You don't have to run, you can jog, or walk - and you are even guaranteed to finish ahead of the big names.
The guest athletes will literally get behind the nation as so-called Tail Walkers', volunteers who ensure no one ever finishes last at parkrun events.
More than 630 free parkruns (5k) and junior parkruns (2k) take place every Saturday morning in parks across the UK.
The National Lottery and UK Sport, which funds elite UK athletes from Lottery ticket sales, have now teamed up with organisers parkrun UK for a series of high profile #teamparkrun events on Saturday, August 19.
The aim is to get the nation active, while celebrating the public’s support of elite and community sport through playing The National Lottery.
It is backed by Sport England, sportscotland, Sport Wales, Sport Northern Ireland, the British Olympic Association and British Paralympic Association, as well as a host of national governing bodies.
REGISTER TO TAKE PART: It's free to take part but you need to register in advance. For full details and to register visit www.teamparkrun.com.
VIDEO: World Championship gold and Olympic bronze curler Eve Muirhead brought up the rear at a parkrun in Falkirk. Watch her four tips on how to Parkrun in the UK Sport video at the top of this page.
It is hoped some people will take part in a parkrun for the very first time – either walking, jogging, running or volunteering themselves – with a view to starting their journey to a more healthy, active lifestyle.
The #teamparkrun event follows the success of last year's I am Team GB, which inspired nearly 1 million people to take part in the UK's biggest ever sports day - with athletes joining in community sports events as part of a Rio 2016 Olympians homecoming.
That day celebrated the role the nation played in supporting elite athletes by playing The National Lottery.
This year's event follows the IPC and IAAF World Athletics Championships, hosted in the iconic London Stadium, which was the epicentre of the London 2012 Games,
National Lottery players have been backing Britain’s record-breaking Olympic and Paralympic athletes for 21 years.
Dame Katherine Grainger, five time Olympic medallist and the newly appointed Chair of UK Sport, said: “The nation, and specially National Lottery players, have been backing us as athletes for 21 years now and none of us would be where we are today without their support.
“While sport and activity are integral to our lifestyles, we know that for some people taking up activity for the first time can be a scary prospect. parkrun offers a free, friendly and welcoming way to start, and our athletes will be there on August 19 to make any newcomers feel extra welcome.
“If you’ve been thinking about getting active, join #teamparkrun on August 19; you’ve been right behind us for so long and now your athletes will be right behind you!”
Nick Pearson, Chief Executive of parkrun, said: “One of the most common reasons that people register with parkrun but don’t go on to take part is because they don’t feel capable of running 5k. This initiative, which will see GB athletes supporting parkrunners, will reinforce the message that not only do we encourage walkers at parkrun, but that all of our events have volunteer Tail Walkers who provide support along the course.”
Arabella Gilchrist, Head of The National Lottery Brand, said: “#teamparkrun offers a brilliant way of celebrating the support the public gives British sport by playing The National Lottery.
“No one does more to contribute to elite athletes or community sports projects than our players. #teamparkrun will thank our players by connecting our Lottery-funded athletes with their local parkrun to inspire everyone, no matter what their level of fitness, to get active. We hope to see plenty of first-time parkrunners, joining their sporting heroes at their local event.”