I wanted to know how many days of rest is recommended between workouts. I heard it was three days on to one day off...is this enough? I workout on a treadmill for 50 minutes every day and have for the last 14 months. I was not aware of how rest played a very important role until I recently read a brief article on it. I guess my question is, do I need to take that day of rest and how important is it?

For as long as I can remember, I've been using my back muscles when I did sit-ups. In fact, I distinctly remember the first time we did them in second grade. After a few reps, it was already so painful that I was having trouble breathing properly. Being eight years old, however, I didn't realize this was a warning sign and assumed it was normal.

Flash forward ten years, and I have almost no strength in my abdominal muscles. I've tried to teach myself to do curl-ups properly, but no matter how hard I try, I can't even lift my head without using my back muscles. Exercise balls are no help either. Even when I concentrate on using my abs to keep myself steady, my back is still doing 95% of the work.

So, in short, I have two questions: Am I at risk for having damaged my back from years of abuse, and how can I work on strength training my abs now?

I have a question about dehydration. I am an eighteen-year-old female and play on a varsity basketball team. We usually have two-hour practices in which we work very hard. Our coach does not give us water breaks, and usually by the end of practice, we have cottonmouth and are "dying" for water. It is horrible. Is there any way that not having water during that time can be dangerous? Sometimes the team can feel sick or weak by the end of a practice.

I have bowlegs. It is quite frustrating because I cannot do exercises that isolate and tone the thighs (lunges, squats, etc). When I do squats, my pressure/force comes from the calves and the knees, but not the thighs. Reason being is that the legs are not properly aligned, and pressure/force cannot go up to the thighs. It even hurts when I do squats because they involve bending the (crooked) knees. Are there any alternative thigh exercises?