When I cant get to the gym for what ever reason, I like to smash out a quick workout at home. My usual choice is a Tabata Training.
Tabata training is one of the most popular forms of high-intensity interval training (HIIT). It consists of eight rounds of ultra-high-intensity exercises in a specific 20-seconds-on, 10-seconds-off interval.
I use an app called workout timer, the does all the timing for you.
I normally make an all over body routine and put the app on and away I go.
Which is about a total of 4 minutes
I normally do an additional two rounds with different exercises.
* Please make sure you warm up before starting any exercise and stretch afterwards.