3 Hour Run
3 Hour Run
Designed for Marathon runners
Intensity
Easy to Moderate
Recovery
none — continuous run
Exertion
9/10
Periodization
General Period, Extension Block
Context & Details
Cytokines are a broad and loose category of small proteins important in cell signaling in the human body.
There is a cytokine called interleukin-6 (IL-6) which plays a variety of roles in coordinating our body’s response to tissue trauma and stress — including the stress of and trauma associated with exercise. During exercise, large amounts of IL-6 are released into the bloodstream by the muscles and travel to organs throughout the body.
IL-6 is an agent which causes fatigue by inhibiting motor impulses sent from the brain to the muscles.
It may seem like IL-6 is to be avoided by runners, however, its presence and production is something to embrace.
Author Matt Fitzgerald, in his book Brain Training for Runners, explains:
In addition to causing fatigue during running, IL-6 is believed to facilitate many of the body’s adaptions to exercise training, ranging from increased fat burning to greater resistance to muscle damage to improve cognitive function. Meaning the very molecule that causes fatigue during exercises helps you become fitter after exercise.
The primary trigger for IL-6 release during exercise is glycogen depletion.
Since glycogen depletion produces high levels of IL-6, and because IL-6 coordinates many fitness adaptions to training it follows that training in a glycogen state will tend to produce stronger training adaptations.
You may have heard about Glycogen Depletion Runs, as it is becoming a key training staple used by more and more marathoners at all levels.
The desired training adaption of these runs is to increase glycogen storage capacity in the runner’s muscles and organs and elicit a shift towards better developed fatty acid metabolization.
The traditional practice of a Glycogen Depletion Runs is to start and sustain running for 90+ minutes in a fasted state, but this method is very traumatic on the body and comes with a long recovery penalty — it can take several days or a couple of weeks to recover from this severe of a training activity.
However, by understanding IL-6, its triggers and its role in the body, a marathoner does not need to perform Glycogen Depletion Runs to increase glycogen storage and develop fat utilization. IL-6 shifts the focal point of import away from the training activity itself to the activities which follow afterward.
A glycogen depleting run, like today’s workout of easy to moderate 3 hours running, acts as a catalyst to release IL-6.
Longer runs (90+ minutes) — with or without glycogen intake before or during the run — result in glycogen depletion. Within 24 - 48 hours after longer runs, muscle glycogen is not fully replenished and there is still lingering muscle damage. When these conditions are present, recovery runs actually become “workouts” which elicit strong training adaptions, as Fitzgerald details:
Instead of promoting recovery, recovery runs actually enhance running fitness by challenging the runner to perform in a glycogen-depleted state. Thanks to IL-6, short, slow easy runs will increase fitness. Prefatigued running also alters the muscle recruitment patterns used to produce movement. The brain tries to avoid using the worn-out muscle fibers and instead involves fresher muscle fibers that are less worn-out precisely because they are less preferred under normal conditions. When the brain is forced out of its normal muscle recruitment patterns it finds neuromuscular “shortcuts” that enable you to run more efficiently in the future.
Traditional Glycogen Depletion Runs are can be so taxing that little to no running happens in the 24 - 48 hours afterward, so runners miss out on the training benefits recovery running in this state offers. But an easy to moderate 3-hour run should be less taxing for the marathoner, allowing for more running to take place in the days afterward, and resulting in an overall stronger training adaption.
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Good books on Marathon training
Advanced Marathoning by Pete Pfitzinger
Run Faster from the 5K to the Marathon by Brad Hudson
Running Rewired: Reinvent Your Run for Stability, Strength, and Speed by Jay Dicharry
Hansons Marathon Method: Run Your Fastest Marathon the Hansons Way by Luke Humphrey