You must complete each set consecutively before moving onto the next
You must do 5 consecutive double unders without breaking before you can move to 10 double unders. You must do 10 consecutive double unders before you move to 15 double unders etc. You will start over on the set you were attempting if you do not get the desired number consecutively. If you are on set 25 and trip on 23 double unders…you will start over and try for 25 again and continue this until you either get 25 consecutive double unders or the time runs out.