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
cycling-training
A modular Claude skill that provides periodization logic, workout design, research-backed protocols, and interpretation guidance for endurance and off-road cycling training — designed to companion an Intervals.icu MCP server, not replace it.
The companion-to-MCP architecture
This skill deliberately holds no data and no calculators. It is the reasoning half of a two-part system:
| Layer | Owns | Examples |
|---|---|---|
| Intervals.icu MCP server (data + computed metrics) | Fetching and computing everything numeric | activities, wellness, power curves, CTL / ATL / TSB, training-load ramp, zones, TSS, best efforts, streams |
cycling-training skill (knowledge + reasoning) |
Deciding what the numbers mean and what to do next | periodization logic, workout design, research-backed protocols, interpretation of trends, confound-aware caveats |
The split is a hard rule. If a script would only reproduce math the MCP API already returns (zones, TSS, load metrics, CTL/ATL/TSB), it is intentionally absent. Ask the MCP server for the number; ask this skill what to do about it.
How they work together (typical flow)
- MCP returns the data — e.g.
get_athlete_summary(CTL/ATL/TSB),get_wellness_data(HRV, RHR, sleep),get_athlete_power_curves,get_activities. - Skill supplies the reasoning — e.g. "TSB is −25 eight days out from an A-race; the taper doc says pull it toward −5 to +5 by race day," or "this VO2 session accumulated little time ≥90% VO2max; the interval doc says lengthen the reps."
- You (Claude) combine them into a recommendation, always citing which layer supplied what.
Repository layout
cycling-training/
├── SKILL.md # Router — loads the right reference doc by need
├── README.md # This file
├── references/
│ ├── durability.md # Fatigue resistance as a trainable quality + field test
│ ├── mtb-xco-demands.md # MTB/XCO demand profile; power governs, HR caveat
│ ├── strength-for-cyclists.md # Heavy strength; masters rationale; from-zero ramp
│ ├── vo2max-intervals.md # Maximizing time ≥90% VO2max; work:rest; rep length
│ ├── periodization.md # Distribution philosophy; base/build/peak; CTL ramp; taper
│ ├── data-confounds.md # HR reliability; power-governs; decoupling/RHR caveats
│ └── citations.md # Master citation list with PMID/DOI — single source of truth
└── assets/
├── plan-template-base.md # Backward-mapped base mesocycle skeleton (3:1 / 2:1)
├── plan-template-build.md # Build block: VO2 + durability + strength integration
└── field-test-durability.md # The ~1,500 kJ → 1-min hill durability field test
Installing as a Claude skill
A Claude skill is a directory containing a SKILL.md with YAML frontmatter (name +
description). To install:
Claude Code (project or personal):
# Personal (available in every project):
git clone <this-repo> ~/.claude/skills/cycling-training
# Or project-scoped (checked in with a repo):
git clone <this-repo> .claude/skills/cycling-training
Claude auto-discovers any SKILL.md under a skills/ directory. The description field in the
frontmatter is what Claude matches against to decide when to load the skill, so keep it intact.
Claude.ai / Claude Desktop: upload or sync the folder as a skill per the current skills UI.
Once installed, this skill loads automatically when you ask cycling-training questions, and it pairs with your connected Intervals.icu MCP server for the live data.
How to read the docs
SKILL.mdis a router, not a manual. It points to the one reference doc that answers the question at hand. Load docs on demand; don't read them all up front.- Every quantitative claim carries a citation (author/year, with PMID/DOI in
citations.md). This is deliberate: it lets future-you verify rather than trust. - Where the mechanism is established but the optimal dose is not, the docs say so — marked
⚠️ under-researched — track individual response. Treat those as hypotheses to test on yourself, not settled protocol.
Scope & honesty notes
- Content is written for balanced road/TT and MTB use; discipline-specific numbers are labelled and not over-transferred (small-n elite XCO data ≠ masters marathon reality).
- This skill gives general training-science reasoning, not individualized medical advice.
Nothing here overrides a physician, and readiness/overtraining calls should use the
confound-aware logic in
references/data-confounds.md, never naive single-number rules.