Plantar fasciitis (PF) is one of the most common foot issues faced by runners and everyday athletes alike. Often, people report that their symptoms appeared "out of nowhere," whether it’s after wearing a new pair of shoes or completing a marathon. But the reality is, plantar fasciitis doesn't develop overnight. It's the result of accumulated stress, microtears, and underlying factors that have been building up over time.
Let’s break down this misconception using two real-world examples.
Example 1: The One-Star Shoe Review
A reviewer criticized a new model of running shoes, claiming they developed discomfort immediately after their first wear. They mentioned switching from a previous model (a shoe they loved) to the new model, noticing foot issues right away, and concluding the new shoes were the problem.
However, this review overlooks several key points:
-
Underlying Load Accumulation: Discomfort likely didn’t stem from one wear. The plantar fascia was probably already stressed due to repetitive strain, inadequate recovery, or biomechanical issues.
-
Ignoring Contributing Factors: Changes in training volume, terrain, foot mechanics, or even the natural aging process could have been at play.
-
Confirmation Bias: Because they were attached to their previous shoe, any discomfort with the new one may have felt more significant.
While it's true that the wrong shoe can exacerbate existing issues, it's rarely the sole cause. Plantar fasciitis symptoms typically surface when tissue stress reaches a tipping point.
Example 2: Post-Marathon Plantar Fasciitis
Another common scenario: runners reporting plantar fasciitis showing up "immediately" after a marathon. Marathons are physically demanding, but PF doesn’t develop in the span of 26.2 miles. The race simply serves as the final stressor that pushes already overworked tissues past their threshold.
Contributing factors include:
-
Cumulative Mileage: The long months of training leading up to the race gradually load the plantar fascia.
-
Fatigue-Related Biomechanical Shifts: As runners fatigue, their form can deteriorate, increasing strain on the feet.
-
Insufficient Recovery: High training intensity without adequate rest reduces the body’s ability to repair microdamage.
The Zone of Confusion: Why PF Feels Like It Shows Up Suddenly
Here’s where things get tricky—the "Zone of Confusion." This is that frustrating space where your foot feels fine one day, then suddenly it doesn’t. You might think, "It must be the new shoes," or "It must’ve been yesterday’s long run." But plantar fasciitis doesn’t work like that. The pain is the last domino to fall, not the first.
The Zone of Confusion happens because the body is great at compensating—until it isn’t. Microtears in the plantar fascia build up over weeks or months. Your body quietly tries to repair the damage, and you don’t notice anything. But eventually, the stress outpaces the recovery, and pain flares up seemingly out of nowhere. This lag between cause and effect is what makes it confusing.
One day, you’re walking around pain-free. The next, you step out of bed and feel that sharp, stabbing sensation in your heel. It feels sudden, but it’s really the result of a long-term process that’s been brewing under the surface.
So, What Really Causes Plantar Fasciitis?
Plantar fasciitis is the result of cumulative factors such as:
-
Overuse and repetitive strain from running or standing for long periods
-
Sudden changes in training load (mileage, intensity, terrain)
-
Poor biomechanics, like overpronation or tight calf muscles
-
Weak foot muscles and reduced tissue resilience
-
Inadequate footwear support (but not necessarily new shoes alone)
Key Takeaways
-
Plantar fasciitis doesn’t appear overnight. It’s a slow-developing condition masked until symptoms reach a noticeable level.
-
New shoes or endurance events are often just the tipping point, not the root cause.
-
The Zone of Confusion is real, but understanding it helps you avoid misattributing the cause of your pain.
-
Address the underlying issues: Focus on load management, strengthening, flexibility, and proper recovery.
Next time you feel sudden foot pain, instead of blaming the newest variable, take a step back. Look at the broader picture of training, biomechanics, and lifestyle habits to uncover the real source.