By Monday, my brain was in full on rebellion because it had been7 days since I did any sort of exercise. It was 40 degrees and sunny when I got out of work so I went for a walk; just an easy walk, to see how my breathing would go. It felt beyond good to move and I slept like a log that night. This morning, I decided to get up and go back out as the temp was still 37 and the forecast for Wednesday and Thursday was showing rain and snow. I walked as fast as I could and threw in some jogging, which immediately brought on coughing spasms. So yeah, not quite ready to run it out but again it felt good to get out there.
What was fascinating about both those outings were the Garmin stats. VO2 Max is a measure of your maximum oxygen intake and output. The higher it is, generally the faster you are and the more endurance you have as a runner - elite runners have VO2 Max levels that other runners dream of. Mine is usually just average. Sometimes if I have to use my inhaler because I'm worried about the cold causing some asthma, it goes to the higher end of average but it never goes high.
On both those outings my VO2 Max was below normal - not surprised - but my heart rate actually got as high as when I run. So, even though I was much slower, I was actually working just as hard as running. This explain why coaches will often tell someone who is in recovery to work at a "perceived exertion" rate: depending on what is going on with your body, a walk can be just as hard as a run.