Despite undergoing treatment for cancer and suffering from a dropped foot, the 77-year-old was desperate for something to do during lockdown, so he set out a challenge to walk as far as he could every day.
And, between March and October, he had clocked up 3,018 miles walking and 512 miles cycling, measured via the AA Route Planner.
"That’s when I became obsessed,” said the former chair of the Scottish Borders Disability Sport Group, an organisation he still collates PVGs for and is a level one trainer for the local Boccia players.
He added: “My wife Ella made a fatal suggestion that I should download an app to accurately measure my steps and mileage.
“So I downloaded a health tracker app, and since the end of October to this week, I have recorded a further 3,950 miles. That’s about the same as walking to the earth’s core.
"It was not all plain sailing, however.
"Due to my dropped foot, I had 22 falls, but thankfully no breaks or fractures, only a few head stitches and free flowing blood.
"Once, I wore the wrong socks with footwear on a single-day longish walk, and I now lack a big toenail, and although it’s still pretty sore it is starting to grow back.
"The weather was not always kind and I got thoroughly soaked many times, got battered by hailstones, snow and sleet and heavy winds, and I flattened the soles of four pairs of trainers.”
However, it wasn’t all doom, gloom and lost toenails. David says he took his camera along on his jaunts, and took more than 200 photos of wildflowers “and I’ve named almost all”, as well as the beautiful scenery of the Borders countryside.
He's also lost a bit of weight, and picked a “phenomenal amount” of litter on his travels.
He added: “I did not seek sponsors at the time as so many people were doing so and I did not want to impact on their efforts, but under a little pressure from others I have set up a voluntary donation fund this week to raise some funds for Cancer Research UK.
"So many of my friends have died of cancer during Covid, or, like myself, are still undergoing treatment.”
“My original consultant oncologist was Alan McLaren at BGH who is to retire in August so this would be my tribute to him also.”