This is a 4 minutes training method whereby you will perform a exercise  for 20sec and rest 10sec, repeat this the whole 4min. When 2 exercises have been mentioned you will alternate between the 2 exercises e.g. Squats for the 1st 20sec rest for 10sec then sit ups for the next 20sec rest 10sec and then you repeat this for 4 minutes

Quick feet VS High Knees
1Min Rest
Superman VS Hollow Hold
1Min Rest
Mountain Climbers VS Hip Thrusters
2Min Rest

Up/Down Squats
45sec On 15sec Off
4 Rounds

Death By Burpees ( Till Failure)
Minute 1 = 1 Burpee
Minute 2 = 2 Burpees
Minute 3= 3 Burpees
Minute 4 =4 Burpees
Minute 5 = 5 Burpees
Minute 6 = 6 Burpees

For every minute you do a burpee, when you get to 10 minutes you do 10 burpees in that minute then rest the left over seconds. Minute 1 you do 1 burpee then rest the rest of the time.