Tabata Thrusters goes for 4 minutes - of those 4 minutes, you are moving for 2 minutes and 20 seconds.
That 4 minutes is better than a 15 minute exercise bike.
If he does this morning, lunch and night, it is already more cardio work than he was getting.
Add that 30 minute complex GHOSTY put up at lunch and it's the best bang for buck he could get.
First time I tried Tabata Thrusters, I decided to start light so I used 7.5kg DB in each hand.
4 minutes later I lay on the floor for 14 minutes.
Just remember the point is to get as many reps in the 20 second intervals as you possibly can.