Andy McIntyre (BOst, MSc) says his clinic is always fully booked in January.

The associate osteopath from The Livewell Clinic in London says the reason injuries tend to always flare up at the start of the year is simple.

Lack of time is often the main reason people don’t exercise regularly. But a type of interval workout recently popularized by actress Jessica Biel could be the solution – with research showing it can improve fitness faster than traditional, steady-pace workouts, such as jogging or cycling.

The Norwegian 4×4 workout has traditionally been used by athletes. It’s a form of high-intensity interval training (Hiit) that involves four-minute sets of very intense cardio exercise, followed by three minutes of very light exercise.

A typical training session includes a five-minute warm-up, four high-intensity intervals and a five-minute cool-down.

Related: There’s One Simple Trick to Boost The Health Benefits of Your Run

The 4×4 workout format follows the same format as other Hiit workouts, which alternate periods of high-intensity exercise with periods low-intensity exercise (or rest). Most Hiit workouts involve work intervals that last anything from ten seconds up to a couple of minutes. In contrast, the 4×4 workout employs four minute work periods, which raises your heart rate for longer than most Hiit protocols.

Decades of research has shown that regular Hiit workouts are often more effective than moderate-intensity workouts (such as running or cycling at a steady pace continuously) in improving cardiovascular fitness and other health outcomes (such as improving blood sugar and cholesterol levels). Hiit is even effective for improving health in adults with type 2 diabetes and cardiovascular disease.

Hiit also offers these benefits with less training time than traditional endurance training. A 2008 study showed that as few as six Hiit sessions over two weeks improved the muscles’ endurance capacity.

Several studies have also explored the benefits of the 4×4 protocol. For example, an eight-week study showed that the 4×4 workout produced greater aerobic fitness improvements than 45-minute moderate-intensity running sessions.

The reason the 4×4 workout specifically is so effective for improving cardiovascular fitness is because the four-minute intervals are intense enough to maximally challenge your heart and lungs while minimizing muscle fatigue. This helps improve your maximum oxygen uptake (or VO₂ max), which is the highest rate at which your body can take in, transport and use oxygen during intense exercise.

VO2 max is considered the gold standard measure of cardiovascular fitness. Higher VO₂ max values are associated with reduced risk of cardiovascular disease and premature death, and better overall health.

During a 4×4 workout you’ll spend roughly 16 minutes close to you maximum heart rate. This means that it can improve VO2 max more effectively than longer duration, moderate-intensity workouts.

Choosing the right workout

For people with busy schedules, Hiit is a time-efficient option because it offers the same health and fitness benefits as longer workouts with less training time. However, a 4×4 Hiit session still lasts between 35–40 minutes, which might be too long for some people.

For those seeking a shorter workout option, the 10×1 Hiit protocol is a suitable alternative as it can be completed in just 30 minutes – including warm-up and cool-down periods.

This involves doing ten one-minute intervals of intense exercise. Each minute of hard work is followed by a minute of light exercise or complete rest.

But while this protocol also improves VO₂ max, the shorter work periods must be performed at a much higher intensity than the four-minute intervals to challenge the cardiovascular system. This could make it difficult to pace yourself consistently during each interval.

Another Hiit workout option is sprint interval training. This involves exercising as hard as possible for ten to 20 seconds – followed by three minutes of recovery. These sprints can be done running, cycling or even rowing.

One 12-week study found that participants who performed three, 20-second sprints (followed by three-minute recovery periods) just three times a week significantly improved their cardiovascular fitness compared to those doing longer, steady-state workouts.

However, the 4×4 workout has been shown to produce better gains in aerobic fitness than sprint interval training.

Although most research shows that Hiit produces rapid health and fitness benefits, it’s difficult to know exactly how effective it is in the real world because most studies use specialized equipment and are supervised by researchers. As such, study results may not reflect what happens when people train on their own.

The very demanding nature of Hiit may also make it less enjoyable for some people – particularly those who aren’t used to intense exercise. This is important, because lower enjoyment is linked to poorer motivation and lower likelihood of sticking to a workout program.

Also, while Hiit is often promoted as exciting and time efficient, its novelty may wear off. What feels new and motivating at the start may become tiring or repetitive, especially without variety or support. As a result, some people may struggle to stick with a workout program after a few weeks.

Long-term fitness improvements come from training consistently. For that reason, it’s essential to choose a form of exercise that you enjoy.

If Hiit is less appealing to you than alternatives, such as steady jogging, cycling or weightlifting, it may be more effective to focus on workouts you’re more likely to stick with.

You don’t always have to push yourself to the limit to improve your health and fitness. Even consistent activity, such as accumulating around 7,000 steps a day, can still lead to meaningful physical and mental health benefits.

The Norwegian 4×4 protocol is just the latest popular Hiit workout. While it can offer many health and fitness benefits for you in a short period of time, it might not suit your needs – so be sure to pick a workout that best suits your goals and schedule.

Paul Hough, Lecturer Sport & Exercise Physiology , University of Westminster

This article is republished from The Conversation under a Creative Commons license. Read the original article.

[This is the latest installment of “Cobb Cuisine, Culture and Community” by Brian Benefield. Photo above by Brian Benefield] 

Staying fit is essential for many reasons, but let’s be honest: the most compelling one is that gravity is undefeated, and it is coming for all of us. Every squat, push-up, and awkward plank is essentially a strongly worded letter to the universe saying, “Not today.” Fitness is less about vanity and more about delaying the moment when you make a noise just standing up, and your family asks if they should call someone.

​First, staying fit helps you perform basic daily activities without turning them into dramatic events. A fit person bends down to tie their shoe and pops right back up. Another person bends down, pauses to reflect on life choices, and considers whether this shoe really needs to be tied. Fitness allows you to carry groceries in one trip, which is the truest measure of human success. Nothing humbles the soul like standing in a parking lot, staring at five bags of groceries, knowing that multiple trips are the sensible choice but refusing, because of pride.

​It is also crucial for long-term health, which sounds boring until you realize it’s really about avoiding awkward conversations with doctors. Doctors have an unsettling ability to look at you over their glasses and say things like, “We need to talk about your numbers.” Staying fit helps keep those numbers from becoming characters in a horror movie. No one wants cholesterol levels that could be used as a zip code. Exercise is basically bribing your heart to keep working properly by promising it a steady supply of oxygen and good intentions.

​My wife, Cecilie, and I do some form of exercise almost every day.  A bike ride in the often bipolar Atlanta weather, lifting weights at home, or a yoga session are all ways we stay functionally fit.  I will be turning the big 6-0 in a few years, and have found that strength training and yoga are increasingly important as I age and strive to stay strong and be more flexible. 

Cecilie has recently joined a new gym named LuLu Belle, an all-women’s boutique studio that offers small-group classes.  And it doesn’t hurt that it is located directly behind our house.  The owner, Shelly Thomas, believes that movement is a gift and not everyone has that privilege, so you must take advantage of it every single day.  

​Then there’s mental health. Exercise releases endorphins, which are tiny chemical messengers that whisper, “Everything is fine,” even when your inbox says otherwise. Staying fit turns mild inconveniences into manageable annoyances. Without exercise, spilling coffee can ruin your entire week. With exercise, you spill coffee and think, “This is a test, and I am emotionally strong.” Fitness doesn’t solve your problems, but it makes you less likely to scream at a toaster for burning your bread.

​Being in good shape also prepares you for unexpected moments of heroism, like chasing a runaway shopping cart before it dents a luxury SUV, or running to catch a flight when the gate agent says your name in that tone. Fit people hear the “Final boarding call” and jog calmly. Others may hear it and immediately start negotiating with destiny. Fitness gives you options like stairs. Fit people take the stairs for exercise. Some folks take the stairs because the elevator is broken and then file a formal complaint with the building.

​Being fit is about future you. Future you wants to travel, dance at weddings, and get out of a chair without a sound effect. Present you can make that happen by occasionally lifting something heavy or moving quickly for no reason. Fitness is a gift you give yourself that keeps on giving, mostly in the form of not needing help opening jars.

So yes, staying fit is important. Not because you want six-pack abs or Facebook likes, but because life is easier, funnier, and far less creaky when your body cooperates. And because one day, you’ll bend down, stand up effortlessly, and realize you’ve won a small but meaningful victory over gravity.