Acute exogenous ketone monoester supplementation decreases indices of cardiac vagal modulation in a dose-dependent manner in healthy adults.

Both doses of ketone monoester increased plasma β-hydroxybutyrate compared to placebo.

• Study involved 18 healthy adults (23 ± 3 years; n = 10 females)
• Participants ingested 0.3 or 0.6 g/kg ketone monoester or placebo
• Randomized crossover, double-blind design was used
• Plasma β-hydroxybutyrate was elevated following both ketone doses relative to placebo

Both ketone monoester doses reduced pRR50 (percentage of successive R-R intervals differing by ≥50 ms) at 45 and 120 minutes post-ingestion.

• Reductions in pRR50 were observed compared to placebo at both time points
• Effect was statistically significant at 45 minutes post-ingestion (p < 0.02)
• Effect was statistically significant at 120 minutes post-ingestion (p < 0.01)
• Both the 0.3 g/kg and 0.6 g/kg doses produced this effect

Both ketone monoester doses reduced RMSSD (root mean square of successive differences) at 45 and 120 minutes post-ingestion.

• Reductions in RMSSD were observed compared to placebo at both time points
• Effect was statistically significant at 45 minutes post-ingestion (p < 0.02)
• Effect was statistically significant at 120 minutes post-ingestion (p < 0.01)
• Both the 0.3 g/kg and 0.6 g/kg doses produced this effect

Exogenous ketone monoester supplementation decreases heart rate variability measures associated with cardiac vagal modulation.

• pRR50 and RMSSD are both indices associated with cardiac vagal modulation
• Effects were observed at two time points: 45 minutes and 120 minutes post-ingestion
• The supplementation also elevated heart rate, consistent with reduced vagal tone
• Reductions occurred in a dose-dependent manner across 0.3 and 0.6 g/kg doses