Watch metric
Acute vs Chronic Training Load
Acute vs Chronic Training Load Definition
A comparison of your recent training over about a week against your longer-term baseline over about a month, meant to flag when you have ramped up too fast.
Acute Load - your training load over the last 7 days.
Chronic Load - training load over a longer time period, normally 30 days.
The actual figure is normally worked out via some combination of multiplying average heartrate by distance. Longer runs with a high average heartrate giving you a higher 'load' figure as they're likely to put more strain on your body and take longer to recover from.
Conversly, short runs at a low average heartrate probably put less strain on your body.
Most watch brands add their own spice on this metric, possibly taking elevation into account. The general rule remains the same though.
Load ratio is simply the ratio of acute to chronic load, helpful for seeing how your recent training relates to your recent average.
When it helps
For more experienced runners managing a build-up, being aware of total load is helpful for managing to prevent injuries.
When it doesn't
For beginners, where the simple rule of building gradually does the same job without the maths.