I'm trying to keep breast cancer away. I've had it once, and I really don't want it again. So I am committing myself to all strategies for keeping the disease out of my life -- like eating right, maintaining a normal weight, not drinking, not smoking, and as of yesterday, exercising strenuously.

New research shows strenuous exercise is what it takes to minimize the risk of breast cancer. Not moderate. Strenuous.

OK, I'm on board.

Now I've been a student of moderate fitness for most of my life. But now I'm embracing this new approach, this new way of pushing my body to its near limits. I figure if my choice is cancer or strenuous exercise, I better take the route that will leave me sweating and huffing and puffing, not sick and weak and bald. And so yesterday I took my first stab at what I will try to do at least five hours per week -- what experts say it takes to make a difference.

It all started with a warm-up lap on my treadmill -- just one lap at 4.5 miles per hour. Then I upped my speed to 5.3 and ran for a mile and a half. I continued running for another half mile at 6 miles per hour and then began walking again. I started at incline 1 for one minute, then moved to incline 2 for one minute, then incline 3 for one minute, and so on until I reached incline 10. My goal was to then continue walking while decreasing the incline each minute for ten minutes -- but I was so out of breath and fatigued, I jumped the incline down to 4 for one minute, then did 3 for one minute, 2 for one minute, 1 for one minute, and then I stopped. The whole process took about 40 minutes and left me soaked with sweat and gasping for air. Then, just in case my workout wasn't strenuous enough, I did 20 push-ups, a handful of sit-ups, and a few other floor exercises before heading to the shower.

So that's my version of strenuous. Now, I don't plan to do this same exact routine for all five hours I must complete each week, but I do intend to sweat and huff and puff just as much as I did yesterday. Because if strenuous is what it takes to ward off evil cancer cells, then I'm game.

Regular. Strenuous. Exercise. Memorize these three words. Live these three words. And abandon all thoughts of a fitness routine that is easy, moderate, or periodic.

Brisk walking, golf, and volleyball are considered moderate forms of exercise. Swimming laps, aerobics, and running are considered strenuous. And these are the activities we should be taking part in -- for the rest of our lives -- if we really truly wish to prevent breast cancer.

A new study, published in the February 26 issue of the Archives of Internal Medicine, shows women with a long-term history of engaging in strenuous exercise for more than five hours per week were 20 percent less likely to develop invasive breast cancer and 31 percent less likely to develop in situ breast cancer than those logging less than 30 minutes of strenuous exercise per week.

It seems strenuous exercise most affects estrogen-receptor negative breast cancer. But clearly, everyone can benefit from vigorous fitness training -- the American Cancer Society recommends moderate to strenuous exercise five days per week for at least 30 minutes each day -- and this is exactly why I am headed out for a run. Today!

MTV is currently airing another installment of the Real World/Road Rules Challenge reality show. This season -- called Fresh Meat -- pairs former show contestants with individuals who have never before appeared on any MTV reality show. These new contestants -- the fresh meat -- compete with the veterans in tense and strenuous physical and mental challenges for an array of prizes and for a grand award of $250,000. Winning the money could be life-changing for any one of these participants. But for one woman, it could also be life-saving.

Diem Brown, 25, was cast on the MTV challenge show before hearing her diagnosis of ovarian cancer. She didn't want to regret passing on the opportunity so with two chemotherapy treatments completed and armed with medication to manage nausea and other side effects, she packed her bags and headed for Australia where her days consisted of challenging stunts and tough competition. She survived it all -- although fatigue and pain sometimes slowed her down -- and she is busy surviving ovarian cancer too.

Brown has started a foundation called Live for the Challenge -- kind of like a Make-A-Wish Foundation for patients who are stuggling with medical difficulties. And her own personal wish is that ovarian cancer -- "the disease that whispers" -- would get a megaphone to attract more attention and more research. Because one in 50 women will get ovarian cancer and with no accurate screening for this disease, it leads to tragic outcomes for many women.

It is clear that Brown is one tough contender -- both on TV and in her everyday life. And that makes her a winner no matter what.