Start Boosting Your Running Speed Before Winter Is Over

By Rebecca Kurtz, CTS Expert Coach

Triathletes and runners are familiar with Fartlek intervals, but many reserve them for periods of the year that are closer to their goal races. They are often seen as race-specific or race-prep workouts, but they can also be used to build your energy systems. These intervals are above-threshold running intervals, so you will produce a lot of lactate throughout the course of the workout.

As such, they will help improve your body’s ability to process lactate quickly. That’s important because processing lactate is the key to increasing the pace you can maintain at lactate threshold. Fartlek runs can be done at a variety of intensities and durations, but because it’s early in the training year (at least in the Northern Hemisphere), during this phase of training we want the pace and heart rate to be above lactate threshold and faster than your goal race pace.  Fartlek runs are also a great way to add speed back into your program if you have taken a couple of months off from speed work.

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Why Do Speed Work Now?

There is a big misconception that the winter is the time for “long, slow miles”.  While this can work for some athletes who have 25+ hours a week to train, for most of us who have full-time jobs and families, we need to make sure we are not spending a bunch of time going slow.  To go fast in a race, you have to train fast.

It can be challenging to incorporate the high-intensity component into a 70.3 or Ironman plan, since in the few months leading into a race of such a distance, the focus is on developing power/pace at lactate threshold with longer rides and runs.  Trying to increase both intensity and volume can be a recipe for disaster.

You either can’t complete each one sufficiently enough to provide a good adaptation, or you end up injured and highly fatigued. When there’s doubt about how to balance intensity and volume, many triathletes default to increasing volume and skipping intensity. Fartlek intervals during this early portion of the season helps to mitigate the conflict between the two later on.

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Focus on Three Basic Areas of Training

Let’s get a little more technical for a bit.  There are three basic areas that endurance athletes want to focus on throughout the year: your maximal aerobic capacity (VO2max), lactate threshold (glycolysis), and oxidative phosphorylation (base aerobic conditioning).  If you have been training consistently for a couple of years, your oxidative system is fairly well developed, which means that time-crunched athletes can get away with spending a bit less time focusing on that system.

The two areas that will make a big difference in your 70.3 performance are VO2max and your glycolytic system.  In 70.3 and Ironman racing, the number one limiter is your power/pace at lactate threshold. And although lactate threshold responds well to training, you also have to improve your performance at VO2max in order to maximize the improvements you can see at lactate threshold.

Think of it this way: there’s a gap between your performance at lactate threshold and your performance at VO2max. Focusing on lactate threshold training can move your power/pace at threshold closer to your power/pace at VO2max. Training your VO2max can give your performance at lactate threshold a bigger space to move up into. It “raises the ceiling”, so to speak.

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While your VO2max number (the maximum amount of oxygen you can take in and use) is largely genetically determined and only somewhat trainable, the pace you can run at VO2max is much more trainable.  And high-intensity running intervals are the key to improving the pace you can achieve at VO2max.

This will give your lactate threshold more room to move.  And the reason you want to insert high-intensity running into your January and February training is because you will spend the summer months focusing on threshold training for the 70.3 distance. Before you get there, you need to make sure that you have room to increase that threshold so that you don’t see a plateau in fitness mid-season. Plus, the training necessary to improve your performance at VO2max also applies a training stimulus to all the energy systems below it (aerobic and glycolytic), so training at the high end helps improve performance at all other levels. Think of it as “a rising tide lifts all ships”.

Spend some time now working on above-threshold training.  It will pay off in dividends on race day, especially when you are comfortably passing all of your competitors who did “slow miles” during the winter.


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The Workout:

Warm up 10-15 minutes

Complete 6 x 20 second RunningStrides (RS) with 1 minute easy running between each

6×3 minute RunIntervals (RI) at as close to max heart rate as can be achieved. (RPE 9)

Recovery between intervals (RBI): 3 minutes easy running

Cool down 10 minutes easy.

Related Articles

Triathlon Training: A Workout to Pump Up the Benefits of Your Long Runs

Time-Crunched Triathlete: Short Runs that Pack the Punch of a Longer One


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Comments 11

  1. This is really really useful, TJ. I didn’t know about Microsoft Fix It, so will be looking into that. I’ve also been meaning to have a run through my programs and see which ones I no longer use and need, so thanks for the reminder.

    For the browser clean, how many days back do you recommend?

  2. Thanks, I appreciate reading a Tri based article. Keep them coming. This can obviously be beneficial information that can be applied to any sport at this time of year.

  3. Thanks for this topic. Your above mentioned VO2max training (6×3 minute RunIntervals (RI) at as close to max heart rate) sounds good. But my question is what would you define as threshold exercise in comparison? In my point of view it would not need much longer intervalls and simply some heart beats lower. Do you agree?
    Thanks.

    1. Sandro,

      Thanks for your comment and question!

      For lactate threshold, or any type of training for that matter, the focus is on time at intensity. We need X amount of time at a certain intensity range to stress the body and produce the desired adaptation. Volume and intensity have an inverse relationship. As the intensity increases, volume necessary to stress the body and produce an adaptation decreases. As intensity decreases, the volume necessary to stress the body and produce an adaptation increases.

      In order to improve our lactate threshold/threshold pace we need to spend time working just below or at lactate threshold. Lactate threshold pace is below Vo2Max intensity. Going back to the inverse relationship between intensity and volume above, being a lower intensity we know that we need more time at Lactate Threshold when compared to Vo2Max in order to stress the body and produce an adaptation.

      In addition, in order to induce a lactate threshold adaptation (increased lactate tolerance, buffering capacity, and pace at lactate threshold) you must spend time tolerating high levels of lactate, but not so high your body cannot clear the lactate produced. To accomplish this, intervals must be longer than with Vo2Max.

      Typical time at lactate threshold in running (called tempo workouts) is 20 to 60 minutes depending on the level of the athlete. This gives your body more time developing the lactate tolerance and buffering capacity that is necessary for increasing lactate threshold/threshold pace. You can do this a multitude of ways. Intervals and time at intensity depend on each athlete’s ability. But here are a few examples of typical running LT sessions:

      4 x 5 min at LT pace
      4 x 8 min at LT pace
      1 x 20 min at LT Pace
      4 x 12 min at LT
      2 x 20 min at LT

      – Scott Wrigley, CTS Expert Coach

  4. I would make sure you spend three to four weeks doing submax intervals with very short rest period before jumping right into max efforts. Jumping too max interval too soon to lead the injury

  5. How do you know when you’ve done enough? Do you recommend a standard 30, 60 , XX day cycle before building another system?

  6. This is spot on with the philosophy we have been preaching to time-crunched triatheltes since 2007: Build your Fast, then put Far on top of it. This kind of workout is good year round, for sure. In the winter, you could do it just 1x a week, with another interval workout that’s more at threshold pace (say 3 x 1 mile or 2 x 1.5 miles, etc), and then a steady run of an hour, etc., for the “base” work that you preach.

    I’d also note that you should do the interval runs outside if possible; treadmills are good but nothing like the real thing!

  7. VO2Max can be also improved by training up in the mountains where oxygen supply is lesser than in the valley. Yet, according to some scientists you must live at least 6 months to make a difference that may be statistically meaningful.

  8. what are running strides in this context? what do you mean by rbi? run between intervals? how are you determining lactate threshold pace for the purposes of this workout?

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