Heddiw, fe fyddwch chi'n rhedeg mor bell ac y gallwch am 15 munud, cerdded am 1 munud ac ailadrodd unwaith eto. Mi fyddwch chi'n rhedeg am 5 munud ar y diwedd cyn gorffen. Ydych chi'n barod? Today, you'll run as far as you can for 15 minutes, walk for 1 minute and repeat once more. To finish, you'll run for an extra 5 minutes. Are you ready?