anchor: training for her first marathon, tracy evangelos worried about cramps slowing her down. >> i particularly get a lot in my feet. reporter: diagnosed with multiple sclerosis nine years ago, tracy didn't need an extra challenge. she looked for a solution, and found hotshot, a small spicy drink designed specifically to treat muscle cramps. >> you feel that sigh of relief. and it's like oh, it's gone away. bruce bean developed the recipe with his friend, nobel prize winner dr. rod mackinnon. >> hot pepper, radishes, wasabi, a whole list of things. reporter: the spicy flavors target cramps at the source. >> scientifically, we always thought it started in the muscle. now we know it starts in the nerve and the way to treat it is through the nervous system. reporter: that discovery, a total turnaround from what doctors learn in medical school, and how trainers usually treat helpless athletes in agony on >> it's actually like a mini-seizure of the neuron that controls the muscle. reporter: those neurons have receptors, and the scientists discovered how certain spices can overload those