Fig. 1

Experiment design. Visual schematic of the experimental design employed in the current study. Performance measures and biometric data (outlined in Table 1) were collected 3 days prior to the study commencement. Blood and saliva were collected on days 0, 4, 8 and 12, to calculate D₂O precursor enrichment. Fifty millilitres of 99.8% D₂O was consumed by all participants 4 × per day for the first 6 days. This dose was lowered to 2 × per day for days 6–12. Vastus lateralis biopsies were taken on day 8 and day 12 of the experimental period. Diet and physical activity monitoring were conducted throughout the experimental period (day 0–12)