jump from Olympic distance to half-Ironman," says Maitland. "Many people make the mistake of not taking on enough food."Lyle Butler, a sub-10-hour age-group Ironman triathlete, advises pouring gels into small race-belt bottles. "I pour six gels into a

50-55 per cent of your calories from carbs you should half-fill your plate with vegetables, fruits and some whole grains.Sass says the rest should be made up as follows: 25-30 per cent from fats (olive oil, avocado and so on) and 15-20 per cent from

equal parts orange juice and water, plus a pinch of salt.Drink 100-200ml of an isotonic solution every 10-15 minutes; a standard 750ml bottle containing an isotonic drink should see most people through 50-75 minutes of training. You can have solid food

. For triathletes though, carbohydrate-rich foods are essential. New research shows that most people, including endurance athletes, easily meet their protein requirements and don't consciously need to eat more. You require around 1.2g to 1.4g of protein per kg

up to jogging at least some of the way on race day.Training helpThere's further reading in our Best Beginners' Index, Best Weight Loss Index, and Best Women's IndexI've never run before...the best way to start is a little jogging with walk breaks