A fourteen week training regimen for a triathlon is all you really need. Any thing shorter, your body will not be ready, and anything longer is not necessary. For the first ten weeks you need to spend a minimum of three days a week, one for each sport, with specific training exercises and workout regimen designed for each sport. You can add a fourth day that centers on your weakest area. The last four weeks of sprint triathlon preparation will be practicing the transitions from one event to the next, called bricks training. The bike to running “brick” needs the most practice.