I recently had one of those restless, no sleep, toss and turn nights from hell. The following morning, I still went to the gym as it wasn't my designated "rest day." After I got home, I put on a Tabata video to finish out my workout. After doing several pushups, I had a horrible back spasm that left me breathless and ready to cry. The reason I was upset was because I KNEW I should have taken the day off from exercising. I was drained both mentally and physically from lack of sleep. I simply chose not to listen to my body that morning. I didn't honor its needs and in turn, I didn't honor myself. There is a big difference between being lazy and not honoring your body. That difference is physical pain. Lazy is just...lazy. It's not painful. It's blah, dull, uninspired--makes you skip the gym. Lack of self honor hurts, whether it stems from an emotional or physical place (often they bleed together). My body was telling me loud and clear to rest. It finally forced the issue by dropping me to my knees. And guess what? I rested that day, got a good night of sleep and rested the following day as well. My back pain practically disappeared overnight and my next workout went perfectly fine.
Listen, listen and then listen some more to your body and honor what it's telling you.