Too busy to exercise? All you need is 15 MINUTES a day – PT reveals how
15 minutes is all you need to get fit - according to PTs and the NHS. But just how easy is it to see results? We investigate...
JOE Wicks has made a fortune from advising people on how to get "Lean in 15".
But is it really possible to get fit and shed fat in such a short space of time? And if so, why do any of us bother going to gym classes that last up to an hour?
Well, the says that in order to stay healthy, adults aged between 19 and 64 should do at least 150 minutes of moderate - or 75 minutes of vigorous - aerobic activity and strength training a week.
That works out at 30 minutes a day of moderate exercise for five days a week - or 15 minutes of vigorous exercise on those five days.
Vigorous means high-intensity training (HIIT) - meaning that 15 minutes a day works, but only if you're going hard.
"The goal of 10-15 minutes of high-intensity training is to cause the greatest possible disturbance on muscle fibres in the shortest possible time, which in turn greatly increases heart rate, oxygen uptake as well as hormonal release," Zana Morris, founder of HIIT gym The Library, told The Sun.
"That means that you burn fat and build muscle faster. There's so much research that shows your body's metabolism goes up for anything between two and 48 hours after your session."
Zana explained that shorter workouts mean maximum recovery time between sessions too.
"Compare that to a longer session which can actually cause your body to start eating into muscle for fuel, which can ultimately lead to fat gain and a weaker body," she said.
And the science is there to back that claim up.
A 2016 study found that a ten-minute workout with just one-minute of high-intensity (in this case, sprinting), had the same benefits as 45 minutes of jogging.
A group of volunteers did a two-minute warm-up on an exercise bike, followed by a 20-second sprint and then a slow two-minute ride.
They repeated that sequence for a total of ten minutes, while another group rode steadily on their bikes for 45 minutes.
After 12 weeks, both groups showed a 20 per cent increase in cardiovascular endurance - proving that the shorter programme offers the same benefits for a tiny fraction of the time.
Another study published in the journal Medicine & Science in Sports & Exercise, found that men who did just 13 minutes of HIIT burned more calories per minute than those who did steady-state cardio for 40 minutes.
And, according to scientists from the European Society of Cardiology, working out for just 15 minutes a day can have the added benefit of actually increasing your lifespan.
They found that people who exercise at any level are less likely to die than those who do nothing, but that those who exercised at high levels for 15 minutes reduced their risk of death by 35 per cent compared to those who did so at a low level (22 per cent) or medium (28 per cent).
In other words, 15 minutes is all you need but you've got to be working at your maximum output with little-to-no break in between reps or sprints.
The idea is to keep your heart rate up for the entire window of time, so that you burn more fat even after you've finished (something called "afterburn").
Because you only reap the benefits of HIIT workouts if you're giving 90-100 per cent of your overall capability, it should only be physically possible to go for a short amount of time.
"If you can go longer than 30 minutes, you weren't actually working hard enough," Rachel Vaziralli, creative manager of celeb gym group Equinox told .
Work hard for longer than that, and your body simply adjusts - meaning that you're forced to spend more time on trying to achieve the same results.
CHEMICAL REACTION How your HORMONES affect your work out from weight gain to sore muscles
Short, intense exercise enhances things like bone mineral density, cardiovascular function, muscle tone and fat loss.
There's no rule about what kind of exercise you should be doing during a 15-minute session; they can take many forms - from treadmill sprint intervals to boot camp circuits.
But one of the most effective is probably weight strength training.
Gyms like get their clients to lift heavy weights for 15 minutes, five days a week.
Sessions are split into shoulders and back, legs, and arms - with a five-minute core blast at the end of each.
The idea is that you lift your heaviest weight for six reps, lowering your weight after each set - there are three sets. You then go onto your next exercise, but there are never any more than four-five exercises per day.
"All strength training will help build muscle, however, for the absolutely best and most dramatic results, the higher the intensity, the better," Zana told us.
"The intensity is achieved through the weight lifted and the speed of the entire workout, i.e the maximum weight for you, with no or minimal resting, while still maintaining as perfect a form as possible throughout."
In order to get lean, you need to re-jig your body composition by increasing your lean muscle mass.
The higher your muscle mass rises, the lower your body face percentage drops.
All strength training will help build muscle, however, for the absolutely best and most dramatic results, the higher the intensity, the better
Zana Morris, founder of gym The Library
The more muscle you have, the more calories your body burns.
But there are caveats we need to remember with 15-minute workouts.
As we say, they only work if you put your all into them (so you leave feeling like you literally can't do any more), and - crucially - if you eat right.
The saying goes that you can't out-train a bad diet, and you definitely can't in just 15 minutes.
Zana Morris, founder of The Library and Clock gyms, told The Sun that she puts her clients on high-fat diets, which she says compliment the workouts.
"The most effective formula for getting rid of belly fat is combining high-intensity training (e.g sprinting or whole body weighted exercises like squats) with a very low carb (sugar) and high fat plan."
Her plans are high protein, high fat and very, very low sugar.
Joe Wicks' HIIT workouts (these days, he seems to advise spending 20 rather than 15 minutes exercising...) are designed to run alongside his meal plans.
And you can bet your bottom dollar that Joe Wicks probably works out for a lot longer than the regimes he creates for clients.
You're not going to become as lean or chiselled as the fitness models you see on Instagram or magazine covers with such short blasts.
Short workouts are far better than no work out at all, but many trainers and influencers workout for hours every day chipping away at their abs and pecs.
But 15 minutes is enough to stay fit and make gains, so long as you're honest with your diet and your set up; the time only starts the moment you actually start running/lifting/cycling - not when you're faffing around arranging equipment or warming up.
It's also worth saying that many people don't actually perform HIIT correctly, which can leave them open to injury.
Max Bridger, founder of LDN Muscle, previously told The Sun: “In general, HIIT isn’t performed correctly.
"It’s jumped on by so many ‘experts’, but it can mean anything from a circuit class to general interval training.
"The issue is simply that people are doing workouts that they're not conditioned for. There is no emphasis on flexibility, mobility or activation."
MORE ON FITNESS & EXERCISE
Everybody's got 15 minutes that they could work out in, it's just a case of how hard they're prepared to go in that space of time - and how knowledgeable they are about fitness to do it properly.
You might be better off starting with a PT or in a gym class and learning the correct techniques before going off to do it on your own.
That'll save you a lot of injury time in the long run.
Last week we revealed why saving your carbs until dinner time might be the key to burning more fat and sleeping better.