Chris Farhood
f6dd9dfc27
Modular cycling-training skill: periodization logic, workout design, and research-backed protocols that companion an Intervals.icu MCP server (the server owns all data + computed metrics; the skill owns knowledge + reasoning). Structure: - SKILL.md router + README (companion-to-MCP architecture, install steps) - references/: durability, mtb-xco-demands, strength-for-cyclists, vo2max-intervals, periodization, data-confounds, citations - assets/: base + build plan templates, durability field-test protocol Every quantitative claim carries an inline citation; citations.md is the single source of truth with PMID/DOI, each verified against PubMed on 2026-07-20. Notable honesty flags baked in: - VO2 rep-length: running (Fleckenstein 2025) vs cycling (Ronnestad) conflict documented rather than asserted; cycling evidence favors short intervals. - 'Yu et al. 2025' (frequency > distribution) could not be found; not cited. - Under-researched doses (durability, taper TSB, CTL ramp) flagged 'track response'. - HR-confound doc forbids naive decoupling<5% / RHR+5 rules. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01TqrhBhC3GEcKyaw8RTk8G6
77 lines
4.3 KiB
Markdown
77 lines
4.3 KiB
Markdown
# Data confounds — when to trust HR, RHR, HRV, and decoupling
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**Load this doc when:** interpreting heart rate, resting HR, HRV, sleep, or aerobic decoupling —
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i.e. any time a number is about to drive a training decision.
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**Data/knowledge split:** MCP gives you the raw and computed signals (HR streams, RHR, HRV, sleep,
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readiness, decoupling). This doc governs **whether that signal is trustworthy today** and forbids
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naive single-number rules.
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---
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## Core stance: power governs; HR is conditional
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**Prescribe from power.** Heart rate is a *response* variable contaminated by many non-training
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factors. Use HR only where it is genuinely informative:
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- **Aerobic decoupling on steady rides** (Pw:HR drift) — valid only on steady efforts.
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- **Recovery trends** (RHR, HRV) — as *trends*, screened for the confounds below.
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Do **not** use HR to prescribe or judge intensity for **intermittent** efforts — see the MTB
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dissociation below.
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## The confounds (screen every HR-based signal against these)
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Any of these can move HR, RHR, HRV, or decoupling independent of fitness or fatigue:
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| Confound | Effect | Implication |
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|---|---|---|
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| **Heat / dehydration** | ↑ HR, ↑ cardiac drift, ↑ decoupling | High decoupling on a hot ride ≠ poor fitness |
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| **Alcohol** (prior evening) | ↑ RHR, ↓ HRV, disrupted sleep | A bad HRV morning after drinking is not overtraining |
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| **Travel** (jet lag, altitude, transit) | ↑ RHR, ↓ HRV, poor sleep | Expected; not a training signal |
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| **Poor / short sleep** | ↑ RHR, ↓ HRV, ↑ perceived effort | Fatigue signal, but from sleep — adjust the day, don't panic |
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| **Illness / stress / caffeine timing** | ↑ RHR, altered HRV | Interpret in context, not in isolation |
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| **Intermittent effort (MTB)** | HR lags surges; VO2 stays high on descents | HR mis-reads MTB intensity entirely (see below) |
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## ⚠️ The MTB / intermittent-effort dissociation
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In intermittent off-road riding, **HR, power, and VO2 dissociate**: VO2 stays elevated on descents
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where power drops, and HR lags the short bursts that define the effort. In XCO, %VO2max did **not**
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correlate with %HRmax or %MAP (Hays et al. 2018, *Front Physiol* 9:1062; PMID 30158873;
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DOI 10.3389/fphys.2018.01062). **For MTB, HR is unreliable for intensity — power governs.** See
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`mtb-xco-demands.md`.
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## Do NOT hardcode naive rules
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These single-number rules are **wrong as written** because they ignore the confounds above:
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- ❌ "**Decoupling < 5% = fresh / fit**." Decoupling is inflated by heat, dehydration, fueling, and
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any non-steady effort. It is only interpretable on a **steady** ride in **controlled conditions**,
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and even then as a **trend**, not a threshold. High decoupling on a hot, long, or surgey ride tells
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you little about fitness.
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- ❌ "**RHR + 5 bpm = overtrained**." A single elevated RHR morning is far more often alcohol,
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short sleep, travel, heat, or illness. Overtraining/non-functional overreaching is a **multi-signal,
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multi-day** picture (RHR trend + HRV trend + performance + mood + sleep + training load), never one
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morning's number.
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**The correct pattern:** look at **trends across days**, **corroborate across signals** (RHR + HRV +
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sleep + performance + subjective), and **explain-away confounds first** before attributing a change
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to training fatigue.
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## Using decoupling for durability (the one HR job that's valid)
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On a **steady** endurance ride, Pw:HR decoupling is a reasonable aerobic-durability signal: as
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aerobic fitness/durability improves, HR drifts less for the same power late in a long ride. Use it:
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- Only on **steady** rides (not intervals, not MTB).
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- Only when **conditions are controlled** (not a heat outlier, not dehydrated, not post-alcohol).
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- As a **trend** across comparable rides, alongside the power-based durability field test
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(`../assets/field-test-durability.md`), which is the more direct measure.
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## Practical workflow
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1. Pull the signal from MCP (HR stream, RHR, HRV, sleep, decoupling, readiness).
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2. **Screen for confounds** (table above). If a confound is present, discount the signal.
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3. **Corroborate** across signals and across days before acting.
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4. **Prescribe from power**; use HR only for steady decoupling and recovery trends.
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5. When signals conflict and confounds are present, **default to caution** (easier day) rather than
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trusting one number in either direction.
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