Comparison

HRV4Training vs Compex Coach

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

HRV4Training

Quantify stress, balance training and lifestyle, and improve performance with scientifically validated heart rate variability insights. This app accurately assesses HRV using your phone's camera or compatible devices, offering actionable interpretations for optimizing your training plan.

Highlights
  • HRV-based stress quantification
  • Training and lifestyle balance
  • Performance improvement insights
  • Camera-based HRV assessment
  • Integration with wearables
  • Training load analysis
  • VO2max and Lactate Threshold estimation
Features
Read full description

The first scientifically validated Heart Rate Variability (HRV) app. HRV4Training provides HRV based insights to help you quantify stress, better balance training and lifestyle, and improve performance. HRV4Training does not require a heart rate monitor, since it can accurately assess your HRV using the phone's camera. HRV4Training also works with Apple Watch, the Oura ring and all compatible Bluetooth SMART sensors. HRV4Training is also the first app that goes beyond simple measurements and provides insights on: 1) acute or day to day HRV changes in response to different stressors (alcohol, travel, sick days, training, menstruation, etc.) 2) long term multi-parameter trends to look at the big picture 3) correlations between physiological measurements and annotations 4) training load analysis, fitness, fatigue, readiness to perform and injury risk 5) VO2max estimation for runners linking the app to Strava or TrainingPeaks and using a heart rate monitor during their workouts 6) Training Polarization analysis (or 80/20) 7) Lactate Threshold Estimation for runners linking the app to Strava or TrainingPeaks and using a heart rate monitor during their workouts 8) Weekly and monthly summaries to track progress. All data is processed inside the app in order to provide you with actionable interpretations that can help optimizing your training plan and performance. Supported devices for the camera measurement: iPhones 5, 5S, 6, 6S, 6+, 6S+, SE, 7, 7+, 8, 8+, X, XS, XS Max, XR, 11, 11 Pro, 11 Pro Max, 12 mini, 12, 12 Pro, 12 Pro Max, 13 mini, 13, 13 Pro, 13 Pro Max, 14, 14 Plus, 14 Max, 14 Pro, 15, 15 Max, 15 Pro, 16, 16 Max, 16 Pro Currently unsupported devices for the camera measurement: iPhones 4S, iPads and iPods - These devices require a chest strap. Other features: - HRV-based advice helps you to adapt your trainings based on objective measures of recovery - TAGS: lets you tag your sleep, mental energy, muscle fatigue, stress and all other parameters that can help you understand what is influencing your physical condition and physiological stress - Works with Bluetooth SMART heart rate monitors (a Polar H7 is recommended) or simply your phone's Camera - Integrates with the Health app (writes heart rate, and sleep, read sleep time) - Configurable test (single or orthostatic, choose test duration between 1, 3 or 5 minutes) - Extracts and stores the following features while lying down and/or standing: heart rate, mean of beat-to-beat intervals (AVNN), standard deviation of beat-to-beat intervals (SDNN), square root of the mean squared difference of successive R-Rs (rMSSD), number of pairs of successive R-Rs that differ by more than 50 ms (pNN50), low frequency power (LF, 0.04-0.15 Hz), high frequency power (HF, 0.15-0.40 Hz) - Shows the PPG signal view to ensure signal quality during the test if the camera is used instead of a bluetooth SMART sensor - HRV4T Recovery Points to provide a single, straightforward metric to analyze your physical condition - Population summaries and people like you comparisons to put your data into perspective - Analysis of compliance and consistency - Data export via email or Dropbox - Integrates with TrainingPeaks, Oura, Strava and Coros HRV4Training requires to register an account with your email address, so that your data can be backed up safely and retrieved in case anything happens (app issue, changing phone, etc.). HRV4Training does not provide medical advice. It is intended for informational purposes only. Consult a medical professional before making health or lifestyle decisions. Please find an overview of the relevant scientific literature in our guide, here: https://marcoaltini.substack.com/p/the-ultimate-guide-to-heart-rate

About

Compex Coach

This app guides users in setting training objectives, planning sessions, and receiving reminders for their Compex device. It offers detailed instructions on electrode placement, intensity management, and program specifics for various fitness and recovery goals. Users can also share their progress with friends.

Highlights
  • Set training objectives
  • Plan Compex sessions
  • Reminders for sessions
  • Electrode placement guidance
  • Program details and explanations
  • Share sessions with friends
Features
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Compex Coach App will guide you to set up your objectives, it will help you to plan your training and remind you when to have your next Compex session. Also, you can easily share your sessions with your friends. Examples of objectives available*: - Prepare for a 10km, half-marathon, marathon - Prepare for a cycling race - Prepare for a triathlon - Improve your core stabilisation - Increase your muscle volume - Improve your strength - Treat your tendinopathy - Treat your cervical pain - Treat your contracture - Prevent cramps - Prevent low back pain - Tone your arms - Firm your thighs And many others... App features: - Find an objective that fits your needs (eg: Prepare for a marathon, triathlon or cycling race, Treat a back pain or tendinopathy, Increase your strength…) and set up the plan to reach it. - Show you the right electrode placements - Display precise images of electrodes placements and body position according to the programme - Explain how to manage the stimulation intensity according to the programme - Provide all the details for each Compex programme (description, usages, effects, stimulation intensity, electrode placements) - Explain how muscle stimulation works For more information on Compex product, please visit our website www.compex.com *Objectives availability related to the product ***This app doesn't control your Compex device, it is meant to be used as a standalone app***

Screenshots

HRV4Training4 screens
Compex Coach4 screens

Verdict

The call

The clearest difference is price: Compex Coach at Free against HRV4Training's $9.99. Compex Coach also leads on rating (4.7 vs 3.6) and iOS requirement (12.0 vs 15.6). HRV4Training's advantage is chart position (#30 vs unranked). On review sentiment, ratings volume, update cadence and ads there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Compex Coach is free to download; HRV4Training costs $9.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Compex Coach holds the better App Store score, 4.7 against 3.6. Both are backed by a comparable volume of ratings — 290 and 309 respectively. Written reviews complicate that: 61% of HRV4Training's written reviews are positive against 57% of Compex Coach's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

HRV4Training ships an update every 6 weeks, Compex Coach every 3 months. The most recent releases landed on November 1, 2026 and October 29, 2026 respectively.

Scorecard5 real differences · 6 level
HRV4Training versus Compex Coach: the parameters behind the verdict, then further details
ParameterHRV4TrainingCompex Coach
Price$9.99Free — better
Rating3.6 (290 ratings)4.7 (309 ratings) — better
Positive reviews60.9% of reviews — better57.1% of reviews
Number of ratings290309 — better
Update frequencyEvery 6 weeks — betterEvery 3 months
AdsNoNo
In-app purchasesNoNo
MonetizationPaidFree — better
Best chart rank#30 — better—
DevicesiPhone, iPodiPhone, iPod
Requires iOS15.612.0 — better
Further details — not scored
Size35 MB73 MB
Age rating4+4+
DeveloperA.S.M.A. B.V.DJO, LLC

Customer experience

HRV4Training

All ratings288 ratings
Positive62.2%
Neutral5.6%
Negative32.3%
Written reviews453 reviews
Positive60.9%
Neutral7.3%
Negative31.8%

Compex Coach

All ratings241 ratings
Positive94.6%
Neutral2.1%
Negative3.3%
Written reviews14 reviews
Positive57.1%
Neutral7.1%
Negative35.7%

User reviews

HRV4Training

From 290 App Store ratings

What we love

  • 👍 Accurate HRV measurements
  • 🚀 Straightforward and easy to use
  • 💡 Provides valuable insights for training and recovery
  • 👍 Integrates well with other fitness apps
  • 👍 Responsive and helpful developer support

Room to improve

  • 🐛 Inconsistent readings and technical issues
  • 🔒 Requires user account and data sharing
  • 🔒 Concerns about data privacy
  • 🔋 Drains battery when using camera for measurements

Compex Coach

From 309 App Store ratings

What we love

  • 👍 Helpful for electrode placement
  • 📈 Good for tracking progress (Workload Score)
  • 💪 Aids in bodybuilding and cycling
  • ✨ Helps firm/shape body areas
  • 💡 Useful for logging past settings

Room to improve

  • ❓ Poor or vague instructions
  • 🤔 Lacks detailed exercise routines/videos
  • 🚫 No shipping service/slow processing
  • ✉️ No response to emails
  • 🔠 Limited electrode placement options

Bugs and requests

HRV4Training

Reported bugs

3 issues
  • App crashes frequently, especially with iOS updates
  • Syncing issues with Strava, TrainingPeaks, and Apple Health
  • Camera-based measurements often unreliable or inconsistent

Requested features

4 requests
  • Allow multiple measurements per day
  • Improve integration with Apple Watch and other wearables
  • Add more customization options and data visualization
  • Expand support for non-athletic use cases

Compex Coach

Reported bugs

1 issue
  • 🐛 Won't let add multiple muscle groups on different programs

Requested features

8 requests
  • More comprehensive electrode placement map
  • More detailed instructions and exercise examples
  • Video demonstrations of exercises and calibration
  • Ability to rearrange missed sessions in the app
  • Synchronize functionality between the app and online coach
Show 3 more
  • More reporting and analytics for progress monitoring
  • Connect wireless devices for automatic progress monitoring
  • Track races and training periodisation

In-app purchases

None

HRV4Training

No in-app purchases

None

Compex Coach

No in-app purchases

Questions

Is HRV4Training free?
HRV4Training costs $9.99, with no in-app purchases.
Is Compex Coach free?
Compex Coach is free to download, with no in-app purchases.
Which has better reviews, HRV4Training or Compex Coach?
Compex Coach is rated higher. HRV4Training averages 3.6 out of 5 from 290 ratings, while Compex Coach averages 4.7 from 309 ratings.
Do HRV4Training or Compex Coach have ads?
Neither HRV4Training nor Compex Coach shows ads.
Which is updated more often, HRV4Training or Compex Coach?
HRV4Training ships an update every 6 weeks, and Compex Coach every 3 months. Most recently, HRV4Training was updated on November 1, 2026 and Compex Coach on October 29, 2026.

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