[4] When McArthur was 12 he won the under 14s category at the British Youth Climbing Series Finals in Edinburgh.

[5] At junior level, McArthur won the gold medal at the IFSC Junior Boulder World Championship in Voronezh, beating his previous best result of silver at the 2019 IFSC Youth World Championships.

[6] On McArthur's senior debut, he won third place in at the 2021 IFSC Climbing World Championships § Lead in Moscow.

[7] McArthur represented Great Britain in the sport climbing at the Paris Olympics finishing fifth in the Combined Boulder and Lead final.

In December 2019, he redpointed Jungle Speed 9a (5.14d), followed shortly after by A Muerte 8c+ (5.14c); both are located in Siurana.