Understanding the FITT principle for endurance athletes

• Frequency 
• Intensity
• Type
• Time

The four elements of FITT can be used to guide the training of anyone from a total beginner to elite athletes. Here's how.

Frequency: How often you train (frequency) is important. Too often, and you leave yourself unable to recover properly and become more prone to injury, fatigue and lethargy. Too infrequently and you just won't progress optimally. You'll be wasting valuable time. The correct frequency is key.

For endurance athletes in sports like triathlon and its three component sports, we apply frequency to aerobic type training. The minimum I would suggest is three sessions over a week, and this would only be for highly stressed individuals or anyone working around imbalances. Five or six sessions a week is more like it, particularly in multi-sport, where we have so many different things to train for! For most general athletes (even high level club athletes), there is little to be gained from training more frequently than six times a week. In fact, it may lead to injury.

For intermediate triathletes, I am likely to recommend two sessions per week of swim, bike and run (six sessions in total) although it may be optimal to double up on one day, leaving two full days free for recovery.

The only way I would build a high frequency of training (6+ sessions a week) into an athlete's programme is as part of a periodised approach. It could take the form of a more intense block of training, perhaps an over-reaching week, and would be followed by a deload period.

Remember, more is not always better, and the body needs time to rest if it is to perform well next time out!

Intensity: How much effort should you put into your next training session or a particular block of training? As with frequency, it's important to periodise intensity. All-out is good, but go hard 100% of the time and you risk over-training - or under-recovering as I prefer to call it.

Of course, intensity is one of the factors which overloads the body during training, leading to adaption and progression. So it's not good enough to just get through your sessions without an intensity goal.

For endurance athletes like you, I'd recommend using biofeedback and hard data to manage intensity. Heart rate monitors and perceived rate of exertion are good tools during the session, and recovery time and fatigue are great markers for afterwards.

Do you know your maximum heart rate? If you don't, I suggest you carry out a proper max HR test using hill sprints, bike/turbo sprints or similar (if you're not sure, ask me how). I also encourage some of my athletes to get into the habit of checking resting heart rate upon waking (ideally whilst still in bed). From here, you can calculate your heart rate ranges which are an excellent guideline for reaching (but not exceeding) intended intensity during training.

Higher intensity will be used for shorter sessions, including interval and tempo training, and lower intensity is the goal for longer, steadier rides and runs.

Type: Type of training for endurance athletes and triathletes is pretty simple. We are training for a sport, often for a key race, so our training needs to be sport specific. We can add in resistance training sessions, but our key work is in the water, on the bike and out running. For cross training and recovery sessions, I advise you select a type of training which still challenges the cardiovascular system to a degree, and uses the larger muscle groups: power walking, cycling, etc. 

Time: Finally, time: how long should training sessions last? For endurance athletes, this will be largely dictated by your goal event. An Ironman athlete will train for longer than someone training for a super-sprint triathlon. But some guidelines run through all training programmes, and here are some of the questions I'd consider:

• What is your existing fitness level?
• How well recovered are you?
• How often are you training this week, and how many sessions are you doing of this type of training?
• Can your fitness and stress levels cope with the volume?
• Are we doing speedwork, tempo training, or race-specific skills training or is the goal endurance?

As with intensity and frequency, I would cycle the volume of training by using periodisation.

FITT gives us a great basis on which to build a training programme. But for triathletes and endurance athletes, I strongly suggest you apply it alongside more in-depth principles of training, such as overload and adaptation, progression and periodisation.