Citation: Puccinelli, P.J.; de Lira,
C.A.B.; Vancini, R.L.; Nikolaidis, P.T.;
Knechtle, B.; Rosemann, T.; Andrade,
M.S. The Performance, Physiology
and Morphology of Female and Male
Olympic-Distance Triathletes.
Healthcare 2022, 10, 797. https://
doi.org/10.3390/healthcare10050797
Academic Editors: Parisi Attilio, João
Paulo Brito and Rafael Oliveira
Received: 9 March 2022
Accepted: 21 April 2022
Published: 25 April 2022
Publisher’s Note: MDPI stays neutral
with regard to jurisdictional claims in
published maps and institutional afﬁl-
iations.
Copyright:
© 2022 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed
under
the
terms
and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/).
healthcare
Article
The Performance, Physiology and Morphology of Female and
Male Olympic-Distance Triathletes
Paulo J. Puccinelli 1
, Claudio A. B. de Lira 2
, Rodrigo L. Vancini 3
, Pantelis T. Nikolaidis 4
,
Beat Knechtle 5,6,*
, Thomas Rosemann 6
and Marilia S. Andrade 1
1
Programa de Pós-Graduação em Medicina Translacional, Department of Physiology, Federal University of
São Paulo, São Paulo 04021-001, Brazil; paulopuccinelli@hotmail.com (P.J.P.); marilia1707@gmail.com (M.S.A.)
2
Human and Exercise Physiology Division, Faculty of Physical Education and Dance, Federal University
of Goiás, Goiânia 74690-900, Brazil; andre.claudio@gmail.com
3
Center of Physical Education and Sports, Federal University of Espírito Santo, Vitória 29075-910, Brazil;
rodrigoluizvancini@gmail.com
4
School of Health and Caring Sciences, University of West Attica, 12243 Athens, Greece; pademil@hotmail.com
5
Medbase St. Gallen Am Vadianplatz, St. Gallen and Institute of Primary Care, 9100 St. Gallen, Switzerland
6
Institute of Primary Care, University of Zurich, 8091 Zurich, Switzerland; thomas.rosemann@usz.ch
*
Correspondence: beat.knechtle@hispeed.ch; Tel.: +41-71-226-93-00
Abstract: Sex differences in triathlon performance have been decreasing in recent decades and little
information is available to explain it. Thirty-nine male and eighteen female amateur triathletes were
evaluated for fat mass, lean mass, maximal oxygen uptake (VO2 max), ventilatory threshold (VT),
respiratory compensation point (RCP), and performance in a national Olympic triathlon race. Female
athletes presented higher fat mass (p = 0.02, d = 0.84, power = 0.78) and lower lean mass (p < 0.01,
d = 3.11, power = 0.99). VO2 max (p < 0.01, d = 1.46, power = 0.99), maximal aerobic velocity (MAV)
(p < 0.01, d = 2.05, power = 0.99), velocities in VT (p < 0.01, d = 1.26, power = 0.97), and RCP (p < 0.01,
d = 1.53, power = 0.99) were signiﬁcantly worse in the female group. VT (%VO2 max) (p = 0.012,
d = 0.73, power = 0.58) and RCP (%VO2 max) (p = 0.005, d = 0.85, power = 0.89) were higher in the
female group. Female athletes presented lower VO2 max value, lower lean mass, and higher fat mass.
However, females presented higher values of aerobic endurance (%VO2 max), which can attenuate
sex differences in triathlon performance. Coaches and athletes should consider that female athletes
can maintain a higher percentage of MAV values than males during the running split to prescribe
individual training.
Keywords: triathlon; sports medicine; sports physiology; female athlete; VO2 max
1. Introduction
The participation of women in amateur and elite endurance sports events, includ-
ing triathlon, has increased and their performance has improved during the last three
decades [1–6]. Factors that are possibly associated with the increasing participation of
women are the acceptance of female athletes in society, the importance of regular physical
activity for the prevention and treatment of noncommunicable diseases, and the feeling of
well-being that comes from a more active lifestyle [7].
Sex differences in triathlon performance seem to be decreasing, and currently vary
between 12 and 18% [8,9], which seems to be inﬂuenced by distance, the level of competition,
and the participation of the athletes [10,11].
Longer triathlon events, such as the Ironman (3.8 km of swimming, 180 km of cycling,
and 42.2 km of running), or ultra-triathlons such as the Double Iron ultra-triathlon (7.6 km
of swimming, 360 km of cycling, and 84.4 km of running) seem to be associated with
decreased sex differences in performance, compared to shorter triathlon distances [12].
Healthcare 2022, 10, 797. https://doi.org/10.3390/healthcare10050797
https://www.mdpi.com/journal/healthcare
Healthcare 2022, 10, 797
2 of 9
In addition, a lower tendency to sex difference was observed for elite athletes when com-
pared to amateur athletes [12].
Some morphological sex differences related to body composition, such as lower fat
mass percentage and higher muscle mass in the male sex [13–15], seem to be associated
with better male performance [16].
Regarding the physiological factors that inﬂuence endurance performance, maximal
oxygen uptake (VO2 max), ventilatory threshold (VT), and running economy (RE) are
variables commonly investigated to predict aerobic performance [17].
In terms of VO2 max values, average values for females are approximately 75% of
the values for males [18]. However, among athletes, these differences may be lower [19].
Lower blood hemoglobin concentrations typically found in women, as well as lower red
cell mass and hematocrit level, which result in lower arterial oxygen content (CaO2) and
lower O2 delivery to muscles during exercise [20,21] are the main factors responsible for
these VO2 max gender differences.
Differently from VO2 max, data about sex differences according to the %VO2 max at
VT seems to be contradictory. Female athletes have 7 to 23% more type I muscle ﬁbers
than men [22–24]. This difference in muscle ﬁber composition means that women have a
greater oxidation of fat [25] and faster oxygen consumption kinetics [26], which should
directly impact the VT, since this is dependent on the oxidative capacity of the muscles
during exercise [27]. In addition, female athletes also have a higher rate of mitochondrial
respiration [28]. These differences impact muscle metabolism, making women more apt
to resynthesize ATP through the oxidative metabolism. Considering these sex differences,
higher VT could be expected for female athletes; however, literature data show conﬂicting
results. [17–20]. Moreover, as for VO2 max, there are very few data for VT in Olympic-
distance triathletes [19].
Women’s participation in amateur triathlon events has increased in recent years. As a
result, women’s performance has also improved, and sex differences have decreased [19].
So far, it is not possible to deﬁne whether the difference is associated with training volume
or physiological limitations. Therefore, understanding physiological differences between
the sexes can help clarify this issue.
Considering the importance of understanding the differences between sexes in en-
durance sports performance and the lack of data regarding both Olympic-distance triath-
letes and amateur athletes, we compared the physiological and morphological character-
istics of male and female amateur triathletes of the same mean age who competed in an
Olympic-distance event. Better knowledge about gender differences and female character-
istics can explain the narrowing performance gap between the sexes of amateur triathlon
athletes, and may help women reach their best performance.
We hypothesized that male triathletes would present higher VO2 max, higher lean
mass, and lower fat mass than female triathletes, but that there would be no sex differences
according to VT. Because of their higher VO2 max levels and better body composition, we
hypothesized that men would present lower overall race time and split times than female
triathletes in the Olympic triathlon race.
2. Materials and Methods
2.1. Ethical Approval
All experimental procedures were approved by the Human Research Ethics Commit-
tee of the Federal University of Sao Paulo (approval number 1659697) and conformed to the
principles outlined in the Declaration of Helsinki. The study was conducted in accordance
with recognized ethical standards and national/international laws. After receiving instruc-
tions regarding the experimental procedures, their possible risks and beneﬁts, the objectives
and justiﬁcation of the research, and the principles of respect for persons involved, which
encompassed a guarantee of privacy, conﬁdentiality, and anonymity rights, the athletes
signed the consent form.
Healthcare 2022, 10, 797
3 of 9
2.2. Participants
Ninety-three athletes who had applied for Olympic-distance triathlon races accepted
an invitation to participate in the study. However, thirty-six did not meet the inclusion
criteria. Therefore, ﬁfty-seven athletes participated in the study.
The inclusion criteria to participate in the study included having participated in at
least one Olympic-distance triathlon race, with at least one year of triathlon practice. The
exclusion criteria included having no medical approval for maximum effort, being pregnant,
having acute pain in the lower limbs, edema, or not ﬁnishing the race.
The main reasons for the thirty-six exclusions were giving up on participating in the
Olympic-distance triathlon race (n = 21), not ﬁnishing the race (n = 6), having injuries
during the training period (n = 4), absence on the day scheduled for laboratory evaluations
(n = 4), and one woman got pregnant.
Characterization of the sample according to the age and training habits are presented
in Table 1.
Table 1. Characteristics of participants.
Male Triathletes
(n = 39)
Female Triathletes
(n = 18)
p Value
Age (years)
38.8 ± 6.9
41.3 ± 6.68.4
0.210
Triathlon experience (years)
2.7 ± 1.7
3.3 ± 1.6
0.232
Training per week (hours)
13.2 ± 4.1
14.4 ± 3.5
0.287
Data are presented as mean ± standard deviations.
As the number of female athletes who participated in the study was smaller than the
number of male athletes, the power of the statistical analysis is shown with the p-value.
This was employed to identify the possible lack of statistical difference between the groups
due to the small sample size.
2.3. Procedures
Each participant reported to the laboratory for one day, in which they answered a
questionnaire about training habits. Afterwards, anthropometric data measurement and a
cardiorespiratory maximal test on a treadmill were performed. The organizing committee
of the races provided the overall triathlon race time and split times. Thirty-nine male and
six female amateur triathletes participated in the same race.
2.4. Assessments
2.4.1. Questionnaires
The athletes answered a questionnaire about training habits with the four following
questions: (1) How many years have you been practicing triathlon? (2) How many hours a
week do you train swimming? (3) How many hours a week do you train cycling? (4) How
many hours a week do you train running?
2.4.2. Body Composition and Anthropometry
The height and body mass of the participants were assessed using a calibrated sta-
diometer and were measured to the nearest 0.1 kg and 0.1 cm, respectively. Dual energy
X-ray absorptiometry (DXA, software version 12.3, Lunar DPX, GE Healthcare, Madison,
WI, USA) was used to assess body composition (lean and fat mass). Athletes were instructed
to follow their normal ad libitum hydration habits. They were evaluated after bladder
voiding; no fasting or other limitations on their usual activities were implemented [29]. This
method has been previously demonstrated as a reliable technique for body composition
assessments [30,31].
Healthcare 2022, 10, 797
4 of 9
2.4.3. Cardiorespiratory Maximal Test on a Treadmill
Cardiopulmonary exercise testing (CPET) was conducted on a motorized treadmill
(Inbrasport, ATL, Porto Alegre, Brazil) using a computer-based metabolic analyzer (Quark,
Cosmed, Italy). The calibration procedure was performed prior to each test, according to
the manufacturer’s guidelines. CPET was used to measure VO2 max, VT, respiratory com-
pensation point (RCP), and maximal aerobic velocity (MAV). The VO2 max was determined
as the stabilization of VO2 (increase lower than 2.1 mL·kg−1·min−1) even after increasing
the treadmill velocity during the last stage of the CPET [32]. All the volunteers reached
VO2 max. VT was determined based on the following criteria: an increase in the ventilatory
equivalent for oxygen without an increase in the ventilatory equivalent for carbon dioxide,
and an increase in the partial pressure of exhaled oxygen. RCP was determined based on
the increase in the ventilatory equivalent for carbon dioxide and the decrease in the partial
pressure of exhaled carbon dioxide [33]. VT and RCP were determined separately by two
experienced investigators; a third investigator was asked in cases of discordance. MAV was
determined as the minimal velocity eliciting the VO2 max [34]. The percentage of MAV
that the athlete maintained during the running split was also calculated.
Athletes warmed up for 4 min at 10 km·h−1 (males) and 9 km·h−1 (females). After
the warm-up period, the running velocity was increased by 1 km·h−1 every minute until
voluntary exhaustion [35]. The entire CPET lasted between 8 and 12 min and treadmill
grade was set at 1% to simulate the energetic cost of outdoor running [36]. The heart
rate was measured by a monitor (Ambit 2S, Suunto, Finland) throughout the entire test,
and perceived exertion was rated according to the Borg scale (a 10-point scale) [37].
2.5. Statistical Analysis
Data are presented as the mean and the standard deviations. All variables presented
normal distribution and homogeneous variability according to the Shapiro–Wilk and
Levene tests, respectively. In order to compare the triathlon race times and morphological
and physiological characteristics of the sexes, Welch’s unequal variances t-test was used.
This test was chosen because it is more reliable when the two samples have unequal
sample sizes [38]. The measures of the effect size for differences between sexes were
determined by calculating the mean difference between the two sexes, and then dividing
the result by the pooled standard deviation. Calculating effect sizes, the magnitude of
any change was judged according to the following criteria: d = 0.2 was considered a
“small” effect size; 0.5 represented a “medium” effect size; and 0.8 a represented “large”
effect size [39]. Considering that the study had a convenience sample, the power of all
between-sex comparisons were calculated. Power analysis was performed using G*Power
software [40]. The power of the tests varied from 0 to 1. Usually, researchers use 0.80 as the
power level of the test [41]. Therefore, the same values were considered in this study to
interpret the results. The level of signiﬁcance was set at p < 0.05.
3. Results
Female athletes presented significantly lower body mass (p < 0.01, d = 2.00, power = 0.99)
and height (p < 0.01, d = 1.80, power = 0.99) than male athletes. There was no difference
in mean age between the groups (p = 0.21, d = 0.35, power = 0.65). Overall race time
and split times were compared for sexes who participated in the same triathlon event.
Regarding performance, female athletes presented higher race times for swimming (+11%),
cycling (+7.5%), running (+7%), and overall race time (+8%). According to morphologic
characteristics, male athletes presented higher lean body mass (kg) (p < 0.01, d = 3.11,
power = 0.99). According to fat mass distribution, the percentage of trunk fat mass was
not different between sexes (p = 0.522, d = 0.17, power = 0.73), nor was the percentage of
android fat mass (p = 0.921, d = 0.02, power = 0.74), but the percentage of gynoid fat mass
was higher in female athletes (p < 0.01, d = 1.37, power = 0.98). VO2 max (p < 0.01, d = 1.46,
power = 0.99), MAV (p < 0.01, d = 2.05, power = 0.99), and velocities associated with VT
(p = 0.02, d = 1.26, power = 0.97) and RCP (p < 0.01, d = 1.53, power = 0.99) were signiﬁcantly
Healthcare 2022, 10, 797
5 of 9
higher in the male group. %VO2 max at VT (p = 0.012, d = 0.73, power = 0.58) and %VO2
max at RCP (p = 0.005, d = 0.85, power = 0.89) were higher in the female group. During the
running split, female athletes were running at a higher percentage of MAV (75 ± 8%) than
males (62 ± 6%) (p < 0.01, d = 1.83, power = 0.99) (Table 2).
Table 2. Descriptive characteristics of the triathletes and comparison between the sexes.
Male
(n = 39)
Female
(n = 18)
p Value
d Value
Power
(1-Beta)
Anthropometric proﬁle
Age (years)
38.9 ± 6.9
41.3 ± 6.6
0.21
0.35
0.65
Body mass (kg)
74.3 ± 8.8 *
59.5 ± 5.6
<0.01
2.00
0.99
Height (cm)
174.8 ± 6.5 *
164.5 ± 4.8
<0.01
1.80
0.99
Fat mass (%)
16.8 ± 5.6 *
23.2 ± 9.2
0.02
0.84
0.78
Lean Mass (kg)
59.0 ± 5.7 *
43.0 ± 4.5
<0.01
3.11
0.99
Trunk fat mass (%)
19.8 ± 6.8
21.3 ± 10.2
0.52
0.17
0.73
Android fat mass (%)
22.7 ± 8.6
22.4 ± 12.0
0.92
0.02
0.74
Gynoid fat mass (%)
21.9 ± 6.2 *
33.2 ± 9.8
<0.01
1.37
0.98
Maximal graded exercise test
VO2 max (ml·kg−1·min−1)
59.9 ± 6.3 *
49.5 ± 7.8
<0.01
1.46
0.99
VT (%VO2 max)
74.4 ± 5.6 *
78.7 ± 6.1
0.01
0.73
0.58
Velocity at VT (km·h−1)
12.4 ± 1.4 *
10.5 ± 1.6
<0.01
1.26
0.97
RCP (%VO2 max)
87.5 ± 4.6 *
91.2 ± 4.1
0.01
0.85
0.89
Velocity at RCP (km·h−1)
14.8 ± 1.5 *
12.5 ± 1.5
<0.01
1.53
0.99
MAV (km·h−1)
17.8 ± 1.4 *
14.6 ± 1.7
<0.01
2.05
0.99
Running split
%MAV
62 ± 6 *
75 ± 8
<0.01
1.83
0.99
Velocity (km·h−1)
11.0 ± 1.0 *
11.0 ± 1.8
0.99
0.00
0.99
Data are presented as mean ± standard deviations. d value: Effect size (Cohen’s D). VO2 max: maximal oxygen
uptake. VT: ventilatory threshold. RCP: respiratory compensation point (RCP). MAV: maximal aerobic velocity.
* signiﬁcant difference between sexes (p < 0.05).
4. Discussion
The primary aim of this study was to compare the sex differences of amateur Olympic-
distance triathletes in relation to performance and physiological and morphological char-
acteristics. The main ﬁndings were that: (i) the sex differences in performance were 8.0%
for overall race time, 11% for swimming, 7.5% for cycling, and 7% for running; (ii) female
athletes presented a lower VO2 max and a higher %VO2 max at VT and RCP than male
athletes; (iii) female athletes presented lower lean mass than males; and (iv) female athletes
presented higher total fat mass and gynoid fat mass than males, but the same android and
trunk fat masses.
The sex differences in 1.5 km of swimming, 40 km of cycling, 10 km of running, and
overall race time were 11.0, 7.5, 7.0, and 8.0%, respectively. Higher sex differences were
previously shown for the top 10 athletes of each age group of the World Championship
from 2009 to 2011, with a 13.3% performance difference in swimming, 10.7% difference in
cycling, 7.5% difference in running, and 12% difference in overall race time [42]. Higher
sex difference between the top ﬁve athletes from the “Zurich triathlon”, which occurs in
Zurich, Switzerland, in each category have also been shown (18.5% in swimming, 15.5%
in cycling, 18.5% in running, and 17.1% in overall race time) [6]. Therefore, it is evident
that the sex differences in a given performance depend on the race level (world, national
or regional championship). In the present study, minor differences were found between
the sexes; however, only amateur athletes were studied, which differs from the studies
mentioned above that evaluated elite athletes.
As expected,
female athletes presented lower VO2 max and MAV values
(49.5 ± 7.8 mL·kg−1·min−1 and 14.6 ± 1.7 km·h−1, respectively) than male athletes
(59.9 ± 6.3 mL·kg−1·min−1 and 17.8 ± 1.0 km·h−1, respectively), showing a sex differ-
Healthcare 2022, 10, 797
6 of 9
ence of approximately 19%. Similar sex difference have previously been shown for elite
younger triathletes, reporting 20% lower values for females than for males (56.1 and
67.9 mL·kg−1·min−1) [43]. However, VO2 max values for ultra-endurance triathletes seem
to be more similar between the sexes (68.8 and 65.9 mL·kg−1·min−1 for males and females,
respectively), evidencing a sex difference of only 4.4% [44].
Besides maximal capacity for oxygen uptake, endurance performance also depends
on VT. It has been suggested that 70% of success in endurance running depends on these
physiological parameters [17]. An important new ﬁnding from the present study is that the
female athletes presented higher values for VT (78.7 ± 6.1% for females and 74.4 ± 5.6% of
VO2 max for males) and RCP (91.2 ± 4.1% for females and 87.5 ± 4.6% VO2 max for males)
than male athletes. In addition, female athletes maintained a velocity corresponding to
75% of the MAV during the running split, which is higher than the value for males, who
maintained 62% of their MAV [34]. The VT is limited by the peripheral conditions (i.e.,
mitochondrial volume, capillary density, oxidative enzyme capacity) [45,46]. Consider-
ing this context, females present different metabolic (greater proportional area of type I
ﬁbers [22–24], greater whole-muscle oxidative capacity [26], and greater mitochondrial ox-
idative function [28]), contractile (Ca2+ transients were smaller in magnitude and longer in
duration in females [47]), and hemodynamic (greater vasodilatory responses of the arteries
to muscles and higher density of capillaries per unit of skeletal muscle [22]) properties of
skeletal muscles than males, favoring ATP resynthesis from oxidative phosphorylation
during exercise [48,49], which could contribute to a higher VT.
Triathlon performance is also associated with body composition [16,50]. In this study,
female athletes presented lower lean mass than males and higher total fat mass and gynoid
fat mass percentage. The android and trunk body mass did not differ between the sexes.
Moreover, fat mass values for both sexes were higher than those reported for elite athletes
(<13% for female and <5% for males) [43]. Therefore, female body composition seems to be
disadvantageous for athletic performance [13,14,51].
Regarding the limitations of this study, the test measurements cited were performed
only on a treadmill. Thus, as the physiologic characteristics were only measured during a
running activity using a treadmill, it would be very interesting to identify sex differences
with the same measurements in tests performed during cycling or swimming activities.
The inclusion of amateur athletes rather than elite athletes was another study limitation.
Furthermore, this was a cross-sectional study, which prevented us from the studying the
performance difference between sexes over time. Considering the increased popularity of
Olympic-distance triathlon, especially among women, who were underrepresented in this
sport until recently [52], the ﬁndings of the present study have practical applications for
training monitoring. Strength and conditioning coaches working with triathletes might
develop separate exercise programs for each sex.
Thus, an awareness of physiological sex differences related to performance would
help coaches to prescribe sex-tailored training. In this context, the main ﬁnding from the
present study was that the female athletes presented higher values of aerobic endurance
(%VO2 max) than male athletes. These ﬁndings suggest that female athletes can maintain a
higher percentage of MAV values than males during the running split; therefore, coaches
could consider these ﬁndings to prescribe individual training.
5. Conclusions
In summary, female athletes present lower VO2 max and lean mass, and higher fat
mass. However, they present higher values of aerobic endurance (%VO2 max), which can
attenuate sex differences in triathlon performance. However, the sex differences in VT
require further investigation, as there are few data about this variable in the literature.
Healthcare 2022, 10, 797
7 of 9
Author Contributions: Conceptualization, P.J.P. and M.S.A.; methodology, P.J.P. and C.A.B.d.L.;
software, R.L.V.; validation, C.A.B.d.L. and M.S.A.; formal analysis, P.J.P. and R.L.V.; investigation,
M.S.A.; data curation, P.T.N.; writing—original draft preparation, C.A.B.d.L.; writing—review and
editing, P.T.N., B.K. and T.R.; visualization, B.K. and T.R.; supervision, M.S.A. All authors have read
and agreed to the published version of the manuscript.
Funding: This research received no external funding.
Institutional Review Board Statement: The study was conducted according to the guidelines of the
Declaration of Helsinki, and approved by the Human Research Ethics Committee of the University
(approval number 1659697).
Informed Consent Statement: Informed consent was obtained from all subjects involved in the study.
Data Availability Statement: Data supporting reported results can be asked to corresponding author.
Acknowledgments: We would like to thank all of the participants who volunteered their time to
participate in the study, the Olympic Training and Research Center (Centro Olímpico de Treinamento
e Pesquisa, COTP, São Paulo, Brazil).
Conﬂicts of Interest: The authors declare no conﬂict of interest.
References
1.
Jokl, P.; Sethi, P.M.; Cooper, A.J. Master’s performance in the New York City Marathon 1983–1999. Br. J. Sports Med. 2004, 38,
408–412. [CrossRef]
2.
Leyk, D.; Erley, O.; Ridder, D.; Leurs, M.; Rüther, T.; Wunderlich, M.; Sievert, A.; Baum, K.; Essfeld, D. Age-related changes in
marathon and half-marathon performances. Int. J. Sports Med. 2007, 28, 513–517. [CrossRef]
3.
Hoffman, M.D.; Wegelin, J.A. The western states 100-mile endurance run: Participation and performance trends. Med. Sci. Sports
Exerc. 2009, 41, 2191–2198. [CrossRef]
4.
Hoffman, M.D. Performance trends in 161-km ultramarathons. Int. J. Sports Med. 2010, 31, 31–37. [CrossRef] [PubMed]
5.
Lepers, R.; Cattagni, T. Do older athletes reach limits in their performance during marathon running? Age 2012, 34, 773–781.
[CrossRef] [PubMed]
6.
Etter, F.; Knechtle, B.; Bukowski, A.; Rüst, C.A.; Rosemann, T.; Lepers, R. Age and gender interactions in short distance triathlon
performance. J. Sports Sci. 2013, 31, 996–1006. [CrossRef]
7.
Deaner, R.O. Distance running as an ideal domain for showing a sex difference in competitiveness. Arch. Sex. Behav. 2013, 42,
413–428. [CrossRef]
8.
Lepers, R.; Knechtle, B.; Stapley, P.J. Trends in triathlon performance: Effects of sex and age. Sport. Med. 2013, 43, 851–863.
[CrossRef]
9.
Stiefel, M.; Rüst, C.A.; Rosemann, T.; Knechtle, B. A comparison of participation and performance in age-group ﬁnishers
competing in and qualifying for Ironman Hawaii. Int. J. Gen. Med. 2013, 6, 67–77. [CrossRef]
10.
Lepers, R.; Rüst, C.A.; Stapley, P.J.; Knechtle, B. Relative improvements in endurance performance with age: Evidence from
25 years of Hawaii Ironman racing. Age 2013, 35, 953–962. [CrossRef]
11.
Knechtle, B.; Zingg, M.; Rosemann, T.; Rust, C. Sex difference in top performers from Ironman to double deca iron ultra-triathlon.
Open Access J. Sport. Med. 2014, 5, 159–172. [CrossRef]
12.
Joyner, M.J. Physiological limits to endurance exercise performance: Inﬂuence of sex. J. Physiol. 2017, 595, 2949–2954. [CrossRef]
[PubMed]
13.
Fleck, S.J. Body composition of elite American athletes. Am. J. Sports Med. 1983, 11, 398–403. [CrossRef]
14.
Knechtle, B.; Wirth, A.; Baumann, B.; Knechtle, P.; Rosemann, T. Personal best time, percent body fat, and training are differently
associated with race time for male and female ironman triathletes. Res. Q. Exerc. Sport 2010, 81, 62–68. [CrossRef]
15.
Heydenreich, J.; Kayser, B.; Schutz, Y.; Melzer, K. Total Energy Expenditure, Energy Intake, and Body Composition in Endurance
Athletes Across the Training Season: A Systematic Review. Sport. Med.-Open 2017, 3, 8. [CrossRef] [PubMed]
16.
Landers, G.J.; Blanksby, B.A.; Ackland, T.R.; Smith, D. Morphology and performance of world championship triathletes.
Ann. Hum. Biol. 2000, 27, 387–400. [CrossRef]
17.
Millet, G.P.; Vleck, V.E.; Bentley, D.J. Physiological requirements in triathlon. J. Hum. Sport Exerc. 2011, 6, 184–204. [CrossRef]
18.
Sharma, H.B.; Kailashiya, J. Gender difference in aerobic capacity and the contribution by body composition and haemoglobin
concentration: A study in young Indian National hockey players. J. Clin. Diagnostic Res. 2016, 10, CC09–CC13. [CrossRef]
[PubMed]
19.
Lepers, R. Sex difference in triathlon performance. Front. Physiol. 2019, 24, 973. [CrossRef] [PubMed]
20.
Cureton, K.; Bishop, P.; Hutchinson, P.; Newland, H.; Vickery, S.; Zwiren, L. Sex difference in maximal oxygen uptake—Effect of
equating haemoglobin concentration. Eur. J. Appl. Physiol. Occup. Physiol. 1986, 54, 656–660. [CrossRef]
Healthcare 2022, 10, 797
8 of 9
21.
Ansdell, P.; Thomas, K.; Hicks, K.M.; Hunter, S.K.; Howatson, G.; Goodall, S. Physiological sex differences affect the integrative
response to exercise: Acute and chronic implications. Exp. Physiol. 2020, 105, 2007–2021. [CrossRef] [PubMed]
22.
Roepstorff, C.; Thiele, M.; Hillig, T.; Pilegaard, H.; Richter, E.A.; Wojtaszewski, J.F.P.; Kiens, B. Higher skeletal muscle α2AMPK
activation and lower energy charge and fat oxidation in men than in women during submaximal exercise. J. Physiol. 2006, 574,
125–138. [CrossRef] [PubMed]
23.
Simoneau, J.A.; Bouchard, C. Human variation in skeletal muscle ﬁber-type proportion and enzyme activities. Am. J. Physiol.-
Endocrinol. Metab. 1989, 257, E567–E572. [CrossRef]
24.
Staron, R.S.; Hagerman, F.C.; Hikida, R.S.; Murray, T.F.; Hostler, D.P.; Crill, M.T.; Ragg, K.E.; Toma, K. Fiber type composition of
the vastus lateralis muscle of young men and women. J. Histochem. Cytochem. 2000, 48, 623–629. [CrossRef]
25.
Tarnopolsky, M.A. Sex differences in exercise metabolism and the role of 17-beta estradiol. Med. Sci. Sports Exerc. 2008, 40,
648–654. [CrossRef]
26.
Beltrame, T.; Rodrigo, V.; Hughson, R.L. Sex differences in the oxygen delivery, extraction, and uptake during moderate-walking
exercise transition. Appl. Physiol. Nutr. Metab. 2017, 42, 994–1000. [CrossRef]
27.
Weltman, A. The Blood Lactate Response to Exercise; Human Kinetics: Champaign, IL, USA, 1995; ISBN 0873227697 9780873227698.
28.
Cardinale, D.A.; Larsen, F.J.; Schiffer, T.A.; Morales-Alamo, D.; Ekblom, B.; Calbet, J.A.L.; Holmberg, H.C.; Boushel, R. Superior
intrinsic mitochondrial respiration in women than in men. Front. Physiol. 2018, 9, 1133. [CrossRef] [PubMed]
29.
Sanﬁlippo, J.; Krueger, D.; Heiderscheit, B.; Binkley, N. Dual-Energy X-ray Absorptiometry Body Composition in NCAA Division
I Athletes: Exploration of Mass Distribution. Sports Health 2019, 11, 453–460. [CrossRef] [PubMed]
30.
Hill, A.M.; LaForgia, J.; Coates, A.M.; Buckley, J.D.; Howe, P.R.C. Estimating abdominal adipose tissue with DXA and anthropom-
etry. Obesity 2007, 15, 504. [CrossRef] [PubMed]
31.
Choi, Y.J.; Seo, Y.K.; Lee, E.J.; Chung, Y.S. Quantiﬁcation of visceral fat using dual-energy x-ray absorptiometry and its reliability
according to the amount of visceral fat in Korean Adults. J. Clin. Densitom. 2015, 18, 192–197. [CrossRef] [PubMed]
32.
Longstreet Taylor, H.; Buskirk, E.; Henschel, A. Maximal oxygen intake as an objective measure of cardio-respiratory performance.
J. Appl. Physiol. 1955, 8, 73–80. [CrossRef]
33.
Whipp, B.J.; Ward, S.A.; Wasserman, K. Respiratory markers of the anaerobic threshold. Adv. Cardiol. 1986, 35, 47–64. [CrossRef]
[PubMed]
34.
Puccinelli, P.J.; Lima, G.H.O.; Pesquero, J.B.; de Lira, C.A.B.; Vancini, R.L.; Nikolaids, P.T.; Knechtle, B.; Andrade, M.S. Previous
experience, aerobic capacity and body composition are the best predictors for Olympic distance triathlon performance: Predictors
in amateur triathlon. Physiol. Behav. 2020, 225, 113110. [CrossRef] [PubMed]
35.
de Lira, C.A.B.; Peixinho-Pena, L.F.; Vancini, R.L.; de Freitas Guina Fachina, R.J.; de Almeida, A.A.; Andrade, M.D.S.; da Silva, A.C.
Heart rate response during a simulated Olympic boxing match is predominantly above ventilatory threshold 2: A cross sectional
study. Open Access J. Sport. Med. 2013, 4, 175–182. [CrossRef]
36.
Jones, A.M.; Doust, J.H. A 1% treadmill grade most accurately reﬂects the energetic cost of outdoor running. J. Sports Sci. 1996, 14,
321–327. [CrossRef] [PubMed]
37.
Noble, B.J.; Borg, G.A.V.; Jacobs, I.; Ceci, R.; Kaiser, P. A category-ratio perceived exertion scale: Relationship to blood and muscle
lactates and heart rate. Med. Sci. Sports Exerc. 1983, 15, 523–528. [CrossRef] [PubMed]
38.
Ruxton, G.D. The unequal variance t-test is an underusedalternative to Student’s t-test and the Mann–Whitney U test. Behav. Ecol.
2006, 17, 688–690. [CrossRef]
39.
Cohen, J. Statistical Power for the Behavioral Sciences, 2nd ed.; Lawrence Erlbaum Associates: Hillsdale, NJ, USA, 1988;
ISBN 0-8058-0283-5.
40.
Kang, H. Sample size determination and power analysis using the G*Power software. J. Educ. Eval. Health Prof. 2021, 18, 17.
[CrossRef] [PubMed]
41.
Banerjee, A.; Chitnis, U.; Jadhav, S.; Bhawalkar, J.; Chaudhury, S. Hypothesis testing, type I and type II errors. Ind. Psychiatry J.
2009, 18, 127–131. [CrossRef]
42.
Stevenson, J.L.; Song, H.; Cooper, J.A. Age and sex differences pertaining to modes of locomotion in triathlon. Med. Sci. Sports
Exerc. 2013, 45, 976–984. [CrossRef]
43.
Bunc, V.; Heller, J.; Horcic, J.; Novotny, J. Physiological proﬁle of best Czech male and female young triathletes. J. Sports Med.
Phys. Fitness 1996, 36, 265–270. [PubMed]
44.
O’toole, M.L.; Douglas, W.; Crosby, L.O.; Douglas, P.S. The ultraendurance triathlete: A physiological proﬁle. Med. Sci. Sports
Exerc. 1987, 19, 45–50. [CrossRef] [PubMed]
45.
Holloszy, J.O.; Coyle, E.F. Adaptations of skeletal muscle to endurance exercise and their metabolic consequences. J. Appl. Physiol.
Respir. Environ. Exerc. Physiol. 1984, 56, 831–838. [CrossRef]
46.
Coyle, E.F.; Coggan, A.R.; Hopper, M.K.; Walters, T.J. Determinants of endurance in well-trained cyclists. J. Appl. Physiol. 1988, 64,
2622–2630. [CrossRef]
47.
Wasserstrom, J.A.; Kapur, S.; Jones, S.; Faruque, T.; Sharma, R.; Kelly, J.E.; Pappas, A.; Ho, W.; Kadish, A.H.; Aistrup, G.L.
Characteristics of intracellular Ca2+ cycling in intact rat heart: A comparison of sex differences. Am. J. Physiol.-Heart Circ. Physiol.
2008, 295, H1895–H1904. [CrossRef]
48.
Mitchell, E.A.; Martin, N.R.W.; Bailey, S.J.; Ferguson, R.A. Critical power is positively related to skeletal muscle capillarity and
type I muscle ﬁbers in endurance-trained individuals. J. Appl. Physiol. 2018, 125, 737–745. [CrossRef] [PubMed]
Healthcare 2022, 10, 797
9 of 9
49.
Vanhatalo, A.; Black, M.I.; DiMenna, F.J.; Blackwell, J.R.; Schmidt, J.F.; Thompson, C.; Wylie, L.J.; Mohr, M.; Bangsbo, J.;
Krustrup, P.; et al. The mechanistic bases of the power-time relationship: Muscle metabolic responses and relationships to muscle
ﬁbre type. J. Physiol. 2016, 594, 4407–4423. [CrossRef]
50.
Ackland, T.R.; Blanksby, B.A.; Landers, G.; Smith, D. Anthropmetrlc proﬁles of elite trlathletes. J. Sci. Med. Sport 1998, 1, 52–56.
[CrossRef]
51.
Knechtle, B.; Knechtle, P.; Rosemann, T. Similarity of anthropometric measures for male ultra-triathletes and ultra-runners.
Percept. Mot. Skills 2010, 111, 805–818. [CrossRef]
52.
Wonerow, M.; Rüst, C.A.; Nikolaidis, P.T.; Rosemann, T.; Knechtle, B. Performance trends in age group triathletes in the olympic
distance triathlon at the world championships 2009–2014. Chin. J. Physiol. 2017, 60, 137–150. [CrossRef] [PubMed]

The Performance, Physiology and Morphology of Female and Male Olympic-Distance Triathletes.
Puccinelli, Paulo J,de Lira, Claudio A B,Vancini, Rodrigo L,Nikolaidis, Pantelis T,Knechtle, Beat,Rosemann, Thomas,Andrade, Marilia S