With the seven-minute-workout and quick exercise becoming increasingly popular, many are wondering how and whether or not these ‘fast workouts’ really work.

The workouts, which involve doing intense full-body exercises for short intervals, are popular among those who have busy schedules and full calendars, as they promise results with minimal time commitment.

The '7 Minute Workout' app, which been downloaded by over two million people and is the number one fitness app in 127 countries, suggests 12 short high-intensity body-weight exercises for just seven minutes per day can help people keep in shape.

The most recent fast fitness routine is the three-minute workout, which is based on a study that suggests a number of short intense workouts that last less than three minutes can burn 200 calories and kick up the metabolism throughout the day. 

The '3 Minute Workout' app has already had over 100,000 downloads and over 1,500 five-star ratings. 

However, whether this ideal scenario works for everyone is debatable. 

‘Short, hard workouts are proving to be a very efficient way to get results, but you've got to be prepared to push yourself harder than a normal workout,’ health and fitness expert, Amelia Phillips, told Daily Mail Australia. 

‘For an average sized person it would be pretty much impossible to burn 200 calories in just three minutes.’

Exercise physiologist, Dr Bill Sukala, says to achieve this kind of drastic result, people will have to be working at 100 per cent to the point they feel like throwing up.

‘The reality is, is that this kind of exercise is not sustainable for regular people as humans are pleasure seekers and pain avoiders,’ Dr Sukala told Daily Mail Australia.

‘Working at that level isn’t appropriate for everyone and if people are time poor they should be doing high intensity exercise, but they probably won’t be achieving that kind of result.'

Mrs Phillips says while people probably won’t see an immediate dramatic calorie burn, a short burst of high intensity exercise can boost the metabolism.

‘What you might experience is the 'calorie after burn' whereby your body's metabolism remains elevated after the workout which can lead to more calories being burned that day,’ Mrs Phillips said.

‘Some of the best exercises for maximum calorie burn in minimal time include running (especially sprints), skipping, burpees, jumping jacks, spider crawls and box jumps.’

People who lack time due to office jobs should try and exercise throughout the day rather than a short burst however, with Mr Sukala saying excessive sitting can lead to health risks, even if people are doing high intensity short workouts earlier in the day or at night.

‘When people exercise for a short amount of time but are then sitting down for 23 hours of the day, the health risks are increased significantly…those people are best off getting standing desks, or taking regular breaks and getting a drink or a tea or walking around,’ Dr Silkala said.

'In general people just need to remember the basics as it seems they are being waved aside for the gimmicks - do the key things like eat less, move more, don't smoke and get rest, it's as simple as that.'