Days 17 & 18 in Polyphasic Sleep ChallengeApril 14, 2018 in Polyphasic Sleep Challenge tagged challenge / polyphasic sleep / sleep cycles by Armin Days 17 & 18 in Polyphasic Sleep Challenge Just 2 more days left and finally something has started to change. Watch the video and you will know more about i [adzbuzzer]Read more about the challenge itself.