Norwegian researchers studying the modern man found that four minutes of rigorous exercise three times a week is enough to reform your neighborhood slacker.

Inactive men don’t have to spend endless hours in the gym to get healthy. New research from the Norwegian University of Science and Technology (NTNU) says that 12 minutes is all it takes.

Specifically, vigorous activity for four minutes three times a week is enough to improve a person’s maximal oxygen uptake (VO2max), which researchers say is a well-established measure of physical fitness.

The lead author of the study published in Plos ONE, Arnt Erik Tjønna, said this could be an easy way for people to incorporate exercise into their daily lives.

Tjønna and fellow researchers at NTNU’s KG Jebsen Centre of Exercise in Medicine in Trondheim recruited 24 overweight men to undergo 10 weeks of training. Thirteen subjects underwent high-intensity workouts for four minutes with three minutes of recovery, a method known as 4×4 training. The others only did one four-minute exercise session at a time. All subjects repeated the training three times a week.

After each session, researchers measured the health of all the participants. The surprising fact was those who only did one four-minute session at a time saw the greatest decrease in blood pressure in both systolic and diastolic measurements. Their VO2max increased by 10 percent, while those following the 4×4 method increased their VO2max by 13 percent.

“It has to be noted that the subjects were previously inactive, and the same effect on physical fitness cannot be expected in active individuals,” Tjønna said in a press release. “Nevertheless, since we know that more and more people are inactive and overweight, the kind of improvement in physical fitness that we saw in this study may provide a real boost for inactive people who are struggling to find the motivation to exercise.”

Researchers said that because the sample size was small, a larger study is needed to verify their findings.

Exercise experts at the Human Performance Institute recently developed a seven-minute workout using high-intensity circuit training, a method first used in 1953.

The exercise routine uses a person’s own body weight and involves, in quick succession, the following exercises: jumping jacks, wall sits, push-ups, abdominal crunches, step-ups onto a chair, squats, triceps dips on a chair, planks, running in place, lunges, push-ups and rotations, and side planks.

Learn more about the seven-minute workout.

If you are currently inactive, remember to talk with your doctor before starting any new exercise regimen.