SPORT::Athletics::Sprints (SPOS.ATH.SPR)
= repeatable sprint performance (acceleration × max velocity × speed endurance × start execution)
  across training blocks and competition days,
  while keeping hamstring/Achilles/hip load below injury threshold.
Output is “speed reliability under high intensity”, not random PR attempts.

P3
- stable mechanics at speed (no form collapse)
- high-intensity exposures dosed safely
- hamstrings/Achilles robust; low niggle recurrence
- starts consistent; race model executed
- CNS recovery managed; performance peaks on schedule
P2
- fast on good days, flat on others
- mechanics degrade late in reps; speed “leaks”
- recurring tightness (hamstring/calf/hip flexor)
- inconsistent starts; competition nerves affect execution
P1
- frequent missed speed days due to tightness
- cautious running; cannot hit high intensity safely
- speed stagnation; fatigue dominates
- anxiety around injury; degraded mechanics
P0
- hamstring strain/Achilles injury/hip injury or severe burnout
- cannot sprint/train reliably

Z0 sleep debt + Z1 high-intensity spike (too soon)
→ Z0 hamstring tightness ignored
→ Z0 mechanics degrade at speed → overload increases
→ Z2 missed speed sessions + compensation
→ P2 → P1 → P0 (strain)
Repair: reduce intensity, rebuild mechanics, reintroduce speed exposures with gates.

TIMEFLOW::SPRINT_FUNCTION
T0 survival: chase/escape bursts, combat closing distance
T1 ancient civilisations: messenger bursts, military drills, public contests of speed
T2 pre-modern: games/festivals; local status display
T3 industrial: standardized track events, records, clubs
T4 modern: elite performance engineering + national projection
T5 sensor era: biomechanics + load governance + hamstring risk management

SPR::Primitives
PR0 Acceleration mechanics (push angles, shin angle, stiffness)
PR1 Max velocity mechanics (front-side mechanics, posture, relaxation)
PR2 Speed endurance (maintain near-max speed; 200–400m)
PR3 Start execution (reaction + first 10–30m)
PR4 Strength/power base (hip extension, posterior chain, calf stiffness)
PR5 Elastic capacity (plyometrics with safety)
PR6 Hamstring robustness (eccentric strength + sprint exposure tolerance)
PR7 CNS recovery governance (sleep, spacing, deload)
PR8 Race model (distribution of effort; 200/400 pacing)

Z0::Top Failure Modes (Sprints)
FM0.SP1 too much speed work too soon (intensity spike)
FM0.SP2 sprinting when tight → hamstring strain risk
FM0.SP3 poor mechanics at speed (overstriding, tense shoulders)
FM0.SP4 insufficient posterior chain strength
FM0.SP5 plyometrics without base strength (Achilles risk)
FM0.SP6 poor warm-up / no progressive build-up
FM0.SP7 too many max efforts close together (CNS fatigue)
FM0.SP8 no race model → dies late (200/400)
Z0::Sensor Pack (Minimum viable)
S0.SP1 high-intensity exposures/week (max velocity days)
S0.SP2 “tightness index”: hamstring/calf/hip tightness (0–10) pre-session
S0.SP3 pain map: hamstring/Achilles/hip (0–10) + next-day stiffness
S0.SP4 performance marker: flying-10m or timed 30m trend (not daily)
S0.SP5 mechanics score: video check (posture, contact, relaxation)
S0.SP6 recovery: sleep hours + fatigue score
S0.SP7 warm-up compliance (progression completed or skipped)
Z0::Repairs
R0.SP1 intensity cap: 1–2 true speed days/week (most athletes)
R0.SP2 stop rule: tightness above threshold → switch session
R0.SP3 technique: relax cues + posture drills + wicket runs (if used)
R0.SP4 strength: hinge + hip extension + single-leg support
R0.SP5 hamstring eccentrics (Nordics/slider) 2×/week (progressed)
R0.SP6 warm-up SOP: gradual buildups before max sprints
R0.SP7 deload weeks + spacing (48–72h between max speed sessions)
R0.SP8 race model practice (split targets for 200/400)

Z1::Failure Modes
FM1.SP1 no periodization (random maxing)
FM1.SP2 too much volume at high intensity
FM1.SP3 no technical feedback (mechanics drift)
FM1.SP4 strength/plyo not integrated with sprint load
FM1.SP5 competition schedule not matched to training peak
Z1::Sensors
S1.SP1 speed trend across blocks (4–8 weeks)
S1.SP2 hamstring niggle incidence around speed spikes
S1.SP3 rep quality drop-off within sessions (fatigue signal)
S1.SP4 CNS fatigue indicators (flat times, mood, sleep disruption)
S1.SP5 meet performance variance (execution vs fitness)
Z1::Repairs
R1.SP1 block design: accel → maxV → speed endurance → taper
R1.SP2 quality-first: stop reps when mechanics degrade
R1.SP3 weekly video micro-review + 1 correction target
R1.SP4 coordinate strength/plyo with speed days (not stacked randomly)
R1.SP5 taper logic before key meets

Z2::Failure Modes
FM2.SP1 youth overloaded with too many races + hard training
FM2.SP2 no strength base development
FM2.SP3 selection bias toward early maturers; late developers lost
FM2.SP4 medical/physio not integrated for niggle management
Z2::Sensors
S2.SP1 race density per athlete/season
S2.SP2 hamstring/Achilles injury days lost
S2.SP3 dropout/burnout rate
S2.SP4 progression curves by age band (watch plateau)
Z2::Repairs
R2.SP1 meet budgeting + recovery windows
R2.SP2 strength foundation standards before heavy plyos
R2.SP3 development squads for late bloomers
R2.SP4 integrated niggle containment SOP

Z3::Failure Modes
FM3.SP1 too many heats in short time windows (fatigue + injury risk)
FM3.SP2 unsafe track conditions or inadequate warm-up access
FM3.SP3 travel scheduling crush (sleep debt before races)
Z3::Sensors
S3.SP1 injury incidence around multi-round meets
S3.SP2 false start / performance variability spikes (pressure signal)
S3.SP3 travel-to-race sleep compression frequency
Z3::Repairs
R3.SP1 rest standards between rounds where feasible
R3.SP2 warm-up facility/time standards
R3.SP3 travel buffers and scheduling protections

STATE::SPRINT
- SpeedExposure SE = maxV/accel days per week
- Tightness T = pre-session tightness index trend
- TissueRisk TR = hamstring/Achilles pain trend
- Mechanics M = video score at speed
- CNSRec CR = sleep + fatigue + “flat times” trend
- Performance P = timed markers trend across blocks
Phase Estimator:
IF SE controlled AND T low AND M stable AND P improving → P3 drift
IF T rising OR TR rising OR CR falling OR M degrading → P2/P1 warning
IF strain/injury stops sprinting → P0 risk

Trigger: tightness trend rising OR sharp sensation at speed
1) stop max speed immediately; switch to low-intensity mechanics + mobility
2) reduce intensity exposure for 7–14 days
3) strengthen eccentrics + hip extension support
4) rebuild sprint exposure ladder: submax → controlled fast → max
5) enforce spacing + warm-up SOP + deload

1) identify leak: posture? overstriding? tension? stiffness?
2) drills + cues (relaxation, hips tall, quick contacts)
3) quality reps only; stop when mechanics degrade
4) add strength/plyo that supports the leak (targeted)
5) re-test timed marker after 2–4 weeks

1) set race model (splits + controlled early effort)
2) build speed endurance progressively (longer reps with quality)
3) rehearse relaxation under lactate (form cues late)
4) taper properly before races
5) post-race review: where form broke, then re-train that segment

CivOS Link:
- Sprinting is the “max-intensity human output” module:
  high transfer to many sports and a public symbol of peak capability.
- Brittleness risk: intensity spikes + ego culture → injury cascades.
- Repair: strict exposure governance + technique gating + recovery protection.