Corresponding author: Assoc. Prof. Sergej M. Ostojic, M.D., MSc, Ph.D., Biomedical Sciences Dept., Exercise Physiology Lab., Faculty
of Sport Sciences and Tourism, Metropolitan University, Radnicka 30/II, Novi Sad 21000, SERBIA. Phone: (++381)-21-530-633, Fax:
(++381)-21-530-232, E-mail: sergej@panet.rs
Received: March 12, 2010; Revised (Final Version): May 15, 2010; Accepted: July 9, 2010.
2011 by The Chinese Physiological Society and Airiti Press Inc. ISSN : 0304-4920. http://www.cps.org.tw
Chinese Journal of Physiology 54(×): ×××-×××, 2011 1
DOI: 10.4077/CJP.2011.AMM018
Ultra Short-Term Heart Rate Recovery after
Maximal Exercise: Relations to Aerobic Power
in Sportsmen
Sergej M. Ostojic1, 2, Marko D. Stojanovic1, and Julio Calleja-Gonzalez3
1Faculty of Sport Sciences and Tourism, Metropolitan University, Serbia
2Exercise Physiology Lab, City Center For Physical Culture, Belgrade, Serbia
and
3Faculty of Sport Sciences, University of the Basque Country, Spain
ABSTRACT
The main aim of the study was to investigate whether different levels of aerobic power influence
heart rate (HR) responses during the first minute of recovery following maximal exercise in athletes.
Thirty-two young male soccer players were recruited for the study during the final week of their training
prior the competition. Following the maximal exercise on treadmill the participants were placed supine
for 60 s of HR recording. The time between exercise cessation and the recovery HR measurement was
kept as short as possible. At the end of exercise (i.e., the start of recovery), HR was similar in both trials.
At both 10s and 20 s of recovery period, the players characterized by high aerobic power (> 60 ml/kg/
min) revealed significantly lower HR as compared to their sub-elite counterparts (< 50 ml/kg/min; P <
0.05). No differences between the groups were found at later stages of the analyzed post-exercise HR.
The data suggest that the athletes characterized by high aerobic capacity could be better adapted to
maximal exercise with faster recovery HR immediately following an exercise test. These results gener-
ally suggest that the aerobic power along with autonomic modulation might have played a role in the
ultra short-term cardiovascular responses to all-out exercise.
Key Words: soccer players, VO2 max, tredmill, autonomic control
Introduction
Heart rate recovery (HRR) is the rate at which
the heart rate (HR) decreases (i.e., the time taken for
HR to recover) following a moderate to heavy exercise
in response to a combination of parasympathetic
activation and sympathetic withdrawal (2, 15, 16).
HRR is known to change in response to acute and
seasonal changes in training load (3, 19, 29). How-
ever, there are no clear data indicating whether HRR
is a sensitive measure of autonomic control and, in
particular, whether HRR can be used as an index
representing the body’s capacity to respond to training.
Aerobic fitness is another variable that could influence
HRR response. Short & Sedlock (24) showed that
Query:
throughout the recovery period the group of trained
athletes with superior aerobic capacity had had a
consistently lower HR as compared to untrained
subjects, but there is still no clear explanation of this
phenomenon. HRR after maximal exercise has been
neither studied in elite athletes characterized by
superior aerobic fitness nor compared it with athletes
characterized by lower aerobic capacity. The evalua-
tion of the post-exercise HRR can be quantified by
different methods, including the absolute difference
between the final HR at exercise completion and HRR
recorded following 60 s of recovery (HRR60s) (5),
first 30 s of HRR via semi-logarithmic regression
analysis (T30) (12), or the time constant of the HR
decay obtained by fitting the post-exercise HRR by a
CJP E-prepublication Ahead of Print

2 Ostojic, Stojanovic and Calleja-Gonzalez
first-order exponential decay curve (18). Concerning
the fact that initial HRR progresses in a decreasing
monoexponential fashion and seems to be predomi-
nantly influenced by parasympathetic function it has
been suggested that short-term indexes (i.e. T30 and
HRR60s) could be considered as markers of cardiac
parasympathetic tone in human studies (6, 9) Yet,
there are no data describing the time course of 10-20
seconds of recovery of HRR immediately following
the exercise cessation (i.e., corresponding to the ultra
short-term HRR [UST-HRR]). Assessing UST-HRR
responses to the maximal exercise tasks could be of
particular interest for monitoring recovery during
soccer training due to the fact that the average duration
of recovery in soccer matches is less than 20 s (17).
Within the present study we tested the hypothesis that
the differences in the level of aerobic power would
influence heart rate responses during the 10-s intervals
of the first minute of recovery following the maximal
exercise in soccer players.
Materials and Methods
Participants
Thirty-two healthy and young male soccer
players were recruited from two soccer squads during
the spring half-season of 2007. All participants re-
questing a pre-competition medical examination with
exercise-stress testing at the exercise physiology lab,
who were participating in consistent training for the
past 2 years and who were between 20 and 22 years
of age, were candidates for inclusion in the study.
The exclusion criteria were: [1] a history of heart
diseases, [2] a musculoskeletal dysfunction, [3] known
metabolic disease, [4] use of any performance enhanc-
ing substance within the past 14 days, [5] smoking, or
[6] an impaired response to stress test. All partici-
pants gave their informed consent and volunteered to
participate in the study with the approval of the in-
stitutional IRB. Eight weeks prior to the testing all
subject followed a similar soccer-specific training
program controlled by a certified physical conditioning
coach. Participants were classified into two groups
based on the level of aerobic fitness. Specifically,
they were classified either as elite (VO2max > 60 ml/
kg/min) or sub-elite (VO2max < 50 ml/kg/min). All
participants were fully informed verbally and in
writing about the nature and demands of the study as
well as the known health risks. They completed a
health history questionnaire and also were informed
that they could withdraw from the study at any time,
even after giving their written consent. All but six of
the initial subject pool met the criteria and completed
the testing. The final compositions of the groups
were 12 players in the elite and 14 players in the
sub-elite group.
Experimental Procedures
Physiological measurements were performed
during the final week of preparatory training for
competition. Twenty-four hours prior to the experi-
ment, the participants were asked neither to participate
in any prolonged exercise nor to drink alcohol and/or
caffeine beverages. They reported to the physiology
laboratory at 10 a.m. after a rest of between 10 and 12
h. Prior to the experimental session body mass, body
height and percentage of body fat from skinfold
thickness were determined. The skinfold thickness at
seven sites was obtained using a caliper (Harpenden
Skinfold Caliper, British Indicators Ltd., Burgess
Hill, West Sussex, UK). The skinfold sites were
triceps, subscapula, mid-axillary, anterior suprailiac,
chest, abdomen, and thigh. The landmarks were iden-
tified and measured according to Wilmore & Behnke
(28) with the median of three measurements used to
represent skinfold thickness. Percentage of body fat
was determined according to equations of Jackson &
Pollock (13) (SEE = 8.8%). Thereafter, the subjects
were instrumented for VO2 max, ECG and telemetric
HR assessment. Exercise test was performed according
to individualized ramp protocol to symptom-tolerated
maximum using a treadmill system (Trackmaster
TMX425C, Full Vision, Inc., Newton, KS, USA).
Gas-exchange data were collected throughout the
exercise test using a breath-by-breath respiromonitor
system (Vacu-med CPX, Ventura, CA, USA) with
VO2 max defined as the highest VO2 achieved during
the test. The guidelines of the Bentley and co-workers
were followed to confirm that VO2max was achieved
(1). The electrocardiogram was continuously recorded
using a 12-stress analysis system (Custo-Med EC1000,
Ottobrunn, Germany), while HR was also recorded
using a HR monitor at beat-to-beat interval (Polar
S810, Polar Electro Oy, Kempele, Finland).
Immediately upon exercise cessation, the par-
ticipants were placed supine with the face mask on for
60 s of HR recording. The time between exercise
cessation and the recovery HR measurement was kept
as short as possible. The ECG tracing was reviewed
for correct identification of all beats. HR during the
first minute of recovery was measured at 10 sec
intervals via both heart rate monitor and ECG, at-
tempting to correctly identify all beats. The mean of
the two readings with a coefficient of variation below
15% was used in the study. HR decrease during the
recovery phase was also quantified as a percent HR
decrease from the peak exercise heart rate (100%)
during the first minute of recovery. Due to the fact
that the HRR following exercise typically progresses
in a decreasing monoexponential fashion (5), we