Premier League clubs are gradually beginning to open their training grounds with strict social-distancing measures in place, so how have they been able to monitor player fitness for the past six weeks?
One key tool has been GPS equipment, and data provided to Sky Sports News shows Kieran Tierney has registered some impressive numbers this week, Leighton Baines has covered over 30 miles in the last seven days, and Harry Maguire has also put the effort in.
The advanced equipment is based at training grounds so STATSports - a company that includes Manchester United, Liverpool, Tottenham and Manchester City among their clients - supplied clubs with an alternative.
"Since this COVID-19 crisis kicked in, we've been working with a lot of the teams by providing our consumer product," co-founder Sean O'Connor tells SSN.
"The player has his own pod and vest, with the data synced to their phone. It allows them to get a programme from the conditioning coaches and the data gets fired back to the coaches' app.
"It shows distances, speed, high-speed running, step balance, and acceleration."
It means household names are beginning to appear on the top 20 leaderboards alongside amateur and youth footballers, providing professional players choose for their data to be shown.
England defender Harry Maguire scored 2515m this month in the High Metabolic Load Distance (HMLD) category. This measures how intense the running load is, and Maguire is 14th narrowly behind Crystal Palace defender Joel Ward.
There are also weekly leaderboards and the app shows Arsenal players have been hard at work in the past seven days.
Tierney tops the HMLD category ahead of team-mates Hector Bellerin, Eddie Nketiah and Bukayo Saka, and they have James Tarkowski and Baines for company in the top seven.
Arsenal players also impress in the High Speed Running (HSR) category that registers any speed over 5.5 metres per second. Gary Cahill has enjoyed a good week in this area as he moved into the top 20.
Baines is No 3 overall for distance covered in the past week narrowly ahead of Burnley's Matt Lowton and Ben Godfrey of Norwich.
"There are things you might not expect to see like a centre-half who is regularly hitting 33 or 34 km/h speeds," O'Connor explains.
"They might not always get the chance in games to showcase that but they're showing they are athletes who can hit high speeds and run at big distances for a sustained period of time."
That could apply to Stoke defender Ryan Shawcross who clocked a top speed of 35.25 km/h this week. That was similar to Aaron Lennon but the highest registered speed from a professional belongs to Hearts and Northern Ireland striker Conor Washington (36.2km/h).
"It's a bit like an off season when these clubs may not know if a player is in shape so they benefit from being able to give them instructions and to follow that, including live recording.
"They can ask them to hit a certain number of accelerations or to hit X metres of high speed running."
Mauricio Pochettino is another user of the technology and his sons Sebastiano and Maurizio regularly appear on the leaderboards.
Such data is becoming an increasingly important tool for clubs and players to prove to others they are having success. Last summer, Romelu Lukaku released his running stats on social media to prove doubters wrong, but it caused members of the public to focus on Luke Shaw and others who appeared further down the list.
"Players sometimes put their data out there, especially if they're doing well on leaderboards," says O'Connor. "A group of 20-odd people will generally embrace that competition.
"The average age of these guys, they're younger guys and data is part of their daily life. Players come off the pitch wanting more. What was my high speed? What was his speed? Did I beat my friend? How many accelerations did I get? It encourages that healthy competition."