Friday Fartlek Run – 8 Weeks to a faster 10k: 10-12x 400m - Coach Ray

Coach Ray

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Friday Fartlek Run – 8 Weeks to a faster 10k: 10-12x 400m


This workout will develop your speed as well as your speed endurance.

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 the previous post about training intensity (levels) to know how hard to work. If you are working directly with Coach Ray he will in most cases prescribe either a Pace Zone or Heart Rate Zone to work within if you are training with these tools.

Over the next 8 weeks I will post a workout that when done in sequence will help you run a faster 10km. The key to success is to set a realistic 10km time that is challenging. Over the coming 8 weeks we will look at a hypothetic goal time for a typical person trying to run 10km under 50min, 45min, 40min or 35min. These sessions are best done on an athletic track.

This is the second workout in this series (the first can be found here) and this workout is very similar to the one I wrote about a few months ago here.

10-12x 400m, 200m RI

  • 10min Warm Up Level II;
  • 10-12x 400m, 200m RI;
  • 10min Cool Down Level I-II;
  • 10min Stretching

The warm up should be done at an intensity that is steady but not over consuming at Level II. Run for a minimum of 10 minutes.

The main set: Complete between ten and twelve reps of 400m at your 5km pace. See the table below for your target times for each rep. Then jog slowly for 200m before starting the next rep. For the first rep, start at the finish line on the track (using the inside lane if you can) and run one complete lap at the hard pace. Then jog half a lap for your recovery. When you get to the 200m start point commence your second rep of hard running for a complete lap back to this point. The recovery this time goes through to the finish line where you commence the third rep the same as you did for the first rep.

Your target times for your respective 10km goal times are:

Goal 10km Time

400m Target Time









To execute this session correctly you want to be hitting each repetition a few seconds below your target time for ALL 12 reps. If you start off too fast you might run out of steam/energy and start slowing down. Everyone feels fresh and good at the start, however the first few reps don’t really contribute to the success of the session. You’ve got to do them to get the benefit of the session, however the quality of the session comes from how well you do the last few reps. Hold back on the reins until you get to the 8th rep. If you are still feeling fresh at that point then go for it. If you miss the target time for a rep, whilst you are doing the recovery jog, refocus, freshen up and give the next rep your absolute best shot. If you miss the next one repeat the process in the recovery jog. If you miss three in a row, pack it in for the day and cool down (early if you need to).

The cool down is at a low intensity, jogging for a minimum of 10 minutes.

Finish with 10 minutes stretching to assist with the recovery.

Credit for the inspiration of these sessions needs to be given to Greg McMillan who is a coach and writer for Runners World.

Here is myself doing the workout and taking you through the markings on the track so you know where to start each repetition. Here is the workout on Strava.

You will note that the red (HR) line is flat until the start of the second rep, as this is when I remembered to put my Heart Rate strap on and that in the sixth rep I appear to cut across the middle of the track. My Garmin cut out at the start of the sixth RI and didn’t start recording until the end of the seventh rep. Between those two point I was now on the opposite side of the track (having completed the RI and ran another rep) and the Garmin assumes that I got their in a straight line in the time that it was turned on. Technology aye? Not always perfect.

Add your times as a comment below.  You can add your results to future posts to ensure that you are keeping on target as you work through the 8 weeks.

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. Make sure you sign up to my informative newsletter.

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

For more great workouts see my eBook: ‘Top 10 Workouts from Coach Ray – The Ten Most Popular Training Sessions from”.  Use the workouts within the eBook to enhance your fitness.

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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