Fitness Belt Built From Extreme

4.3

(11.6k Total Review)

clarity

Smartwatches versus silence

Smartwatches are notification machines that ruin your focus. BY FIT is a silent lab on your wrist. It captures medical-grade biometrics 24/7 without ever buzzing you out of the zone.

Distraction

Notifications, emails, and constant buzzing pull you away from training.

Data

Silent biometric tracking that never interrupts your work.

ECG and HRV

Detect stress loads via Lorenz scatter plot analysis.

Metabolic chems

Non-invasive trending for glucose, uric acid, and lipids.

elite

Built for the 1%

If you train casually, buy a smartwatch. BY FIT is engineered for those who train 5+ days a week. We track the toll your lifestyle takes on your body.

The CrossFit grind demands precision

  • Real-time heart rate & HRV tracking
  • Training load & recovery readiness insights
  • Stress & fatigue detection
  • Muscle vs fat performance tracking
  • Metabolic efficiency monitoring
HRV: Optimal

Recovery Ready

High Intensity Detected

Training Load
  • Train harder. Recover smarter. Perform longer.

  • Smart App Integration

    Turns complex health data into clear, actionable insights in a secure app.

  • 24/7 Continuous Monitoring

    Collects health data throughout the day without disrupting your routine.

  • Adaptive Intelligence

    Learns from your body patterns over time to deliver more personalized health insights.

  • Comfortable, Discreet Design

    Lightweight, flexible fabric designed for all-day wear under any outfit.

  • Battery Life

    180mAh high-voltage battery powers up to 15 days typical use.

  • Fast Charging

    Magnetic fast charge gets you back in the game quickly.

  • Water Resistant

    IP68 waterproof rating handles sweat, rain, and pool sessions.

  • Continuous Health Monitoring

    Advanced sensors track your key health metrics around the clock—without interrupting your routine.

outcomes

Don't guess. Know.

Three pillars separate the serious from the sidelined. Overtraining kills progress. Sleep quality determines recovery. Energy processing fuels performance.

Avoid injury before it happens

Overtraining flags before you snap.

Sleep hacking through data

Analyze deep versus REM sleep to fix your recovery window.

Metabolic fuel understanding

Understand how your body processes energy with glucose trending.

Tested by Athletes

Across the World

ComfortDurabilityStyle

Women

Built for female athletes

Cycle tracking and ovulation prediction synced with your recovery metrics. Automated SOS and fall detection for solo training sessions.

Hormonal rhythm awareness

Track your cycle and understand how hormonal changes impact energy levels, training performance, and recovery.

Cycle-synced training insights

Adjust workout intensity and recovery based on where you are in your cycle for better results and reduced fatigue.

Safety & solo training support

Automated SOS and fall detection provide added confidence during solo workouts and outdoor sessions.