The first day you...
  1. Lose a toenail
  2. Suffer from arm pit or weird body chaffing
  3. Cry during your run
  4. Cry after your run
  5. Wake up with the joints of an 80 year old
  6. Realize your resting heart rate is in the 40s
  7. Describe a 10+ mile run as "an easy run"
  8. Have your phone battery die on your run before you do
  9. Have to eat in the middle of your run before you can carry on with miles