BY DESONTA HOLDER

''My three biggest challenges are teaching technology to teachers, being a single mom and keeping MS away,'' said Lee Munro. ``The hardest: teaching technology.''

Munro, 35, was diagnosed with multiple sclerosis in 2000. ''It just happened,'' she said. ``You have to deal with it the best you can.''

Sunday, the technology coordinator at Boca Raton's St. Andrew's School and mother of 7-year-old Christian will deal with it by earning her second Miami half-marathon medal.

Take one look at Munro , and you easily guess that she's a runner. Look for signs of multiple sclerosis; you will find none. Munro was diagnosed about four months after she had started running to stay in shape and relieve stress.

''I thought I had a pinched nerve,'' she said. 'I started feeling a tingling in my foot, and it lasted for about three days. And every time I ran, it felt like my foot was asleep. . . . Then, all of a sudden, my lower leg from my knee to my foot was asleep. I said, `What is going on?' ''

When a neurologist delivered the bad news, ``I dove into the Internet to find out what I could do. . . . I found a site of a man . . . who had been in a wheelchair for two years. He started eating healthy and exercising . . . and the more he did it, the healthier he got. And that was my inspiration.''

Munro became a certified spinning instructor three months after her diagnosis. She teaches weight aerobics, too. And she continues to run, farther and faster, leaning forward to mimic the elite Ethiopians' running posture.

''As I kept running, the symptoms went away faster,'' Munro said. ''The running really helped.'' So did changing her diet. She now piles on veggies and avoids red meat, soda and chocolate. She takes no medication and sees her neurologist only once a year.

''The day after I ran the half-marathon last year, my calves were killing me because I ran it so fast,'' Munro said. 'I went to see my neurologist, and I could barely walk. He goes, `You're not supposed to come in here and tell me you can't walk because you ran a half-marathon.' . . . He says I'm as healthy as I am because of the running. . . . I love feeling the sweat pour down my face. I love feeling my wet T-shirt when I'm done, knowing I had a really good workout. And knowing I can do it.''