Training Load landed in watchOS 11 and is Apple’s first real attempt at answering “am I doing too much?”. It is more conservative than WHOOP strain or Garmin’s training status, and like the Sleep Score its virtue is that the model is simple enough to audit.
Effort ratings, 1 to 10
Everything starts with a per-workout number. For many cardio workouts, running especially, the watch estimates it from your age, height, weight, GPS pace, heart rate and elevation. You get a rating without doing anything.
The scale runs from Easy at the bottom through Moderate and Hard to All Out at 10. Apple treats these as ratings of perceived exertion with a sensor-driven first guess, which is a sensible framing: RPE has held up well in sports science for decades precisely because the athlete knows things the instruments do not.
The 7 versus 28 day comparison
Training Load does not report an absolute figure you can compare with anyone else. It sums the effort of your last seven days and compares it against your last 28, then tells you whether the week sits above, below or in line with that baseline.
This is a version of the acute-to-chronic workload idea that endurance coaching has used for years. The logic: injury and illness risk tends to track sudden increases relative to what you are conditioned for, rather than absolute volume. A 60-mile week is routine for one runner and a disaster for another, and a ratio captures that where a raw number cannot.
The consequence people find counterintuitive: taking a genuinely needed rest week will show as a large drop, and then your first normal week back will show as a spike. Neither is a problem. The ratio is deliberately sensitive to change.
The 28-day wait, and why it cannot be skipped
Training Load displays nothing until it has 28 days of workouts. This is the single most common complaint about the feature and it is not a bug. The metric is defined as a comparison against a four-week baseline, so before four weeks there is literally nothing to compare against.
It is also why the feature disappears for people coming back from injury or a long off-season, right at the moment ramp-rate advice would be most useful.
Where it falls down: lifting
The automatic effort estimate leans on the relationship between pace, heart rate and intensity. In strength training that relationship collapses. A heavy triple at 90 percent of your max barely moves your heart rate and is one of the most demanding things you can ask of your body; a circuit of light accessories spikes your heart rate and costs comparatively little.
So a lifting session either gets no automatic rating or gets a low one, and the load calculation quietly under-counts the training that most needs tracking. Setting the rating by hand fixes the arithmetic but not the deeper problem, which is that one whole-body number cannot express that your legs are wrecked and your back is fresh.
We took that argument apart in why your wearable has no idea which muscles are tired.
How it compares to strain and training status
WHOOP strain runs 0 to 21, is computed from heart rate across the entire day rather than logged workouts alone, and counts the cardiovascular cost of a stressful commute. Broader, harder to audit.
Garmin’s training status sits on top of a longer-established load model and adds an aerobic and anaerobic split, plus recovery time estimates. More opinionated, and free with the watch, which we compared in Garmin vs Apple Watch for recovery.
Apple’s Training Load is the narrowest of the three and the easiest to reason about. Workouts only, effort 1 to 10, this week against the last four.
If you want the load number to mean something, the zones underneath it have to be right first. That is zone 2 heart rate, and why yours is probably wrong.