EXERCISE SNACKING

Too busy to f it a solid 30 minutes of training into your day? Then go for bite-size chunks instead and join the time-poor who thrive on…

WE ALL know how important it is to do exercise and remain active. Yet a World Health Organisation study published on Wednesday suggested that a third of Britons aren’t getting the recommended 150 minutes of moderate exercise a week. I suspect the reality is much worse than that.

This study, like most others, is based on self-reporting, which is notoriously unreliable because they rely on people being both completely honest and having a meticulously accurate memory.

When the British Heart Foundation fitted people with devices that measured how much activity they did, it found less than six per cent hit the recommended levels. Whatever the truth, it is obvious most of us are not doing enough.

One excuse is lack of time. And it’s certainly true that it can be tricky to fit in a 30-minute exercise session five times a week.

Fortunately there’ s a new approach that might help. It’s called Exercise Snacking. Instead of doing the whole 30 minutes in one go, you do the same amount of exercise, but break it into smaller chunks, such as five minutes.

But can doing five minute bursts of moderate exercise really help? For this week’s BBC health show, Trust Me I’m A Doctor, we decided to find out.

MAKING A CHOICE

WE RECRUITED a group of volunteers who usually do very little exercise. People like Kath, who told me: ‘My activity levels are almost zero. I spend most of the day sitting at a desk in front of a computer.’

And there’s Debbie, who is worried about her health. ‘The last time I saw my doctor,’ she said, ‘ he told me I’m borderline diabetic.’

Becoming more active is great for all sorts of reasons, from helping you sleep better to improving your mood. But what we decided to measure was the impact of ‘exercise snacking’ on our volunteers’ blood fats and blood sugar levels. High levels of either put you at much greater risk of diabetes, heart disease and stroke.

Helping us set up and run this experiment were Dr Ian Lahart, an exercise physiologist from the University of Wolverhampton, and Dr James Brown, a specialist i n obesity and diabetes from Aston University.

Our volunteers came into the lab on three separate days. Each time they had the same lovely high-calorie breakfast, full of fat and carbs. Soon after breakfast they had blood tested and were then given a brief rest, before being put on a treadmill.

On one day they had to do a single block of 30 minutes walking at a brisk pace. Then more bloods tested before lunch, more bloods after lunch, then home. On another day they did six lots of five minutes on the treadmill, spread throughout a sevenhour day, with the same number of bloods taken. On the third day it was the same breakfast, lunch and bloods, but they were asked to hang around all day without doing any exercise.

After 30 minutes of continuous walking, their blood sugar and blood fats levels were, across the whole day, 40 per cent lower on average than on the day when they did no exercise at all.

But astonishingly, very similar results were seen in the ‘exercise snacking’ group - proof, it would seem, that you can get the same benefits from the little-and-often approach as you can from longer sessions.

But, mosre importantly, which was more enjoyable?

Kath said she liked getting it all over in one go.

Debbie, who was worried about developing diabetes, said she preferred the five-minute approach.

The great thing is they now have a choice.

MUSCLE MATTERS

THE muscles can benefit from exercise snacking, too. And that’s good news. From the age of 50, we lose about one per cent of our muscle mass every year, and our strength deteriorates at more than double that rate. If we don’t do something about it, this decline accelerates.

The best way to keep your muscles in good shape is resistance- or weight-training. But not everyone wants or is able to go to the gym. So the University of Bath have been testing the idea of ‘muscle snacking’.

They recently recruited 20 people between the ages of 65 and 80 – which is when muscle loss really kicks in – and divided them into two groups.

One was a muscle snacking group, who did short bursts of muscle-building exercises for a few minutes a day, the other was a control group, who did none. The subjects were given some very simple resistance exercises to do.

Each exercise had to be done as many times as they could in a minute, with a one-minute break before moving on to the next. They did each exercise twice.

The exercises were straightforward and only involved working against bodyweight.

They were the ‘ sit to stand’, which, as t he name i mplies, involves going from sitting on a chair to standing up, rising up on to the toes, marching briskly on the spot, extending the legs to straight while seated, and bending the leg back from the knee while standing.

Each session took about nine minutes, and they were asked to do this once in the morning and once in t he evening for four weeks.

It wasn’t arduous and many did it while watching the television. The researchers measured the subject’s power, strength and muscle size before and after doing their month of ‘muscle snacking’.

Despite the modest amount of exercise, the subjects saw a five per cent improvement in leg muscle strength and a two per cent increase in thigh muscle size.

So all in all, surprisingly significant changes.