There are many relatively simple exercises which will help to build and develop your abdominal muscles. The starting position for the leg raise exercise is to lie down flat on your back on the floor. Then, while maintaining your legs as straight and outstretched as possible, raise them as high as you can or until they are vertical. Then very slowly lower your legs, while maintaining the outstretched position, until they are positioned just above the ground. It is advisable to start with anything up to 5 sets, before you lower completely onto the ground, and then look to increase up to around 15. The slower you do the exercise the more benefit to your abdominal muscles in the longer term – the more reps you do before lowering completely onto the ground the tighter your abs will feel as they are utilised to the full.