What is heart-rate spike filtering?

Heart rate spike filtering is an automatic system in Milo that cleans up bad sensor data so your training metrics stay accurate.

Why it exists

Some wrist-based heart rate sensors, including certain Apple Watch models, can randomly report extremely high heart rates for a few seconds. This often happens at the start of a run and is sometimes called “cadence lock.”

These spikes are not real and would otherwise distort your stats.

How Milo handles it

Milo automatically detects and removes these short, false spikes before calculating:

• TRIMP (Training Load)

• Average heart rate

• Long-term load metrics (CTL, ATL, TSB)

Because TRIMP is exponential, even a tiny spike would inflate your score unfairly. Filtering prevents this.

Can I disable it?

No. Heart rate spike filtering cannot be turned off.

It is a core data integrity safeguard that ensures your training history and analytics stay accurate and trustworthy.