Parasympathetic reactivation after repeated sprint exercise
Martin Buchheit,
1
Paul B. Laursen,
2
and Saı¨d Ahmaidi
1
1
Laboratoire de Recherche EA 3300 (APS et Conduites Motrices: Adaptations Re´adaptations), Faculte´ des
Sciences du Sport d’Amiens, Universite´ de Picardie Jules Verne, France; and
2
School of Exercise,
Biomedical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia
Submitted 16 January 2007; accepted in final form 26 February 2007
Buchheit M, Laursen PB, Ahmaidi S. Parasympathetic reac-
tivation after repeated sprint exercise. Am J Physiol Heart Circ
Physiol 293: H133–H141, 2007. First published March 2, 2007;
doi:10.1152/ajpheart.00062.2007.—The purpose of this study was to
examine the effects of muscular power engagement, anaerobic par-
ticipation, aerobic power level, and energy expenditure on postexer-
cise parasympathetic reactivation. We compared the response of heart
rate (HR) after repeated sprinting with that of exercise sessions of
comparable net energy expenditure and anaerobic energy contribu-
tion. Fifteen moderately trained athletes performed 1) 18 maximal
all-out 15-m sprints interspersed with 17 s of passive recovery (RS),
2) a moderate isocaloric continuous exercise session (MC) at a level
of mean oxygen uptake similar to that of the RS trial, and 3)a
high-intensity intermittent exercise session (HI) conducted at a level
of anaerobic energy expenditure similar to that of the RS trial.
Subjects were immediately seated after the exercise trials, and beat-
to-beat HR was recorded for 10 min. Parasympathetic reactivation
was evaluated through 1) immediate postexercise HR recovery, 2) the
time course of the root mean square for the successive R-R interval
difference between successive 30-s segments (RMSSD
30s
) and 3)HR
variability vagal-related indexes calculated for the last 5-min station-
ary period of recovery. RMSSD
30s
increased during the 10-min period
after the MC trial, whereas RMSSD
30s
remained depressed after both
the RS and HI trials. Parasympathetic reactivation indexes were
similar for the RS and HI trials but lower than for the MC trial (P⬍
0.001). When data of the three exercise trials were considered to-
gether, only anaerobic contribution was related to HR trial-derived
indexes. Parasympathetic reactivation is highly impaired after RS
exercise and appears to be mainly related to anaerobic process
participation.
heart rate recovery; vagal-related indexes; autonomic activity; sprint
interval training
REPEATED SPRINT (RS) training, characterized by recurring ses-
sions of brief repeated bouts of supramaximal exercise, may be
a time-efficient strategy for inducing metabolic adaptations in
human skeletal muscle (15). Adaptations shown after a short
time course of RS training include increased resting glycogen
content (20), increased maximal activities of various enzymes
involved in glycolytic (31) and oxidative energy provision (10,
20), an increased H
⫹
buffer capacity (17, 20), and decreased
cycling time-trial performance (10, 15, 20). As a result, RS
training has been proposed as a viable alternative to classically
prescribed submaximal endurance training (10, 17, 20).
Today, there are growing social and psychological reasons
to encourage RS training within clinical populations. First, RS
training is remarkably time efficient and more compatible with
the Western world’s time-poor modern lifestyle. Second, the
concept of RS training may also be more attractive than
continuous exercise for sedentary individuals who have diffi-
culty handling exercise sessions that are perceived to be of a
long duration and of a monotonous nature. Third, the high level
of muscular power needed to perform RS training stresses
more type II muscle fibers, which comprise approximately
one-half of the fibers within the thigh (vastus) and calf (gas-
trocnemius) muscles of most people and of which are not
recruited during low-intensity exercise. Not surprisingly, RS
training has been shown to result in maintenance of and even
an improvement in muscular strength (17).
Although the effectiveness of RS training for maintaining
and improving muscular performance is established (47), its
influence on postexercise autonomic function is unknown.
Knowledge of this effect, however, is critical for clinicians
dealing with patients with certain disease states that may leave
them more prone to adverse cardiovascular events. Indeed,
sympathetic hyperactivity (4) or reduced cardiac vagal tone (3)
after exercise may confer a poor cardioprotective background
and underlie ischemic heart disease and the pathogenesis of
malignant ventricular arrhythmias and sudden cardiac death.
To quantify parasympathetic reactivation after exercise, the
time course of HR recovery (HRR) and HR variability (HRV)
indexes have been used (7, 13, 22, 42, 45). The validity of
these markers has been examined with the use of drugs that
cause a parasympathetic blockade (i.e., atropine) (22, 45). The
simplest and most used HRR index is the number of heart beats
recovered within 60 s after the cessation of exercise (13).
Fitting postexercise HRR to a first-order exponential decay
curve has also been used (7, 42). Regarding HRV, it is the
vagal-related indexes, such as the root mean square of succes-
sive differences of R-R intervals (RMSSD) or the power
density in the high-frequency (HF) range obtained by spectral
analysis, that are the most widely used methods (50). Finally,
a new and simple temporal time-varying parasympathetic in-
dex has recently been proposed by Goldberger et al. (22). This
index is derived from the time course of the RMSSD measured
on successive 30-s segments (RMSSD
30s
) over the recovery
period.
The acute effects of a single exercise bout on HRV have
been placed into long- and short-term categories. From 24 to
48 h after exercise, a rebound of parasympathetic activity,
which seems independent of the exercise type undertaken (38),
has often been described (18, 26). Concerning the short-term
evolution of autonomic activity, an initial decrease in HRV and
vagal-related indexes has been observed within minutes to
hours after exercise (38, 39, 51). Moreover, vagal restoration
Address for reprint requests and other correspondence: M. Buchheit, Labora-
toire de Recherche Adaptations Re´adaptations (APS et conduites motrices), Fac-
ulte´ des Sciences du Sport, Univ. de Picardie Jules Verne. Alle´ e P. Grousset,
The costs of publication of this article were defrayed in part by the payment
of page charges. The article must therefore be hereby marked “advertisement”
in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
Am J Physiol Heart Circ Physiol 293: H133–H141, 2007.
First published March 2, 2007; doi:10.1152/ajpheart.00062.2007.
0363-6135/07 $8.00 Copyright ©2007 the American Physiological Societyhttp://www.ajpheart.org H133
