Arsenal did run the most km/miles in 2018 and 2019 season
https://www.si.com/soccer/2019/05/24/arsenal-top-premier-league-distance-covered-table-201819-manchester-united-rank-third-bottom#:~:text=It is, in fact, Unai,this season, as per Opta.
So ofcourse they just being realy healthy... only...