A highly professional AI fitness trainer skill for Claude Code, providing evidence-based training advice, nutrition planning, progress tracking, motivation coaching, safety guidance, and supplement recommendations.
This skill transforms Claude Code into a certified fitness coach and nutritionist with over 10 years of practical experience. It combines sports science expertise with empathetic mentorship to deliver personalized, actionable fitness guidance.
- Training Advice: Workout programming, exercise technique, progression planning
- Nutrition Guidance: Meal planning, macronutrient calculation, dietary restriction handling
- Progress Tracking: Data-driven analysis and feedback on fitness metrics
- Motivation & Behavior Change: Goal setting, plateau breaking, habit formation support
- Safety & Injury Prevention: Pain assessment, exercise modification, referral guidelines
- Scheduling Assistance: Workout plan adjustments based on availability
- Supplement Recommendations: Evidence-based guidance on vitamins, minerals, and performance enhancers
- Educational Approach: Explains the "why" behind recommendations for informed decision-making
When activated, the skill follows a structured thinking process before each response:
- Learning Goal Priority: Safety > Correction > Planning > Motivation > General knowledge
- Assess Knowledge Level: Tailors explanations for beginner, intermediate, or expert users
- Check Available Data: Uses user-provided information (goals, fitness level, limitations, training history)
- Apply Progressive Disclosure: Provides only what's needed immediately, with option to elaborate
- Safety Check: Prioritizes safety if pain, injuries, or health risks are mentioned
Use this prompt - filled with your information - to give the LLM all the information it needs about you and your goals to get your results faster and more precise.
I need help with my fitness. Here's my profile:
- Age: [AGE "21 years old"]
- Gender: [GENDER "male"]
- Weight: [WEIGHT "75 kg"]
- Height: [HEIGHT "180 cm"]
- Main Goal: [GOAL "build muscle"]
- Fitness Level: [LEVEL "beginner"]
- Training Days: [DAYS "3 times per week"]
- Training Location: [LOCATION "gym"]
- Available Equipment: [EQUIPMENT "barbells, dumbbells, machines"]
- Any Limitations: [LIMITATIONS "none"]
Please help me with [REQUEST "create a training plan"].
fitness-trainer/
├── SKILL.md # Main skill definition
├── CLAUDE.md # Project instructions for Claude Code
├── README.md # Project description
├── CHANGELOG.md # Changelog
├── LICENSE
├── examples/
│ └── example-interactions.md # Example interactions
└── references/
├── nutrition-reference.md # Nutrition guidelines
├── supplements.md # Supplement recommendations
└── exercises/
├── abdominals.json # Abdominal exercises
├── abductors.json # Abductor exercises
├── adductors.json # Adductor exercises
├── biceps.json # Biceps exercises
├── calves.json # Calf exercises
├── cardio.json # Cardio exercises
├── chest.json # Chest exercises
├── forearms.json # Forearm exercises
├── full-body.json # Full-body exercises
├── glutes.json # Glute exercises
├── hamstrings.json # Hamstring exercises
├── lats.json # Latissimus exercises
├── lower-back.json # Lower back exercises
├── neck.json # Neck exercises
├── quadriceps.json # Quadriceps exercises
├── shoulders.json # Shoulder exercises
├── traps.json # Trapezius exercises
├── triceps.json # Triceps exercises
└── upper-back.json # Upper back exercises
The main skill definition includes:
- Identity & Role: Certified fitness coach and nutritionist profile
- Thinking Process: 5-step internal reasoning before responses
- Core Responsibilities:
- Core Coaching
- Workout Programming
- Nutrition Guidance
- Progress Tracking
- Motivation and Behavior Change
- Safety and Injury Prevention
- Knowledge Integration: Primary (user data), Secondary (science principles), Didactic (concept explanations), Limits (no medical advice)
- Guiding Principles & Style: Progressive disclosure, formatting rules, tone guidelines
- Specific Constraints: What to always do and never do
- Onboarding Protocol: 3-block initial assessment process
- Reference Data: Evidence-based guidelines (REF-1 through REF-8)
- Example Interactions: Practical usage scenarios
- Caloric needs by activity level
- Macronutrient distribution and protein goals
- Meal structure and portion guides
- Budget-oriented nutrition planning
- Allergy and intolerance substitutions
- Medical restrictions (diabetes, hypertension, kidney disease)
- Cultural and religious diets
- Dietary framework comparisons
- Seasonal and regional food access
- Personalization decision logic algorithm
- Hydration guidelines
- Evidence-based supplement ratings
- Tier 1: Strong evidence (Creatine, Protein, Vitamin D3+K2, etc.)
- Tier 2: Moderate evidence (Omega-3, Magnesium, Zinc, etc.)
- Tier 3: Weak evidence/situational
- Timing and stacking guide
- Safety rules and quality standards
See examples/example-interactions.md for detailed scenarios including:
- Training plan request for beginner weight loss
- Injury/pain management (knee pain after running)
- Nutrition planning with allergies and budget constraints
- Progress tracking analysis (strength progression)
- Motivation and plateau breaking strategies
See LICENSE for license information.
Fitness Trainer v2.3.0 - © 2026 itsmarian | All Rights Reserved!
Disclaimer: This AI fitness trainer provides evidence-based guidance for general wellness and fitness purposes only. It does not replace professional medical advice, diagnosis, or treatment. Always consult with qualified healthcare providers before starting any new exercise or nutrition program, especially if you have pre-existing conditions, injuries, or health concerns. The information is tailored based on the details you provide, but individual results may vary. Stop any activity that causes pain or discomfort and seek professional help if needed. Use this guidance at your own discretion and risk.