The Double Threshold Trend Explained

Dr. Gregory Lowe PT, DPT, cert. MDT, CSCS
4 days ago
4 min read

Why is Norway– a small country consisting of about five million people– dominating endurance sports?

We recently saw this dominance in the Winter Olympics, where Johannes Høsflot Klæbo became one of the most decorated Winter Olympians earning six-for-six gold medals across multiple cross-country skiing events– just in these 2026 Milano-Cortina Games! Many of his Norwegian teammates also shared the podium with him.

On the snow, Klæbo leads cross-country skiing; on the track, Jakob Ingebrigtsen has become a household name among track and field fans as he continues to re-shape middle-distance running.

So what’s the secret??

Well, for one, according to this post from author and elite running coach, Steve Magness, some of this dominance is attributed to the fact that youth sports programs in Norway are more sustainable and focused on the “Joy of Sport for All” – as opposed to the typical American method consisting of a more “results–focused” mentality that specializes kids at young age and ultimately leads to many ‘burning out’ by the time they get older.

Additionally, from a physiology standpoint, high VO₂ Max (maximum oxygen uptake) levels are common among Norwegian athletes, and kids typically grow up doing long, low-intensity aerobic work.

To expand on that physiology aspect, Norwegians have mainstreamed high-volume training and lactate-guided threshold training; moreover, in recent years, they’ve popularized the trending “Double Threshold” training among endurance athletes… and that’s the topic we will focus on in this newsletter: double threshold training.

Double threshold workouts, or “double T’s,” have become trendy training methods among distance runners in the past few years as more and more elite athletes and college teams have incorporated that training component into their builds.

So let’s dive into this trendy training topic...

What Is Double Threshold?

We should start by defining threshold training:

Threshold training basically means that an athlete is running (or skiing, biking, etc.) at a comfortably hard intensity. The effort is more difficult than a regular “easy” run and should definitely cause fatigue, but the pace should be manageable enough to handle for a duration of about 20-60 minutes.

Physiologically, threshold pace is equivalent to running at about 86-88% of VO2max, or around 88-92% of max heart rate.

The goal of threshold training is to improve endurance!

Essentially, with threshold workouts, you’re improving the body’s ability to clear blood-lactate for sustained periods– so you’re running as hard as you can right below the line of hitting that “lactic acid” feeling in your legs.

For more about threshold, check out our blog, “Threshold Training: A Key Component to Any Endurance Athlete's Training Plan.”

Now that you have a better understanding of general threshold training, we can discuss that trendy DOUBLE threshold.

Double threshold refers to performing two controlled threshold sessions in the same day, separated by several hours.

Key characteristics of Double Threshold:

Both sessions are run at sub-maximal lactate levels
Pace is controlled — “comfortably hard” effort
Weekly mileage is high
Easy days are truly easy
Fueling and recovery are prioritized

The goal is NOT to hammer the “Double T” workouts…

…the purpose is to accumulate a large volume of aerobic work right below the point where lactate rapidly accumulates.

Physiologically, this improves:

Lactate clearance
Mitochondrial density
Aerobic enzyme activity
Running economy at faster paces

Why This Matters for Recreational Runners

Double threshold is trending, but here’s the reality:

Adding a second threshold session without the volume base, recovery capacity, and fueling to support it doesn’t accelerate progress– it amplifies the body’s stress response.

It’s NOT for everyone– so this emphasizes the importance of having a good evidence-based running coach that can individualize your training!

High-frequency threshold work increases glycogen demand, neuromuscular load, and systemic fatigue; however without a strong foundation, it can cause a breakdown instead of a breakthrough.

Training zones and methods are conceptual tools — not perfect “magic” lines. What matters most is the stimulus relative to the individual athlete.

When Does Double Threshold Make Sense?

Generally, it works best when:

Weekly mileage is already high
Easy days are truly easy
Fueling is consistent and adequate
Recovery markers are stable
The runner has had several years of aerobic development

It’s not a shortcut… in fact, there are NO shortcuts in endurance training.

Consistency over time is the KEY to improving performance.

The Bigger Takeaway

Before chasing a trend, focus on the fundamentals FIRST.

If you’re not supporting your training with a strong aerobic base, proper strength training, quality sleep, and enough fuel to support your training load, then adding double threshold to the mix will only result in burnout, injury-risk, and plateaued performance.

And that’s where coaching matters!

At AWAKEN Performance Rehab, our monthly run coaching is built around individualized programming, performance monitoring, and long-term durability — not trend adoption.

Because the best training plan isn’t the most advanced or “trendy” one– It’s the one that fits YOU.

If you’re wondering whether something like double threshold makes sense for your goals and current fitness, that’s something we can help runners navigate!

And if you're looking for other ways to improve performance, reduce injury risk, or if you have a nagging pain or injury getting in the way of training, WE CAN HELP!

It's our mission at AWAKEN to provide the highest level of care through our process of determining the ROOT CAUSE of your issue, then establishing an individualized plan to help you prevent recurrence and come back stronger than before!