CERBERUS_FIT128_Formal_Specification_v1.0.docx

FIT-128 Formal Specification v1.0 A 128-bit canonical representation for compact fitness prescriptions and performances CORE PRINCIPLE FIT-128 describes a bounded exercise-work atom. TIME-128 describes when that work applies or occurred. Workouts and programs are composed by stacking these small canonical records rather than expanding the atom. CERBERUS 128-bit Domain Specification August 2026 Document Status and Conformance This document defines the proposed FIT-128 v1 binary layout, canonical field semantics, validation rules, common operations, and the composition model by which FIT-128 pairs with TIME-128 for compact fitness tracking and programming. NORMATIVE LANGUAGE The words MUST, MUST NOT, SHOULD, SHOULD NOT, and MAY indicate normative requirements or recommendations for conforming implementations. Field Value Word size 128 bits / 16 bytes Primary purpose Represent one bounded exercise-work prescription or performance block Temporal companion TIME-128 (128 bits / 16 bytes) Combined event payload 256 bits / 32 bytes, excluding external identifiers and database overhead Version code 00000001 = FIT-128 v1 Reserved bits B125-B127 MUST be zero in v1 Design Scope FIT-128 intentionally stores common fitness classifications and five high-value work dimensions: sets, repetitions, external load, distance, and time. It does not attempt to contain every physiological, biomechanical, programmatic, or identity attribute that may be associated with training. Exercise identity belongs to an external exercise NodeKey or equivalent canonical identifier. Participant identity and body models remain external to FIT-128. Calendar date, recurrence, exact clock time, time-zone/reference basis, and temporal exceptions belong to TIME-128. Complex workouts are compositions of FIT-128 records; complex programs are compositions of workouts and/or training events. RPE, RIR, heart rate, cadence, incline, elevation, recovery state, and similar measures are companion Models unless a later FIT version explicitly promotes them into the word. Contents Executive Summary 4 1. Architectural Model 5 2. Canonical 128-bit Layout 6 3. FITCLASS32 Classification Prefix 7 4. Metric Presence Mask 9 5. Sets and Repetitions 10 6. External Weight / Load 11 7. Distance Encoding 12 8. Time Encoding 13 9. Versioning, Reserved Bits, and Canonicalization 14 10. Byte-Level Packing and Serialization 15 11. Common Data Operations 16 12. FIT-128 + TIME-128 Training Events 17 13. Worked Example Workout 18 14. Workouts, Programs, and Composition 20 15. Planned vs. Performed Tracking 21 16. Validation and Error Handling 22 17. Implementation Guidance 23 18. Interoperability with CERBERUS 128-bit Domains 24 Glossary 25 Subject Index 27 Executive Summary FIT-128 is a fixed-width 128-bit fitness representation designed to make common training work compact, queryable, composable, and interoperable with other CERBERUS domain words. The format stores a 32-bit classification mask, explicit presence flags, scalar fields for sets, repetitions, external load, distance, and time, compact scale selectors for distance and time, an 8-bit version, and three reserved bits. Core payload relationship FIT-128 = 128 bits = 16 bytes TIME-128 = 128 bits = 16 bytes Training Event = TIME-128 + FIT-128 = 256 bits = 32 bytes The 32-byte pairing is intentionally narrow. TIME-128 owns temporal applicability and temporal precision; FIT-128 owns the exercise-work description. An external Exercise NodeKey identifies the exact exercise. A Participant record identifies the person. Workouts and programs are higher-order containers that stack these records rather than redefining them. Uniform Exercise Block Rule CANONICAL ATOM One FIT-128 SHOULD describe one exercise performed or prescribed for N equivalent sets with a common reps/load/distance/time definition. If sets differ materially, encode them as multiple FIT-128 records and compose them. This rule keeps the word simple enough to remain a stable 16-byte atom while allowing arbitrary workout complexity through composition. A five-set pyramid, drop set sequence, interval ladder, or circuit can therefore remain explicit without introducing special-purpose fields into the core format. Immediate Capabilities Bitwise classification queries such as Resistance AND Hinge AND Free Weight. Direct extraction of sets, reps, signed external load, distance, and time. Derived metrics such as total repetitions, volume load, total distance, total active time, pace, average speed, and loaded distance. Progression transforms such as add load, add repetitions, add sets, reduce assistance, increase distance, or reduce target time. Exact or recurring scheduling through TIME-128 without embedding calendar logic in FIT-128. Compact planned-versus-performed comparisons using paired prescription and performance records. 1. Architectural Model 1.1 Separation of Concerns Training record anatomy Exercise NodeKey -> what movement/exercise this is FIT-128 -> what physical work is prescribed/performed TIME-128 -> when it applies or occurred Participant -> who performed it Workout -> ordered bundle of training events Program -> composition of workouts/events + progression logic The separation is deliberate. A FIT-128 record is not a complete semantic fitness record by itself because the same work structure can apply to many exercises. A 5 x 5 @ 120 kg prescription has meaning only after the movement identity is resolved. Likewise, an exercise block does not own its calendar date or recurrence; those belong to TIME-128. 1.2 Training Event A Training Event is the minimal composite used for simple tracking. At the binary domain-word level, it is the concatenation or association of one TIME-128 and one FIT-128: 256 bits, or 32 raw bytes. External identifiers, links, database record headers, signatures, and storage-system overhead are not included in that 32-byte figure. 1.3 Prescription and Performance A planned prescription and an actual performed event SHOULD be represented as separate linked records. The prescription remains immutable evidence of intended training; the performance captures what actually occurred. This allows direct comparison without overwriting the plan. Prescription -> TIME-128 planned + FIT-128 planned | +---- Performed As ----> Performance -> TIME-128 actual + FIT-128 actual 2. Canonical 128-bit Layout Bit numbering is canonical from B000 through B127. The layout below is normative for FIT-128 v1. Bits Field Width Meaning B000-B031 FITCLASS32 32 Common classification membership mask B032 Sets Specified? 1 Presence flag for Sets scalar B033 Reps Specified? 1 Presence flag for Reps per Set scalar B034 Weight Specified? 1 Presence flag for signed external load scalar B035 Distance Specified? 1 Presence flag for Distance per Set scalar B036 Time Specified? 1 Presence flag for Time per Set scalar B037-B044 Sets 8 Unsigned count, 0-255 B045-B056 Reps per Set 12 Unsigned count, 0-4095 B057-B072 Weight / Load 16 Signed two's-complement external load, 0.1 kg resolution B073-B092 Distance per Set 20 Unsigned scalar interpreted by Distance Basis B093-B112 Time per Set 20 Unsigned scalar interpreted by Time Basis B113-B114 Distance Basis 2 Selects 0.01 m / 0.1 m / 1 m / 10 m units B115-B116 Time Basis 2 Selects 0.01 s / 0.1 s / 1 s / 60 s units B117-B124 FIT-128 Version 8 Format/version identifier; v1 = 00000001 B125-B127 RESERVED 3 MUST be zero in FIT-128 v1 Conceptual word anatomy FITCLASS32 32 bits Presence flags + Sets + Reps 25 bits Signed external Load 16 bits Distance + Time 40 bits Distance/Time bases + Version + Reserved 15 bits TOTAL 128 bits 3. FITCLASS32 Classification Prefix FITCLASS32 is the first 32 bits of FIT-128 and functions as a coherent fast-routing classification mask. Every bit is independent membership: 0 means the classification does not apply; 1 means it applies. Multiple bits MAY be active simultaneously. Bit Classification Family Meaning B000 Resistance Training / modality External or body-resisted strength work B001 Cardiovascular / Endurance Training / modality Sustained or interval cardiovascular/endurance work B002 Mobility Training / modality Controlled movement through available ranges B003 Flexibility Training / modality Range-of-motion emphasis through stretching B004 Balance / Stability Training / modality Balance, stabilization, or controlled equilibrium B005 Power / Explosive Training / modality High-rate force/power emphasis B006 Plyometric Training / modality Elastic/reactive jump or rebound emphasis B007 Isometric Training / modality Static force or hold emphasis B008 Bodyweight / Calisthenic Equipment / environment Bodyweight-dominant execution B009 Free Weight Equipment / environment Barbell, dumbbell, kettlebell, or similar free load B010 Machine Equipment / environment Selectorized/plate-loaded guided machine B011 Cable / Band Equipment / environment Cable, elastic band, or similar tension device B012 Cardio Machine Equipment / environment Treadmill, ergometer, bike, stepper, etc. B013 Water / Aquatic Equipment / environment Swimming or aquatic context B014 Outdoor / Terrain Equipment / environment Outdoor/terrain execution context B015 Assisted Equipment / environment Exercise uses assistance that reduces effective external load B016 Squat Movement pattern Squat-dominant pattern B017 Hinge Movement pattern Hip-hinge dominant pattern B018 Push Movement pattern Primary pushing pattern B019 Pull Movement pattern Primary pulling pattern B020 Carry Movement pattern Loaded or unloaded carry pattern B021 Rotation Movement pattern Rotational or anti-rotational emphasis B022 Locomotion Movement pattern Walking, running, swimming, cycling, rowing, etc. B023 Jump Movement pattern Jump/leap/landing pattern B024 Upper Body Body-region scope Upper-body dominant B025 Lower Body Body-region scope Lower-body dominant B026 Core / Trunk Body-region scope Trunk/core dominant B027 Full Body Body-region scope Meaningfully full-body B028 Unilateral Structural pattern One-sided / independent-side structure B029 Bilateral Structural pattern Two-sided / paired structure B030 Interval Structural pattern Work organized as discrete repeated work periods B031 Continuous Structural pattern Continuous work without set-like interruption 3.1 Classification Examples Exercise / Activity Representative FITCLASS32 memberships Barbell Deadlift Resistance; Free Weight; Hinge; Lower Body; Full Body; Bilateral 5 km Outdoor Run Cardiovascular / Endurance; Outdoor / Terrain; Locomotion; Lower Body; Continuous Timed Plank Resistance; Bodyweight / Calisthenic; Isometric; Core / Trunk Assisted Pull-Up Resistance; Assisted; Pull; Upper Body; Bilateral Farmer Carry Resistance; Free Weight; Carry; Full Body; Bilateral or Unilateral as applicable CLASSIFICATION BOUNDARY FITCLASS32 is a common fast-routing mask, not the full fitness ontology. Detailed movement families, muscles, equipment models, techniques, contraindications, sport classifications, and coaching taxonomies remain in linked CERBERUS classifications/models. 4. Metric Presence Mask B032-B036 explicitly state whether each scalar is semantically present. These flags prevent the stored numeric zero from being overloaded as both a real value and an unspecified value. Bit Flag 0 means 1 means B032 Sets Specified? Sets dimension is unspecified / not represented Sets scalar is authoritative B033 Reps Specified? Repetitions are unspecified / not represented Reps per Set scalar is authoritative B034 Weight Specified? External load dimension is unspecified Weight/Load scalar is authoritative, including explicit zero B035 Distance Specified? Distance dimension is unspecified Distance scalar + Distance Basis are authoritative B036 Time Specified? Time dimension is unspecified Time scalar + Time Basis are authoritative 4.1 Explicit Zero vs. Unspecified Weight Specified = 1, Weight = 0.0 kg -> explicit zero external load Weight Specified = 0 -> weight/load is not represented by this FIT-128 This distinction is important for bodyweight movements, unloaded locomotion, assisted exercises, and any activity where a metric is irrelevant or unavailable rather than literally zero. 4.2 Canonical Zeroing For canonical FIT-128 v1 encoding, when a presence flag is 0, the associated scalar bits SHOULD be zero. When Distance Specified? is 0, Distance Basis SHOULD be 00. When Time Specified? is 0, Time Basis SHOULD be 00. Decoders MAY tolerate nonzero hidden values in noncanonical data, but validators SHOULD flag them. 5. Sets and Repetitions 5.1 Sets - B037-B044 Sets is an unsigned 8-bit integer with a raw range of 0 through 255. When Sets Specified? = 1, the field states how many equivalent sets are represented by the FIT-128 block. 5.2 Reps per Set - B045-B056 Reps per Set is an unsigned 12-bit integer with a raw range of 0 through 4,095. When Reps Specified? = 1, the value applies to each represented set under the uniform exercise block rule. 5.3 Derived Repetition Count Total Repetitions = Sets x Reps per Set Example: Sets = 4 Reps = 8 Total Repetitions = 32 Total repetitions are derived rather than stored. This prevents duplicated state and allows the underlying atom to remain compact. 5.4 Nonuniform Sets A nonuniform sequence MUST NOT be forced into one FIT-128 when its sets use materially different repetitions, load, distance, or time. Instead, encode each uniform segment as a separate FIT-128 and preserve sequence/order in the surrounding workout container. Sequence FIT-128 representation Set 1: 100 kg x 8 FIT-A: Sets 1; Reps 8; Load 100.0 kg Set 2: 105 kg x 6 FIT-B: Sets 1; Reps 6; Load 105.0 kg Set 3: 110 kg x 4 FIT-C: Sets 1; Reps 4; Load 110.0 kg Set 4: 80 kg x 12 FIT-D: Sets 1; Reps 12; Load 80.0 kg 6. External Weight / Load B057-B072 encode a signed 16-bit two's-complement scalar at 0.1 kg resolution. The canonical semantic is external exercise load, not total system mass or modeled tissue loading. Field Value Encoding Signed 16-bit two's complement Resolution 0.1 kg per integer step Minimum -3276.8 kg Maximum +3276.7 kg Canonical unit kilograms Display conversion May be rendered as lb, plates, or other local units without changing storage 6.1 Signed Assistance Negative values provide a compact representation for assistance that reduces effective external load. This is particularly useful for assisted pull-ups, counterweighted machines, and similar systems. Activity Stored Load Interpretation Bench Press +100.0 kg 100 kg external resistance Weighted Pull-Up +20.0 kg 20 kg added external load Bodyweight Pull-Up 0.0 kg Explicitly zero added external load Assisted Pull-Up -30.0 kg 30 kg external assistance 6.2 Body Mass and Biomechanical Load Body mass is not stored in FIT-128. Participant body mass, lever-arm models, machine ratios, band tension curves, carried-object identity, and estimated effective biomechanical load belong to linked Participant, Equipment, and Movement Models. FIT-128 remains the canonical compact statement of the externally declared exercise load. 7. Distance Encoding B073-B092 contain a 20-bit unsigned scalar. B113-B114 select the scale applied to that scalar. This allows one field to represent centimeter-scale jumps and multi-thousand-kilometer endurance events without spending additional bits on a larger fixed-resolution integer. Basis bits Unit per raw count Maximum raw Maximum represented distance Typical use 00 0.01 m 1,048,575 10,485.75 m (10.486 km) Jumps, carries, short intervals, swimming 01 0.1 m 1,048,575 104,857.5 m (104.858 km) Running, cycling, long sessions 10 1 m 1,048,575 1,048.575 km Long endurance / expedition 11 10 m 1,048,575 10,485.75 km Very long route-scale work 7.1 Decode and Encode DistanceMeters = RawDistance x DistanceUnitMeters Example: RawDistance = 4000 Distance Basis = 01 (0.1 m) Distance = 400.0 m 7.2 Per-Set Semantics Distance is defined as Distance per Set. If Sets Specified? = 1, total represented distance is derived as Sets x Distance per Set. For continuous work, Sets may be 1 or omitted depending on the surrounding modeling convention; a conforming implementation SHOULD avoid inventing artificial sets merely to populate the field. 8. Time Encoding B093-B112 contain a 20-bit unsigned scalar. B115-B116 select the scale applied to the scalar. The field represents Time per Set or per represented continuous work block, depending on the exercise structure. Basis bits Unit per raw count Maximum raw Maximum represented time Typical use 00 0.01 s 1,048,575 10,485.75 s (~2.91 h) Sprints, short sets, precise intervals 01 0.1 s 1,048,575 104,857.5 s (~29.13 h) General exercise timing 10 1 s 1,048,575 ~12.14 days Long activities / multi-day blocks 11 60 s 1,048,575 ~728.18 days Very long duration/expedition scale 8.1 Decode and Encode TimeSeconds = RawTime x TimeUnitSeconds Example: RawTime = 600 Time Basis = 01 (0.1 s) Time = 60.0 s 8.2 Active Work Time vs. Rest FIT-128 time is exercise-work time, not rest-period scheduling unless the record explicitly represents a rest activity by convention. Rest intervals, recovery windows, session timing, and schedule timing are better represented by TIME-128 or linked program structures so that work semantics remain unambiguous. 9. Versioning, Reserved Bits, and Canonicalization 9.1 FIT-128 Version - B117-B124 The 8-bit version field identifies the interpretation contract for the complete 128-bit word. FIT-128 v1 uses the code 00000001. Implementations MUST NOT reinterpret a v1 word using future layouts without an explicit version translation. 9.2 Reserved Bits - B125-B127 All three reserved bits MUST be zero in conforming v1 encodings. A decoder receiving a v1 word with nonzero reserved bits SHOULD report a validation warning or failure according to the host system's strictness mode. 9.3 Canonicalization Rules Use canonical bit numbering B000-B127 exactly as defined in this specification. Set FIT-128 Version to 00000001 for v1. Set B125-B127 to zero. When a metric presence flag is zero, zero the corresponding scalar in canonical output. When Distance is unspecified, Distance Basis should be 00; when Time is unspecified, Time Basis should be 00. Store external load in canonical 0.1 kg units; perform display-unit conversion at the interface boundary. Do not encode exercise identity, participant identity, or temporal scheduling inside reserved bits. 10. Byte-Level Packing and Serialization FIT-128 occupies 16 consecutive bytes. Because several fields cross byte boundaries, byte-level implementations MUST use the canonical bit positions rather than assuming every semantic field begins on a byte boundary. Byte Bits Contents Role Byte 0 B000-B007 Resistance through Isometric FITCLASS32 modality bits Byte 1 B008-B015 Bodyweight through Assisted FITCLASS32 equipment/environment bits Byte 2 B016-B023 Squat through Jump FITCLASS32 movement-pattern bits Byte 3 B024-B031 Upper Body through Continuous FITCLASS32 scope/structural bits Byte 4 B032-B039 Five presence flags + Sets bits B037-B039 Flags and low portion of Sets Byte 5 B040-B047 Sets B040-B044 + Reps B045-B047 High Sets + low Reps Byte 6 B048-B055 Reps B048-B055 Middle Reps bits Byte 7 B056-B063 Reps B056 + Load B057-B063 High Reps + low Load Byte 8 B064-B071 Load B064-B071 Middle Load bits Byte 9 B072-B079 Load B072 + Distance B073-B079 High Load + low Distance Byte 10 B080-B087 Distance B080-B087 Middle Distance bits Byte 11 B088-B095 Distance B088-B092 + Time B093-B095 High Distance + low Time Byte 12 B096-B103 Time B096-B103 Middle Time bits Byte 13 B104-B111 Time B104-B111 Middle Time bits Byte 14 B112-B119 Time B112 + Distance Basis + Time Basis + Version B117-B119 High Time + bases + low Version Byte 15 B120-B127 Version B120-B124 + Reserved B125-B127 High Version + reserved 10.1 Serialized Byte Order A production implementation MUST additionally freeze a byte-order convention for transport/storage. A recommended convention is to serialize the 16 bytes in ascending byte index: Byte 0 first through Byte 15 last. Within each byte, bit extraction MUST follow the host implementation's declared mapping of Bxxx positions to bit significance. This specification treats B000-B127 as the authoritative semantic numbering and requires implementations to document their machine packing convention explicitly. INTEROPERABILITY REQUIREMENT Raw 16-byte exchange requires an agreed serialized byte order and bit-significance convention. The semantic B000-B127 registry remains fixed. 11. Common Data Operations 11.1 Bitwise Classification (FITCLASS32 & RESISTANCE_MASK) != 0 -> record is resistance-classified Required = RESISTANCE | HINGE | FREE_WEIGHT (FITCLASS32 & Required) == Required -> record satisfies all required classifications FITCLASS32 enables fast filtering, indexing, routing, and set-membership tests before more detailed exercise metadata is loaded. 11.2 Scalar Extraction Sets, reps, load, distance, time, and scale selectors are extracted by mask-and-shift operations. Signed load requires sign extension from the 16-bit two's-complement field before multiplication by the 0.1 kg scale. 11.3 Derived Metrics Derived quantity Prerequisites Formula / rule Total Repetitions Sets + Reps specified Sets x Reps per Set Volume Load Sets + Reps + Weight specified Sets x Reps x Weight Total Distance Distance specified; Sets if applicable Distance per Set x Sets, or Distance for continuous work Total Active Time Time specified; Sets if applicable Time per Set x Sets, or Time for continuous work Average Speed Distance + Time specified Distance / Time Pace Distance + Time specified Time / Distance Loaded Distance Weight + Distance specified Weight x Total Distance Assistance Progression Signed Weight specified Less-negative load represents reduced assistance 11.4 Progression Operators and Aggregation Common transforms include ADD_LOAD, ADD_REPS, ADD_SET, REDUCE_ASSISTANCE, SCALE_DISTANCE, SET_TIME_TARGET, and interval-count changes. Operators SHOULD validate field presence, scalar range, and basis precision before emitting a new canonical FIT-128; overflow or unavailable precision MUST produce an explicit error or a valid basis change rather than silent wrapping. Workout-level and program-level analytics aggregate decoded FIT-128 values rather than adding packed words directly. Bitwise operations are appropriate for classification masks; arithmetic operations are appropriate for extracted scalar fields. Packed numeric fields MUST NOT be treated as independent one-bit membership dimensions. 12. FIT-128 + TIME-128 Training Events TIME-128 and FIT-128 are complementary 16-byte atoms. TIME-128 can identify an exact temporal coordinate, a structurally recurring temporal set, or another valid temporal expression within its specification. FIT-128 carries the fitness work. Their combination allows the same training grammar to represent both scheduled prescriptions and historical performance records. TRAINING EVENT Exercise NodeKey = Barbell Back Squat TIME-128 = when FIT-128 = what work Participant = who 12.1 Exact Performance An actual event can use TIME-128 to resolve to a specific year, calendar position, and clock time with declared millisecond precision. For example, a completed set block could start at 07:08:14.283 on its resolved Twelve-Phase calendar day while FIT-128 records the performed 5 x 5 @ 117.5 kg work. 12.2 Recurring Prescription A program prescription can instead use TIME-128 structural recurrence. For example, a training block may apply throughout the first dyad (Months 0 and 1), on all three ordinary weeks (-, =, and ≡), at Phase ○, with a scheduled start of 07:00. FIT-128 does not change: it still expresses the prescribed work. 12.3 Intercalary Precision Selecting Months 0 and 1 does not automatically imply the intercalary transition 0✦1. Intercalary applicability is controlled by the independent TIME-128 intercalary bits. This allows training plans to include or exclude transition holidays explicitly rather than accidentally. 12.4 32-Byte Claim RAW DOMAIN PAYLOAD One TIME-128 plus one FIT-128 is exactly 256 bits = 32 raw bytes. A complete database record will normally consume more because NodeKeys, links, record identifiers, indexes, checksums, provenance, and database storage overhead are separate from the two domain words. 13. Worked Example Workout This example shows a simple Lower Strength A workout represented as four exercise identities, four FIT-128 work atoms, and corresponding TIME-128 temporal records. Values are illustrative and demonstrate the representation rather than prescribe training. Order Exercise NodeKey FITCLASS32 highlights Sets Reps Load Distance Time 1 Barbell Back Squat Resistance; Free Weight; Squat; Lower Body; Bilateral 5 5 120.0 kg — — 2 Romanian Deadlift Resistance; Free Weight; Hinge; Lower Body; Bilateral 3 8 90.0 kg — — 3 Walking Lunge Resistance; Free Weight; Locomotion; Lower Body; Unilateral 3 12 20.0 kg — — 4 Plank Resistance; Bodyweight; Isometric; Core / Trunk 3 — 0.0 kg — 60.0 s 13.1 Scheduled Workout The workout container can provide a shared program identity and ordering, while each Training Event resolves its own TIME-128. A simple prescription might schedule the workout on Month 0, Week -, Phase ○ at 07:00. If all exercises inherit the same session start at the application layer, the runtime may compile that shared context into resolved event times as needed. Workout: Lower Strength A TIME-128 prescription: Month 0 Week - Phase ○ Time 07:00:00.000 Events: 1. Back Squat -> FIT-128: 5 x 5 @ 120.0 kg 2. Romanian Deadlift-> FIT-128: 3 x 8 @ 90.0 kg 3. Walking Lunge -> FIT-128: 3 x 12 @ 20.0 kg 4. Plank -> FIT-128: 3 x 60.0 s 13.2 Performed Workout Suppose the athlete begins the squat block at 07:08:14.283 and performs 117.5 kg rather than the planned 120.0 kg. The performance record remains a separate TIME-128 + FIT-128 pair linked to the prescription. Field Planned Performed Derived comparison Start time 07:00:00.000 07:08:14.283 +8 min 14.283 s Sets 5 5 Matched Reps per Set 5 5 Matched External Load 120.0 kg 117.5 kg -2.5 kg Total Reps 25 25 Matched Volume Load 3,000 kg 2,937.5 kg -62.5 kg 13.3 Example Derived Workout Totals For the illustrative performed values above and assuming the remaining prescribed values were completed, the runtime can derive totals by decoding and aggregating the relevant fields. It does not need a larger workout-specific binary word. Metric How derived Strength repetition count Sum of Sets x Reps for repetition-based events External-load volume Sum of Sets x Reps x external Load where applicable Isometric active time Sum of Sets x Time for hold-based events Classification exposure Union/counts of FITCLASS32 masks across events Temporal adherence Compare prescription TIME-128 against performance TIME-128 14. Workouts, Programs, and Composition 14.1 Workout as an Ordered Bundle WORKOUT -> Training Event 1 = Exercise + TIME-128 + FIT-128 -> Training Event 2 = Exercise + TIME-128 + FIT-128 -> Training Event 3 = Exercise + TIME-128 + FIT-128 -> ... The workout container owns order, grouping, name, notes, and any higher-order relationships. FIT-128 remains unchanged regardless of whether the event is used alone, in a superset, in a circuit, or in a long program. 14.2 Program as a Stack of Workouts / Events PROGRAM: 12-Week Strength Block Workout A Squat / RDL / Plank Workout B Bench / Row / Carry Workout C Deadlift / Pull-Up / Split Squat + TIME-128 applicability + progression Operators The program therefore becomes structured composition rather than prose. It can reuse workouts, fork variants, apply temporal rules, and compile progression into explicit FIT-128 instances. 14.3 Reuse and Bundling A FIT-128 may be reused as a template when exercise identity and surrounding context are stable. A Workout may bundle multiple exercise events and define their order or relationships. A Program may bundle workouts and apply TIME-128 schedules or progression Operators. A Program variant may fork only the changed records while retaining lineage to its source. A completed session can preserve the original prescription and link each performed record to it. 15. Planned vs. Performed Tracking FIT-128 is especially useful when prescription and performance are represented with the same schema. No translation into a separate logging format is required: the plan and the result can be compared field-for-field after decoding. Comparison Example Schedule adherence TIME actual - TIME planned Load adherence Performed Load - Planned Load Rep adherence Performed Total Reps - Planned Total Reps Volume adherence Performed Volume Load - Planned Volume Load Distance adherence Performed Total Distance - Planned Total Distance Time adherence Performed Time - Planned Time Classification consistency Expected FITCLASS32 vs. performed activity classification 15.1 History and Progression A training history becomes a time-addressed series of compact fitness atoms. Queries can locate all Hinge work in a period, all runs above a distance threshold, all Bench Press performances above a load threshold, or all isometric core work above a time threshold. Progression analysis operates on decoded fields while TIME-128 supplies the ordering and temporal scope. 15.2 Avoiding Destructive Updates PRESERVE INTENT Do not mutate a historical prescription into the performed value. Link the actual performance to the plan. This preserves the difference between intended training and observed training as first-class data. 16. Validation and Error Handling 16.1 Required v1 Checks Check Rule Version B117-B124 = 00000001 for v1 Reserved bits B125-B127 = 000 Presence/value coherence Unspecified metric values should be zero in canonical data Distance basis coherence Distance Basis should be 00 when Distance Specified? = 0 Time basis coherence Time Basis should be 00 when Time Specified? = 0 Signed load range Decoded signed integer must be interpreted at 0.1 kg resolution Scalar range No encoder may emit a value outside field width Uniform block rule Materially different sets should be split into multiple FIT-128 records Exercise identity Must be resolved externally when semantic identification is required 16.2 Precision and Overflow If a requested distance or time cannot be represented exactly at the current basis, an encoder SHOULD choose the smallest basis that can represent the required range while meeting the application's precision requirement. If no basis is adequate, the encoder MUST report an out-of-range condition rather than silently wrapping the integer. 16.3 Semantic Validation Binary validity does not guarantee physiological or coaching validity. A syntactically valid FIT-128 can still describe an inappropriate, impossible, or unsafe prescription. Safety, exercise suitability, contraindications, progression constraints, and clinical interpretation belong to higher-level Rules and Models. 17. Implementation Guidance 17.1 Reference Data Model Layer Suggested fields Exercise Registry Exercise NodeKey, name, detailed classification, equipment, movement model, instructions Training Event Exercise link, TIME-128, FIT-128, Participant link, status, provenance Workout Workout ID, ordered Training Event links, shared notes/context Program Program ID, Workout/Event links, schedule rules, progression Operators, version/lineage Performance Link Prescription -> Performed As -> Performance 17.2 Airtable / Transparent Prototype A transparent prototype can expose B000-B127 as checkbox fields, with helper numeric fields for raw and decoded scalars. Automations or scripts can compile human-readable exercise inputs into bit states and decode bits back into inspectable values. This is intentionally verbose at the authoring surface while preserving the same 16-byte conceptual runtime word. 17.3 Production Runtime A production implementation can store FIT-128 as two 64-bit words, one 128-bit integer where supported, a 16-byte binary value, or another exact fixed-width representation. The implementation MUST preserve the v1 bit registry and serialization profile. Indexes may additionally materialize FITCLASS32 and frequently queried scalar fields for database performance. 17.4 Human Interface Human interfaces SHOULD show semantic fields and units rather than raw bits by default, while retaining an inspectable binary/debug view. For example, a user should normally see “5 x 5 @ 120 kg” rather than a 128-character bit string, but a systems/debug view may expose both representations side by side. 18. Interoperability with CERBERUS 128-bit Domains FIT-128 is designed to compose with other bounded 128-bit domain words rather than absorb their concerns. The same record graph can therefore connect training, time, nutrition, music, perceptual projection, and other domains while each word retains a stable responsibility. Domain word Owns Example relationship TIME-128 Temporal coordinates, recurrence, precision, reference basis When a training event is scheduled or performed FIT-128 Exercise-work classifications and quantities What physical work is prescribed/performed FOOD-128 Compact food nutrition/flavor/classification basis Nutrition events before/after training MUSIC-128 Musical event atom Exercise classes or performances synchronized with music MRMM projections Deterministic cross-modal mappings Training metrics projected as color, sound, motion, or haptics 18.1 Temporal Correlation with FOOD-128 TIME-128 + FOOD-128 -> Eating Event TIME-128 + FIT-128 -> Training Event Shared TIME-128 coordinates allow higher-level Models to relate intake and training without making FOOD-128 understand fitness or FIT-128 understand nutrition. 18.2 Domain-Word Principle BOUNDED WORDS, COMPOSED SYSTEMS A 128-bit word should not try to contain the universe. It should contain enough canonical structure that the universe can operate on it through composition, Models, Operators, Rules, and linked identity. Glossary Term Definition Assistance External support that reduces effective exercise load; represented by a negative signed load when Weight is specified. Basis A compact scale selector that determines the unit represented by each integer step in a scalar field. Bit mask A binary pattern used to select, test, set, clear, or compare specific bits. Canonical encoding The single preferred normalized representation of a semantic value under this specification. Continuous FITCLASS32 structural classification indicating work is intended as continuous rather than interval-organized. Distance Basis B113-B114; selects 0.01 m, 0.1 m, 1 m, or 10 m per raw distance count. Distance per Set B073-B092 interpreted with Distance Basis; the represented work distance for each set/block. Exercise NodeKey External canonical identity for the specific exercise or movement. FIT-128 does not itself encode this identity. External load Declared exercise resistance external to the participant body model; encoded as a signed 0.1 kg scalar. FIT-128 The 128-bit / 16-byte fitness work representation defined by this specification. FITCLASS32 B000-B031; 32-bit common classification membership prefix. Metric Presence Mask B032-B036; five bits indicating whether sets, reps, weight, distance, and time are semantically specified. MRMM Mathematical Relationship Modality Modeling; a system for deterministic perceptual projections across modalities. Participant External identity/model describing the person performing or receiving the training prescription. Performance A record of what actually occurred, represented separately from the prescription. Prescription A planned training event or work target. Program A higher-order composition of workouts and/or training events, schedules, and progression logic. Progression Operator A transform that modifies a training parameter according to a declared rule, such as adding load or repetitions. Raw scalar The unsigned or signed integer stored directly in a FIT-128 field before basis/resolution scaling. Reps per Set B045-B056; unsigned 12-bit repetitions applying to each equivalent set. Reserved bits B125-B127; MUST be zero in FIT-128 v1. Serialization profile The agreed byte order and bit-significance convention used to exchange the 16-byte word. Sets B037-B044; unsigned 8-bit count of equivalent sets. Signed two's complement Binary signed-integer representation used by the 16-bit external load field. TIME-128 Companion 128-bit temporal representation used to describe exact time, recurring temporal applicability, and reference basis. Time Basis B115-B116; selects 0.01 s, 0.1 s, 1 s, or 60 s per raw time count. Time per Set B093-B112 interpreted with Time Basis; active exercise time for each represented set/block. Training Event A composite linking an Exercise identity with TIME-128, FIT-128, and usually a Participant. Uniform Exercise Block One FIT-128 describing N equivalent sets/blocks that share the same reps, load, distance, and time semantics. Version B117-B124; identifies the FIT-128 interpretation contract; v1 is 00000001. Volume Load Derived Sets x Reps x external Load for records where those dimensions are meaningful and specified. Workout An ordered bundle of Training Events. Subject Index Assistance 11 Participant 5 Airtable prototype 23 Performance record 21 Average speed 16 Planned vs. performed 21 Bit numbering 6 Prescription 21 Byte packing 15 Program 20 Canonical encoding 14 Progression Operators 16 Cardiovascular / Endurance 7 Repetitions 10 Classification mask 7 Reserved bits 14 Continuous work 7 Serialization 15 Distance 12 Sets 10 Distance Basis 12 Signed load 11 Exercise NodeKey 5 TIME-128 17 External load 11 Time Basis 13 FIT-128 4 Training Event 17 FITCLASS32 7 Two's complement 11 FOOD-128 interoperability 24 Uniform Exercise Block 4 Glossary 25 Validation 22 Interval 7 Version 14 Metric Presence Mask 9 Volume Load 16 Nonuniform sets 10 Worked example workout 18 Pace 16 Workout 20 End of FIT-128 Formal Specification v1.0