HRV4Training vs GroundApp

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

Your nervous system already knows how to heal. Ground gives it the right breath to do it. Ground is an AI-powered breathwork app built for people who want to feel calm, focused, and present in their bodies. Whether you are managing stress, improving sleep, building resilience, or training your nervous system, Ground meets you exactly where you are and guides you to where you want to be. 33 SCIENTIFICALLY-BACKED TECHNIQUES From beginner-friendly to expert-level, every technique is rooted in science and designed with intention. Practice Box Breathing, 4-7-8 Breathing, Wim Hof, Coherent Breathing, Physiological Sigh, Alternate Nostril Breathing, Breath of Fire, Cyclic Sighing, Resonance Breathing, Vagal Toning, and dozens more. Each technique includes detailed how-to guides so you always know exactly what to do and why it works. AI-GUIDED SESSIONS THAT ADAPT TO YOU Ground uses AI to understand your current state, your goals, and your biometrics. Through an intelligent intake process, the app recommends the perfect technique for your moment. Feeling anxious? Overwhelmed? Low on energy? The AI reads your signals and prescribes the right breathwork session, personalized to your nervous system. VOICE-GUIDED BY REAL VOICES Choose from multiple voice guides or unlock voice cloning to hear guidance in your own voice. Every session can be voice-guided, haptic-only for silent practice, or visual-only. You decide how you want to be guided. WEARABLE INTEGRATION AND BIOMETRIC INSIGHTS Connect Apple Health, Oura Ring, Whoop, and Garmin to get a complete picture of your nervous system. Ground tracks your HRV, resting heart rate, sleep quality, and recovery scores. A real-time Autonomic Nervous System (ANS) state badge shows whether you are in a calm, activated, or stressed state, and recommends breathwork accordingly. Personal baselines adapt to your unique physiology over time. AMBIENT SOUNDSCAPES AND BINAURAL BEATS Enhance your practice with rain, ocean waves, forest sounds, fireplace, night sounds, and thunderstorm soundscapes. Layer in binaural beats (delta, theta, alpha, beta) to deepen your state. Adjust voice and music volumes independently for the perfect session atmosphere. TRACK YOUR PROGRESS Build streaks, log every session, and watch your practice grow. View session history, track trends in your HRV and resting heart rate, and see how your nervous system responds to consistent breathwork over time. APPLE WATCH COMPANION Practice on your wrist with the Apple Watch app. Get real-time heart rate data during sessions and sync everything back to your iPhone. DESIGNED FOR YOUR PRACTICE Set daily intentions. Choose from quick-access breathing tools for coherence, focus, sleep, energy, and calm. Customize session backgrounds, transition sounds (singing bowl, chime, tibetan bell, gong), and ambient layers. Offline mode ensures your practice is never interrupted. PREMIUM FEATURES Upgrade to unlock all 33 techniques, AI-guided intake, voice cloning, guided programs, biometric insights, community and leaderboards, data export, and advanced analytics. Free users get core techniques, a session timer, streak tracking, and basic stats. YOUR PRIVACY MATTERS Ground does not track you. Your data stays on your device and in your control. We believe your breath is personal, and so is your data. Health disclaimer: Ground is a wellness tool designed to support your breathwork practice. It is not a medical device and does not diagnose, treat, cure, or prevent any disease. Consult your healthcare provider before beginning any new breathing practice, especially if you have cardiovascular, respiratory, or other medical conditions. From the mind into the body. This is where we feel grounded. ---- Terms of Use: https://groundapp.live/terms Privacy Policy: https://groundapp.live/privacy