Purpose: This study assessed the cardiorespiratory fitness, running biomechanics, muscle architecture and training characteristics of a 76-year-old female runner who currently holds the world record 1500m to marathon in the women's 75-79 age category. Methods: maximal oxygen uptake (V̇O2max), running economy (RE), lactate threshold (LT) and lactate turnpoint (LTP), maximal heart rate (HRmax), and running biomechanics were measured during a discontinuous treadmill protocol followed by a maximal incremental test. Muscle architecture was assessed using ultrasound. The testing was done in close proximity to her world record marathon performance in 2024. Results: V̇O2max was 47.9 ml∙kg-1∙min-1, and HRmax was 180 beats∙min-1. At marathon speed (11.9 km∙h-1) her RE was 210 ml∙kg-1.km-1. Fractional utilisation corresponding to LT (11.1 km∙h-1) and LTP (12.5 km∙h-1) occurred at 83% and 92% of V̇O2max, respectively. Fractional utilisation at marathon speed corresponded to 88% of V̇O2max. Average weekly distance was 115 and 84 km∙w-1 in the 6 weeks prior to the marathon world record and world-championships track (where she achieved 6 medals out of 6 events), respectively, with on average 90%, 9%, and 1% of training time performed in the moderate, heavy, and severe intensity domain, respectively. Conclusion: The 76-year-old female world-record holder 1500m to marathon showed the highest V̇O2max ever recorded for a female >75 years old, a very high fractional utilization of V̇O2max at LT, LTP, and at marathon pace, but RE was modest in comparison to other world-class master athletes and younger elite runners.
Keywords: Case report; V̇O2max; aging; master athlete; middle distance running; oxygen consumption; running.