/fitness namespace · APlicious

Fitness API — one-rep max, heart-rate zones, and workout plan generation

The /fitness namespace covers strength training, cardio zones, recovery, and program generation — one-rep max alone averages three named formulas instead of committing to one.

22fitness endpoints

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GET /api/v1/fitness/one-rep-max

const res = await fetch(
  'https://aplicious.com/api/v1/fitness/one-rep-max?weight=100&reps=5&unit=kg',
  { headers: { 'X-API-Key': 'lapi_live_••••' } }
);
const { data } = await res.json();
// { one_rep_max: { epley: 116.7, brzycki: 112.5, lombardi: 117.5, average: 115.6 } }

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What's included in /fitness

One-rep max, 3 formulas averaged

Epley, Brzycki, and Lombardi computed separately and averaged, with an accuracy note for high rep counts.

Heart-rate training zones

Karvonen and Tanaka methods, using resting heart rate when available for more accurate zones.

Structured workout plans

Multi-week programs from goal, experience level, and days-per-week — with progressive overload and deload week logic.

Body composition tools

Body fat (US Navy and BMI-based formulas), BMI, and ideal weight (4 named formulas: Devine, Robinson, Miller, Hamwi).

One key, all 34 namespaces

Pair fitness with /nutrition using the same API key — no second vendor relationship.

Start using the fitness API today

Free tier — 500 calls/month, no credit card. Upgrade when you need more.

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Frequently asked questions

Why three formulas instead of one?

Every one-rep-max formula has known blind spots at different rep ranges. Averaging three reduces the error from relying on a single estimate.

Does this need a wearable device?

No — all inputs are caller-supplied (weight, reps, age, resting heart rate if available). No hardware integration required.

Is there a free tier?

Yes — 500 calls/month forever, no credit card.

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