old woman. I am interested in increasing my muscle mass. Could you please tell me what steps to take in weight lifting as well as in changing my eating habits for a healthier diet?

I am a woman who has a family, full-time job, and a very busy life, generally.

Three years ago, I joined a local health club because I was not getting enough exercise. Since then, I have tried to work out three times a week. Every time I exercise on the treadmill, even though I am not running but only walking fast, I experience leg pain in the back of my calves. I have tried stretching to warm up but nothing seems to help. Do you have any suggestions? The pain in my calves is preventing me from increasing my speed and improving my conditioning. I would appreciate any suggestions you might have.

Can I run when I am pregnant?

I have recently started to stretch to start learning yoga and I have become sore in my muscles, and was wondering if I am sore the next day after stretching, is it okay to stretch the next day when I am still sore?

I have two questions:

(1) What are the benefits of jumping on a mini-trampoline?

(2) Are there any benefits to using a hula-hoop?

As you can probably see, I'm looking for exercises that are fun.

It's been about three months since I worked out regularly. I find that lifting for strength (i.e. 80% of max for 5-8 reps) causes me to feel nauseated about 3/4 through the workout sometimes, so that I can't bring myself to finish. I took a weight training course last semester and was affected the same way every once in a while. I warm up, stretch before and after, breath when I lift, drink plenty of water, take care not to eat 1 hour before working out, skip a day between workouts, don't lift more than I can handle (I reduced the weight from what I ended on in the class to a seemingly suitable weight. I got a 98 in the class incidentally). What's going on?