Dimensions

Dimensions are the measurable axes of a set — reps, load, duration, distance, and so on. Every set declares a dimensions array listing which dimension names are required for that set.

How It Works

Each set explicitly declares its dimensions:

{
  "dimensions": ["reps", "load"],
  "reps": { "type": "fixed", "value": 5 },
  "load": { "type": "fixed", "value": 100, "unit": "kg" }
}

The dimensions array tells validators and consumers which fields are required for this set. Any other known dimension may be added optionally.

Rules

1. Every set must have a dimensions array with at least one entry
2. Each name in dimensions must be a known dimension (see table below) or a valid extension dimension
3. All dimensions listed in the array must be present as fields on the set
4. Any known dimension not in the array may still appear on the set -- it is treated as optional
5. Universal dimensions (rest_after, note) are always allowed and never need to be listed in dimensions

Known Dimensions

There are 22 known dimension names. By category: count (reps, sides, rounds); load; time (duration, duration_per_side, rest_between_sides, rest_after); tempo; distance and space (distance, height, incline); cardio and effort (pace, speed, power, heart_rate, heart_rate_zone, rpe, rir, velocity, calories, cadence, resistance).

Dimension	Allowed Types	Units
reps	fixed, range, min, amrap	(count)
sides	fixed	(count)
rounds	fixed, amrap	(count)
load	fixed, range, max	kg, lb, %1RM, %BW
duration	fixed, range, min	s, min, h
duration_per_side	fixed, range	s, min, h
rest_between_sides	fixed	s, min, h
rest_after	fixed, range	s, min, h
tempo	fixed	(string, e.g. "3-1-2-0")
distance	fixed, range, min, amrap	m, km, mi, ft, yd
height	fixed, range	cm, in
incline	fixed, range	%
pace	fixed, range	min/km, min/mi
speed	fixed, range	km/h, mph
power	fixed, range	W, %FTP
heart_rate	fixed, range, max	bpm
heart_rate_zone	fixed, range	(zone number)
rpe	fixed, range, max	(scale, typically 1–10)
rir	fixed, range, max	(reps in reserve, typically 0–5)
velocity	fixed, range	m/s
calories	fixed, min, amrap	kcal
cadence	fixed, range	rpm, spm
resistance	fixed, range	level, %

Power: Use W for absolute watts or %FTP for power relative to the athlete's FTP. %FTP makes workouts portable across riders (e.g. shared cycling/ERG workouts).

Examples

Strength set (reps + load)

{
  "dimensions": ["reps", "load"],
  "reps": { "type": "fixed", "value": 5 },
  "load": { "type": "fixed", "value": 100, "unit": "kg" },
  "rpe": { "type": "range", "min": 7, "max": 8 }
}

Here reps and load are required (listed in dimensions), while rpe is optional.

You can also use RIR (reps in reserve) as an effort cue alongside or instead of RPE:

{
  "dimensions": ["reps", "load", "rir"],
  "reps": { "type": "fixed", "value": 5 },
  "load": { "type": "fixed", "value": 100, "unit": "kg" },
  "rir": { "type": "fixed", "value": 2 }
}

RIR is typically logged on a 0–5 scale (0 = failure, 2 = two reps left). A rough mapping between RPE and RIR is:

• RPE 10 ≈ RIR 0 (to failure)
• RPE 9 ≈ RIR 1
• RPE 8 ≈ RIR 2

They are related but not interchangeable: RPE considers overall effort and context; RIR focuses on how many reps remained at the end of the set.

Bodyweight set (reps only)

{
  "dimensions": ["reps"],
  "reps": { "type": "fixed", "value": 20 }
}

Cardio set (distance)

{
  "dimensions": ["distance"],
  "distance": { "type": "fixed", "value": 5, "unit": "km" },
  "pace": { "type": "range", "min": 4.5, "max": 5.0, "unit": "min/km" }
}

Timed set (duration + power)

{
  "dimensions": ["duration", "power"],
  "duration": { "type": "fixed", "value": 20, "unit": "min" },
  "power": { "type": "range", "min": 200, "max": 220, "unit": "W" }
}

Portable cycling workout using %FTP (same file works for any rider):

{
  "dimensions": ["duration", "power"],
  "duration": { "type": "fixed", "value": 5, "unit": "min" },
  "power": { "type": "fixed", "value": 0.65, "unit": "%FTP" }
}

Per-side set

{
  "dimensions": ["reps", "sides"],
  "reps": { "type": "fixed", "value": 10 },
  "sides": { "type": "fixed", "value": 2 },
  "load": { "type": "fixed", "value": 20, "unit": "kg" }
}

Resistance machines and bands

Use the resistance dimension for machine resistance levels or percentages, keeping values numeric:

{
  "dimensions": ["reps", "resistance"],
  "reps": { "type": "fixed", "value": 12 },
  "resistance": { "type": "fixed", "value": 8, "unit": "level" },
  "note": "Leg press — level 8, green band assist"
}

When you need to preserve the exact band identity (e.g. band color or model), keep load/resistance numeric and add an extension dimension such as x_resistance_band:

{
  "dimensions": ["reps", "resistance", "x_resistance_band"],
  "reps": { "type": "fixed", "value": 10 },
  "resistance": { "type": "fixed", "value": 6, "unit": "level" },
  "x_resistance_band": { "type": "fixed", "value": "zelena_guma" }
}

Core consumers can ignore x_resistance_band and still understand the numeric prescription; apps that care about band names can read the extension.

Compound loads (e.g. dumbbells + chains)

For prescriptions like "3kg ball + 15kg kettlebell", keep the core load dimension as the total external load and store the breakdown in a note or extension:

{
  "dimensions": ["reps", "load", "x_load_components"],
  "reps": { "type": "fixed", "value": 8 },
  "load": { "type": "fixed", "value": 18, "unit": "kg" },
  "x_load_components": { "type": "fixed", "value": [3, 15] },
  "note": "3kg medicine ball + 15kg kettlebell"
}

This keeps the core data model simple and interoperable (everyone understands load: 18kg), while still allowing apps to reconstruct or display the detailed components if they know about x_load_components.

Custom Dimensions

Custom dimensions are supported via namespaced prefixes (e.g., x_, app_). Extension dimensions can be listed in the dimensions array just like built-in ones:

{
  "dimensions": ["reps", "load", "x_band_tension"],
  "reps": { "type": "fixed", "value": 10 },
  "load": { "type": "fixed", "value": 60, "unit": "kg" },
  "x_band_tension": { "type": "fixed", "value": 20, "unit": "lb" }
}

See Extensions for details on namespacing conventions.

Dimension Conflicts

Some dimensions are mutually exclusive within a single set:

• pace and speed -- Cannot specify both
• heart_rate and heart_rate_zone -- Cannot specify both

The validator will emit E012 if conflicting dimensions are found on the same set.

Intensity scales and guideline alignment

OpenSet’s intensity-related dimensions are designed to mirror common guideline usage (including ACSM) without locking into a single standard:

• RPE (rpe)
  • Recommended scale is 1–10, which aligns with ACSM’s use of Borg CR10-style ratings for light, moderate, and vigorous domains.
  • Apps that prefer the original 6–20 Borg scale can still use rpe with fixed/range values and document the scale in app UI, but 1–10 is the shared baseline for interoperability.
  • Typical mapping (approximate) for 1–10:
    • Light: 2–3
    • Moderate: 4–6
    • Vigorous: 7–8
    • Near-maximal to maximal: 9–10
• Heart rate (heart_rate, heart_rate_zone)
  • Use heart_rate when prescribing intensities relative to absolute heart rate (bpm) or guideline-style relative markers:
    • Absolute: unit: "bpm" (e.g. 140–155 bpm).
    • Relative to reserve or max: unit: "%HRR" or unit: "%HRmax" (e.g. 0.4–0.59 for moderate, 0.6–0.89 for vigorous when following ACSM domains).
  • Use heart_rate_zone when you maintain your own zone model (e.g. 1–5) that maps to %HRR/%HRmax in app logic. OpenSet does not define the zone table; it only stores the zone index or range.
• Cardio pace/speed and effort (pace, speed, power)
  • Use pace (min/km or min/mi) or speed (km/h or mph) for running/walking prescriptions derived from guideline tables (e.g. ACSM MET-based walking speeds), optionally alongside:
  • power (W or %FTP) for cycling/ERG prescriptions where guidelines are expressed as % of threshold or absolute watts.

Guideline-specific rules (e.g. how %HRR, %HRmax, RPE, and METs combine to define “moderate” or “vigorous”) live in app logic. OpenSet provides the common intensity fields and units so those rules can be implemented consistently.

Hold (isometric) exercises

Exercises where the athlete holds a position for time (e.g. plank, wall sit, hollow hold) are prescribed using the duration dimension. There is no separate "hold" dimension — use dimensions: ["duration"] and set duration to the hold time (e.g. 30s, 60s).

To failure

To prescribe "to failure", use reps with type amrap or rpe with type max as appropriate.

Universal Dimensions

The following dimensions are always allowed on any set, regardless of what is listed in dimensions:

• rest_after -- Rest period after the set. It can also appear at series level; when both are present, set overrides series.
• note -- Freeform coaching notes