ZYRA

Training and nutrition, by the numbers

The gym and the kitchen,
tracked honestly.

Two focused apps — one for training, one for food — and the whole set of formulas they run on, published here for anyone to read, check and use for free. No ads, no data sold, no numbers we can’t stand behind.

Open Zyra NutritionOpen Zyra Workouts
  • Your data is yours — export or delete it, any time
  • No ads, no third-party trackers in the apps
  • Every formula published, with worked examples
  • Training guidance, never medical advice

Each app’s own screens, rebuilt from its design system — Zyra Workouts’ shipped dark theme and Zyra Nutrition’s dark design. Sample data.

Trybench press 1RMhow big should a deficit be3-day full body

The apps

One for the gym. One for the kitchen.

Built by the same people, on one account and one backend. Use either on its own — or both, and the numbers line up.

Zyra Workouts

Web app · offline-first

Live

Log a set in seconds, then see what your own training says — volume, muscle balance, consistency — without handing it to anyone.

A worked example, not a screenshot: check it in the 1RM and plate calculators.

  • A keypad built for the gym: sets, reps, weight in seconds
  • Warm-ups, drop sets, failure sets, left/right sides, partials
  • Supersets, a rest timer with presets, per-exercise overrides
  • Plate math that knows which plates your gym actually has
  • Works fully offline — an account is optional
Open Zyra Workouts

Runs in your browser at workout.zyra.fit — on an iPhone, Add to Home Screen installs it. Still in active development and not yet on the App Store; what is built and what is not.

Its math, free here: 1RM · Plate · RIR / RPE converter · Warm-up set builder · Weekly sets

Zyra Nutrition

Web · nothing to install

Live

A short setup turns your goal into daily calorie and macro targets, then food logging and a weight trend show whether they are working.

A worked example, not a screenshot: check it in the macro calculator.

  • Food log: 540,000+ foods, barcode and label scanning, real portions
  • Recipes and plates; import a recipe from a link, text or photo
  • A weekly check-in that reads your expenditure and re-plans targets
  • Weight trend, weigh-in calendar, day nutrient explorer
  • Local-first: your log stays on your device and works offline
Open Zyra Nutrition

Runs at nutrition.zyra.fit in your browser; an iOS app is in development. What it does.

Its math, free here: Macro · Calorie · Calorie deficit · Protein

  • One account, one backend. Both apps are clients of the same Zyra backend. In Zyra Workouts the account is optional — the app works fully offline without one.
  • Sync backs you up; it does not mine you. When you do sign in, sync exists to restore your data on a new device. No ads, no third-party trackers or analytics SDKs; usage events go only to our own server.
  • Where things stand. Zyra Workouts is live as a web app at workout.zyra.fit and under active development, with no store listing yet. Zyra Nutrition is live and under active development. This page changes when that does.

Free tools

The same arithmetic, with the working shown.

Nine calculators running the formulas the apps run — no sign-up, no email. Runs in your browser — nothing you type is sent anywhere.

Macro calculator

Daily calories and protein, fat and carb grams from the Zyra Nutrition v2 formula.

Open →

Calorie calculator

BMR (Mifflin-St Jeor), activity multiplier and TDEE, with maintain / lose / gain targets.

Open →

Calorie deficit calculator

Weekly rate to a daily deficit, with the 35% cap and calorie floors the algorithm applies.

Open →

Protein calculator

Grams per day from body weight and a protein tier — the same table Zyra Nutrition uses.

Open →

1RM calculator

Estimated one-rep max from a set (Brzycki to 12 reps, Epley above) and a rep-max table.

Open →

Plate calculator

Plates per side for a target bar weight from your plate inventory, in kg or lb.

Open →

RIR / RPE converter

Reps in reserve to rate of perceived exertion and back, with the app's clamps.

Open →

Warm-up set builder

A warm-up ramp to a top set, every row rounded to a load you can actually put on the bar.

Open →

Weekly sets calculator

Working sets per muscle for a planned week against the app's landmarks, plus a balance score.

Open →

Reference

Generated from the apps’ own data.

The exercise catalogue, the volume landmarks and the program rules the apps use — published as pages you can read, check and link.

Exercises61

Muscles worked, rep targets, progression step, alternatives.

Muscle groups11

Weekly-set landmarks and the exercises that count toward them.

Programs6

Full body, upper/lower, push/pull/legs — generated from the app’s rules.

Glossary40

RIR, e1RM, TDEE, trend weight — one tight definition each.

Methodology

Every formula on the site, with constants and worked examples.

Research

Every source the articles cite, most-cited first.

Guides

212 guides that show their working.

Every number traced to the formula or the source it came from. All articles →

App guides

Getting started with Zyra Workouts

Zyra Workouts is an offline-first iOS workout logger in development. The four tabs, the first workout, the day-one settings, and what it does not do yet.

Nutrition fundamentals

Does your metabolism slow down with age?

A study of 6,421 people aged 8 days to 95 found daily energy use, adjusted for body size, stays flat from 20 to 60 and falls slowly after 60. What that means.

Body metrics

How often should you weigh yourself?

Daily gives the smoothest trend; once a week is the floor Zyra Nutrition's expenditure screen sets. What trials of daily weighing found; how gaps are handled.

Dieting & troubleshooting

How fast should I lose weight?

Rates of loss as a percent of body weight per week — the 0.3, 0.5 and 0.75 settings, what a faster rate cost in one athlete trial, and picking a rate to hold.

Training methods

RIR vs RPE: what's the difference?

RIR counts the reps you had left; RPE rates how hard the set felt out of 10. They convert as RIR = 10 − RPE. The table, the clamp at 6, and how the app logs it.

Dieting & troubleshooting

Can you lose fat and gain muscle at the same time?

Yes: body recomposition showed up in 4- to 10-week trials, most clearly in beginners. Why fat and muscle are not an even swap, the calories, and how to tell.

Start with the one you need today.

Both run in your browser now. Zyra Workouts is still in active development — its page says exactly what is built and what is not.

Open Zyra NutritionOpen Zyra Workouts