Bootsie- MsP and Idream are right! It is usually electrolyte imbalance and dehydration. So drink some water, eat a banana, and if that doesn't help, I suggest a trip to the doctor for a check-up, and labwork if it has been awhile. Potassium can be over-done, so be careful. Too much is really not good either.... hope you feel better soon!
As for me, I had to literally talk myself into doing my intervals today...UGH! but I feel sooooo much better now that they are out of the way!
9/1= workout 1A (NROWL)- will walk extra at work tonight
9/2- 20 minute interval training walk/jog
, 30 min walking with dog