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Privacy Policy

Privacy Policy

Effective Date: April 2, 2026

1. Introduction

SinewFit LLC ("SinewFit," "we," "our," or "us"), a New Jersey Limited Liability Company, operates the website sinewfit.ai and the SinewFit application (collectively, "the Service"). We are committed to protecting your privacy. This Privacy Policy explains how we collect, use, store, and share your personal information when you use the Service. By using the Service, you agree to the practices described in this policy.

2. Information We Collect

We collect the following types of personal information when you create an account and use the Service:

Account Information

  • Email address
  • Name
  • Password (stored securely via our authentication provider)

Physical and Health Information

  • Date of birth
  • Height and weight
  • Strength benchmarks (e.g., bench press, squat, deadlift, overhead press maxes)
  • Bodyweight fitness benchmarks (e.g., push-up and pull-up maxes)
  • Cardio benchmarks (e.g., mile time, longest run)
  • Injury information and physical limitations

Fitness Preferences

  • Fitness goals
  • Experience level
  • Equipment access and gym type
  • Preferred workout days and session length
  • Cardio activities and sport-specific interests
  • Exercise preferences and swap history

Usage Data

  • Workout logs (exercises completed, sets, reps, weights used)
  • Workout plan history
  • Weekly feedback responses
  • Progression and personal records data

Analytics and Engagement Data

We collect anonymized usage data to improve the app experience. This includes which features you use (e.g., workout logging, plan generation, exercise swap), how often you use the app, page views, and general engagement metrics. We also store usage events (such as "workout completed" or "plan generated") linked to your user account to understand how the app is being used. These events contain minimal metadata (such as the type of workout completed) and never include sensitive data like exercise weights, injury information, or health details.

We use Vercel Analytics to collect anonymous page view and web performance data. This data does not include personal information and cannot be used to identify individual users.

3. How We Use Your Data

We use your personal information for the following purposes:

  • Personalized workout plans: Your profile data (physical stats, goals, experience level, equipment, injuries) is used to generate AI-powered workout plans tailored to your needs
  • Progress tracking: Your workout logs and benchmarks are used to track your progress over time and adjust future plans accordingly
  • Service improvement: Aggregated, de-identified usage data may be used to improve our AI algorithms and overall service quality
  • Account management: Your email is used for authentication, password resets, and essential service communications
  • Analytics: To analyze app usage patterns, understand which features are most valuable, and identify and fix technical issues

4. Data Storage and Security

Your data is stored using Supabase, a secure database platform hosted on Amazon Web Services (AWS) infrastructure. All data is encrypted in transit using TLS/SSL encryption. Supabase implements industry-standard security measures including row-level security policies to ensure that users can only access their own data.

While we take reasonable measures to protect your personal information, no method of electronic storage or transmission over the internet is 100% secure. We cannot guarantee absolute security of your data.

5. Third-Party Services

We use the following third-party services to operate SinewFit:

Anthropic API (Claude)

Your profile data — including physical stats, fitness goals, experience level, equipment access, injuries, and workout history — is sent to Anthropic's Claude AI to generate personalized workout plans. Anthropic processes this data according to their own privacy policy and data handling practices. We send only the minimum data necessary for plan generation.

Vercel (Hosting & Analytics)

Our application is hosted on Vercel's platform. Vercel may collect standard server logs including IP addresses and request metadata as part of their hosting service. We also use Vercel Analytics for anonymous page view and web performance tracking — no personal data is shared with Vercel Analytics.

Supabase

Supabase provides our database, authentication, and backend infrastructure. Your data is stored in Supabase's managed PostgreSQL databases hosted on AWS.

6. Data Minimization

We follow data minimization principles. Our analytics tracking intentionally excludes sensitive health and fitness data such as exercise weights, body measurements, injury details, and specific workout performance metrics. We collect only the minimum usage data necessary to improve the app.

7. What We Do NOT Do

  • We do not sell your personal data to third parties
  • We do not serve advertisements or share data with advertising networks
  • We do not use your data for purposes unrelated to the Service
  • We do not share your individual data with other users

8. Data Retention

Your personal data is retained for as long as your account remains active. If you wish to delete your account and all associated data, you may request deletion by contacting us at the email address listed below. Upon receiving a verified deletion request, we will delete your personal data within 30 days, except where we are required by law to retain certain information.

9. Your Rights

You have the following rights regarding your personal data:

  • Right to access: You may request a copy of the personal data we hold about you
  • Right to correction: You may update or correct your personal data at any time through the profile settings in the app
  • Right to deletion: You may request deletion of your account and all associated personal data
  • Right to data portability: You may request your data in a structured, machine-readable format

To exercise any of these rights, please contact us at the email address listed below.

10. Cookies

SinewFit uses minimal cookies strictly necessary for authentication and session management. We do not use tracking cookies, analytics cookies, or advertising cookies. The cookies we use are essential for the Service to function and cannot be opted out of while using the Service.

11. Children's Privacy

SinewFit is not intended for use by children under the age of 13. We do not knowingly collect personal information from children under 13. If we become aware that a child under 13 has provided us with personal information, we will take steps to delete such information promptly. If you believe that a child under 13 has provided us with personal data, please contact us at the email address listed below.

12. California Residents (CCPA)

If you are a California resident, the California Consumer Privacy Act (CCPA) provides you with additional rights regarding your personal information. These include:

  • The right to know what personal information we collect, use, and disclose
  • The right to request deletion of your personal information
  • The right to opt out of the sale of your personal information (we do not sell your data)
  • The right to non-discrimination for exercising your CCPA rights

To make a request under the CCPA, please contact SinewFit LLC at the email address listed below.

13. European Residents (GDPR)

If you are a resident of the European Economic Area (EEA), the General Data Protection Regulation (GDPR) provides you with additional rights. SinewFit LLC acts as the data controller for your personal data. Our legal basis for processing your personal data includes:

  • Consent: You consent to data processing when you create an account and agree to our Terms of Use
  • Contract performance: Processing is necessary to provide you with the Service
  • Legitimate interests: Processing is necessary for our legitimate interests in improving the Service

Under the GDPR, you have the right to access, rectify, erase, restrict processing, object to processing, and port your data. You also have the right to lodge a complaint with a supervisory authority. To exercise any of these rights, please contact us at the email address listed below.

14. Changes to This Policy

We may update this Privacy Policy from time to time. We will notify users of material changes by updating the effective date at the top of this page. Your continued use of the Service after any changes constitutes your acceptance of the updated Privacy Policy. We encourage you to review this policy periodically.

15. Contact Information

If you have any questions about this Privacy Policy or wish to exercise your data rights, please contact us at:

support@sinewfit.ai