README

Fitness Tools is a Python package that facilitates healthy lifestyles using validated, research-backed equations. Whether you’re a wellness professional, veteran gym rat, or just starting your fitness journey, this package will benefit you.

Features

Body Composition — Estimate body fat percentage from skinfold measurements using Durnin-Womersley and Jackson-Pollock (3/4/7-site) equations
Rep Max Estimation — Convert between weight and rep ranges using a validated percentage-of-1RM table
Macronutrient Planning — Calculate daily calorie ranges and macro distributions by body type, activity level, and goal

Quick Start

No third-party dependencies. Python 3.11+ only.

pip install fitness-tools

Body Composition

from fitness_tools import DurninWomersley, Sex

calc = DurninWomersley(30, Sex.MALE, (12, 8, 15, 10))
density = calc.body_density()
body_fat = calc.siri(density)

Rep Max Estimation

from fitness_tools import RM_Estimator

est = RM_Estimator(current_weight=185.0, current_reps=8, desired_reps=1)
result = est.estimate_weight(base=2.5)

Macronutrient Planning

from fitness_tools import MakeMeal, BodyType, ActivityLevel, Goal

meal = MakeMeal(
    weight=150,
    body_type=BodyType.MESOMORPH,
    activity_level=ActivityLevel.VERY,
    goal=Goal.MAINTENANCE,
)
daily = meal.daily_requirements()
per_meal = meal.make_meal(number_meals=5)

API

All public types are importable from fitness_tools:

Category	Classes
Body Composition	`DurninWomersley`, `JacksonPollock3Site`, `JacksonPollock4Site`, `JacksonPollock7Site`
Exercise	`RM_Estimator`
Meal Planning	`MakeMeal`
Enums	`Sex`, `BodyType`, `ActivityLevel`, `Goal`
Data Models	`BodyCompositionResult`, `MacroTargets`, `RepEstimate`

Agent Skills

This package includes 3 skills for AI-assisted fitness calculations:

Skill	Description
`body-composition`	Skinfold-based body fat assessment
`rep-max`	One-rep max estimation via validated percentage table
`meal-planner`	Macronutrient planning by body type

Install

Claude Code plugin — run inside a Claude Code session:

/plugin marketplace add Jeffallan/Fitness-Tools
/plugin install fitness-tools@fitness-tools

skills.sh — from any terminal:

npx skills add Jeffallan/Fitness-Tools

How To Contribute

Read the contributing guidelines
Check the changelog to see where this project has been

All skill levels are welcome and our maintainers will help you in whatever way we can.

License

This project is licensed under the Apache 2.0 License.