One of the biggest fears coaches have is high lactate work or high intensity interval training.  If done too much or too early this generally leads to early peaking and a dramatic drop in performance as time passes.  At every level of the sport, there is a fear of doing interval work too early.  Arthur Lydiard was one of the first to put forth this idea.

While the idea that too hard too early does lead to a premature peak is correct, the idea has grown to mean that any interval training or intense training done early causes this premature peak.  That’s simply not the case.  There are two problems with this idea that have developed over the years

1. Interval training does NOT equal high lactate work/high intensity/high acidosis.
2. We’ve ignored the idea of specificity of the high lactate/intensity work.

Interval training does NOT equal Anaerobic training
For many reasons, any interval training done has been associated with anaerobic training, to use Lydiard like times.  It’s assumed that you do longer runs, steady runs, threshold runs to improve aerobically and then you start doing intervals to improve “anaerobically” or “VO2max” or basically “high intensity fatigue resistance.”

There is a problem with this line of thinking.  It’s not true!  We’ve associated interval training with anaerobic training so much that we’ve forgotten that the way the intervals are modulated is what matters.  It does not matter whether you call something a tempo run, an interval workout, or a fartlek.  What matters is what the run/workout is actually accomplishing, and what is going on physiologically.  By manipulating the length of the intervals, the intensity, and the rest periods you can make an interval workout that accomplishes anything from pure speed to pure endurance.

So it is not whether you are doing interval training or not that causes you to peak early or cease progression at the end of the season, it is how those intervals are done.  You can do intervals year round and be fine, it’s all about how it is manipulated.

Misunderstanding the Igloi method:
Mihaly Igloi was a coach who had enormous success as a distance coach in the 50’s-70’s, including Olympic 5k champ Bob Schul and mile WR holder Lazlo Tabori.  Some of his coaching protege’s include the coaches of the Santa Monica Track Club.  Despite the success of the training system both in the past with Igloi and by athletes whose times would still compete today (think Johnny Gray, Khadevis Robinson, David Mack- i.e. a bunch of 1:42-3 800m runners), little is known about the system and there are a lot of misconceptions about it. For a system that produced some of the best milers in the world (Tabori, Beatty, etc.) in the 60’s, produced several 1:43 or better 800m runners in the 80’s-90’s, and has worked on some of our best athletes in present day (Khadevis Robinson) it seems worthwhile to investigate.

The Igloi system of training is misunderstood because it was portrayed as the complete opposite of the Lydiard approach.  Lydiard was simplified to all aerobic long running, while Igloi was simplified as the all interval approach.  Because Lydiard’s approach gained so much popularity and people started to make the connection of intervals=anaerobic conditioning, the Igloi method got seen as a high intensity “anaerobic” training system.

The key to the Igloi method of training is not in looking at intervals vs. distance, it’s looking at what the actual workouts accomplished.  As mentioned above, people make the connection of intervals=anaerobic.  Igloi’s system, however was not like the HS systems you here about where they run 400’s in 65 all year long.  Igloi manipulated the intervals to create both aerobic and anaerobic adaptations.

The basis of the system is running by feel and progression.  The system is based on running at different levels of effort (easy, fresh, good, fast good, hard, very hard).  The athletes run each rep/run at given effort levels.  By doing this, the emphasis is on running by feel and this creates a built in natural progression as the athlete develops.  This means at the beginning of the season 200m good speed might be 30 for some athlete, but by the end it’s 26-7.

In addition to the various effort levels, there are also two different ways of running (or as he called them, swings). Basically, the belief is that altering how you ran would slightly change the muscle fibers used, thus delaying fatigue.  It is a very interesting idea that has not recieved any attention.  Think of it like switching gears in biking.  The two basic ways to run were a short swing and a long swing.  These basically amount to a style with a shorter stride with quick turnover and a longer stride with reduced turnover.  The idea was to be able to change from one style to another within runs, races, and workouts.

There are many variations in how the intervals are done, but typically modern Igloi users have gone to a system that uses interval training and easy/steady running.  In Igloi’s day there was a more heavy emphasis on interval training, with most of it being shorter intervals.  The reason for the use of short intervals is partly due to the idea that it minimizes lactate build up at similar speeds.  Run 100m repeats seperated by 50m jogs at 800m pace and you’ll produce much less lactate than if you did 200 or even 300m repeats at that pace, and it would take longer to clear that lactate.  In addition, the longer intervals were thought to take too much out of athletes, and thus used sparingly.

If you look at what Igloi’s training actually accomplished instead of getting infatuated with the fact that it is interval training, you can see that early on his intervals are no different than aerobic training or threshold type work.  You can do 100m repeats at moderate paces with short rest and have it be a similar stimulus to running a 5mi threshold run.  Sometimes people get caught up in the volume of interval training they were doing at times, but the key is it wasn’t that different from similar mileage levels for other athletes.  Yes, the stress of running intervals on a grass loop or track is intesne mentally, but from a purely physiological standpoint doing 6mi worth of 100-400m repeats at fresh to good intensities was very similar to do a 6mi progression/threshold run.  One thing to remember is that Igloi’s athletes weren’t low mileage runners.

One other thing to take into account is the vast modulation in the workouts themselves.  Instead of doing most of the repeats at similar paces like in most modern training programs, the speed of the reps varied greatly throughout the workout.  The workouts themselves seem to have different phases within them so that there will be hard, moderate, and easy parts of an entire workout.  For example, instead of doing 10×400 at 60 like in a traditional program, the Igloi method might include 3×400 (fresh, good, good), 3×400 (good, good, fast good), 4x150m w/ 50m jog at fresh speed, then repeat some more 400’s at various efforts.

Instead of taking a long break between sets, the 4x150m functions in that way.  It’s an interesting way to enhance recovery while still getting some work in and keeping the Heart Rate up.  The 150’s are easy and would serve to enhance lactate clearance.  This method of an “active break” is an interesting one that needs some consideration.

Let’s look at some example workouts:
Early workout for 800m:
6x150m good speed w/ 50m walk,  2x(5×200 good speed) w/ 100m jog b/t reps, 400m b/t sets, 1 lap jog, 6x150m (2 fresh, 1 good) w/ 50m walk

A late season example for 800m runner:
4x200m (good speed, 25-26) w/ 100m jog, 1 lap easy, 2x300m (35) w/ 400m jog, 2-3 laps easy, 3x200m (1 fresh, 1 good, 1 hard) w/ 100m jog, 2-3 laps easy, 10x100m easy

The best way to think of Igloi’s system is in terms of swimming.  Swimmers train both aerobically and anaerobically, yet they do it all through interval training.  This is essentially what Igloi did.  The genious of Igloi’s system and what you should take away from it is he created a type of training that allowed for athletes to run at or near specific paces, using specific biomechanics, while keeping the internal stress low enough that he could build up massive volume of this type of work.

The downfall to Igloi’s system was the fact that they did a lot of work on the track and in spikes.  Mentally this could be very tough and stressful mechanically on the body.  It seems like a better way to do it would be to incorporate some of the ideas of the shorter intervals in a type of natural fartlek system.

A modern take on the Igloi system of short intervals with short recoveries can be seen in the Kenyan’s use of diaganols.

Looking at it Physiologically:
What does this massive amount of interval training potentially do (that could take several hours to complete the whole workout)?
-The variation in pace/effort intersperced with period of 1-3 lap jogs is likely to recruit a lot of different muscle fibers.
-It’s likely that it enhances the endurance/fatigue resistance of FT fibers because of the large volume, and the mixing of paces with longer easy recoveries.
-The Heart Rate is kept elevated for a prolonged time and likely varies between 140-180-90bpm a lot.  Because of the short nature of the intervals and short recoveries it’s likely that you don’t go up to max even on faster work and then you don’t go down a whole lot during the recovery.
-One has to wonder about time spent at VO2max?  No long traditional VO2max intervals leads me to believe that once again, VO2max as a system to stress is not important.
-Lactate levels are likely lower then comparable volumes of work in traditional training because of the short intervals.  This likelyt results in training to use lactate as a fuel.

What intervals should you do?

What’s the takeaway message?

It matters how you manipulate the training, not what someone calls or classifies it.
Remember, that just because it is interval training does not mean it’s hard training.  Since the focus is on early season interval training, here’s what I recommend.

Aerobic Development that is more specific:
One way that I like to use interval training early is a way to get in aerobic development that is more specific in pace.  This means that you get good aerobic development in similar fibers that are going to be used in the race, using similar biomechanics.  In particular, this works well for middle distance runners (especially 800m runners) and FT orientated athletes.

What you do is use very short repeats at faster paces with a good volume of work during the set, but long breaks between sets to bring everything back down.  Doing it this way, you can get in running as fast as 800-1mile pace with lactate levels similar to those seen during a steady threshold run.

An example for an 800m runner(racing 1:52, 14sec per 100m):
3x10x100m at 16 w/ 20-25sec b/t reps, 6min b/t sets
3x 400m of 60m at 800m pace, 40m easy w/ 6min rest b/t sets
2x5x150m at 15sec pace w/ 50m jog in 30sec b/t reps, 5-6min b/t sets

For a 5k runner:
-Easy run w/ 30sec pickups in the middle
-9mi easy w/ 8x45sec at 10k down to 5k pace with 2:15 east after
-8×200 at 3k pace w/ 200m easy
-8×100, 8×200 w/ 100s at 1500 pace and 20sec rest, 200s at 5k down to 3k pace w/ 200m easy

Specific Endurance
Another good way to use early interval training is to use it as a foundation for specific endurance.  Essentially the goal is to include short interval training at goal race pace.  This early work sets a foundation on which to develop specific endurance.  So start off with very short intervals at specific pace and increase the distance of the reps, increase the volume of the workout and/or manipulate the rest between.

For an 800m runner, a specific endurance progression might look like this:
sets of 8x100m w/ 45sec rest at date 800m pace
sets of 8x100m w/ 35sec rest at goal 800m pace
sets of 4x200m w/ 40sec rest at 800m pace
sets of 300,500m
sets of 400,400
sets of 500/300

For a 5k runner, you might start with 200m repeats at goal pace (12×200 at 5k w/ 200m jog), and progress to sets of 400s (4x4x400m at 5k pace w/ 45sec rest, 4min b/t sets) and progress onwards.

Muscle Fiber recruitment:
In addition, using short intervals in the middle or at the end of a long run is a good way to stimulate the recruitment of muscle fibers when fatigued.  Including 4x30sec, 4x45sec of moderate pickup in the closing miles of a long run would accomplish this goal.

Intervals for recovery/lactate use:
Another use for short aerobic intervals is to teach lactate use as fuel and enhance recovery.  As most of you know, lactate is not some horrible substance that causes fatigue.  Lactate can be used as an energy source through the lactate shuttle.  One goal of training is to teach your body how to use lactate as a fuel at higher intensities.  The best way to do this is through alternation work, but another option is by using aerobic interval work in the middle of a more intense interval session.

Besides promoting lactate use/clearance, it also aids in recovery.  If you see a runner struggling during an intense workout and you still want him to get more volume of training in, a good way is to insert a couple of short aerobic intervals.  The short aerobic intervals keep the athlete getting some work in, which helps him mentally, and aids in recovery.

An example of this would be if during 6x800m at 5k down to 3k pace the athlete is struggling hard after 4, insert 3x200m at 10k-LT w/ easy 200m.  Then give him 2min rest and finish with the last 2×800.

Use relaxed 100s, 150s, 200s, 300s, etc. at 3k to threshold type paces in the middle of workouts, or in between sets, such as 2x5x400 at mile pace w/ 60sec recovery.  After set, 2min rest, 4x150m at 10k w/ 150m easy, then start the next set of 400’s.

Some great sources for Igloi training info are below:

Next, we’ll look at non-specific lactate work.

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    1. Fat Rat on February 16, 2010 at 2:06 am

      Hey Steve,

      Really like this slinkset concept. we have spoken about setting up an open access journal under the same idea. We wonder about having both a popular ranking and scientific merit ranking simultaneously.


    2. Anonymous on February 16, 2010 at 8:01 am; You saved my day again.

    3. Bruce on August 13, 2010 at 8:27 am

      I trained with Lazzlo Tabori and found him to be an intuitive coach. We would do multiple sets of short rest intervals at a variety of speeds and distances. Between sets we would run 2-5 laps at an easy pace. All training was taylored to individual needs. We ran on the track only 3 days a week.

    4. Bruce Tharp on October 16, 2011 at 6:15 am

      I think the only one today who still uses anything close to classic igloi is Bob Schul and even his training is a modified system. There are so many aspects of Igloi's system that deserves to be studied. His use of 100yd shake up runs at easy speed between sets of of intervals that seldem exceeded 330yds not only aids recovery but allows interval work to be done daily.

      In my humble opinion, daily but carefully controled and monitored interval work will enhance neuromuscular recruitment patterns and promote specific localized muscle endurance of the primary running muscles such as hamstrings, glutes etc. that come into play only at a fast pace. Because of the variation in tempo during the workout there is less chance of repetitive motion or over use injuries.

      I am now 65 years old and I still train like this daly on the sawdust trails here in Eugene.

    5. best personal training certification on November 1, 2011 at 2:46 pm

      There is a problem with this line of thinking. It's not true!

    6. hplum40 on January 8, 2014 at 6:27 pm

      "The basis of the system is running by feel and progression." And in this key respect it is very similar to Lydiard's method!

    7. track4127 on December 19, 2015 at 8:01 pm

      The only problem with a system like Igloi's is that the coach must be able to see when the athlete is struggling. He must then be able to reduce the speed, or shut the workout down. In some cases he might have to have the athlete run faster, if the workout is not producing overload!

      This is a great system for a coach who understands how to apply it. I think that it may take some practice to do it right!

    8. Kevin G on November 2, 2016 at 7:14 pm

      I’m glad I found this article. I ran for Norm Higgins, an Igloi disciple, and would run similar workouts. As a high school coach I have added some of these facets into training. I would do several sets of 300m with 100m jog recoveries. One similarity I see is a 9 mile run followed by shorter intervals. I typically ran 8miles home from work stopped at the local track and ran 25×200 or 12×400 with a short jog rest, then jogged home. I have found this type of training less taxing when running fast but able to familiarize the body with the desired pace work.

    9. Dreux V on June 24, 2018 at 4:52 pm

      Good article. Igloi had a few more paces in the workouts. Aside from fresh, good, hard, very hard speeds, he also had swing steps at each level. My dad and Igloi worked together and I trained under his system and even worked with Igloi for a few weeks when he was in PV visiting his daughter in the early 90s. I have a bunch of his workouts and letters to my dad about the trainer np if you would like to dig further into his training.
      Coach V

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