The director of UKAF Rugby, Lieutenant Commander Michael 'Doc' Cox, is aiming to complete a cycling challenge for NHS and Armed Forces charities.
The task will see him pedal from Glasgow to London – visiting all the Nightingale hospitals along the way.
He plans to cycle 80km a day to complete the 840km trip.
He says the reasoning for the challenge is to say thank you to the key workers.
He explained: "I wanted to do something to say 'thank you very much' to the NHS for all that they've done during COVID-19 over the last 12 to 16 months.
"And also for SSAFA for the support that they've given families during this incredible unprecedented time.
"I suppose you can tie that also into the fact that servicemen and women last year were paramount in building the Nightingale centres.
"It's a way of saying thank you to them," he added.
His challenge is set to begin on 25 June and will end on 15 July at the UK's first Nightingale hospital, which was built in London last year.
He will have the help of the UKAF U23s head coach, Petty Officer 'Pony' Moore, during the cycle challenge.
"For me, it's trying to keep Doc's morale up," said Petty Officer Moore.
"It's going to be an absolute challenge for him physically and, no doubt, emotionally.
"My role is not just going to be driving his items from place to place, it's also going to be trying to spur him on and drive him forward for some morale."
Their route for the challenge will go from Glasgow to Edinburgh, into England via Berwick, to Sunderland and Harrogate, before dropping down to Birmingham and then onto London Docklands, via PJHQ (Permanent Joint Headquarters) at Northwood and the Houses of Parliament.
The UKAF rugby director knows it will be a tough test.
He said: "I'm not a cyclist in any shape or form. I'm a rugby player.
"It's going to be emotional and there's going to be dark places as well, and I'm really thankful to 'Pony' for being the support driver.
"It's been horrific this last year and it will bring back memories of people who have been lost on operations over the last couple of years.
"Looking forward to it but not looking forward to it," he added.