
Sim
Anaesthetic & Intensive Care Doctor, FitnessCheck co-founder
Simran is an anaesthetic and intensive care doctor who runs most days with Tofu the Cockapoo. He competes in Hyrox with his wife and Canicross with his dog, and co-founded FitnessCheck to bring lab-grade lactate threshold testing to age-group athletes.
Simran spends his days monitoring physiology in theatre and intensive care, and his evenings and weekends pushing his own. He co-founded FitnessCheck because he kept seeing committed athletes train hard for years on zones a single afternoon of testing could have settled for them.
Posts by Sim
- When Should You Retest Your Lactate Threshold? · 9 October 2026
- Your Watch's "Lactate Threshold" Feature Isn't Measuring Your Lactate Threshold · 24 September 2026
- Your FTP Is an Estimate. Your Heart Rate Zones Are an Estimate of an Estimate. · 30 August 2026
- Lactate, VO2 Max, or Combined: Which Test Should You Book? · 20 August 2026
- FitnessCheck Comes to Heathwood Swimming and Triathlon Club in Cardiff · 1 August 2026
- FTP and the Female Cyclist: What the Standard Training Numbers Get Wrong (Both Ways) · 29 July 2026
- Why Your VO2 Max Isn't Improving (The Oxygen Cascade Explained) · 15 July 2026
- Lactate vs Ventilatory Thresholds: Our Findings and Why We Measure Blood, Not Breath · 29 June 2026
- How Quickly Can You Improve Your Lactate Threshold? · 23 June 2026
- What an Elite Hyrox Athlete's Lactate Profile Actually Looks Like · 15 June 2026
- Hyrox Pacing Strategy: Run Below Your Anaerobic Threshold (Here's Why) · 9 June 2026
- How Your Lactate Zones Match Your Watch’s Zones · 30 May 2026
- Lactate Test Case Study: Garmin Zone 2 Was 17 bpm Too Low · 26 May 2026
- Your Zone 2 Heart Rate Is Probably Wrong. Here's How to Tell. · 20 May 2026
- What's Actually in a Lactate Threshold Test Report · 12 May 2026
- Why You Blow Up in the Second Half of a Hyrox (And How to Fix It) · 9 May 2026
- Do You Actually Need a Lactate Threshold Test? An Honest Answer · 8 May 2026