Acute hydrogen-rich water ingestion stimulates cardiac autonomic activity in healthy females

Background: Hydrogen-rich water (HRW) has been shown to have a stimulating effect on the human body. Objective: The aim of study was assess influence acute HRW intake autonomic cardiac regulation during 50 min rest sitting. Methods: Fourteen healthy females (age 21.7 ± 1.2 years, body mass 67.8 8.7 kg, height 167 5.5 cm) took part in this double-blind, randomized, placebo-controlled trial with crossover design. Heart rate variability (HRV) monitored sitting position after administration 1260 ml or placebo. Time domain indexes HRV as square root mean squares differences between adjacent RR intervals (RMSSD), standard deviation all (SDNN) and ratio SDNN/RMSSD an index sympatho-vagal balance were used response. values transformed using natural logarithm (Ln). Results: After HRW, we found significantly increased Ln when comparing it placebo 25 (HRW: 0.40 0.30, placebo: 0.26 0.25, p = .049) 35 0.44 0.28 0.28, .029) SDNN compared 45 4.41 0.42 ms, 4.28 0.31 Conclusions: Acute ingestion induced relative increase sympathetic activity post-ingestion, whereas vagal not affected.