Training load

What it is

Training load is a way of putting a number on how much training stress you’ve absorbed. There are two sides to it:

• External load: the work you did, such as kilometres, metres climbed, watts or kilograms lifted.
• Internal load: how hard that work was for your body, measured with heart rate or how hard it felt.

A simple internal-load method is session RPE: rate the whole session from 0 to 10 and multiply by its length in minutes. Heart rate methods such as TRIMP, and power-based scores, do a similar job automatically.

Why it matters for training decisions

Fitness comes from training load applied consistently over weeks, and many injuries in team-sport research are linked to large, rapid jumps in load rather than to high load itself. Looking at load by the week, and how it compares with what you’re used to, is more useful than judging any one session.

How wearables measure it, and the limits

Each platform calculates load its own way. Apple Watch compares the intensity and duration of your workouts over the last 7 days with the previous 28 days, using effort ratings. intervals.icu can calculate load from power, heart rate or pace. Numbers from different platforms aren’t interchangeable.

Heart-rate-based load can under-count strength work, sled pushes and short sprints, where heart rate lags behind the real effort. It also can’t see stress from work, travel or poor sleep.

How P247 uses it

P247 works out a heart-rate-based load for your workouts from Apple Health and Strava. Recent training load is one of the inputs to the daily recovery score, and the weekly report checks whether your load rose faster than your recovery.

This glossary is general information to help you understand your training data. It isn't medical advice, diagnosis or treatment. For injury, illness, medication, blood test results or any health concern, speak to a qualified health professional.

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