Session Plan – 400m Intervals

I love the challenge of interval training.  If I was training purely with the goal of getting in the best possible shape I would without any doubt use this session to benefit from the effects of high intensity interval training (HIIT).

But it is more than that for me.  Yes…I like the challenge.  Yes…the narcissist in me likes the undoubted results.  But this session is forming a key part of my half marathon preparation for an attempt at a PB in Amsterdam.  My current PB (from Amsterdam 2016) is 1:17:35, with an average pace of 3:40/k.  I am semi secretly hoping to go below 1:17 and, if things go especially well, to push for a time as close to 1:15 as I can manage.

I have used 400m reps as part of my training for a number of years, but normally keeping the number of reps between 5 and 8.  The idea for this session came from Matt Llano of the Hoka One NAZ Elite Training Squad.

This clip got me thinking of adding reps and working towards a target speed for each rep.  I haven’t pushed on toward’s Matt’s 30 reps at this stage, however, I am a up to 20 reps with 400m jog recoveries.  My target time for each rep is to complete it in under 85 seconds.  This is equates to a speed of 3:35/k, slightly faster than my intended race pace.

This image taken from my Garmin shows you the increasing pace and the associated spikes in heart rate.  I usually do a 2 kilometre warm up and cool down for this session, with dynamic stretching as part of the warm up, and then a thorough stretch after finishing.  The 2k cool down helps flush the lactic acid out of the system and starts the recovery process.  The early reps seem fairly comfortable, but if you have set a challenging enough pace, the difficulty soon starts to build.

What is the aim of the intervals session?

  1. Learn to Run Fast –  To learn to run at a speed faster than my intended race pace.  The intention is to make race pace comfortable, so that come the day, after a solid taper, I can sustain somewhere between 3:35 and 3:38/k.
  2. Push the Limits –  By pushing the pace and increasing my heart rate to close to 90% of my maximum, I am working close to lactate threshold.  Over time I aim to gradually raise my threshold, meaning I can sustain faster speeds for longer periods without the onset of fatigue.
  3. Develop Mental Strength – As I said earlier the first few reps at this pace for 400m should be quite comfortable.  But it soon starts to build up if you have selected a challenging enough speed for each of the intervals.  Knowing that you have 20 reps to complete is not easy and requires you to dig in for the last 5 reps, and work hard to make sure you stay underneath your intended target.

This is one of my key sessions building up to Amsterdam.  With 5 weeks to go I am pleased with where I am heading.  Time will tell if it plays a part in helping me to that all important personal best.

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