Let me intrude here...(Sportlegs)
I am part of that testosterone brigade that seems to not be discussing the claims of SportLegs, and since I find a discussion here, and not much anywhere else, please allow me to chime in. My wrench swears to me that his wife was greatly helped by Sportlegs, and I examined the label and saw that I could buy the Calcium Lactate in powder form for about 10 bucks a bottle. This translates into MANY bottles of SportLegs. A teaspoon of this is close to the Sportlegs dose (1.462g @ each 50 lbs = 5.8g for me, I am 175 lbs, the teaspoon translates to about 4.6g). I have been adding this to any drink about an hour before any long ride (more than an hour).
I am also diabetic and have had humongous cramps while trying to examine my feet after a long ride, a routine which always requires me to bend down or lie down and pull upper legs toward my chest. I have found that in all long rides since starting this lactate addition (3 so far) I have had cramps only one time, and I attribute this to lying down with an ice pack on my knee instead of stretching after a 77-mile ride, as I was supposed to be doing. I have a century ride (I hope) this weekend and so another test of this is impending.
I do suspect that the calcium lactate made the difference; I stopped taking calcium citrate, potassium, or magnesium supplements during this period to help my test case. Lactate from magnesium would presumably be the same.
I make my own Sports Drink with Smart Water, Nuun tabs, and maltodextrine and fructose, and use this during my rides.
The Tums alternative did not work for me, but the lactate appears to have done so.
Just my two cents, but I agree with other posts that Sportlegs is horribly overpriced.