Multiple studies reveal runners, triathletes, and other endurance athletes improve the most when they consistently do 80 percent of their training at low intensity and the other 20 percent at moderate to high intensity. David Warden, co-author of 80/20 Triathlon explains why and how you will become faster if you start doing more slow training. 

• What is 80/20 intensity distribution in practice. 
• What is the science behind 80/20 intensity distributions.
• How most age-groupers fall way short of doing 80% of their training at an easy intensity: most do only 50%, if that. 
• Does 80/20 still apply if total training volume is low?
• Practical advice for getting started with 80/20 training. 

00:40 - 

• David is a triathlon coach at 80/20 Endurance. 
• He is co-author of the book 80/20 Triathlon which is coming out later this year (currently available for pre-order).
• He is also the author of several of the chapters in the book Triathlon Science.  

6:09 -

• I can define polarised training, but I suspect many other researchers or coaches would come up with different answers.
• From the colleagues I work with, it's training that focuses on intensity at the upper end of an athlete's ability, and easy training well below this.
  • At threshold or higher, or well below threshold.
• In Matt Fitzgerald's introductory book to 80/20 training in 2011, he separates training into low, moderate and high intensities.
  • Polarised training excludes moderate intensities.
• Polarisied training is different to an intensity distribution.
• The term threshold can hold a bit of debate: in general assume it's a point of intensity you can only maintain for a finite period of time.
  • This may be 30-60 minutes.
• Anything threshold or above I would consider high intensity.
• Moderate intensity is very hard to define so there are a variety of opinions about what it means.
• In the 80/20 world, Matt and I have defined what we think moderate intensity is.

10:09 - 

• Back in 2011, Matt Fitzgerald worked with Stephen Seiler who is a world renowned physiologist and researcher.
• Stephen presented information to Matt about how world class athletes train.
• Stephen found that almost without exception, world class athletes spent 80% of their time at low intensity, and the remaining 20% at moderate to high intensity.

• From this, Matt wrote a book called 80/20 running.
  • Matt and I will be coming out with the follow up: 80/20 Triathlon, later this year.
• 80/20 is an intensity distribution concept, as opposed to a polarised training concept.
  • The 80/20 concept is as simple as saying we believe the best results come from spending 80% of your time at low intensity and the other 20% at moderate to high intensity.
  • This has been supported by what the best athletes in the world do, regardless of their sport.
• The polarised piece, is how much of the 20% you spend at moderate training compared to high intensity.
  • Matt and I distribute the 20% in a periodisation process.
  • Throughout your training season, you spend different amounts of time at different intensities.
• Our book includes training plans for all different distances of triathlon and at all different levels.
  • We spend the 'general' phase of the triathlon at a very polarised level.
  • For about the first 8-12 weeks of our training plans we avoid the moderate intensity.
  • Our goal is to increase your thresholds overall.
  • Whether you're training for a sprint or an Ironman, our goal is to get your base speed up as fast as possible.
    • When you move to specificity of endurance training you can maintain a higher speed because we're asking you to maintain a higher percentage of that threshold
    • If we want you to maintain 80% of your FTP during a half Ironman race, if your FTP is 250 watts you'll have better performance than if it's 200 watts.
• Then we move into the specific phase of the training plan, and this is where training diverges based on the distance of the plan.
  • For half and full Ironman training, we'll introduce more moderate intensity because that's the best intensity to race at.
    • These events will take much more than an hour to complete so moderate intensity is appropriate.
  • For Sprint and Olympic, we will not do the high end of the polarised training, we stick with zone 3-4 work and avoid zone 5.
    • Zone 5 is not necessary for any level of racing.
    • This upper level of intensity that you can only maintain for 1-2 minutes is not called upon in amateur non-draft legal racing.

15:50 - 

• Visit 8020endurance.com for a zone calculator.
• We employ a 7-zone scale, which is common.
  • Our zone distribution goes 1, 2, X, 3, Y, 4, 5.
• The reason for that is when Matt introduced his book in 2011, he made a decision to not name the zones that he wanted you to avoid.
  • He decided that he wasn't even going to name them.
  • In his zone system it went 1, 2, 3 (with an unknown gap between 2 and 3).
  • His idea was that if he didn't name the zone, you would avoid it.
• This wasn't a bad idea, but it caused some confusion so when we introduced 80/20 triathlon, we decided to name the zones.
  • In order to maintain the integrity with Matt's old system we named them X and Y.
• In an 80/20 zone distribution system, low intensity, or zone 1 and 2, would be between 72-89% of your lactate threshold heart rate.
  • For example, if your threshold heart rate was 160, zone 1 would start at 115, and the upper end of zone 2 would be 143.
  • That would be our proposed 80% of your training time.
• Our proposed moderate intensity is zone X.
  • We feel most athletes fall into a trap in zone X.
  • It's the zone most athletes like to train in because it's hard enough that you feel like you're getting a good workout but it's not so hard that it's uncomfortable.
  • Athletes naturally fall into this zone X, but they don't really gain new fitness and also fatigue themselves enough to not gain new fitness in the next workout.
  • In the general phase we try and get athletes to avoid this because we want to build new fitness.
• Zone 3 is approximately 96-100% of your lactate threshold.
  • It's about a 7-9 beat range that we call your threshold range.
  • It goes up to your lactate threshold.
  • If 160 was your lactate threshold your zone 3 would be 153-160.
• Zone 4 and 5 are tiny slivers of additional intensity above your threshold.
• For listeners used to Mikael talking about zones, his zone 3 is the moderate range, and his zone 4 would correspond to David's zone 3 & 4 combined.
• Zone 3 being high intensity in David's system means it's close to threshold.
  • Not the way you're used to zones in a 5 zone system.
• I don't feel comfortable specifying where the aerobic threshold would fall in zone X because I am unsure.
  • I feel very confident in our lactate threshold testing, but I am unsure where it falls in with ventilary or aerobic threshold.
• I propose that the upper end of zone 3 is approximately 4mmol accumulation of lactate.
  • You'll have about 2mmol lactate at the upper end of zone 2.
  • That area between 2-4mmol is what we call our zone X.

21:15 - 

• We have a whole chapter on calculating percentages in terms of an 80/20 split for your training plan.
• Although we do provide plans that have the 80/20 ratios built in, we want athletes to be able to make their own custom plans and be able to calculate this on their own.
• In Seiler's work it has always been done at a macro level.
• I've never seen anything done over less than 8 weeks of training time.
• We follow a similar idea.
• We don't prescribe that an individual workout be 80/20 because that would be ineffective.
• We do say that in a given month, your ratios should be approximately 80/20 for total time accumulated.
• In our plans, and with our individual athletes, we have it down to a week level.
• The calculation is simple, calculate the total time you spent cycling and running.
• Then calculate the total time spent in zone 1 or 2.
• If that equals 80%, you have achieved 80/20 training for the week!
• All of our plans use duration instead of distance on the bike and run, which we feel is the best for 80/20 training.
• For the swim we make an exception because most people will be swimming in a fixed distance pool.
• So we target a 75/25 ratio in the pool in terms of distance, because we've found this ends up equaling 80/20 in time.
• This makes it easy in the pool because if you're doing a 2km swim, we propose that 400m must be at moderate to high intensity, and the remaining 1600m at zone 1-2.
• For swim, bike and run we offer various measures of intensity.
• We currently just use pace on the swim.
• We know heart rate and power are possible, but we don't think they're adopted well enough to introduce in our plans at this time.
• For the run, we have heart rate zones, pace zones and power zones.
• For the bike we have heart rate and power zones.
• These are all included in the plans, as well as our 80/20 calculator for the sports.

25:29 - 

• We propose two separate tests for the swim.
• Critical velocity test/critical swim speed test:
• The athlete performs two time trials: 400m or yards, and then 200m or yards.
• The athlete chooses the distance based on the pool they do most of their training in.
• There's a mathematical formula that takes those two and proposes a lactate threshold.
• You can go to 8020endurance.com, plug the numbers in and it'll do the math for you.
• Alternatively there is the calculation in our book to do yourself.
• 1000m or 1000 yard time trial:
• Your threshold is your average pace per 100 of that test.
• Many new athletes struggle with this workout because they tend to fade across the 1000m but have more success with the critical velocity test.
• Let's say we have a swimmer with a 2 min/100m critical swim speed:
• Zone 1 is 75-85% which is 2:38-2:21 per 100.
• Zone 2 is 86-90% which is 2:20-2:12 per 100.
• Zone X would be 2:11-2:05 per 100.
• Zone 3 would be 2:05-2:00.
• The key with 80/20 training is the 80% allows you to get enough rest in between hard sessions.
• When you combine this with a philosophy of 'hard/easy' - so easy days and hard days, it allows you to go harder on the hard days to build new fitness.
• You still get all the benefit from aerobic training, but you're not so fatigued that you can't increase your threshold through intense training.
• You're avoiding the moderate intensity trap that doesn't let you recover and go harder on the next day.

31:05 - 

• Some athletes need to follow low volume programmes for practical reasons, and they usually take a high intensity approach.
• I don't want the 80/20 philosophy to come across as dogmatic, it doesn't work in every single situation.
• I think it works in virtually all situations, but for someone that can only afford 5-6 hours a week of training it may not be the most appropriate.
• Any individual can handle 90 minutes a week of moderate to high intensity.
• If you're only training 3 hours a week, 50% of it could be high intensity.
• This shouldn't have a long or short term detriment.
• Anything below 7 hours, the 80/20 rule starts to have diminishing returns.
• Beyond 7 hours, it becomes paramount as you can over train if you vary from those ratios.
• When you get up to 15+ hours, which most half and full Ironman athletes will be doing, it becomes paramount to follow 80/20 training.
• At that point you can easily start to accidentally do 5-6 hours of moderate to high intensity training and fall into the trap where you can't gain new fitness.
• For a brand new athlete, I would start off on 80/20 training regardless of the amount of time they're training each week - even if it’s only 3 hours.
• A new athlete needs some sort of guideline to stick by so they don't injure themselves.
• For an experienced athlete who has done this for a long time and is just getting back into training after an absence, I would prescribe an hour of high-moderate intensity training, with 3 hours training per week.
• More of a 50% high intensity, until you get back to an 8+ hour week.

35:24 - 

• There was a meta study recently published looking at intensity distribution.
• From looking at this result it's surprising how frequently they follow the 80/20 training.
• I was recently looking at research from Norway in 2011 looking at cross country skiers.
  • They found they spent 85% of their training in zone 1.
• When I looked at another study of world class pursuit cyclists, they spent 90% of their time at low intensity.
• The distribution is so broad so I can't accurately answer how the different intensity distributions compare against each other.
  • It could be that 10 years from now for cross country skiing it needs to be 85/15, or for rowing it need to be 75/25.
  • It may be more sports specific than a broad endurance sports ratio.
• I can be confident that the 80/20 ratios, whether you're in the general or specific phase of training, are going to be within a few points of what the research will continue to support in 5-10 years.
• There is research on the distribution of athletes in the pre-competition phase, the competition phase and the rest phase.
  • There a little bit of different distribution: e.g. cross country skiers in 2014 were shown to have 87% time low intensity in preparation phase, 84% during competition phase.
  • That is a fairly consistent model across sports and across studies.
• I don't have a specific example of research about moderate versus high intensity in the 20% specific phase.
  • I am going off of the principle of specificity, which says if you want to do well at half Ironman racing, you need to training at half Ironman pace.
  • So the distribution of moderate and high intensity in each phase is based on my experience as a coach knowing I need to have them have at least 10% of their time at the intensity at which they'll race.
  • For some athletes this may by zone 2 - so in the specific phase they'll spend 10% at high intensity and 90% at zone 2.
  • For other athletes who can handle zone X for Ironman or half Ironman, I'd spend 10% of their time at race specific intensity (moderate intensity).
  • This isn't based directly on research it's based on the principle of specificity.
• In our plans, on a macro level, we have 80/20 for each discipline individually.
  • Of the swimming we go 75/25 distance.
  • On the bike and run, on a week by week basis I don't ensure whether the bike and run and separately 80/20, but I do on a monthly level.
  • So bike and run together on a weekly level must be 80/20, but monthly the separate bike and separate run must also be 80/20.
  • In a given week, you might have a 90/10 or a 75/25 based on a bike or a run, but the other discipline will be making up for that.

42:59 - 

• The first reason is that you have likely already fallen into a moderate intensity trap, and are likely already training at a 50/50 or 60/40 ratio.
• It's easy to make the change if you monitor your workouts: monitor your intensity and understand the zones.
• It's an easy thing to fix on paper, the hard part is giving yourself permission to do it.
• There are multiple platforms out there to monitor your training.
• Assuming you're using Training Peaks, you can go and put in these 80/20 zones, the way we've recommended them.
• You can set this up and going forward you can easily track and see how much time you're spending in each zone.
• Historically this is harder to do, because once you complete a workout it is stuck in whatever zone it was defined at when you did the workout.
• You can retroactively change the TSS or threshold, but not the zones.
• You can go and work out how much time you're spending in what you think would be zone 1 or zone 2.
• It will be somewhat accurate, it won't be precise but it will probably be close enough.
• Most people will be shocked at how much time they spend in zone 1 and 2 - very few will be spending more than 50% of their time in these zones.
• I know this because most athletes I've worked with start here.
• The best think you can do is make a commitment going forwards to some sort of zone philosophy.
• Then record all your workouts and check to see how much time you're spending in zone 1 and zone 2.
• You don't have to buy the book to use our resources, at 8020endurance.com we can walk you through the process.
• We have documents on how you determine your zones, manage your zones, add the zones to various training log platforms and monitor them.
• The most important practical tip is making sure you understand what your true threshold is.
• Test yourself frequently throughout the season as it can often change.
• All of the information I've given here is based on an anchor point of know what your threshold is.
• If you know your thresholds is it becomes easier to define what is low, moderate and high intensity.
• Testing is uncomfortable and difficult - but it should be!
• It's well worth doing it every rest week, or every 3/4 week of your training.

48:40 - 

• What is your favourite book, blog or resource related to triathlon or endurance sports.
  • Joe Friel's Triathlete's Training Bible.
• What is your favourite piece of gear or equipment?
  • My Scott Plasma. I love that bike and treat it like a member of my family.
• What do you wish you had known or done differently at some point in your career?
  • I wish earlier in my career I'd understood the value of interval training and how it improves performance at all endurance levels.

Links and resources mentioned

• 80/20 Endurance website
  
• 80/20 Triathlon: Discover the Breakthrough Elite-Training Formula for Ultimate Fitness and Performance at All Levels
• 80/20 Running: Run Stronger and Race Faster By Training Slower
• Training Zones part 1: Swimming | EP#27
• Training Priorities: Seiler's Hierarchy of Endurance Training Needs | EP#120

Connect with David Warden

• On his website

Connect with host Mikael Eriksson

Hi! I'm your host Mikael,

I am a full-time triathlon coach and an ambitious age-group triathlete. My goal is podium at the Finnish national championships within the next few years.

I first started the website Scientific Triathlon in autumn 2015 as a passion project to share my learnings with a larger triathlon audience. Later on, in early 2017 I started the podcast That Triathlon Show. 

I sincerely want you to contact me to

• Send me feedback
• Give constructive critic​ism 
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• Send me your triathlon-related questions 
• Tell me that you've rated and reviewed That Triathlon Show so I can give you a shout-out on the show and tell you how much it means to me!