Frequently Asked Questions

Training in Zone 2 (moderate intensity) builds your aerobic base - the foundation of cardiovascular health and longevity. Zone 3+ (vigorous intensity) strengthens your heart and improves VO2 max.

The CDC's 150 moderate OR 75 vigorous minutes per week isn't arbitrary - it's the threshold where research shows significant improvements in:

• Cardiovascular health and disease prevention
• Metabolic efficiency and mitochondrial function
• All-cause mortality reduction
• Healthspan and functional fitness as you age

Most people work out regularly but stay in Zone 1 (too easy) or Zone 4-5 (too hard, unsustainable). Zone 2-3 is where the magic happens - hard enough to drive adaptation, sustainable enough to do consistently.

HeartHealthier helps you track whether you're actually hitting these zones each week, so you're not just working out - you're working out effectively.

These are based on the CDC and WHO physical activity guidelines for adults:

• 150 minutes of moderate-intensity activity per week, OR
• 75 minutes of vigorous-intensity activity per week

Research shows that meeting these minimums significantly reduces risk of heart disease, diabetes, and early death. HeartHealthier helps you track whether you're actually hitting these targets based on your heart rate data - not just workout duration.

VO2max is basically your body's maximum capacity to use oxygen during exercise. Think of it like the engine size in a car — a higher VO2max means your body can deliver and use more oxygen to fuel your muscles when you're working hard. It's measured in milliliters of oxygen per kilogram of body weight per minute (ml/kg/min).

Why it matters: VO2max is one of the best predictors of cardiovascular fitness and overall health. Higher levels are associated with lower risk of heart disease, diabetes, and even early death.

How this connects to the CDC's 150/75 recommendation:

The CDC guidelines are designed to improve and maintain your VO2max. Here's the key distinction:

• Moderate activity (like brisk walking, casual cycling) typically means you're working at roughly 50–70% of your VO2max — you can talk but not sing
• Vigorous activity (like running, fast cycling) means you're at 70–85% of your VO2max — you can only say a few words before needing to catch your breath

The reason 75 minutes of vigorous equals 150 minutes of moderate is that vigorous exercise challenges your cardiovascular system more intensely, so you need less time to get the same benefits.

When you regularly hit these targets, you're training your heart, lungs, and muscles to get better at using oxygen — which gradually improves your VO2max over time. It's like regularly pushing your engine to make it stronger.

Yes. HeartHealthier requires an Apple Watch to track heart rate during workouts. The app pulls data from Apple HealthKit, which receives workout and heart rate data from your Apple Watch.

Without heart rate data, we can't calculate which zones you're training in - which is the core feature that helps you understand if you're working hard enough.

HeartHealthier works with any device that syncs workout and heart rate data to Apple HealthKit. This includes:

• Apple Watch (all models)
• Some Garmin devices (via Garmin Connect syncing to Health)
• Some Fitbit devices (via third-party sync apps)
• Peloton (syncs workouts to Apple Health)

If your device writes workout data with heart rate to Apple Health, HeartHealthier can read and analyze it.

HeartHealthier uses a different methodology of calculating heart rate zones.

Click the "Download Beta" button on our home page to join via TestFlight. TestFlight is Apple's official beta testing platform - it's safe and easy to use.

Once installed, you'll create an account and connect your HealthKit data. The app will analyze your workout history and show you your zone breakdown immediately.

We'd love to hear from you! During the beta, you can:

• Use TestFlight feedback - Take a screenshot in the app to send feedback directly through TestFlight
• Email us - Reach out directly to sequel_destiny.6p@icloud.com with suggestions or bug reports

Your feedback helps shape the future of HeartHealthier. We read every message.

HeartHealthier requests read-only access to the following HealthKit data:

• Workouts - Your workout history (type, duration, start time)
• Heart Rate - Heart rate samples during workouts
• Resting Heart Rate - Used to calculate your personalized heart rate zones
• Date of Birth - Used to calculate your max heart rate
• Biological Sex - Optional, for more accurate fitness calculations

No. Raw heart rate data never leaves your device.

Your iPhone processes heart rate samples locally to calculate how much time you spent in each zone (Zone 1 through Zone 5). We only store the final weekly totals:

• Moderate minutes - Total time in Zone 2+ (fat burning, endurance)
• Vigorous minutes - Total time in Zone 3-5 (VO2 max, fitness gains)

Individual heart rate readings (like "125 bpm at 10:05am") are never transmitted or stored on our servers.

To provide personalized heart rate zones and track your progress, we store:

• Account info - Email address, display name
• Profile data - Age, biological sex, resting heart rate (for zone calculations)
• Fitness goals - The goals you select during onboarding
• Workout sessions and weekly summaries - Your moderate and vigorous activity minutes per week
• Goal history - Whether you hit your weekly targets

Your email is used as your unique account identifier. All data is linked to your account so you can access it across devices. If you have privacy concerns, we recommend using the Hide My Email feature or using a non-personally identifiable email address (i.e., magic.dust@gmail.com) and display name (i.e., Yoda).

Your data is used for one purpose only: to provide and improve your HeartHealthier experience.

Specifically, we use your data to:

• Calculate your personalized heart rate zones
• Track your weekly progress toward activity goals
• Show you trends over time
• Improve the app based on aggregate, anonymized usage patterns

HeartHealthier is built by a solo developer who cares deeply about privacy. Your trust matters more than any potential profit from selling data.

Yes. You can request complete deletion of your account and all associated data by contacting us at sequel_destiny.6p@icloud.com. We will remove:

• Your account and profile information
• All weekly summaries and goal history
• Any fitness level progression data

Data stored locally on your device (in HealthKit) is not affected - that remains under your control through Apple's Health app.