The Reply Loop — Your Pacer Wiki

Definition

The reply loop is the channel through which your subjective input reaches the coaching engine. Each email sometimes ends with a single specific question — a talk test, a breathing cadence check, a perceived-effort score — and your reply feeds back into the plan the following week. It is selective (not every email asks), targeted (never a quiz), and structurally acknowledged (you see what your reply changed).

The mechanics sit inside a pure email flow, with no app, no form, no survey UI. Reply in natural language whenever you choose. The extractor parses structured values where present; the coach reads the rest.

Why it matters to runners

Heart rate and pace, taken alone, cannot reliably distinguish certain states. The AeT entry spells this out: a 30-minute plateau can be the real aerobic threshold or an LT-zone plateau that has not yet started to drift. Without subjective cues, heart rate data remains ambiguous in those borderline weeks.

The reply loop is how Your Pacer resolves that ambiguity without asking you to wear more sensors or run lab tests. One targeted question when the device signal needs calibration, nothing when it does not. Most weeks you will not see a question; on the weeks that matter, you see one.

When we ask

A question is added to the weekly letter when any of the following holds:

The AeT trend across recent sessions is ambiguous — not clearly confirming, not clearly rising.
Your AeT / AnT ratio sits in the ADS-border band (~0.88 to 0.92), where small signal changes matter.
It has been four or more weeks since you last gave a subjective input.
You are in your first two weeks on Your Pacer, and the system still lacks enough device data to calibrate.
The two independent AeT estimators (single drift test vs. multi-session trend) disagree by more than 5 bpm.

In a typical week with clean data and high-confidence estimates, the email ends with an open reflective question — not a calibration probe. The calibration question only fires when it earns its place.

What we ask

One of three question types, matched to the current ambiguity:

Talk test. "After the last interval, could you say three full sentences, or only a few words?" Full sentences suggests Z1–Z2; words only suggests Z3 or above. A binary, high-signal check most useful when the trend suggests the session ran hot.
Breathing cadence. "Was your breathing 3:3 — three steps in, three out — or 2:2?" 3:3 is typically AeT or below; 2:2 is typically at or near threshold. Discriminates Z2 from Z3 cleanly, most useful in borderline weeks.
RPE (1 to 10). "How did the session feel on a 1 to 10 scale?" The broadest of the three, used in the first calibration weeks or when the current device data is thin.

One question per email. Reply in one short line — "full sentences" / "3:3" / "6" is enough. A longer answer is always welcome, but the mechanic works with a single word.

What happens to your reply

Your reply is read automatically, parsed for the structured value (talk-test type / cadence / RPE score), and stored in your memory alongside the session it references. The next letter — weekly, pre-workout, or post-workout — opens with a short acknowledgment naming your reply and how it landed in the plan. That is the closing of the loop: you see the answer you gave, and you see the adjustment it drove.

When a reply indicates the last session ran hotter than prescribed (words only on a threshold session, 2:2 on a run that should have been Z2), next week's target shifts downward — a slower threshold pace, a lower HR ceiling on easy days, or a rescheduled quality session. When a reply indicates room to push (full sentences on what was supposed to be hard), the progression steps up slightly.

Related terms

AeT — the estimate most often in need of reply-loop calibration.
HRV — a different recovery signal that feeds the same convergence read.
Intensity Zones — what the calibration ultimately refines.
HR Drift Test — the device-only counterpart that the reply loop disambiguates.