(originally published in The Telegraph Magazine 8th March 2008)
FITNESS Interval training means exercising at an intense level for short bursts, broken up with regular rests. By doing this, your muscles achieve energy depletion and ‘oxygen debt’ more quickly, so your heart and lungs work hard to provide replacement oxygen and nutrients while you rest. This helps your muscles become more e!cient at using the energy provided, so your heart doesn’t have to work as hard to pump blood around the body when resting,. Try running fast for one minute and then walking for one minute (or longer, if needed). You can apply the principle to any piece of kit – treadmill, rower, cross trainer or bike. It’s important to work hard enough in your ‘intense’ phase to push your body to improve its e!ciency. By doing it correctly, you will burn more calories and, over time, you will see an improvement in your recovery and therefore your cardiovascular health.