The Role of Cholinesterases in Post-Exercise HRV Recovery in University Volleyball Players

Some studies show interest in measuring heart rate variability (HRV) during post-exercise recovery. It is known that the parasympathetic system is relevant during this process, where one of the factors of this modulation is the interaction of acetylcholine and cholinesterases (ChE). However, the behavior of ChE and its relationship during recovery is little known; therefore, the objective of this study was to analyze the behavior of ChE and its relationship with recovery evaluated in HRV indicators in volleyball players. An exercise protocol with long-term and intermittent high-intensity phases was applied in nine volleyball players. HRV measurements were made, and blood samples were drawn to evaluate the ChE before exercise and after 24 and 48 h post-exercise. The results show a modification of the variables after exercises with respect to the baseline values (ChE: 1818.4 ± 588.75 to 2218.78 ± 1101.58; RMSSD: 42.64 ± 12.86 to 17.72 ± 12.55 (p < 0.05); SS: 8.76 ± 1.93 to 21.93 ± 10.05 (p < 0.01); S/PS Ratio: 0.32 ± 0.14 to 3.26 ± 3.28 (p < 0.01)), as well as recovery after 24 and 48 h with respect to postexercise (ChE: 1608.81 ± 546.88 (p < 0.05) and 1454.54 ± 580.45 (p < 0.01); RMSSD: 43.83 ± 24.50 and 46.18 ± 33.22 (p < 0.01); SS; 10.93 ± 5.16 and 11.86 ± 4.32 (p < 0.01); S/PS Ratio: 0.46 ± 0.32 and 0.50 ± 0.28 (p < 0.01)). ChE correlations (p < 0.001) were found with moderate (SS: r = 0.465) and large (RMSSD: r = −0.654; S/PS Ratio: r = 0.666) HRV indexes. In conclusion, ChE modifications are related to changes in HRV showing a very similar behavior in the case of the study subjects.