Metabolic Response shows how your glucose moved during one recorded workout. Body Insights reads available CGM data in two windows. The first covers 30 minutes before exercise. The second covers the workout.
Open Fitness, select Activity and a day, then open a workout. This section needs at least one glucose reading during the workout.
What Metabolic Response shows
The workout card keeps three parts of the result together:
Pattern
The category that best describes the glucose response during the workout.
Pre-Workout
The latest glucose reading from the 30 minutes before the workout. If none is available, Body Insights uses the first reading during the workout.
Delta
The signed change from the first glucose reading during the workout to the last one.
The pattern can be Glycolytic, Oxidative, Mixed, or Hypoglycemic Risk. Glycolytic describes a rise linked with higher-intensity work. Oxidative describes a steady decline during aerobic work. Mixed covers a stable or more variable response. Hypoglycemic Risk appears when glucose falls sharply to a low level.
How Body Insights builds the result
- Apple Health supplies the workout and available heart-rate data. A compatible CGM or its app adds glucose records.
- Body Insights checks the 30 minutes before the workout. It selects the latest glucose reading as the starting value.
- It checks the direction, variation, and lowest value during the workout.
- It shows the category on the workout card. Pre-Workout and Delta appear beside it.
How to compare similar workouts
Start with two recorded sessions of the same activity at a similar effort. Read Pre-Workout first. Then compare Delta and the pattern category.
For example, one cycling session might have a positive Delta and a Glycolytic pattern. Another might have a negative Delta and an Oxidative pattern. The starting value shows whether the sessions began from a similar place. The category adds more context. Body Insights also checks variation and the lowest reading.
One workout is not a baseline. Look for a repeated response across similar sessions before you change your routine. Use the result to ask simple questions:
- Did glucose rise, fall, or stay relatively stable during this workout?
- Did a similar session produce a different response?
- Was the starting glucose different before the pattern changed?
Metabolic Response is a workout pattern, not an immediate safety alert. Use your CGM alerts and personal care plan for decisions about low or high glucose.
When the card is available
The Metabolic Response section needs at least one glucose reading during the workout. If Apple Health has no in-workout reading, Body Insights does not show the section. A pre-workout reading is optional. If it is missing, the first in-workout reading becomes the starting value.
Recording coverage affects what the card can show. Check that your CGM writes glucose records to Apple Health. Body Insights also needs permission to read them.
See your Metabolic Response
Body Insights keeps the glucose pattern, starting value, and in-workout change together in your workout view.
See my Metabolic Response