The Marathon des Sables (six stages, ~250 km running) in the Sahara Desert requires physiological and metabolic adaptations by physical training and nutritional strategies. PURPOSE: Four weeks before competition in the Marathon des Sables 2023, we examined effects of 7-day intake of New Zealand blackcurrant (NZBC) extract (210 mg anthocyanins per day) on 1-hr treadmill running-induced physiological and metabolic responses in the heat (~34°C, relative humidity: ~30%) in an amateur female and male athlete (23, 38 yrs, BMI: 24.2, 28.4 kg·m-2, body fat%: 29.2%, 18.8%, V ̇O2max: 50.1, 52.1 mL·kg-1·min-1). METHODS: During the 1-hr run at 50%V ̇O2max (female: 7.3, male: 7.5 km·h-1), indirect calorimetry was used and heart rate recorded at 15-min intervals with core temperature monitoring (0.05 Hz). The runs were 3-hr after breakfast (slice of bread and water) and 2-hr after intake of the final dose of NZBC extract with water ad libitum. RESULTS: With NZBC extract, there were no effects in the female athlete. The female athlete RER in the non-supplement condition was 0.77±0.01, indicating ~77% contribution of fat oxidation to energy requirements. In the male athlete during 1-hr of running (mean of 4 measurements), fat oxidation was higher by 21% (control: 0.84±0.11, NZBC: 1.02±0.08 g·min-1, P<0.01), carbohydrate was 31% lower (control: 1.07±0.29, NZBC: 0.71±0.12 g·min-1, P=0.05), RER was 0.03 units lower (control: 0.80±0.02, NZBC: 0.77±0.01, P=0.04), core temperature was 0.4°C lower (control: 37.7±0.3; NZBC: 37.3±0.3°C, P<0.01) with no differences for heart rate (control: 136±10, NZBC: 134±7 beats·min-1, P=0.50), minute ventilation (control: 51.3±1.8, NZBC: 49.8±3.1 L·min-1, P=0.43), oxygen uptake (control: 2.51±0.02, NZBC: 2.60±0.09 L·min-1, P=0.10) and carbon dioxide production (control: 2.01±0.05; NZBC: 1.99±0.04 L·min-1, P=0.72). CONCLUSION: Seven-day intake of New Zealand blackcurrant extract (210 mg anthocyanins per day) provided beneficial physiological and metabolic responses during 1-hr of indoor (~34°C) treadmill running in a male Marathon des Sables athlete 4 weeks before competition. Future work is required to address whether New Zealand blackcurrant provide a nutritional ergogenic effect for Marathon des Sables athletes during long-duration running in the heat with personalized nutrition.

Supplements were provided by Health Currancy Ltd (UK). Blackcurrant New Zealand Inc (NZ) and Health Currancy Ltd (UK) provided funding for conference attendance.