The Upsides and Downsides of the 80/20 Rule

At its core, the 80/20 rule is straightforward, yet it becomes convoluted due to the various training zone models available. Some athletes adhere to a 3-zone framework, where 80% of training occurs below the first ventilatory threshold, corresponding to the top of zone 1. Others might rely on a 5-zone heart rate model, with easy efforts classified within zones 1 and 2. Additionally, many follow a 0–10 RPE scale, using their perceived effort to guide easy training.

Regardless of the system you choose, the essence of the 80/20 rule remains unchanged: the majority of your running should be at an easy pace, with a small fraction dedicated to higher intensity. On the surface, this approach appears logical. Training at a low intensity aids in building an aerobic foundation, optimizing fuel usage, and reducing injury risk. However, there is a significant caveat to consider:

The 80/20 rule is primarily applicable to those who run extensively.

I was reminded of this when I recently viewed a YouTube short on zone 2 training. The presenter emphasized that 80% of our training volume should occur in zone 2 for optimal cardiovascular performance. While the argument was compelling, a critical component was overlooked.

He cited Tadej Pogačar, the reigning Tour de France champion, as an example, suggesting that his success stems from this training philosophy. While this may hold some truth, it’s essential to recognize that Tadej dedicates 20–30 hours weekly to perfecting his craft—something most of us cannot feasibly manage. From the outset, this "rule" was an observation of elite athletes and was never intended to serve as a blanket guideline for everyone.

Now, while cycling and running differ, we can draw parallels to elite runners like Cam Levins, who logs 150-200 miles weekly. The reality is that most of us lack the capacity or resources to train like these elite competitors, meaning optimal training looks quite different for the average runner.

“I want runners to think more critically than blindly following any rule. We should always be listening to our bodies and doing what works best for us, not necessarily what some arbitrary rule says.” — Jason Fitzgerald, Running Coach

Unfortunately, this advice is often stripped of its elite context and presented as a universal training standard. Compounding the issue is the fact that there are far more novices than professionals in this sport, leading many to adhere to a system not designed for them. To illustrate this point, consider the following example…

If you’re a novice runner putting in three sessions per week, achieving a precise 80/20 ratio of easy to hard work is quite challenging. I would argue that one hard session alongside two lighter runs is a more effective approach, allowing for adequate recovery. While this may deviate from the 80/20 mark, it’s likely to yield better long-term results.

For intermediate runners, who often train five to seven times weekly, two hard sessions can mean that up to 40% of their training volume is at a higher intensity. Is this inherently wrong? Not at all—if you are well-conditioned and prioritize recovery and nutrition.

Beyond being a beginner, there are various scenarios where strictly following the 80/20 rule may not be ideal. These include:

• Training during the offseason with a focus on building a base
• Competing when volume is low but intensity remains high
• Preparing for an ultra where threshold training is not prioritized
• Recovering from an injury
• Preferring easier workouts over speed work

In any of these situations, adhering rigidly to an 80/20 framework can hinder your progress. It’s a tough realization for many who have chased this standard, but acknowledging it is crucial for moving your training forward constructively.

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