Sometimes, you might forgot/not allowed to bring your phone or wearable device(like swimming, diving). You can use the manual input exercise to add an activity or exercise to maintain the consistence of your activity tracking.
Sometimes, you are doing an activity that does not require steps (like cycling, yoga, aerobic), or an activity that requires more than just steps (like hiking). The calculation of calories burned, distance, active time by Pacer might not reflected your actual amount of exercise. Under this circumstances, manually input exercise could improves the accuracy of the activity tracking.
Here is a detailed instruction for how to manually input exercise:
Within Pacer, tap the "+" button at the top right corner
Go to "Input Exercise"
Choose a exercise or custom your own activity
Adjust your activity data, and tap "Save"
To view or organize your activities, go to "Me" tab and find "Activity & Log History"