Kim Collison has broken a fresh ultrarunning record, reaching 33 Munros and climbing 29,500ft in just 24 hours.

Collison ran 100 miles as he reached the summits the Scottish mountains – all with a height of 3,000ft or more – finishing in 23 hours and 48 minutes. Collison added an extra mountain to the 32 completed by previous record holder Sasha Chepelin last year: Braeriach, the third highest in the British Isles.

It is just the latest record Collison has broken in the last 15 months. Last summer he set a new record for the Lake District 24-hour challenge, summiting 78 peaks in just shy of 24 hours. More recently he broke the Runners World UK record in Wales this April, which includes 47 peaks across more than 60 miles of mountainous terrain.

Celebrating on social media, Collison said: ‘Over the moon to run 33 Munro’s in a day. Could not done it without the support of so many. What an adventure pushing my limit.’

In an Instagram post, he thanked his wife and support team and said: ‘At times the views were magnificent and weather was good for running before the rain and mist arrived with darkness adding to the lack of visibility. However I like a challenge!’

Munros are Scottish mountains over 3,000ft, named after Sir Hugh T Munro, who catalogued them in 1891. Although they are found throughout Scotland, in recent years the 24-hour challenge has been focused on the Cairngorms in the eastern Highlands.

Collison told Runner's World UK that he suffered from serious fatigue during the challenge. He hit the wall with about three hours to go, and had to sit while he ate a slice of pizza and a chocolate crêpe. 'I had about a minute of eating those and then got up and thought: “right, I’ve got to do this",’ he said.

There were high points, too. Towards the end of the challenge, Collison had a surreal brush with nature: 'We’ve come out, we’ve gone right through the night. I’m just approaching the last summit, thinking “is this going to happen today?” The cloud starts to lift and then there’s these two magnificent stags.'

He said: 'We’re looking at them, they’re looking at us, and it’s just like, wow this is stunning. You really do appreciate those moments. It’s kind of why I do these big rounds in the national parks, for that exploration and that contact with nature.

'It takes your mind to that feel good place, and anything that does that and makes you smile is going to give you that little bit of a boost for a while.'

As for the next challenge, Collison said he is focused on rest for the time being. But he is eyeing up the Dragon's Back Race in Wales this September. He said: 'I haven’t raced for so long and that fits my journey, adventure, endurance bill. It’ll take my mind off records for a while.’