Welcome to Data-Driven Running

Run Analytics transforms your running workouts into actionable insights using Critical Run Speed (CRS), Training Stress Score (rTSS), and Performance Management Chart (PMC) metrics. This guide will take you from first setup to advanced training load analysis in 4 simple steps.

Quick Start (5 Minutes)

1

Download & Install

Download Run Analytics from the App Store and grant permission to access Apple Health. The app syncs running workouts automatically—no manual logging required.

Download App →

2

Perform CRS Test

Complete a 5K and 3K time trial to establish your Critical Run Speed. This is the foundation of all metrics—without CRS, rTSS and training zones cannot be calculated.

Protocolo de Prueba CRS ↓

3

Enter CRS Results

Input your 5K and 3K times in the app. Run Analytics calculates CRS, pace zones, and personalizes all metrics to your physiology. Update every 6-8 weeks as fitness improves.

4

Start Tracking Workouts

Run with Apple Watch and Health app. Run Analytics automatically imports workouts, calculates rTSS, updates CTL/ATL/TSB, and tracks progress. No manual data entry needed.

Complete CRS Testing Protocol

📋 What You Need

Track access: 400m athletics track or flat road
Timing: Stopwatch, running watch, or Apple Watch
Warm-up time: 15-20 minutes before test
Recovery: 5-10 minutes between trials
Effort: Maximum sustainable pace (not all-out sprint)

⏱️ Test Day Conditions

Rested: No hard training 24-48 hours before
Hydrated: Well-hydrated, normal eating
Conditions: Dry, low wind ideal (avoid extreme heat/cold)
Time of day: When you normally train best
Equipment: Normal running gear (shoes, comfortable clothes)

Step-by-Step CRS Test

Warm-up

15-20 minutes

400-800m easy running, drills, and progressive build-ups. Include 2-3×50 at increasing pace (60%, 75%, 85% effort). Rest 2-3 minutes before test.

Trial 1

1200m Maximum Effort

Run 1200m (3 laps on a 400m track) at the fastest pace you can sustain for the full distance. This is NOT a sprint—pace yourself. Record time in mm:ss format (e.g., 4:30).

Pacing tip: Aim for even 100m splits. Second 200m should be ≤ first 200m (negative split ideal).

Recovery

5-10 minutes

CRITICAL PHASE: Easy running or complete rest. Wait until heart rate drops below 120 bpm and breathing fully recovered. Insufficient recovery = inaccurate CRS.

Trial 2

400m Maximum Effort

Maximum sustainable effort for 400m (1 lap). This should feel harder per 100m than the 1200m. Record time in mm:ss format (e.g., 1:20).

Validation check: 400m pace per lap should be significantly faster than 1200m pace per lap. If not, recovery was insufficient or pacing was off.

Cool-down

10-15 minutes

300-500m easy running, stretching. Record your times immediately—don't trust memory.

⚠️ Common CRS Test Mistakes

Going out too fast on longer trial: Results in blowup, inaccurate CRS. Use even pacing.
Insufficient recovery between trials: Fatigue slows the second trial, making CRS artificially fast → overtrained zones.
Inconsistent terrain: Using hills for one trial and flat for another skews calculations. Always use flat ground.
Testing when fatigued: Heavy training load 24-48h before = depressed results. Test when fresh.
Not recording immediately: Memory is unreliable. Write times down before cool-down.

Entering CRS Results in Run Analytics

Step 1: Open CRS Settings

In Run Analytics app, go to Settings → Critical Run Speed. Tap "Perform CRS Test" or "Update CRS".

Step 2: Input Times

Enter your 1200m time (e.g., 4:30) and 400m time (e.g., 1:20). Use the exact format shown. Tap "Calculate".

Step 3: Review Results

App displays:

CRS speed: 4.00 m/s
CRS pace: 4:10/km
Training zones: 7 personalized zones (Zone 1-7)
rTSS baseline: Now enabled for all workouts

Step 4: Save & Sync

Tap "Save CRS". The app immediately:

Recalculates training zones
Retroactively updates rTSS for past 90 days
Adjusts CTL/ATL/TSB calculations
Enables zone-based workout analysis

💡 Pro Tip: Historical CRS Testing

If you already know your CRS from previous tests, you can input those times directly. However, for most accurate results, perform a fresh test every 6-8 weeks. Your CRS should improve (get faster) as training progresses.

Understanding Your Metrics

Critical Run Speed (CRS)

What it is: Your aerobic threshold pace—the fastest speed you can sustain for ~60 minutes without exhaustion.

What it means: CRS = 4:10/km means you can hold 4:10 pace for sustained threshold efforts.

How to use: Basis for all training zones and rTSS calculation. Update every 6-8 weeks.

Learn CRS →

Training Zones

What they are: 7 intensity ranges based on your CRS, from recovery (Zone 1) to sprint (Zone 7).

What they mean: Each zone targets specific physiological adaptations (aerobic base, threshold, VO₂max).

How to use: Follow zone prescriptions for structured training. App shows time-in-zone for each workout.

Training Zones →

Running Training Stress Score (rTSS)

What it is: Quantified workout stress combining intensity and duration. 1 hour at CRS pace = 100 rTSS.

What it means: rTSS 50 = easy recovery, rTSS 100 = moderate, rTSS 200+ = very hard session.

How to use: Track daily/weekly rTSS to manage training load. Aim for 5-10 rTSS increase per week max.

rTSS Guide →

CTL / ATL / TSB

What they are:

CTL: Chronic Training Load (fitness) - 42-day average rTSS
ATL: Acute Training Load (fatigue) - 7-day average rTSS
TSB: Training Stress Balance (form) = CTL - ATL

How to use: Positive TSB = fresh/tapered, negative TSB = fatigued. Race when TSB = +5 to +25.

📊 Your First Week Goals

After entering CRS and completing 3-5 workouts:

Check rTSS values: Confirm they match effort perception (easy ~50, moderate ~100, hard ~150+)
Review zone distribution: Are you spending 60-70% in Zone 2 (aerobic base)?
Establish baseline CTL: Your first week's average rTSS becomes initial fitness baseline
Identify patterns: Which workouts generate highest rTSS? Are you recovering adequately?

Typical User Journey (First 8 Weeks)

Week 1-2: Establish Baseline

Perform CRS test and enter results
Complete 3-5 normal training workouts
Observe rTSS values and zone distribution
Establish initial CTL (fitness level)
Goal: Understand metrics, no changes yet

Week 3-4: Apply Zones

Use CRS zones in workout planning
Intentionally run Zone 2 for aerobic sets
Track weekly rTSS totals (aim for consistency)
Monitor TSB (should be slightly negative = training)
Goal: Train by zones, not feel

Week 5-6: Progressive Overload

Increase weekly rTSS by 5-10% from baseline
Add 1 threshold (Zone 4) session per week
CTL should gradually rise (fitness improving)
ATL may spike on hard weeks (normal)
Goal: Controlled fitness progression

Week 7-8: Retest & Adjust

Perform second CRS test (should be faster)
Update zones in app (pace improves)
Compare CTL Week 1 vs Week 8 (should be +10-20)
Review progress: Are times dropping? Feel easier?
Goal: Validate training effectiveness

✅ Success Indicators

After 8 weeks of structured training with Run Analytics, you should see:

CRS improvement: 1-3% faster CRS pace (e.g., 1:49 → 1:47)
CTL increase: +15-25 points (e.g., 30 → 50 CTL)
Consistent rTSS: Weekly totals within 10-15% variance
Better pacing: More even splits, better effort calibration
Improved recovery: TSB cycles predictably (-10 to +5)

Troubleshooting & FAQs

My rTSS seems too high/low for workout effort

Cause: CRS is outdated or inaccurate.

Solution: Retest CRS. If you tested when fatigued or paced poorly, CRS will be wrong. A proper CRS test is critical for all downstream metrics.

App shows "No CRS configured"

Cause: CRS test not completed or not saved.

Solution: Go to Settings → Critical Run Speed → Perform Test. Enter both 5K and 3K times, then tap Save.

Workouts not syncing from Apple Watch

Cause: Health app permissions not granted or workout not categorized as "Running".

Solution: Check Settings → Privacy → Health → Run Analytics → Allow Read for Workouts. Ensure Apple Watch workout type is "Outdoor Run", "Indoor Run", or "Track Run".

CTL not increasing despite consistent training

Cause: rTSS totals too low or inconsistent frequency.

Solution: CTL is 42-day exponentially weighted average. It rises slowly. Increase weekly rTSS by 5-10%, and maintain 4+ workouts/week for consistent CTL growth.

How often should I retest CRS?

Recommendation: Every 6-8 weeks during base/build phases. Retest after illness, injury, long break, or when zones feel consistently too easy/hard.

Can I use Run Analytics for trail running?

Yes, with limitations: CRS is typically tested on flat ground. For trail running with significant elevation change, rTSS may be underestimated if only using pace. We are working on incorporating Grade Adjusted Pace (GAP) for future updates.

Next Steps

Learn Training Zones

Understand how to train in Zone 2 (aerobic base), Zone 4 (threshold), and Zone 5 (VO₂max) for specific adaptations.