Former Gloucester lock forward Ed Slater said he "had a little cry" as he completed a 350-mile cycle ride.
He completed the three-day ride, which started and finished at Gloucester's Kingsholm Stadium, alongside former team-mates.
The aim was to raise money for the 4Ed campaign, set up to cover his treatment costs and to support his family.
Slater's Just Giving page has reached more than £150,000 so far.
"I don't know where to start. I had a little cry coming down Birdlip Hill [seven miles from Kingsholm]," he said.
Slater told BBC Radio Gloucestershire on Wednesday evening that it was a "massive relief" to get to Kingsholm.
"We arranged it so quickly I didn't have a chance to grasp how difficult a challenge it was going to be," he added, saying fellow Gloucester player Billy Twelvetrees dragged him up some "really dark hills".
Day one of the ride saw Slater cycle from Kingsholm to Welford Road - home of his former club Leicester, alongside Cherry and Whites captain Lewis Ludlow, Fraser Balmain and Billy Twelvetrees, as well as friends and former teammates, including Charlie Sharples, Alex Brown and Jim Hamilton.
The group travelled south to Milton Keynes - Slater's hometown - and visited his first club Milton Keynes RFC on day two, before making the 106-mile return trip to Gloucester on the final day.
'Sadness'
Slater said his friends and former teammates had done "every mile" with him.
"It just suddenly dawns on you that all the things you worry about and get stressed about really are insignificant and what it really boils down to is being around good people," he said.
He added he also felt "sadness" among other emotions.
"It's such an amazing club," he said.
"I've been so proud to play for Gloucester. To think I wont be able to play on the pitch again is difficult."
Slater joined Gloucester in 2017 and played 78 times for the club, the last of which came in January when he had already begun experiencing twitches in his left arm.
He spent seven years previously with Leicester Tigers, winning the Premiership title in 2012-13 and also skippering the side between 2014 and 2016.
The second-rower's career began in Australia, playing with the Eastern Suburbs. He was called up to the England Saxons squad in 2012 and captained them to victory over the Crusaders in New Zealand two years later.
In an interview with BBC Breakfast, Slater said he had been experiencing symptoms for 11 months prior to his diagnosis and now does not look too far into the future.
Following the ride, he said: "I am not going to help anyone by stewing at home - my kids don't need it, my wife doesn't need it, I don't need it - so I am determined to carry on and try and keep that attitude."
MND is a degenerative condition that affects the nerves in the brain and spinal cord.
Slater is among a number of sports people who have been diagnosed with the condition.
Former rugby league player Rob Burrow, Scotland rugby union lock Doddie Weir, ex-Liverpool right-back Stephen Darby and former Burnley and Blackburn Rovers midfielder Len Johnrose all have MND and have campaigned to raise awareness about the disease.