Fartlek was developed by the Swedish coach Gösta Holmer back in the 1930’s. Runners initially used it, but many other endurance sports have adopted it as a part of their training. For example, if you read in Wikipedia, you will find a description that sounds like this:
“Fartlek, which means ‘speed play’ in Swedish, is a form of conditioning that puts stress mainly on the aerobic energy system due to the continuous nature of this exercise. The difference between this type of training and continuous training is that the intensity or speed of the exercise varies, meaning that aerobic and anaerobic systems can be put under stress. Most Fartlek sessions last a minimum of 45 minutes and can vary from aerobic walking to anaerobic sprinting.”
Fartlek is unorganized interval training
As you can see, Fartlek is a combination of many different intervals with both aerobic and anaerobic events. These intervals are not organized as the intervals you know from regular interval training. Instead, you use the terrain, the winds, or your friends to get inspired to make attacks of various lengths. The motivating factor in Fartlek is the best thing about this kind of cycling training.
I know many riders that do this training without knowing that there is a name for it. They do it because it is great fun, effective, and similar to races.
Fartlek with a theme
There are many ways you can use Fartlek. For example, you can decide to give your sessions a tactical theme: E.g., Try to make an explosive, surprising attack when the group slows down.
Or maybe you could give it a technical theme:
E.g., Ride fast in areas with many sharp curves.
Or you can make a personal theme with something you want to improve. I always recommend that riders train towards what they are aiming for. High specificity is needed to achieve the proper adaptations to your training. So, it makes sense to design Fartlek sessions that reflect your goals.
Difficult to reproduce training sessions
If you have a period where your motivation for regular interval training is low or non-existing, then try Fartlek. It is fun, and often you will experience that you get an excellent workout.
The only problem is that it is impossible to reproduce a good training session. Simply because the amount of aerobic and anaerobic training you get is based on how spontaneous you (or your friends) are. Thus, the outcome will vary from time to time. If you have a power meter, you can compare the data files from different training sessions, but you can only use these files for analyses. It is impossible to reproduce a previous training session.
Make a finish time or line
You have to ride on feeling, just like you do in races. But as a thumb of rule, set a time for the duration of the Fartlek, so you will know when it is time to make the session harder or be more passive. I have tried to ride these sessions without a defined finish time. Believe me when I say that Fartlek without time or finish line is enjoyable only for the strongest rider who can punish his so-called friends.
My experience with fartlek training is that it works best when you have a group of motivated riders who understand the rules of this training type. Then you will have a great time racing with the activity that will bring you all the physiological benefits you would have achieved in a criterium.
Enjoy your Fartlek training session
I can only recommend all riders to try Fartlek if they haven’t tried it yet. Although it is an unorganized way to train compared to most of the other advice I give here on training4cyclists.com, it is still a very effective and inspiring way to get a good workout for your aerobic and anaerobic systems.