1. Determine your goals
There are a wide variety of triathlon distances to pick from, ranging from a Sprint (500-750 meter swim, 12-15 mile bike, 5k run) to an Iron distance (2.4 mile swim, 112 mile bike, 26.2 mile run) and the training for each is quite different. It is best to pick a distance that fits into the time commitment you have for the training.
2. Get the gear
To do triathlon, you do need appropriate swim gear (bathing suit, goggles, swim cap), bike gear (bike, helmet and a variety of accessories for maintenance and safety), and run gear (shoes, clothing). When you race, you will race in a “triathlon kit” which is made to be worn during the swim, bike and run. These things can get pricey pretty quickly—don’t be afraid to borrow some of the gear, or use that old mountain bike you have sitting in the garage for your first few races.
3. Find a group
Just about every community has a triathlon club that meets for weekly workouts swimming, biking and running. This is a great way to find some training partners and have fun while you get in your workouts.
4. Hire a coach
Learning one sport is hard enough, let alone trying to master three of them! Whether you find a coach informally at your local track workouts, or hire a one-on-one individual coach to help you through the training, having guidance from an experienced athlete in the field is a good idea. A coach is always great for seeing the bigger picture of training, and can be very helpful in scheduling rest and recovery, as well as the workouts.