Adjust the workout settings on Apple Watch Ultra
Update your height and weight
Open the Apple Watch app on your iPhone.
Tap My Watch, go to Health > Health Details, then tap Edit.
Tap Height or Weight, then adjust.
Your Apple Watch Ultra uses the information you provide about your height, weight, sex, age, and wheelchair status to calculate how many calories you burn, how far you travel, and other data. The more you run with the Workout app 
, the more your Apple Watch Ultra learns your fitness level—and the more accurately it can estimate the calories you burned during aerobic activity.
Your iPhone GPS allows your Apple Watch Ultra to achieve even more distance accuracy. For example, if you carry your iPhone while using the Workout app on a run, your Apple Watch Ultra uses the iPhone GPS to calibrate your stride. Then later, if you’re not carrying your iPhone, or if you’re working out where GPS is unavailable (for example, indoors), your Apple Watch Ultra uses the stored information about your stride to measure distance.
Apple Watch Ultra may use the built-in GPS to calibrate your movement.
Change measurement units
If you prefer meters to yards or kilojoules to calories, you can change the measurement units the Workout app uses.
Open the Settings app
on your Apple Watch Ultra.Tap Workout, scroll down, then tap Units of Measure.
You can change units for energy, pool length, cycling workouts, and walking and running workouts.
Pause running and cycling workouts automatically
Open the Settings app
on your Apple Watch Ultra.Tap Workout, then turn on Auto-Pause.
Your Apple Watch Ultra automatically pauses and resumes your outdoor running and cycling workouts—for example, if you stop to cross the street or get a drink of water. You can manually pause your workouts by pressing the side button and Digital Crown at the same time.
Turn workout reminders on or off
For walking, running, swimming, and other workouts, your Apple Watch Ultra senses when you’re moving and alerts you to start the Workout app. It even gives you credit for the exercise you’ve already done. It will also remind you to end your workout, in case you get distracted when you’re cooling down. Follow these steps to turn workout reminders on or off.
Open the Settings app
on your Apple Watch Ultra.Tap Workout, then change the Start Workout Reminder and End Workout Reminder settings. (Workout reminders are on by default.)
You can also open the Apple Watch app on your iPhone, tap My Watch, tap Workout, then change the workout reminder settings.
Avoid accidental taps
If the exercise you’re doing or the gear you’re wearing causes accidental taps on your Apple Watch Ultra, lock the screen so your workout record isn’t interrupted.
Lock the screen: Swipe right, then tap Lock.
Dismiss a notification: Press the Digital Crown.
Unlock the screen: Press and hold the Digital Crown.
Conserve power during a workout
You can extend battery life during Apple Watch Ultra workouts.
Open the Settings app
on your Apple Watch Ultra.Tap Workout, then turn on Low Power Mode.
During workouts, Low Power Mode turns off Always On Display, background heart rate and blood oxygen measurements, and heart rate notifications. Other notifications may be delayed, emergency alerts may not arrive, and certain cellular and Wi-Fi connections are limited.
Tip: To extend battery life even further while performing walking, running, and hiking workouts, turn on Low Power Mode, then turn on Fewer GPS and Heart Rate Readings. Doing so reduces the frequency of GPS and heart rate readings, and turns off alerts, splits, and segments.
For more information, see the Apple Support article Get the most accurate measurements using your Apple Watch.