Talk to your doctor about hormone replacement therapy which does benefit many women. This sounds great, but the problem with the preventative therapy is that tamoxifen can increase the risk of endometrial cancer and blood clots. Evista is more selective than tamoxifen and might protect against breast cancer without increasing the risk of endometrial cancer. Check out the National Cancer Institute's Cancer Trials web page for more information. There is lots of talk about sports supplements like Creatine and Androstenedione.
Creatine is useful for brief intense exercise such as weightlifting and sprinting.
Creatine is widely to increase muscle strength. It is not useful for endurance. Androstenedione is a testosterone precursor. It provides short boosts in testosterone levels usually less than 2-3 hours. The extra hormone helps to build muscle mass.