Four-second workout: Short bursts of exercise key to lockdown fitness

By | May 12, 2020

If you were told that just four seconds of exercise, repeated five times throughout the day, might cancel out a sedentary lifestyle, would you try it?

new study from the University of Texas at Austin shows that short bursts of high-intensity interval training (HIIT) over just 160 seconds in a day, can not only burn fat, but can have a huge impact on our metabolic responses.

In the study, published in the Medicine & Science in Sports & Exercise journal, eight men and women showed 30pc lower blood levels of triglycerides – less fat in their blood, even after eating a high-fat meal – after cycling and sprinting for just four seconds.

According to the Irish Heart Foundation, the average Irish person will sit for 7.3 hours a day. Factoring in that we are all now working from home, it is likely we are sitting even longer. As well as musculoskeletal injuries such as back pain and neck pain, prolonged periods of sitting can also contribute to deep vein thrombosis.

Professor Niall Moyna, head of the School of Health and Human Performance in DCU, says that any type of exercise is good, whether it’s four seconds or four minutes, but that this recent Texas study could be the key to cracking health and fitness during lockdown.

“We are not genetically programmed to sit for eight to 10 hours a day,” says Professor Moyna.

“If you run up a flight of stairs, blood flows through your blood vessels much more rapidly, your blood vessels sense that, and for the next two or three hours they modify and become very healthy. Whereas if you sit for a long period of time, it’s like a river, with very little flow and the blood vessels maladapt.

“If you’re at home and you haven’t been doing a lot of exercise – you’re very busy during the day with work or family – this study indicates that if you get up for four seconds every hour and sprint up the stairs, you’re going to benefit.”

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One woman who knows the benefits short bursts of exercise has on your overall wellbeing is Andrea Bracken, a personal trainer in south Dublin.

Having never set foot in a gym until she was 39, Andrea credits HIIT workouts with making her “fitter and healthier in my 40s than I was when I was in my 20s”.

“HIIT is a very different type of workout to cardio or resistance training,” says Andrea. “You’re working in intervals in relatively short sets to get your heart rate up. On a scale of one to 10, if you’re going for a light walk, your heart rate might be at a three. If you’re going for an all-out sprint, you would be at a 10. During a HIIT workout, you’re looking to be around the eight mark, to really get your heart rate up there.

“But because that’s quite a taxing thing to do, we keep the working sets short. You should be going for really explosive working sets and then taking short recoveries. No HIIT class should really be more than 30 minutes.”

Andrea switches it up from plyometrics, such as jumping jacks, squat jumps, or lateral jumps, to mountain climbers, knee jumps, plank burpees to more static movements like squats with your feet planted. She also incorporates a lot of core work, engaging the lower back, abs and glutes. All of these can be done at home, without equipment.

“There are different ways to do it, and it depends where you are in your fitness journey. You can do different ratios so your working sets and your resting sets can be 1:1, work for 30 seconds, rest for 30 seconds; 1:2, you go full out for 30 seconds, rest for 60 seconds.”

This type of training has a metabolic effect, says Andrea, which allows you to burn calories and pump oxygen around the body very quickly. “You are improving your cardiovascular fitness; your heart health, lung health, your muscle’s capacity to receive oxygen. And by doing that you’re expending energy and burning calories, so there is a fat-loss effect.”

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But HIIT alone won’t give you rock-hard Instagram-worthy abs, or make you lose those excess quarantine pounds.

“Wasting your time,” says Professor Moyna, bluntly. “If you eat a slice of pepperoni pizza, that’s a 50-minute cycle. I think an important message here, and particularly in this time, is that you can’t out-exercise a bad diet.

“It’s very easy at home, particularly when you add the sedentary lifestyle that many of us are engaging in now, to consume excess calories.

“To lose weight, a calorie deficit is far more important than exercise. But to maintain weight loss, that’s where exercise is very important. You’d have to do more than four seconds up the stairs, because that’ll probably only burn 10 calories. But HIIT is beneficial from a cardiovascular, muscular and fitness perspective. There is no magic bullet for weight loss.”

Andrea, unfortunately, agrees. “It’s all part of a bigger picture. You have to take the whole thing in totality,” which is why she combines her HIIT workouts with running, resistance training and yoga.

“The mental benefit of doing something like a HIIT workout should also be considered,” says Andrea. “It’s a complete endorphin rush for most people because it’s so high energy.”

And Andrea says lockdown is the perfect opportunity to take stock of our health and fitness, even if we’re busy homeschooling and working.

“I don’t see how we’ll ever have this time to concentrate on something again,” adds Andrea. “You’ve no commute, you’re not stuck in traffic, you’re bound to have 30 minutes now that you didn’t have when you were working in the office.

“I understand it can be difficult – I have two kids that I’m homeschooling, my husband is at home working full-time – but we always make time within the house each day for some form of exercise. For kids to see their parents taking care of themselves physically and mentally right now, there is no better time.”

Professor Moyna agrees. “This is the ideal time to say, ‘At this time every day as a family we’re going to start putting a routine into our day’. It does take effort, but the rewards are so great, both physically and mentally,” he says.

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“Getting out for that 20-minute walk, or deciding you’re going to jog every three minutes to get your HIIT into the middle of a walk. The benefits of exercise are contemporaneous, that is, it’s not a drug that you have to take every day to really get the benefits. We can’t take our exercise and store it away and take six weeks off.

“But any exercise is better than none. The more you do, the greater the health benefits you’re going to get.”

Tomorrow: Part 3 of our exercise series looks at the many benefits of yoga

Andrea Bracken’s HIIT SESSION

Do each exercise for 30secs on and 30secs rest, or if you are not a complete beginner, 40secs work and 20secs rest, depends on your level and stamina. The key is to work hard for the full set time to push yourself. One round would take 10 minutes and then you could do it a second and third time depending on your time to train.

It is important that people have correct form for exercises so a static move done right is far better than a plyometric move done wrong, which could cause injury. Always warm up and cool down before exercising too and it can be useful to use a timer app to set your workout times in advance so you don’t need to worry about checking times.

1 SQUAT or SQUAT Jump (as advanced move)


3 LATERAL LUNGES or LATERAL JUMPS (as the advanced move)

4 PUSH-UPS KNEES (or on the toes as advanced move)

5 JUMPING JACK or AIR JACK (as the advanced move)

6 BICYCLE CRUNCH (add leg extension for advanced core workout)




10 PLANK BURPEE or CHEST-TO-FLOOR BURPEE (as advanced move) – Health & Wellbeing RSS Feed