Getting Started
The following sections describe how to train for triathlons for people with little or no triathlon experience, but the information is general enough that it can be used for almost any endurance sport. First things first. You need to gauge your current fitness level. Get a physical done by your physician. Ask yourself questions such as, "Do I work out regularly (3 or more times a week)?", "How far can I run/bike/row comfortably?", and "Do I have any medical conditions and/or injuries (e.g. asthma, strained ligaments) I should be aware of?" It is important to understand your current fitness level so that you can properly train and build onto your fitness without becoming injured.

You should determine your training heart rate ranges. First, you need to know your maximum heart rate (HRmax). You can estimate it using the following formulas:

------------------------------
Women: 226 - AGE = HRmax
------------------------------
Men: 220 - AGE = HRmax
------------------------------

Be aware that the above formulas only give estimates - your actual maximum heart rate may be higher or lower. There are tests to determine this, but the formulas give a good starting point.

Now you should find your resting heart rate (HRrest). This can be done by taking the average of your pulse for a few mornings after you wake up but while still in bed. From these two numbers you can determine your training heart rate ranges using the Karvonen method. The formula below is used to find your heart rate at a specific exertion level (from a range of 0 to 100%).

---------------------------------------------------------
(HRmax - HRrest) x (%effort) + (HRrest) = HR%effort
---------------------------------------------------------

Example:

HRmax = 220 - 26 = 194 (assuming a 26-year-old male)

HRrest = 45 (averaged over 7 consecutive mornings)

HR_80% = (194 - 45) x 0.80 + 45 = 163

Using the table below, you will know what your heart rate should be for certain types of workouts. In the beginning of your training, you'll mostly be training in the lower ranges. As the races get closer, you'll begin to explore the higher ranges of your heart rate.

----------------------------------------------
Level %effort Type of Training
==============================================
I 60% - 70% Overdistance, Endurance
----------------------------------------------
II 71% - 74% Endurance, Speedwork
----------------------------------------------
III 75% - 80% Endurance
----------------------------------------------
IV 81% - 90% Intervals
----------------------------------------------
V 91% - 100% Race
----------------------------------------------

A PLAN
Would you try to build a new home without a floorplan? You don't want to train without a plan, either. With a plan, you know exactly what you need to do to achieve your goals. The plan also prevents you from overtraining, which is discussed later, and allows you to fit training in around other activities and work. You may want to base your training on the amount of time you have to work out. Instead of trying to run 5 miles over your lunch hour, you may want to plan on running 40 minutes and not be late for your 1:00 meeting. Know how hard or easy you want to work out - use your heart rate to make yourself work harder or to keep yourself from working too hard.

Your plan doesn't need to be detailed, but it should be flexible for those unplanned for instances. Keep a training log with notes of what you did each day and how you felt. You should also write it down so you can compare notes later when you create a plan for next season. The following sections divide up the season into 5 parts: Base, Intensity, Peak, Race, and Recovery. After reading these sections, you should have a better idea of how to plan your season.

BASE BUILDING
Before you start "real" training, you'll want to strengthen and prepare your body for the stresses it will need to handle. This is done by doing easy training and slowly increasing the amount of time or distance spent swimming, biking, and running. It is not a time to see how fast you can run 5 miles or to be hammering in the biggest gears on your bike - these types of activities will most likely lead to injuries. This is because it takes longer to build up the strength of your ligaments, tendons, and muscles than the time it take to build up your aerobic capacity (i.e. lungs and heart). Base building will slowly but surely strengthen the muscles your need to do your chosen sport. Most of this training should be done in heart rate zones I and II. You should avoid training in zone III - in this zone you can build your endurance, but your body doesn't recover as well and can become depleted over a period of time if you continue to train at that level. Zones IV and V should be avoided until you have built up enough strength to handle the higher intensities.

You can prevent injury by following your plan. Depending on your current level of fitness, Base building can last anywhere from 6 weeks to 26 weeks. Follow the 10% rule - never increase the distance more than 10% above the maximum distance you have done in the last few weeks. For example, you rode your bike 100 miles last week, you wouldn't want to ride more than 110 miles this week. Base building workouts should seem easy, but may leave you tired. It is important to get enough rest and eat properly during this time. This may also be the time to put yourself on a regular schedule, fatigue can creep up unnoticed at any time.

Don't worry about speed or times yet, that is what the next periods are for. At the end of the Base period, you should be able to easily cover the distances you want to race. For example, if I wanted to do an Olympic distance triathlon such as the Sun-Times in Chicago, I should be able to swim 1 mile, bike 25 miles, and run 6 miles. Even if you can cover the distances now, you would still want to have some sort of Base period to prevent injuries later.

Plan on spending more time training in the sports you are weaker in. For example, if you already run 10K's, you'll probably want to devote more of your time to swimming and biking.

INTENSITY
Now that you have a Base of fitness, you're ready to add more Intensity to your workouts. Again, most of the training will be done with your heart rate in zones I and II, but now you should also be doing some speedwork and intervals where your heart rate goes into zone IV for short periods of time. The Intensity period should be no longer than your Base period.

To improve performance, push your body just above what it can do comfortably, and then allow it to recover. This translates into the hard/easy training method. If you do a hard workout one day, you probably want to take it easy the next day or even take the day off as rest. This will allow your body to recover and rebuild, and your muscles will become stronger as you adapt to the greater amounts of work.

Intensity can be achieved in different ways. You may want to try some fartlek work in the beginning - going hard for a few minutes when you feel like it. Or timed intervals - go hard for X number of minutes with Y number of minutes rest. Running or biking up hills is also a good way to achieve Intensity.

Group workouts are a great way to force yourself to work hard. Most people find they can train more regularly, at a faster pace, or at greater distances when they have other people to work out with. Try to find a club or group to train with when you want to do some higher intensity workouts. Most cities have a running club, and a bike shop that knows about the local rides. You might need to do some searching, but it is worth the effort.

Keep in mind that group workouts usually end up being a higher intensity than workouts done individually due to the competitive genes that seem to surface when groups of athletes get together to train. The group ride turns into a classic cycling road race with attacks and speed surges. The group run turns into a charge on the course record. If your want an easy workout or plan on training in heart rate zones I and II, you might be better off going out by yourself.

PEAKING
A few weeks before racing, you should reduce the amount of time and distance you are training at and concentrate on speed. You can do this by doing shorter, more intense workouts. Races used as practice are also useful. Do some short cycling time trials or running races, especially if you're having trouble motivating yourself to train - they can be fun and a good workout at the same time. You should be doing some training in heart rate zones I and II to keep your endurance, but a good portion of your training will be in heart rate zone IV.

The idea of peaking is that you have the endurance base necessary to finish the race, now is the time to work on performance.

RACING
Depending on the distance of the race, you need to take a few easy days or more to allow your body to be fully recovered and refueled for the race. Everyone is different - some people need weeks of rest, others can train right up to the day of the race and still perform well. A good sign of how rested you are is your morning heart rate. If it's higher than normal or your legs feel heavy and sluggish, you probably should train lightly or not at all in order to be prepared for the race. A good rule of thumb for longer distance races such as marathons or Ironman triathlons is to reduce your training time with two weeks to go before the event to about 70%, and with one week to go reduce your training even further to about 30% of your normal time.

If you're racing every weekend, you really don't need to worry about adding much Intensity to your workouts during the Racing season. Races can be your hard workout - train lightly to keep active and to keep your endurance between races. If you're not racing much, you need to keep doing some hard workouts or race simulation to keep in race-shape.
As far as what to do during an actual race, experience is the best factor. For specific help, pose your questions to triathletes in your area.