For this kind of workout you need 3 exercises, choose exercises that are demanding but not beyond your level of fitness or expertise. The last thing you want is to compromise your safety and risk getting injured. Isolation exercises won’t be effective for this type of workout so don’t choose exercises like bicep curls or lateral raises. What you could do is incorporate isolation exercises into another exercise to make them more demanding e.g. lunge with a bicep curl or a squat with a lateral raise.

When you have chosen 3 exercises put them in order of hardest first to less demanding last.

Start the workout with the hardest exercise first. Just do one exercise at a time, there’s no need to count reps, perform the exercise for 20 seconds and rest 10 seconds before repeating another 7 times so it gives you 4 minutes worth of 20 seconds exercise followed by 10 seconds rest.

When you have done the first exercise using the approach above move on to the second most challenging exercise on your list and do the same, 20 seconds followed by 10 seconds rest x 8 (4 minutes). Then finally do the third exercise and do the same 20 seconds on and 10 seconds off protocol for 8 rounds like you did for the first 2 exercises.

This kind of workout will make you sweaty and boost your metabolism as long as you choose demanding exercises and resistance that challenge you.