Adventure Sync (Japanese: いつでも冒険モードAnytime Adventure Mode) is a feature in Pokémon GO introduced on November 1, 2018. It allows players to track walking distances, when the game is completely turned off, via the API of Apple's Health app for iOS and Google Fit for Android.
Every Monday, at 9:00 a.m. local time, players can redeem weekly rewards based on the total distance they walked in the past seven days. Rewards are given for hitting total weekly distance of 5 km, 25 km and 50 km. Reaching longer distance benchmarks will also include the rewards earned for shorter distances. At each benchmark, players will receive a set of guaranteed reward bundles plus one randomly selected bundle. Receiving an Egg is not possible if the player does not already have an open Egg slot in the Pokémon Box.