Hmmm....I think Erika might have insight into your problem. You do suffer from back issues, right? I wonder if the recumbent position is impinging a nerve.
I don't get parasthesia after I work out-several hours later I get severe leg spasms, even after stretching. But immediately after my work out, I feel like I used to before MS-energetic, a bit looser (except my legs-that is permanent).

Then as I cool down, the stiffness gets worse and I spend the afternoon lying back in my recliner stiff and exhausted. Everyone tells me to back off a bit on the strenuous nature of my workouts, but I have so much energy in the morning, and I have turned into a blob over the last year, that I am trying to eat less and work out more to lose the blob. So far, no luck

Maybe try an elliptical at a low level of resistance...that's my preferred mode of aerobic exercise. And don't forget to stretch out [U]after[U] you work out.