The FITT Principle

Chances are if you've read any exercise book you've heard of the FITT principle, but if you haven't, I will be defining the FITT principle and applying it to triathlon training in this post.  The FITT principle is an acronym for Frequency, Intensity, Time, and Type.  It's purpose is to identify single domains of exercise that can be changed in order to provide overload--the act of stressing the body in order to gain results.  Without proper overload we can't get faster.  Let's examine how to apply the FITT principle to triathlon training.

Frequency

This refers to how often you train in a given time period (workout frequency).  For example, a triathlete might be on a weekly schedule that includes 3 swims, 4 bikes, and 2 runs.  When beginning a training program, frequency should be the first domain of the FITT principle that is increased.  Doing more workouts for a shorter duration is much better than doing fewer workouts for a longer duration.  Get the body used to training and don't try to do too much in a single session.

Intensity

This refers to how hard the body is working.  You can increase intensity by increasing speed, distance, and resistance (i.e. hills).  Intensity should be the final domain that is increased in your training program.  Depending on the distance you are training for, you may not increase intensity at all.  You should probably have 2 or 3 months of steady training under your belt before actively increasing intensity.

Time

More commonly known as "duration" of exercise, but the word "time" fits better with the acronym.  This domain should be increased after frequency and before intensity.  Duration should gradually increase from the beginning of the training program until you decide to begin increasing intensity.  Duration should remain steady (or even decrease) during the period of intensity increase.  Knowing how long you should train during each workout at the beginning of a program is determined individually.  For example, you may start each run at 20-minutes and add 5-minutes each week.  Safest thing is to start conservatively and gauge how your body reacts.  Then you can make adjustments as needed.  The purpose of this domain is to gradually increase the aerobic base.  This will prepare you for the intensity period.

Type

This part of the FITT principle refers to the type or mode of training.  This part is somewhat predetermined for multisport athletes.  We know that we are going to swim, bike, run, and strength train; casual exercisers may do other types of workouts.  Changing the type of training is also called cross-training and is popular for endurance athletes in a single sport (marathon runners, road cyclists, open water swimmers, etc. will often train in a different discipline for some of their workouts).  For triathletes, the cross-training is automatically built in to the program.

That's the FITT principle in a nutshell.  Increasing any one of these domains will apply overload, which is what we want.  Just remember not to increase too much too soon and it's only necessary to increase a single domain at a time.