Why Even Small Exercises Can Feel Overwhelming: The Science Behind Your Pain
If anyone’s ever dismissed the pain or fatigue you feel after the tiniest bit of exercise as “all in your head,” let’s stop right there.
Science is on your side, and Bud Craig’s homeostatic model of pain explains exactly why this happens.
It’s not about muscle damage or injury—it’s about how your body manages (or struggles to manage) balance.
Why Does Exercise Feel So Hard?
Craig’s research flips the old ideas about pain on their head. Pain isn’t just caused by visible damage like tears or injuries—it’s your body’s way of saying something is out of balance. When you push beyond what your body can handle, even slightly, here’s what can happen:
Inflammation
Your body might react to exercise by kicking off an inflammatory response if it’s not ready to handle the stress.Metabolic Waste Buildup
Exercise creates byproducts like lactic acid, which lowers the pH in your muscles. If your body isn’t conditioned to clear this waste efficiently, it can trigger pain and discomfort.
Why This Doesn’t Show Up on Scans
Here’s the frustrating part: modern medical technology isn’t designed to “see” this kind of pain.
There’s no visible injury or damage to point to on an MRI or X-ray.
Because of this, many people are unfairly dismissed by doctors, told their symptoms are psychological, or simply not believed.
This creates a vicious cycle:
Frustration and Emotional Burnout: Not being taken seriously is exhausting.
Stress Response Overload: Emotional distress ramps up your body’s stress system (the sympathetic nervous system, or SNS), worsening inflammation and pain sensitivity.
A New Way to Understand Pain: Nociplastic Pain
The kind of pain many people with POTS experience, especially after exercise, fits into a groundbreaking new category called nociplastic pain.
Unlike pain caused by injury (nociceptive pain) or nerve damage (neuropathic pain), nociplastic pain is driven by how the nervous system processes pain signals, even when there’s no visible tissue damage or structural issue.
This revolutionary definition validates the experiences of people with persistent pain, showing that their pain is real and rooted in biological changes—not in their imagination.
For people with POTS, this recognition can be a game-changer, offering hope and paving the way for better understanding and treatment.
Finding Your “Exercise Tolerance Window”
For people with POTS, exercise tolerance is like walking a tightrope.
Your body has a narrow window of what it can handle, and stepping outside of it—even a little—can trigger a cascade of symptoms.
When you exceed your threshold:
The Fight-or-Flight System Kicks In
Your SNS goes into overdrive, increasing your heart rate, inflammation, and stress hormones.Tracking Can Help
Using tools like the ELITE HRV app, you can monitor your heart rate variability (HRV). A lower HRV means your body is in a stressed, inflamed state. Recognizing these signs early can help you adjust before things spiral.
This Isn’t Your Fault
Feeling this way after exercise isn’t a sign of failure—it’s your body telling you it needs to start smaller and slower.
Recovery isn’t about pushing harder; it’s about finding your unique window of tolerance and working within it.
Over time, with patience and the right approach, your body can learn to handle more without pushing back.
Trust the process, respect your limits, and know that your experience is valid—even if the medical world doesn’t always make you feel that way.
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