The challenge - named for the 26 miles in a marathon - inspired people to find creative ways to make up for the absence of the race on Sunday, which is the world’s biggest one-day fundraising event.
Here's everything you need to know about it:
What is the 2.6 Challenge?
The 2.6 Challenge is a new charity challenge aimed to pick up the slack from cancelled events like the London Marathon.
The coronavirus has taken its toll on just about every aspect of everyday life, including the cancellation of thousands of sporting events, many of which would have seen public participation in an effort to raise funds for charities of their choosing.
That means that charitable sectors are going to take a significant hit in the wake of the virus; the UK charity sector estimates it will lose £4 billion in income as a result of the pandemic.
"The 2.6 Challenge is a simple way for people of all ages and abilities to help save the UK’s charities," say the event's organisers.
"Your challenge could be as simple as pledging to run 2.6 miles as your daily exercise to doing 26 minutes of juggling non-stop."
While the challenge technically 'began' on 26 April - the day when the London Marathon should have taken place - your challenges can be taken up any time following that date.
The London Marathon is the world’s biggest one-day fundraising event, which raised more than £66.4 million for thousands of charities in 2019; without the 2.6 Challenge, none of that cash would have been raised for charities in 2020.
How can I take part?
"The 2.6 Challenge can be any activity you like," say the organisers, "from running 2.6 miles to holding an online workout with 26 of your friends."
More ideas on what you could do as part of the 2.6 Challenge can be found on the event's official website.
"Whatever your age or ability, you can take part. After all, we’re not looking for superheroes. We’re looking for Home Heroes."
Once you're settled on what you want to do for your own 2.6 Challenge, head to the website for more information on how to support your chosen charity.
How have celebrities helped?
As the 2.6 Challenge got underway this past week, a host of celebrities were on hand to help, taking part in their own inventive challenges.
Dame Kelly Holmes attempted to do 26 reps of 26 exercises on a trampoline as well as hosting a live-streamed workout, with proceeds going to her Dame Kelly Holmes Trust which aims to transform the lives of disadvantaged young people.
Rugby star Jonny Wilkinson attempted 26 keepy-ups with various sporting balls, donating money to Tiny Lives, a charity that supports premature newborn babies in the north east of England.
DJ Trevor Nelson gave himself 26 minutes to complete a particularly tricky looking indoor golfing drill in support of mental health charities, while Leicester City's Christian Fuchs completed 26 keepy-ups of a football in an impressive nine seconds.
For more information on the 2.6 Challenge, head to the official website