When Running Stops Looking Like Running

In Episode 14 of the Stimulus Matters Podcast, Kyle Ruth and Ryne Sullivan dive into one of the most misunderstood elements in functional fitness: running for CrossFit athletes.

After seeing the disconnect in his own training, placing 3rd in the clean & jerk event at the Games with zero recent lifting, but 17th in the 7K run after months of dedicated running, Kyle opens up a broader conversation: Why does run training often fail to translate in the CrossFit space?

The answer? Because running in CrossFit isn’t traditional running.

Running as a Strength-Dominant Sport Skill

One of the most striking insights from the episode: Many CrossFit athletes are naturally strong, dense, and posterior-chain dominant. They’re built for barbell work, not mile repeats.

Yet these same athletes are being handed generic run programs designed for endurance athletes, creating a mismatch in both training stimulus and recovery demands.

Ryne points out that CrossFit runners:

• Have lower lifetime mileage
• Often rely on lower cadence and overstride mechanics
• Struggle more with longer repeats than short bursts

All of which should shape how you program—and what adaptations you prioritize.

Stride Rate Matters More Than You Think

Kyle shares his personal struggle as a 160–165 SPM (strides per minute) runner, which loads the muscular system heavily. Compare that to an athlete like Toby Buckland, running at 180+ SPM, relying more on elasticity and less on brute force.

That difference alone can dictate how athletes handle:

• Running under fatigue
• Box jump or double under transitions
• Recovery in mixed modal workouts

So while cadence might sound like a minor technical note, it’s one of the most important diagnostics in CrossFit-specific running.

Programming for Performance vs. Physiology

Another key takeaway from the episode: Just because someone has a strong 5K time trial doesn’t mean they can run well in a metcon.

Ryne breaks down how running as part of a CrossFit workout introduces variables that completely change the stimulus:

• Posterior fatigue from deadlifts crushes stride length
• Forearm pump from dumbbells affects breathing rhythm
• Heart rate stays elevated from previous movements

Because of this, elite coaches like Ryne will often separate standalone run training from mixed modal run training—both need to be programmed and trained differently.

The Treadmill Trap (And Why it Matters)

A fascinating section covers why treadmill running favors heavier athletes. Due to mechanical advantages on self-powered runners, heavier athletes can artificially improve times—masking flaws in road mechanics.

This matters in CrossFit because:

• Events now often use air runners or treadmills
• Treadmill adaptation doesn’t always transfer to road or field runs
• Movement economy suffers when athletes don’t understand the difference

So if you’re only testing and training on the air runner, you’re likely missing major adaptations needed for real-world performance.

Lactate Threshold, Neuromuscular Load, and “Feeling Fast”

Kyle and Ryne also cover lactate threshold and how CrossFit athletes often misuse zone training—pushing too hard in sub-threshold work, and failing to build sustainable effort ranges.

Their solution? Teach athletes to “run easy so they can run fast”, using long, low-intensity runs to build not just aerobic base, but the psychological confidence to relax under fatigue.

For Kyle, simply running long and easy helped him:

• Build repeatability in metcons
• Smooth out transitions between movements
• Feel in control during running workouts—without blowing up

Takeaways for Coaches and Athletes

This episode is packed with practical insights you won’t find in your average endurance book or Metcon template. Some of the key lessons:

• Running in CrossFit is its own skill—and it should be trained accordingly.
• Stride rate, mechanics, and fatigue profile must inform your running strategy.
• Treadmill data is deceptive—don’t let it fool you into thinking you’re more prepared than you are.
• Long, easy running has carryover to your Metcons and repeatability—even if it’s not sexy.

Final Thought:
There’s no one-size-fits-all approach to run training for CrossFitters. But if you start by understanding how movement, fatigue, and mechanics interact—you can finally stop wasting time running and start getting better at it.