Exogenous ketosis elevates circulating erythropoietin and stimulates muscular angiogenesis during endurance training overload

Eighteen healthy male volunteers took part in a 3-week endurance training overload period with 10 training sessions per week. They received either 25 g of ketone ester (KE, n = 9) or a control drink (CON, n = 9) immediately after each session and before sleep. In KE only, the number of capillary contacts and the capillary-to-fibre perimeter exchange index increased by 44 percent and 42 percent, respectively. KE also increased VEGF and eNOS expression at protein and mRNA level, and serum erythropoietin rose by 26 percent.