Severe leg cramps typically are a sign of metabolic problems.

Things like the low mag, or say, very low blood sugars during fasting, and very problematic for diabetics esp.

They also may signal peripheral artery disease, more common in males.

But I have been thinking about Nide's...sudden problem.
Bob, are you still taking the Chantix? Or did you stop recently?

When a person's body is used to nicotine, all those receptors, work a certain way. Nicotine withdrawal can have global effects on the body, and many sites list muscle pain as one of many symptoms.

If you Google "nicotine withdrawal symptoms".. you can find various lists. So when one stops smoking there can be effects on the body far beyond psychological craving.

Chantix has muscle cramps listed also as side effects.

So it might be that Nide's mega cramp episode is related to his lifestyle change. Add the stress of the longer walking, in the cold, etc, and several things may have added up to the leg cramp scenario.