To STOP segments during a workout on Apple Watch:

Select the Workout Activity, such as "Outdoor Walk" NOTE: Do not start the walk, instead:

1. Tap the 3 dots in the upper righthand corner
2. Then, Tap the Pencil Icon
3. Then, SCROLL down to "Splits"
4. Tap "Splits"
5. Where it says "Splits Alert' ensure you TURN OFF the alert by tapping the righthand "slide" to GRAY instead of GREEN.
6. This should turn off your unwanted segments and splits notifications. The segments should be available once you stop your workout, should you want to access them.