Exercise is best taken in intervals lasting no more than 30 seconds.

Short intensive bursts of activity are healthier than pounding the pavements or toiling at a gymnasium treadmill.

This is my kind of scientific discovery. Our thanks for bringing the good news that less physical activity is worth more go to James Timmons who pursued the topic as professor of sport and exercise science at Heriot-Watt University.

It's called high intensity interval training or HIIT. It involves four half-minute sessions of maximum effort interspersed with a minute's rest. Do this at least twice a week.

To avoid high anxiety, I will commence my high intensity at 15 seconds rather than half a minute. Better safe than sorry.

You will want to know the science behind all this. Prof Timmons and his colleagues say short, sharp bursts of activity are better at burning off fat than longer exercise routines. Glucose is moved from the blood into muscle tissue where it is burned off as energy rather than converted to fat. HIIT produces hormones which may also subdue appetite.

The 30-second bursts of activity can be done on an exercise bike or presumably on a real bike. Or by running upstairs or jogging vigorously on the spot.

Me, I intend to locate myself at a strategic distance from the bus stop to facilitate a mad 30-second dash for the number 66. Indoors, I will run on the spot whilst clutching the remote control in search of a Danish TV series. (It surely will not be long before we have a Freeview channel devoted entirely to programmes from Denmark. Maybe called Dave Streaky Bacon. But I digress.)

Highly recommended would be the childhood game of Ring, Bang, Skoosh. A bit embarrassing, mind you, for adults caught ringing a neighbour's doorbell and running away. Especially when you get an ASBO for your trouble.

You could try press-ups. Or, to make the exercise more interesting, a touch of the conjugals. Four half-minute sessions each interspersed with a minute's rest? That'll do nicely.

Try skipping. Skip a meal. Run away quickly from the fridge.

Those of us with auld-timer's syndrome can exercise by climbing the staircase four times because we have forgot whether we are going up the stairs or down.