Micro workouts are all the talk right now: researchers have found that effective physical activity in small doses provides great health benefits—both for the individual and society as a whole.

Micro workouts “have become very popular,” says NTNU exercise physiologist Ulrik Wisløff.

The news that we can get by with just a few minutes of exercise each day has spread like wildfire in Norway after Wisløff and his research colleague Atefe R. Tari published the book “Mikrotrening—7 uker som booster kondis og styrke” (Micro workouts—7 weeks to boost fitness and strength).

There is an overwhelming amount of exercise advice in the media, both from fitness gurus and academic communities. So why should people listen to Wisløff specifically?

“Because we have done a lot of research on this—almost 20 years’ worth,” said Wisløff.

Get the heart rate going

It all began with a study based on HUNT, a unique database of questionnaire data, clinical measurements and samples from one Norwegian county’s inhabitants since 1984. In 2006, the HUNT Study provided data on 60,000 men and women which showed that 30 minutes of high-intensity cardiovascular exercise per week reduced the risk of premature mortality from cardiovascular disease by half, compared with individuals who exercised much more but at a moderate intensity.

The key word is high intensity—you can get by with just a few minutes, as long as your heart rate is high enough. Several large population studies in the years that followed show the same thing.

“The research showed that bouts of high-intensity exercise have at least the same effect as long periods of moderate-intensity exercise. Then there was a 2022 study from the U.K. that showed that 4.5 minutes per day of high-intensity exercise, one to two days a week, was more than enough,” said Wisløff.

From zero to a little has an effect

An article recently published in Nature Medicine argues that there is enough research to conclude that even small amounts of physical activity provide significant health benefits. Here too, the authors emphasized that the intensity of the exercise—in other words, a high heart rate—is crucial.

“The article—as do we—encourages doctors to provide inactive patients with advice on how to incorporate small doses of activity into their daily lives, even if it is less than what health authorities currently recommend. We believe it is motivating for people to know that even the small amount they manage to do, going from zero to a little, actually has an impact on their health,” said Tari.

Four to five minutes a day doesn’t sound like much, and don’t you need to warm up first? And it probably takes a few minutes before the heart rate is high enough for it to count, right?

“We have included a short warm-up phase in all interval training sessions. But remember, we are not talking about ‘all-out’ exercise here. You should be able to talk, but you shouldn’t be able to sing.”

Your heart needs exercise

The point about high heart rate is that cardiovascular exercise primarily focuses on strengthening the heart, and strengthening the heart reduces the risk of cardiovascular disease. This group of diseases includes atherosclerosis, blood clots, heart attacks and strokes, to name but a few.

“The heart is the engine that pumps blood around the body. This engine must be exercised, and the only way to do so is by increasing your heart rate,” explained Wisløff.

But might it not seem a bit scary to put strain on the heart and increase its rate, especially if you have already had a heart attack?

“It may sound scary, but documented research tells us that not doing so is far more dangerous. We have changed the way heart rehabilitation is viewed,” said Wisløff.

High-intensity cardiovascular exercise is now an established part of rehabilitation after a heart attack.

More strength training

The concept of micro workouts is not just about cardiovascular exercise. The researchers emphasize that strength training is just as important.

“We need to raise more awareness about the importance of strength training. It is a paradox that strength training constitutes 85%–90% of the exercise undertaken by young people between the ages of 18 and 25, but only 30% of the exercise among older adults between the ages of 65 and 70. It should be the other way around,” said Tari.

In their book on micro workouts, the researchers have created an exercise program focused on strengthening the core muscles. All the exercises can be done at home, and the only equipment needed is a resistance band.

“Strength training is something everyone needs throughout their lives. We see that young people, who often do a lot of strength training at the gym, still have weak core muscles. In the book, we focus on the large muscle groups that we rely on throughout our whole lives. This type of exercise needs to be introduced at a young age,” Tari said.

She believes it is important to convey that this training doesn’t require a lot of time and effort.

“It actually makes strength training even more motivating—you quickly notice results and can achieve a lot by doing just a little,” she said.

Weak muscles are expensive

The researchers say that a little bit of regular strength training can lead to significant savings for society.

“Fall injuries represent the greatest health care cost to society—so just think about how much money poor muscle strength costs society!”

Even though many people struggle with muscle aches and pains, these types of problems don’t necessarily make it difficult to start strength training.

“A common problem among adults is a lack of time to exercise, combined with various aches and pains. Such aches and pains are often caused by weakness in the back and shoulders. Musculoskeletal disorders are a major societal problem that can be prevented by strengthening the core muscles,” Tari said.

She said it’s not necessary to warm up before doing strength training that doesn’t involve heavy weights.

“We are of the opinion that extensive warm-ups are not necessary before strength training sessions. The reason is that none of the sessions involve heavy lifting or start with explosive movements that suddenly put strain on the muscles,” she said.

Bodyweight exercises such as squats, planks and push-ups serve as natural warm-up exercises, and you can start in a controlled manner by doing light squats before progressing to deeper ones.

If you have been sitting for a long time, have just woken up, or feel very stiff, it can be helpful to get your body going by doing some light movements before you start, such as arm circles, gentle hip rotations and similar exercises,” Tari said.

A lot is good, but a little is enough

The fact that the advice from the NTNU researchers differs from that of the Norwegian health authorities has garnered a lot of attention.

The recommendations from the health authorities are to be physically active for at least 150 to 300 minutes each week at a moderate intensity, such as brisk walking, or to be physically active for at least 75 to 150 minutes at a high intensity, such as jogging—or a combination thereof.

Wisløff and Tari believe that much less is actually sufficient.

“We do not disagree with the health authorities, but we feel that much of the research literature shows that a little bit of exercise is enough. Not to become world champions, but simply to maintain good health,” said Wisløff.

“This must be clearly communicated to everyone who is physically inactive and believes there is no point in starting unless they exercise as much as the recommendations suggest,” Tari added.

Micro workouts in practice

A cardio session can be as short as 10–15 minutes in total, with three minutes dedicated to warming up until you start sweating and get out of breath. This can include walking up a steep hill, jogging, or cycling.

You can then do six minutes of high-intensity exercise, pushing yourself to the point where you can only speak in short sentences. By the end of the interval, singing should not be possible. If you use a heart rate monitor, your pulse should be at 85%–90% of your maximum heart rate during the last three minutes.

You can also vary your workout by doing intervals, such as 17 seconds of high-intensity activity followed by 13 seconds of rest. This should be done continuously for a total of seven minutes. Alternatively, you can do 45 seconds of high-intensity activity followed by 15 seconds of rest, which should also be done continuously for seven minutes.

Next, you can spend a few minutes doing the same activity but at a lower intensity.

There is no problem doing both strength and cardio workouts on the same day. A good balance is to do strength training twice a week and cardio exercise two to three times a week. Each session can last 10–15 minutes.

Do exercises that target large muscle groups, including squats, lunges, push-ups and triceps dips. You can strengthen your core muscles by doing exercises like planks, side planks, Russian twists and butterfly sit-ups.