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 targets +5 to +15 by race day, so shed fatigue," or "this VO2 session banked little time ≥90% VO2max; the interval doc says check whether rep length / work:rest kept power in the band."
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.md is 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.

README.md Unescape Escape

cycling-training