Fartlek training offers a wide range of athletes an effective ad efficient form of endurance conditioning...
But just like every other form of sports training you must structure the session to meet the demands of your sport..
Fartlek training allows the athlete to run freely over varying distances and at varying speeds. A single session might consist of walking, cruising and sprinting. It might last for 20 minutes or 5 miles. The variations are unlimited. And that means some specific guidelines are in order so each session can be made as effective as possible.
If you've read some of the other articles on the site youll appreciate the importance of specificity. It's one the most important principles of training and one that is often overlooked.
In most fartlek training sessions intervals are kept relatively short and frequent. Anything too long simply becomes more like interval training. Each interval might range from 10 seconds up to 5 minutes for example.
For long distance runners (anything from 1500m to 10k) more structured sessions are beneficial. For example, you might run hard for 5 minutes (above race pace) then jog slowly for 1 minute to recover, and repeat that five or six times.
For multi-sprint sports such as soccer, basketball, racket sports, hockey and so on, shorter and more random intervals will be more appropriate. Consider tennis for example...
Plenty of stop-starting, movement patterns are unpredictable and very few rallies last longer than a minute at most.
A more effective fartlek training session then, would be a jog for 60 seconds, followed by a hard run for 30 seconds, followed by a jog for 30 seconds, followed by all-out sprint for 10 seconds, followed by a walk for 30 seconds. This would then be repeated for a total of 20-30 minutes.
In theory you could make the session up as you go along, throwing in some jogs, runs, sprints, backward running etc. as and when. But in practise this becomes hard for athletes to a) push themselves and b) measure progression over time.
Here are some example fartlek training sessions for different sports and events:
Example 1: Long Distance Events (10k, 5k, 3k, Cycling)
Example 2: Middle Distance Events (1500m, 3k, 5k)
Example 3: Astrand Fartlek (800m)
Example 4: Mulit-Sprint Sports (Soccer, basketball tennis etc.)
Fartlek training is good in the early pre-season. Its an ideal session to re-introduce athletes to more demanding endurance work after the summer or winter layoff. One or two sessions per week combined with interval training is ample.