2 X Sit Ups, 2 X Push Ups in the 1st Minute
4 X Sit Ups, 4 X Push Ups in the 2nd Minute
6 X Sit Ups, 6 X Push Ups in the 3rd Minute
Etc, etc, until you fail to complete the push ups in the current minute. Once you fail to complete the push ups in the required minute, you will continue to complete the sit ups until you run out of time.