Fitness Why Sleep is the Only Supplement that Actually Works You can't out-train a bad diet, and you can't out-diet bad sleep. 2ndhand Editorial · 2023-12-10 · 5 min read Someone once told me... 'Sleep is a time machine to a better you.'The Fix Keep your room cool, dark, and leave the phone outside.What to avoid Caffeine after 2 PM is ruining your deep sleep phases.Pass it on: Sleep more, stress less.