Sympatho-vagal interaction in the recovery phase of exercise
- ISSN: 14750961
- ISBN: 1475-097X (Electronic)\r1475-0961 (Linking)
- DOI: 10.1111/j.1475-097X.2011.01012.x
- PubMed: 21672134
Reciprocal autonomic regulation occurs during incremental exercise. We hypothesized that sympatho-vagal interplay may become altered after exercise because of the differences in recovery patterns of autonomic arms. The cardiac vagal activity was assessed by measurement of beat-to-beat R-R interval oscillations using a Poincare plot method (SD1), and muscle sympathetic nervous activity (MSNA) was measured from peroneus nerve by a microneurography technique during and after exercise in 16 healthy subjects. Autonomic regulation was compared between the rest and after exercise (3.5 +/- 1.0 min after exercise) at equal heart rates (HR). SD1 was at the equal level at the recovery phase (40 +/- 21 ms) compared to the resting condition (38 +/- 16 ms, P = ns) at comparable HR (57 +/- 10 for both). MSNA was higher at the recovery phase (40 +/- 19 burst per 100 heartbeats) than at rest (25 +/- 13 burst per 100 heartbeats, P<0.0001). The difference of MSNA activity between rest and late recovery phase had a strong positive correlation with the difference in SD1 (r = 0.78, P<0.001) at equal HRs. Subjects who have a higher sympathetic activity in the recovery phase of exercise have a more augmented cardiac vagal activity resulting in an accentuated sympatho-vagal outflow. The altered autonomic interaction observed here may partly explain the clustering of various cardiovascular events to the recovery phase of exercise.