Gym bunnies: Prepare to Splutter

When I was on a plane recently an advert in a US airline magazine caught my eye. It was for a piece of exercise equipment, priced at $14,000. The advert said that you only needed to use it for a few minutes a week. They offered a trial period and said they confident buyers would find it more effective than slogging away in the gym for hours.

I pondered on this and then parked it.

And then last night, Horizon "The Truth About Exercise"on BBC TV showed some new research and theory on exercise. It was mind boggling stuff.

For a start, 20% of the population will never benefit from exercise. It's their genetic bad luck. The journalist in the programme, Michael Mosley, (left) turned out to be just such a person. He is slim but has high levels of visceral fat, the "invisible" fat around our internal organs which can lead to conditions like diabetes. He was anxious to avoid the diabetes his father had, but like most of us, not too keen to exercise.

After eating a huge Scottish fried breakfast, the levels of fat in his blood shot up. But by walking for 90 minutes, briskly, the researchers showed that when he ate the same breakfast the next day, the walking activated an enzyme which reduced the amount of fat that he metabolized.

But 90 minutes of brisk walking is still tough if it's to be done daily. So the intepid Mosley had a go on a piece of equipment probably like the one I read about. He was told to cycle flat-out for three bursts of 20 seconds. And that was all that's needed, in a week. His glucose levels improved over time, although his cardio vascular levels didn't because his genetic make-up means he won't ever benefit from exercise.

Meanwhile the Mayo Clinic got him to wear some weird pants with electrodes that measured his normal activity during the day. As he was mostly sitting down at a desk, the result was not good. The next day he moved about more. Walked more often in the office. Used the stairs instead of the lift. And burnt an extra 500 calories without doing anything very strenuous.

Fascinating stuff. The main learning was that the blanket message of "start running or get in the gym" won't work for everyone. Exercise and diet needs to be very tailored. The gym industry obviously has a vested interest in making us want to exercise and buy shoes, equipment and gym memberships. We will hear a lot more about this new science. It's very exciting!