Keri Wallace is a runner, climber, mountain leader and co-founder of Girls on Hills, the UK's only guided trail, fell and sky running company designed specifically for women. She has numerous top ten finishes across a wide range of trail running disciplines from fell racing and ultrarunning to sky running and alpine tours. Keri's first personal challenge was to complete the three UK Big Rounds – the Bob Graham, Charlie Ramsay and Paddy Buckley rounds – solo-supported in a single, multi-day push for charity in 2011. Since then, she has completed a wide range of running projects and holds the female fastest-known time for the Glen Coe Round and the Winter Tranter's Round, as well as establishing the Glen Coe Classic Rock round in 2021. In 2023 she finished third female in the Skyrunner UK & Ireland series and finished fifth female in the 170-kilometre Ultra Tour Monte Rosa. Initially a neurobiologist, Keri has a PhD in Proprioceptive Plasticity but in 2018 made a career change, setting up her own trail running business. Keri now lives in the Scottish Highlands with her husband and children and spends her days run-guiding and juggling being a mum to their two girls. Running Challenges is her first book. www.girlsonhills.com