Exercise class

Published on Friday 21 March 2008 12:33

REVERSE CURL WITH SWISS BALL

LYING face-down on a soft surface, place your hands one on top of the other and rest your head on top of your hands. Have someone place a small Swiss ball just below your bottom and curl your feet up to hold it in place. While keeping your hips on the floor, press your heels into the ball and hold for ten seconds. Relax for a few seconds and repeat ten times, resting for a few seconds between each one.

Q What happens to my heart when I am exercising?

A When you exercise, your heart has to pump more blood to supply oxygen to your muscles. The volume of blood that your heart pumps in a minute depends on the heart rate (beats per minute) and the stroke volume (the amount of blood pumped by each ventricle of your heart with each beat).

When you exercise, your heart beats faster and contracts more forcefully, increasing the stroke volume. During vigorous exercise, the return of blood from your veins to your heart increases, causing the ventricles of your heart to fill more fully, stretching them a bit. Like other muscles, the heart contracts more forcefully if it is stretched a little before contraction, so the increase in returning blood also adds to the stroke volume by increasing the volume of blood in each ventricle and by causing the heart to beat more forcefully.

By training aerobically on a regular basis, you gradually increase the volume of blood your heart can pump in a minute. This change results from an increase in your heart's stroke volume, since the maximum heart rate isn't changed by training.

To keep your heart healthy, keep active and exercise regularly. Eat plenty of fruit and veg, drink lots of water and cut down on fatty foods and alcohol.

• David Calder is a personal trainer based in Edinburgh (07775 811 197, www.davidcalder.com)