Oh, I can really empathize. I planned on 2 2-hour rides this weekend. Local viruses had a different opinion. I spent the weekend in bed, dizzy, coughing and piling tissues to the ceiling. It sucks. Plus the weather here was 65-70 and sunny. I am just turning the corner, so its; start out slow. I rode a stationary bike at the gym for 30 minutes. It felt good but I could tell I wasn't really up to speed. My heart rate was racing, yet my legs were just in average effort mode. As above - listen to your body. Good thing I wasn't out on the road. Today I'll try spin. If it works, tomorrow the road. Good luck to you.