Brave an ice bath like Andy Murray

Try imagining the most painful thing you have ever done to your body. Now double the level of discomfort and you have the effects of an ice bath.

Andy Murray's run to the quarter-finals at Wimbledon, where he takes on Juan Carlos Ferrero today, has been assisted by regular dips in the cubes normally used to cool your gin and tonic.

One entry he posted on Twitter last Friday read: "Taken me four minutes to type this from ice bath, it is so cold."

So why exactly is the world's third best tennis player putting himself through this much torture? In simple terms, it's about helping the muscles, tendons and bones recover from their workout.

During exercise muscles suffer small fibre tears that cause small amounts of internal bleeding. When you get into an ice bath (for between five and 10 minutes), the cold causes the vessels to constrict and the blood to flow out of your limbs.

When you step out of the bath, and your body warms up, blood flows back and this invigorates the muscles with oxygen, helping the cells to repair themselves better.

So does it work? A former Great Britain middle-distance runner introduced me to the principle in the early 1990s at the same time that Paula Radcliffe revealed she used the treatment after exercise.

I have now practised the treatment while training for five London Marathons and the results are impressive, even if the process is enough to reduce you to a shivering wreck.

It is quite simple to set one up in your back garden. First, take one of those unsightly wheelie bins that the council kindly provide and part-fill it with cold water - ensuring first, of course, that it is clear of rubbish.

Next, stand inside the bin and have a friend fill it with ice - around four bags, which can be bought from any supermarket - up to your waist.