HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 296/6/H1733    most recent 00054.2009v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (1) Google Scholar Articles by Manzi, V. Articles by Iellamo, F. PubMed PubMed Citation Articles by Manzi, V. Articles by Iellamo, F.

Dose-response relationship of autonomic nervous system responses to individualized training impulse in marathon runners

¹Facoltà di Scienze Motorie, Università Tor Vergata, and ²Istituto Di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Roma, Italy

Submitted 14 January 2009 ; accepted in final form 24 March 2009

In athletes, exercise training induces autonomic nervous system (ANS) adaptations that could be used to monitor training status. However, the relationship between training and ANS in athletes has been investigated without regard for individual training loads. We tested the hypothesis that in long-distance athletes, changes in ANS parameters are dose-response related to individual volume/intensity training load and could predict athletic performance. A spectral analysis of heart rate (HR), systolic arterial pressure variability, and baroreflex sensitivity by the sequences technique was investigated in eight recreational athletes during a 6-mo training period culminating with a marathon. Individualized training load responses were monitored by a modified training impulse (TRIMP_i) method, which was determined in each athlete using the individual HR and lactate profiling determined during a treadmill test. Monthly TRIMP_i steadily increased during the training period. All the ANS parameters were significantly and very highly correlated to the dose of exercise with a second-order regression model (r² ranged from 0.90 to 0.99; P < 0.001). Variance, high-frequency oscillations of HR variability (HRV), and baroreflex sensitivity resembled a bell-shaped curve with a minimum at the highest TRIMP_i, whereas low-frequency oscillations of HR and systolic arterial pressure variability and the low frequency (LF)-to-high frequency ratio resembled an U-shaped curve with a maximum at the highest TRIMP_i. The LF component of HRV assessed at the last recording session was significantly and inversely correlated to the time needed to complete the nearing marathon. These results suggest that in recreational athletes, ANS adaptations to exercise training are dose related on an individual basis, showing a progressive shift toward a sympathetic predominance, and that LF oscillations in HRV at peak training load could predict athletic achievement in this athlete population.

heart rate variability; baroreflex sensitivity; training load; performance; athletes

This article has been cited by other articles:

				G. E. Billman Cardiac autonomic neural remodeling and susceptibility to sudden cardiac death: effect of endurance exercise training Am J Physiol Heart Circ Physiol, October 1, 2009; 297(4): H1171 - H1193. [Abstract] [Full Text] [PDF]

				M. Pagani and D. Lucini Can autonomic monitoring predict results in distance runners? Am J Physiol Heart Circ Physiol, June 1, 2009; 296(6): H1721 - H1722. [Full Text] [PDF]