Coach Ray

Training for Excellence, with Excellent Training

Fartlek Session
Run Sessions Triathlon Training

Friday Fartlek Run: Half Marathon Alternators

This session is great to improve speed for runners aiming for a Half Marathon (or even Marathon distance). 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 is often used by runners and it means speed-play. See a previous post about training intensity (levels) to know how hard to work.

This work out 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. It is an expansion of last weeks Fartlek Run.

Half Marathon Alternators

  • 10min WU Level II;
  • 4-6x
    • 1,600m Level IV, 400m Level II RI;
    • 600m Level V, 600m Level II RI;
  • 10min CD Level II;
  • 10min Stretching

The Warm Up (WU) should be done at an intensity that is steady, but not over consuming 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 1,600m rep at Level IV.  Follow this with a 400m jog at Level II for your Rest Interval (RI). The next rep is 600m long and is done at Level V.  Follow this with a 600m 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 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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If you enjoyed this workout, here is a similar session I published 12 months ago.

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Ray has competed in triathlons from sprint to ironman distance (both IM Taupo and Challenge Wanaka). Consequently he is aware of the importance of balancing training with lifestyle, thus complimenting other important aspects of an athlete’s life (family, work, study commitments etc…). • Entering your first triathlon? • Stepping up to a longer distance? • Looking to go faster? • Wanting to turn previous negatives into positives? Ray has coached athletes to achieve these and more. Training programmes are accessible online, so athletes can be located anywhere and still reap the benefits of Ray’s coaching. Contact him to discuss how he can assist you to achieve your goals.
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