Did you know that to improve your triathlon performance, you actually need to ease off in the vast majority of your training instead of pushing harder at each session. Sounds interesting, right? This is exactly what 80/20 triathlon training is about. Also known as polarised training, the idea is to spend 80% of your time working out at a low intensity, and 20% at a high intensity.
Here, we explore what the 80/20 triathlon training approach is, the science behind it, and how to incorporate it into your training routine.
What is 80/20 Triathlon Training?
80/20 triathlon training is becoming more popular among endurance athletes, but it is actually nothing new. Elite athletes have been using this approach for years. Collective research of recent years has highlighted this.
It is Dr. Stephen Seiler who has brought the 80/20 training method to light in the early 2000s.
One of the most popular endurance sports writers who has extensively explored the 80/20 training approach for triathlon and running is Matt Fitzgerald. He is a well-known author, internationally recognized endurance coach, and endurance sports expert who co-authored the book 80/20 Triathlon with David Warden and has written several other best books for triathletes, including:
- “80/20 Triathlon: Discover the Breakthrough Elite-Training Formula for Ultimate Fitness and Performance at All Levels” (2018)
- “80/20 Running: Run Stronger and Race Faster by Training Slower” (2014)
- “The Endurance Diet” & “Racing Weight”
Matt Fitzgerald’s work stands out because it is science-backed. In his works, he uses research on elite athletes to support the 80/20 method. He also offers ready-to-use training schedules based on endurance athlete experience. On top of that, Matt is a great endurance sports writer who makes complex concepts easy to understand.
If you’re looking for a well-researched, athlete-tested approach to 80/20 training, Fitzgerald’s books are a great starting point.
Key Principles of the 80/20 Triathlon Approach
This breakthrough elite training formula is based on a well-known Pareto Principle, which suggests that 80% of results come from 20% of efforts. Here are the key principles:
1. Intensity distribution
Most sessions are performed at a conversational pace, typically in heart rate zones 1 and 2 (about 60–77% of maximum heart rate). These workouts are sustainable, promote aerobic adaptations, improve fat metabolism, and allow for higher training volumes with reduced risk of injury.
The remaining training is done at higher intensities- zones 3 to 5 (above 77% of maximum heart rate). These sessions are shorter and more demanding, targeting improvements in anaerobic capacity, speed, and muscular strength.
2. Avoiding the “moderate-intensity rut”
Many recreational triathletes unintentionally spend too much time in the moderate-intensity zone, which can lead to stagnation and increased fatigue without maximizing performance gains.
The 80/20 triathlon training approach helps athletes avoid this pitfall by clearly defining training zones and emphasizing discipline in maintaining the correct intensity.
3. Physiological benefits
Low-intensity training enhances the body’s ability to deliver oxygen to muscles, increases endurance, and improves fat utilization as a fuel source.
High-intensity intervals, though limited in volume, provide the stimulus needed for speed and strength improvements, supporting race-day performance.
When athletes balance training intensity, they minimize the risk of overuse injuries and burnout.
How to Create an 80/20 Triathlon Training Plan
Here’s a step-by-step guide based on expert recommendations and proven methods:
1. Define Your Training Cycle
Duration: Plan a training cycle lasting 12 to 24 weeks, depending on your race schedule, fitness level, and race distance.
Align the cycle with your key race(s) and include necessary breaks for recovery after the cycle ends.
2. Schedule Recovery Weeks
Frequency: Every third or fourth week, reduce training volume and intensity to allow for recovery.
These lighter weeks help prevent fatigue and injuries and should ideally coincide with race days when possible.
3. Establish Training Zones
Before starting the 80/20 triathlon training, perform tests (time trials or threshold tests) to set your pace, power, and/or heart rate zones for swimming, cycling, and running:
- Zone 1 (Recovery): <68% HRmax / Very easy
- Zone 2 (Aerobic Base): 69–83% HRmax / Comfortable, conversational
- Zone 3 (Tempo): 84–94% HRmax / Moderate to high intensity (limit this to avoid “gray zone” training)
- Zone 4 (Threshold): 95–105% HRmax / Hard, sustainable for ~20–40 mins
- Zone 5 (VO2 Max+): >106% HRmax / Max effort, short intervals
4. Create a Default Weekly Workout Schedule
Start with at least two sessions per discipline (swim, bike, run) each week, gradually increasing frequency as you progress.
A typical week might include three swims, three bikes, three runs, and two strength sessions.
Ensure that 80% of your total weekly training time is spent in Zones 1–2, and 20% in Zones 3–5.
5. Plan Your Peak Training Phase
Identify the weeks with the highest training load and race-specific workouts. Gradually build up to this peak to ensure manageable progression.
Include workouts that mimic race conditions and intensity, whether it is a Half Ironman training or a full Ironman workout.
6. Plan Your First and Subsequent Weeks
The first week should be slightly more challenging than your recent training, but not overwhelming.
Then, each week, increase the training load modestly, maintaining the 80/20 intensity split. Adjust based on how your body responds, and don’t hesitate to back off if needed.
7. Monitor and Adjust
Regularly review your training data to ensure you’re staying within the prescribed intensity zones.
Be prepared to adjust your plan if you experience fatigue, soreness, or unexpected schedule changes. Flexibility and listening to your body are key for long-term success.
Sample Weekly Structure (for Reference)
Additional Tips for Creating an 80/20 Triathlon Training Plan
- Start with a solid base. Ensure you’re comfortable with at least 7–8 hours of weekly training, including some interval work. Here are some practical tips on how to train for an Ironman while working full-time.
- Use objective measures (heart rate, power, pace) to avoid unintentionally drifting into higher intensity zones.
- Stay consistent. The 80/20 triathlon approach is most effective when applied consistently over the full training cycle.
How Beginners Can Transition from High-Intensity Training to an 80/20 Approach?
Switching from a high-intensity training program to an 80/20 approach requires planning, patience, and discipline to adjust your mindset and training habits. Here’s how beginners can make this transition:
1. Start with a Gradual Shift in Intensity Distribution
During the off-season or early base training phase, reduce the amount of moderate and high-intensity workouts to less than 20% of your total training time. This allows your body to build aerobic fitness gradually before fully adopting the 80/20 split.
For example, if you currently do mostly high-intensity sessions, start by increasing the volume of low-intensity workouts until they are around 60-70% of your training time, and then gradually move to 80%.
2. Learn to Identify Low-Intensity Effort
Many athletes suffer from “intensity blindness,” where they unknowingly train at moderate intensity when they think they are training easy. Use objective metrics like heart rate, pace, power, or perceived exertion to ensure low-intensity sessions are truly easy, typically below 77% of your maximum heart rate.
Slowing down during easy sessions may feel counterintuitive, but it is essential for recovery and long-term gains.
3. Use Tools to Monitor and Guide Training Intensity
Use heart rate monitors, triathlon watches, or power meters to track your effort zones.
Consider using online calculators or apps that help you determine your individual training zones for swimming, cycling, and running.
4. Be Patient and Trust the Process
The transition can be tough because it requires discipline to slow down and resist the urge to go hard every session.
Over time, you will notice increased comfort during easy workouts, freshness for harder sessions, faster fitness gains, and better race performance.
5. Adjust Frequency and Volume According to Your Schedule
If you train less times per week (e.g. 2-3 sessions) the 80/20 ratio may not be practical. Instead a modified split like 60% easy and 40% hard might be more realistic to ensure enough intensity stimulus.
For triathletes and other endurance athletes training 5 or more times per week, 80/20 is more feasible and beneficial.
6. Include Recovery and Easy Days
Remember that complete training plans should also include rest or active recovery days to allow your body to adapt. Remember that warm-ups and cool-downs, though easier efforts, do not count toward the 20% high-intensity portion.
Periodization and Recovery in 80/20 Triathlon Training
In 80/20 triathlon training, periodization and recovery are the secret weapons behind consistent performance and long-term gains. This method is about training smart by cycling through phases of hard work and strategic rest. These cycles help athletes build fitness steadily, avoid injury, and peak at just the right time.
So, what does this actually look like?
It usually starts with a base phase, where the focus is on building endurance with mostly low-intensity workouts. About 80% of sessions stay in the aerobic zone. Then, in the build phase, more moderate and high-intensity efforts are introduced, still keeping that 80/20 ratio intact. Finally, in the peak or race-specific phase, intensity becomes more race-specific, followed by a taper period to allow full recovery before the race day.
Rest and recovery aren’t just sprinkled in; they’re built into the structure. This includes:
- Weekly rest days
- Easy recovery workouts (like low-intensity swims or short, slow runs)
- Recovery weeks every few weeks, with reduced training load
Matt Fitzgerald, the internationally recognized endurance coach and co-author of 80/20 Triathlon, often references athletes like Ben Kanute, an elite American triathlete and former Olympian, to demonstrate how this principle works at the highest levels.
Kanute’s training, guided by experienced coaches, often includes periods of high-volume, low-intensity training to build aerobic capacity. His peak performance phases feature targeted intensity sessions, but never at the expense of adequate recovery. This mirrors the 80/20 philosophy: keep most sessions easy so the hard ones can truly count.
What’s surprising to many athletes is that elite triathletes actually train easier than most age-groupers. According to Fitzgerald, many amateurs spend too much time in the “moderate” zone, which is too hard to allow for real recovery but not hard enough to build speed. Elite athletes, in contrast, understand the value of true low-intensity training, and they stick to it.
The takeaway?
Whether you’re racing your first sprint triathlon or chasing a Kona qualification, following a periodized 80/20 plan with structured recovery gives your body time to adapt, rebuild, and ultimately perform at its best. Training hard is important, but knowing when to pull back is just as powerful.
What are the Main Challenges When Transitioning to 80/20 Training?
Shifting to an 80/20 training model can feel like a radical change, especially for athletes used to pushing hard most days. While the benefits are clear, the transition to this type of endurance training comes with its own set of challenges.
Let’s explore them one by one:
1. Going Not Easy Enough During Low-Intensity Sessions
One of the biggest hurdles coaches note when working with their current and former clients is learning to truly go easy on easy days. Many triathletes think they’re taking it slow, but they’re often still training in the moderate zone, just below the threshold where effort starts to accumulate. Have you noticed yourself doing the same?
It can feel like you’re not “doing enough” when your pace drops significantly, especially if you’re used to chasing metrics like speed or distance.
Coach David Warden, co-author of 80/20 Triathlon, often shares heart rate data from age-groupers during what were supposed to be low-intensity runs. Many of them were 10-15 beats per minute above their aerobic zone. This led to cumulative fatigue and underperformance during their hard sessions.
How to overcome it?
Use heart rate or perceived exertion to guide you. A good rule of thumb? You should be able to hold a full conversation during an easy workout. If you’re breathing too hard to chat, you’re going too fast.
2. Breaking Old Habits and Mindset
Many recreational athletes are conditioned to believe that harder is better. Slowing down can feel like slacking off. It’s a mental hurdle more than a physical one.
You’re used to seeing your average pace or power as a badge of honor. Slowing down may feel like regression, even when it’s part of a smarter long-term plan.
Professional triathlete Sarah Piampiano, who made a late switch to endurance sports, talked in interviews about how it took her months to embrace slower paces in training. Once she did, her performance soared, including improved fitness and top finishes at Ironman events.
You should think of your low-intensity days as the foundation that supports your high-performance days. Remind yourself: “Train slow to race fast.” Write it on your water bottle if you need to.
3. Monitoring and Managing Training Zones
Knowing your true training zones and sticking to them is key to balancing training intensity. But this can be tricky, especially if you’re new to structured training or lack the right tools.
Common issues include:
- Relying on outdated max heart rate estimates
- Not adjusting zones for changes in fitness
- Misjudging perceived exertion
Using software like TrainingPeaks or devices like Garmin watches, Wahoo bike computers, or Stryd power meters can help you monitor zones more accurately. Many platforms let you program workouts so you stay within target zones automatically.
4. Not Adjusting Training Plans to Race Demands and Individual Needs
While the 80/20 principle offers a solid foundation, every athlete and race is different. An Ironman requires a different approach than a sprint triathlon. Hilly bike courses, hot weather, or limited training time all affect how you apply the method.
If you’re training for a race like Ironman Nice, which features a challenging mountain bike course, you’ll need more time on climbs, even during low-intensity phases. That might mean adjusting your easy rides to include more time at low cadence or simulated hill intervals, while still staying in your aerobic zone.
Work with elite coaches to customize your plan based on race demands and your own life schedule. If you’re short on training hours, you might need to tweak the 80/20 ratio slightly, but keep the spirit of it intact.
5. Resistance to Change
Finally, there’s often a deep-rooted resistance to change. After all, if you’ve trained a certain way for years, it’s hard to believe that slowing down could make you faster.
This resistance isn’t just about habits but about trust as well. It takes time to believe in a process that feels so different from the norm.
Many athletes implement 80/20 triathlon training after they:
- Read success stories from other athletes
- Track their own progress over 4–8 weeks
- Remind themselves of why they are making the change: for better performance, reduced injury risk, and more consistent results.
Wrapping up
At its core, 80/20 training is about letting go of the “no pain, no gain” mentality and learning to trust that going easier, more often, can actually take you further.
It teaches you patience. It challenges your ego. And it forces you to get comfortable with slowing down on most days, so you can show up strong when it really matters on race day.
That’s why the approach goes beyond just splitting your time between hard and easy workouts. It also builds in recovery, mental preparation, and tapering so you’re not just fit, but fresh and focused when the gun goes off. It helps you stay calm when the nerves kick in, pace smart when adrenaline’s high, and dig deep when things get tough in the final miles.
Elite coaches like Matt Fitzgerald and countless age-groupers who’ve transformed their training swear by 80/20 because it works not just in theory, but in the real world. It’s sustainable. It’s science-backed. And more importantly, it helps you fall in love with the training process, not just the finish line.
If you’re willing to slow down, tune in, and trust the system, the 80/20 approach will get you to your goals, not burn out, but strong, healthy, and excited to race. And if you are looking for personalized triathlon training plans, feel free to contact me and let’s create a plan that fits your goals and current fitness status. You can also check out our coaching services for a tailored training approach.
