The book I read to research this post was Triathlon Training For Dummies by Deidre Pitney et al which is an excellent book which I bought from kindle. This book is primarily for novices looking to enter their first triathlon for which it recommends doing a sprint event which if you are a good athlete you can do in 1 1/2 hours although some take up to 4 hours to complete. It's also of interest to those looking to up the type of triathlon they do and the ironman events cover more than 140 miles and take around 15 hours to complete. Triathlons are a combination of running, cycling and swimming over various distances. In the ironman events they run a complete marathon in addition to the cycling and swimming. If you are looking at increasing your endurance at running you should try fartlek which was developed in Sweden and consists of a combination of walking briskly and running which stops your body coming to a complete stop when you are worn out and is done over considerable distances. Swimming training in a nutshell should consist of trying to cover a distance in as few strokes as possible and you should aim to do 25 m in 14-16 strokes, many novices do it in 18 or more. At the beginning ignore how long it takes you and work on that at a later stage. The cycling should be done at a reasonably low gear to prevent lactic acid build up in your legs that too should focus on covering a distance with as few revolutions of the pedals as possible and look at reducing your time later. With both swimming and cycling these are the biggest factors in speeding up your time. With diet you should focus on complex carbohydrates as opposed to simple ones as that helps endurance. A lot of people don't realise fat is a nutrient and you need a certain amount. Energy drinks are important and you should twice what it appears will cure your thirst although obviously this is supplemented with water. I really enjoyed this book and thought it makes a great blog although I have no plans to do a triathlon at least not for the time being. It does contain a lot of information on health and fitness in general.