Author(s): MOSQUERA, E., LOUIS, J., EDMONSON, J., PUGH, J., OWENS, D.J., ARETA, J.L, Institution: LIVERPOOL JOHN MOORES UNIVERSITY, Country: UNITED KINGDOM, Abstract-ID: 1586

INTRODUCTION:
Female-specific research examining post-exercise refuelling is scarce, and the effect of varied carbohydrate sources remains unclear. Additionally, ketone monoester (KME) supplementation is thought to aid recovery by increasing glycogen resynthesis and circulating erythropoietin (EPO), but how females respond to KME is also unknown. This study assessed the effect of a high-carbohydrate diet consisting of: A) typical food items with non-caloric placebo (CON), B) potato-based meals with non-caloric placebo (POT) or, C) potato-based meals with KME (PKE), on skeletal muscle glycogen resynthesis, blood endocrine and metabolic parameters, and subsequent exercise performance. We hypothesized that PKE during recovery would elicit a distinct blood endocrine response and enhance skeletal muscle glycogen resynthesis, thereby improving subsequent exercise performance.
METHODS:
Following a randomized, counterbalanced, placebo-controlled, double-blind, crossover design, 9 Tier 2 female endurance athletes (mean ± SD: age 28 ± 7, body mass 63.6 ± 7.4, maximal oxygen uptake: 45 ± 3.8 ml/kg/min) completed an exhaustive cycle ergometer glycogen-depleting exercise (EX-1) followed by the ingestion of 0.8 g/kg/h CHO and 0.4 g/kg/h protein at 0 and 1 h, and 1.2 g/kg/h CHO at 2 and 3 h (all equal in PKE, POT, and CON). Concomitant with the diets, participants ingested four doses of KME in PKE (0.5, 0.25, 0.25, and 0.25 g/kg), provided at 0, 1, 2, and 3 h of recovery, while POT and CON received volume-matched non-caloric placebo. Following a 4 h recovery, participants completed a ~20-min laboratory-based cycling time trial (TT). Skeletal muscle samples from the vastus lateralis were taken immediately post-EX-1 and pre-TT, and glycogen concentrations were determined using the acid hydrolysis method. Blood samples were drawn throughout and analysed for β-hydroxybutyrate (βHB), glucose, insulin and EPO.
RESULTS:
βHB concentrations were higher in PKE (range: ~2.2–3.2 mM) vs POT and CON (~0.1 mM, P < 0.01) throughout recovery. Glucose tAUC, calculated across recovery and post-TT, was ~17% lower in PKE vs POT (P = 0.08) and ~19% lower vs CON (P = 0.02). No treatment effects were observed for insulin or EPO tAUC during recovery (P > 0.05). Muscle glycogen resynthesis rates did not differ between treatments (PKE: 26 ± 11 mmol/kg/h; POT: 24 ± 12 mmol/kg/h; CON: 27 ± 8 mmol/kg/h; P = 0.97), nor did subsequent TT performance (PKE: 1458 ± 180 s; POT: 1445 ± 185 s; CON: 1428 ± 157 s; P = 0.54).
CONCLUSION:
Contrary to our hypothesis, adding KME to an optimal post-exercise recovery strategy did not positively modulate endocrine responses, glycogen resynthesis, or exercise performance in Tier 2 female endurance athletes. These findings question the efficacy of KME to enhance post-exercise recovery beyond optimal nutrition and provide novel female-specific insights into post-exercise recovery with varied carbohydrate sources.