Frustrated runner

Since stretching and warming up helped during your run, I'd have a PT or running mechanics specialist look at the muscle tightness of that leg vs the one not giving you cramps and shin pain.

Try stretching your calves every hour for 30+ seconds. Use a reminder app if you forget to do it hourly. Post an update in a few days.

My first thought would be the shoe change...

I'll never respond to one of these posts without first highly recommending a specialist (and/or eating more fiber) lol So, for this situation (which is similar to an issue I had back when training up for a marathon), I'd suggest consulting a foot doctor.

For me, the culprit was a mix of flat feet/no arches which affected my stride and the slightest hip misalignment that was coming to the fore since I was weightlifting and running. All that to say, I recall being struck most by the podiatrists' comment that an issue in your leg (or lower back) doesn't necessarily stem from the place where you're having pain.

If you’re talking about a sore muscle pain along the inside length of your shin, that’s what I know as shin splints. I’ve had my share of them over my 25 years of running. They usually crop up when I’m doing too much too soon, or sometimes with a different foot strike, like going on the treadmill after mostly outdoor running. Or possibly from a change in shoes. If you don’t think you’ve increased speed and/or distance too quickly, I’d recommend having your running stride checked out. A lot of dedicated running stores can give great advice regarding gait, foot strike, arch support, etc. I used to have flat arches and needed shoes with a strong arch support, like Brooks Ariel. Now, after years of walking barefoot on my treadmill desk, I actually have arches, and can wear lighter, “neutral” shoes. Good luck!

ETA: I also get these when my shoes go flat, but if you have a new pair then I assume that’s not it (unless the new ones don’t cushion as much as the old). Also, from my experience, you can’t just try different things and see if you feel the shin splints again—they have to heal first before you can test out new things to figure it out.

It does sound like the shoe change. Also keep in mind that a professional shoe fitting will analyze your gait, measure your shoe and suggest the shoe or shoes that match up. Meaning they know which shoes are good for which levels of pronation, which shoes have wide and/or high toe-boxes, narrow heels, etc. They will ask you about your preference for cushioning. They will suggest something (or several things) that match. It doesn’t mean that every one is in right for you.

FWIW-I have a wide (short) foot, PF, a neuroma, and a weird sort of semi-overpronation. The only shoes that work for me are a wide-width Saucony (that is pretty wide to begin with) with an aftermarket insert. I wear a New Balance model for shorter runs. I wear Altra for trails. Every fitting I get suggests Brooks (which have consistently been the worst for me), with New Balance as a distant second (although not the New Balance shoe that I do use for shorter runs).

So my point is just that there are a lot of shoes out there and a professional fitting can get you started and is better than a wild stab in the dark and/or picking by color or by what some random person happens to like. But it doesn’t mean it’s a perfect match every time.