The Claude Training Plan Skill: how Claude builds plans that actually fit you

You ask Claude for a training plan — Claude delivers. It looks reasonable. Usually it is. The catch: the model never tells you what it assumed about you. Anthropic introduced Skills for exactly this problem — instruction sets that force Claude to ask the right questions first. I built one specifically for training planning.

What bothers me about standard AI plans — and why I built this myself

The problem with generic AI plans is not that the models are bad. The problem is the missing structured input beforehand. Without guidance, Claude fills information gaps with default assumptions. The result is a plan that fits somebody — just not the person actually asking.

17 years of coaching practice sit behind the question structure in this Skill — not as a claim to completeness, but as a distillate. The real work was not cramming in as many questions as possible. It was figuring out which questions actually matter — because more questions don't bring an LLM closer to the goal, they tend to confuse it. Too much context produces errors, not precision. The current version hits the sweet spot I consider right for v2.3.3 — more questions only get added once they prove necessary in practice.

Mixed training: the goal type most tools ignore

Running and strength — most apps handle those somehow. Mixed training — meaning both at the same time — is either ignored or handled badly. And yet that is the reality for most serious athletes. Runners who skip strength work neglect injury prevention and leave performance on the table. Strength athletes who cut cardio entirely run into recovery issues in the medium term.

The fact that strength and endurance can interfere with each other is accounted for. Which combination on which day, how much spacing between hard sessions, where strength and endurance training actually get in each other's way — and where that fear is overblown. That is not theory, that is what remains after thousands of plans.

What you actually get — concretely

The output is not a template with your name on it. The plan is built around your goal and your time frame — plus supplementary work tailored to your injury history and equipment. For runners: bpm values for heart-rate zones, pacing, strides, interval structure. For strength athletes: progressive overload, RPE guidance, set and rep structure by goal. For mixed: strength and endurance work coordinated so they don't sabotage each other.

And then it continues. After each training week you give Claude your log — it reads it, spots patterns, adjusts. Same pain twice: plan modification. Three times: recommendation to see a physio. This is not a one-shot output. It is a system that runs alongside you.

What the Skill cannot do — and why that matters

It does not replace a good coach. The questions in the Skill come from the same hands-on experience — the issue is elsewhere: a real coach branches in real time. They hear an answer, pull three new questions out of it, prioritise on the fly. That complexity, built up over thousands of cases, cannot be fully captured in an instruction set.

What the Skill does do: deliver a substantially better starting point than a generic prompt for everyone without access to good coaching. The prompt paradox still applies — anyone who knows a lot about building a training plan via an AI chatbot will get more out of the Skill. If you'd rather work with Gemini instead of Claude: the TheFitFuturist Gemini Gem for training planning follows the same principle — same sports-science foundation, different model. No AI account? free training plan generator — browser-based, no setup.

Nutrition, mobility and recovery are deliberately left out. A tool that tries to do everything at once does none of it well. Training planning first — the rest comes in later versions.

A real example — including a point worth thinking about

Here is a real output from a test assessment: 12-week mixed plan, general fitness, intermediate level. HR zones with real bpm, deload weeks, injury-prevention anchors, pacing estimate with caveats.

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Assessment: Claude asks first

Output: the finished plan

Attentive readers will have spotted something: Claude only suggests running 1× per week — the second run is optional. That is not best practice for a mixed plan. This is exactly what follow-up questions are for — and exactly where the prompt paradox kicks in: anyone who knows what a good plan looks like can see where to steer. Version 2.3.3, not a finished end product.

Installation: 2 minutes

Works with any Claude account, free or paid. The only requirement: "Code execution and file creation" enabled under Settings → Capabilities.

• Download the ZIP: github.com/ChrisSportiveGrwoth/TheFitFuturist → folder claude-skills/tff-trainingsplan-skill/

• In Claude: Settings → Customize → Skills → upload the ZIP

• New chat, describe your training goal — Claude starts the assessment automatically

For anyone who wants to look inside: what is under the hood

A lean main Skill with three goal-type sub-Skills — no fine-tuning, no RAG, no API wrapper. Prompt engineering in file structure.

• SKILL.md — main Skill: assessment logic, routing, mandatory rules

• runner.md / strength.md / mixed.md — goal-type sub-Skills with specific output formats

• assessment.json — structured question logic incl. few-shot examples

A side observation: I checked the Skill against Anthropic's own prompt engineering best practices and built an experimental version — XML tags, compressed rules, few-shot examples, everything that gets recommended. In our tests the experimental version performed worse than the original. Whether that is down to the task, the Skill format or the tests, practice will tell. As of now: the "worse" version by best-practice standards delivers better results.

Tested against 41 synthetic test personas across 10 categories — beginners, seniors, people with injury history, athletes who hate cardio, powerlifters, ultrarunners. Current version: v2.3.3.

If you use it and find weak spots: open an issue on GitHub or send an email.