About Swim Analytics

Science-based swimming performance tracking, built by swimmers for swimmers

Our Mission

Swim Analytics brings professional-grade performance tracking to every swimmer. We believe that advanced metrics like Critical Swim Speed (CSS), Training Stress Score (TSS), and Performance Management Charts shouldn't be locked behind expensive platforms or require complex coaching software.

Meet the Developer

Albert Arnó

Creator

Albert Arnó created Swim Analytics out of a personal need for better swim tracking tools. As someone who enjoys swimming and has programming knowledge, he wanted an affordable, science-based analytics tool that wasn't tied to specific hardware or cloud platforms.

Why Swim Analytics Was Created:

"I was frustrated by expensive subscriptions, vendor lock-in requiring specific devices, and lack of control over my own data. I wanted a tool that calculated CSS and TSS correctly, worked with any Apple Health-compatible device, and kept my data private. When I couldn't find it, I built it."

"Swim Analytics combines sports science (based on Wakayoshi's CSS research and Coggan's TSS methodology) with modern iOS design and complete data privacy."

Our Principles

  • Science First: All metrics based on peer-reviewed research. We cite our sources and show our formulas.
  • Privacy by Design: 100% local data processing. No servers, no accounts, no tracking. You own your data.
  • Platform Agnostic: Works with any Apple Health compatible device. No vendor lock-in.
  • Transparency: Open formulas, clear calculations, honest limitations. No black box algorithms.
  • Accessibility: Advanced metrics shouldn't require a degree in sports science. We explain concepts clearly.

Scientific Foundation

Swim Analytics is built on decades of peer-reviewed sports science research:

Critical Swim Speed (CSS)

Based on Wakayoshi et al. (1992-1993) research at Osaka University. CSS represents the theoretical maximum swimming velocity sustainable without exhaustion, corresponding to lactate threshold.

Key Research: Wakayoshi K, et al. "Determination and validity of critical velocity as an index of swimming performance." European Journal of Applied Physiology, 1992.

Training Stress Score (TSS)

Adapted from Dr. Andrew Coggan's cycling TSS methodology for swimming. Quantifies training load by combining intensity (relative to CSS) and duration.

Key Research: Coggan AR, Allen H. "Training and Racing with a Power Meter." VeloPress, 2010. Adapted for swimming by Swim Analytics using CSS as threshold.

Performance Management Chart (PMC)

Chronic Training Load (CTL), Acute Training Load (ATL), and Training Stress Balance (TSB) metrics. Tracks fitness, fatigue, and form over time.

Implementation: 42-day exponentially weighted moving average for CTL, 7-day for ATL. TSB = CTL - ATL.

SWOLF & Stroke Metrics

Swimming efficiency metrics combining time and stroke count. Used by elite swimmers and coaches worldwide to track technical improvements.

Standard Metrics: SWOLF = Time + Strokes. Lower scores indicate better efficiency. Supplemented by Distance Per Stroke (DPS) and Stroke Rate (SR).

Development & Updates

Swim Analytics is actively developed with regular updates based on user feedback and the latest sports science research. The app is built with:

  • Swift & SwiftUI - Modern iOS native development
  • HealthKit Integration - Seamless Apple Health sync
  • Core Data - Efficient local data storage
  • Swift Charts - Beautiful, interactive data visualizations
  • No Third-Party Analytics - Your usage data stays private

Editorial Standards

All metrics and formulas on Swim Analytics and this website are based on peer-reviewed sports science research. We cite original sources and provide transparent calculations.

Last Content Review: October 2025

Recognition & Press

10,000+ Downloads - Trusted by competitive swimmers, masters athletes, triathletes, and coaches worldwide.

4.8★ App Store Rating - Consistently rated as one of the best swimming analytics apps.

100% Privacy-Focused - No data collection, no external servers, no user tracking.

Get in Touch

Have questions, feedback, or suggestions? We'd love to hear from you.