Female participation rates in ultra-running is considerably lower than that of males, but the reasons for this are not fully understood. In this study, online questionnaire responses were collected from ultra-runners taking part in the Scottish Jedburgh 3 Peaks ultra and Highland Fling race. One-to-one-semi-structured phone interviews were conducted with a subset of runners to further explore themes from questionnaire responses. Similar experiences among male and female ultra-runners were identified. Enablers were: wanting a challenge, nature/outdoors, and the friendliness of the ultra-community. The main barrier was training time. Qualitative responses suggested negotiation-efficacy was important for factoring in training around work and family commitments, and although a greater proportion of males had dependants compared to females, female participation was considerably lower than males. This may be due to the historical influences of traditional gender roles however this effect may be diminishing as female participation in Scottish ultra-races appears to be increasing.