RPA Health
Share
It’s no secret that when you don’t feel your best, it’s hard to live your best life. Message us to get started.
RPA Health is your partner in achieving optimal metabolic health, offering personalized functional medicine solutions for health minded professionals who want to stay lean, sharp, and energetic. That's why our team here at RPA Health is ready to help you achieve your health goals! Our health programs include:
Functional Medicine
Clinical Nutrition
Supplemental Health
Personalized Health Coaching
06/10/2026
Four systems determine your performance output.
➡️ Metabolic Buffering
➡️ ANS Balance
➡️ HPA Axis Regulation
➡️ Structural Resilience
None of them are on your standard lab panel.
None of them show up until you measure them directly.
That's not a mystery. It's a measurement gap.
This week's Performance Brief breaks down what each system controls, why standard medicine misses it, and what the actual measurement looks like.
If you don't have scores for all four, you're managing by symptom.
https://joshuabletzingerdc.com/post/four-systems-that-control-performance
Nobody's testosterone crashes overnight. It drifts.
One to two percent per year after age thirty. By forty-five that can be a fifteen to twenty percent loss. And every annual physical along the way reads "normal."
Here's why. The reference range, three hundred to one thousand nanograms per deciliter, was derived from a broad population study.
That study included sedentary men, older men, and metabolically compromised men.
The range was designed to flag disease, not to describe optimal function in a high-output forty-year-old.
So a result of 420 in a forty-something professional is technically "in range."
It's also in the bottom quartile of a range that should not have applied to him in the first place. That is not a clean bill of health.
That is a thirty percent gap from his likely functional ceiling, hiding inside the word "normal."
The drift is upstream-governed.
The HPA axis under chronic load drives the pattern.
Testosterone, thyroid, and recovery follow.
I walk the full model in the Performance Gap Webinar on Saturday May 30, 10am Central.
Registration link in the comments.
05/18/2026
Hormones don't crash. They drift.
When testosterone, cortisol, and thyroid all drift together, the upstream cause is almost never the gland itself. It is the HPA axis under chronic load. And the standard hormonal workup is not built to find it.
Here's what I see in clinic, week after week, in high-output adults in their 30s and 40s.
The testosterone is 420.
The free T3 is at the floor.
The morning cortisol is blunted.
The SHBG is climbing.
Each marker is individually "in range."
Together, they describe a system compensating for a regulatory load no one has named.
That's the gap between disease and decline.
Disease is the endpoint, the moment a marker crosses a threshold and earns a diagnosis.
Decline is the runway, the 18 to 36 months before that, when the system is loaded but still performing.
Most panels are built to find the endpoint.
They miss the runway entirely.
The HPA axis is the upstream regulator. It translates psychological stress, training load, sleep debt, inflammation, and metabolic stress into a single signal: how much cortisol, when.
Under chronic load, that signal breaks down predictably, and everything downstream, testosterone, thyroid, recovery, s*x hormone binding, follows.
Same upstream every time.
I wrote the full breakdown on the blog today.
Three-stage cortisol arc.
Why TSH alone misses thyroid conversion.
What SHBG does to a "normal" testosterone number.
What an HPA-led panel actually measures.
If you've been told your labs are fine and you still feel like you're operating below threshold, the model you're being measured against may simply be the wrong one.
Blog link in the first comment.
Performance Gap Webinar registration also linked there, Saturday May 30, 10am Central.
One number has a floor of 10. The other starts at 0.5. Same protein. Different resolution.
Only one of them tells you anything useful about a high performer.
Standard CRP was built to catch acute disease. High-sensitivity CRP can resolve the chronic low-grade load that erodes performance underneath a "normal" panel.
If you have never had hs-CRP run, you don't have a full picture.
Ask for hs-CRP on your next draw. The clinically useful range is 0 to 3.0. Below 1.0 is optimal. Above 2.0 in a high performer warrants a conversation.
The Performance Gap Webinar covers the full panel logic. Sat May 30, 10am CT.
Register 👉 https://www.rpa.health/performance-gap/live-training-registration-05302026
Click here to claim your Sponsored Listing.
Category
Telephone
Website
Address
Opening Hours
| Tuesday | 9am - 2pm |
| Thursday | 9am - 11:45pm |