Run Fartlek

Friday Fartlek Run: Alternators

This session is great to improve speed for runners aiming for an event between 5km and 10km. It is perfect for road runners, trail runners, and triathletes alike.

Each week I will be posting the Friday Fartlek Run Sessions that you can do to enhance your running. Fartlek is a Swedish term that runners often use and it means speed-play. See a previous post about training intensity (levels) to know how hard to work.

This workout was devised and made popular by Matt Centrowitz Snr who coaches his son Matt Centrowitz Jnr the current Olympic 1,500m champion. Matt Snr was also a five-time US 5,000m champion.


  • 10min WU Level II;
  • 4-6x
    • 800m Level IV, 200m Level II RI;
    • 300m Level V, 300m Level II RI;
  • 10min CD Level II;
  • 10min Stretching

The Warm Up (WU) should be done at an intensity that is steady, but not overconsuming at Level II for ten minutes.

The main set is made up of two reps and their respective Rest Intervals (RI). Start off with an 800m rep at Level IV.  Follow this with a 200m jog at Level II for your Rest Interval (RI). The next rep is 300m long and is done at Level V,.  Follow this with a 300m jog at Level II for your Rest Interval (RI). This now concludes the first set. Complete between four and six sets.

The Cool Down (CD) is at a low intensity, jogging (Level II) for a minimum of ten minutes.

Finish with 10 minutes of stretching to assist with the recovery.

If you would like further advice feel free to contact me.

I am the Head Coach & Director of Qwik Kiwi – Endurance Sports Consultant.

I specialise in assisting first-timers and recreational athletes to achieve their sporting goals. I can be contacted at and 021 348 729.

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Download the Garmin (.FIT) files for this workout for FREE

If you enjoyed this workout, here is a similar session I published 12 months ago.

Friday Fartlek Run – Half Marathon Tempo Progression B

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