Rev Bras Fisiol Exerc 2021;20(4):443-50
doi: 10.33233/rbfex.v20i4.4081
ORIGINAL ARTICLE
Effects of an official duathlon sprint competition on
lower limb temperature: response according to moments and dominance
Efeitos
de uma competição oficial de duathlon Sprint na
temperatura dos membros inferiores: respostas segundo momentos e dominância
Angélica
Tamara Tuono1, Andressa Mella Pinheiro1,
Nathália Arnosti Vieira2, Tiago Marques de Rezende1,
Sérgio Henrique Borin3, Charlini Simoni
Hartz3, Carlos Roberto Padovani4, João Paulo Borin1
1Faculty
of Physical Education - State University of Campinas (UNICAMP), Campinas, SP,
Brazil
2Red Bull Bragantino, Bragança Paulista,
SP, Brazil
3Methodist
University of Piracicaba (UNIMEP), Piracicaba, SP, Brazil
4State
University of São Paulo (UNESP), São Paulo, SP, Brazil
Received: May 2, 2020; Accepted: July 9, 2021
Correspondence: Angélica Tamara Tuono, Olavo
Bilac Street, 286, São Benedito, 13520-000 São Pedro SP. angelicatuono91@hotmail.com
Angélica Tamara Tuono:
angelicatuono91@hotmail.com
Andressa Mella Pinheiro:
andressamella@gmail.com
Nathália Arnosti Vieira: nathaliaarnosti@gmail.com
Tiago Marques de Rezende: tiagomrezende@hotmail.com
Sérgio Henrique Borin:
sehborin@unimep.br
Charlini Simoni Hartz: charlinih@gmail.com
Carlos Roberto Padovani: cr.padovani@unesp.br
João Paulo Borin:
profjoaoborin@gmail.com
Abstract
Introduction: Infrared
Thermography has contributed to detect physiological changes caused by sports
with the use of skin temperature. Objective: To verify the lower limb
temperature after a sprint duathlon competition. Methods: Seven duathletes (37 ± 8 years, 72.3 ± 6 kg, 15.7 ± 3% and 171 ±
7 cm) participated. A FLIR® E8 thermal imager (sensitivity ≤ 0.06 ° C)
was used to collect images of regions of interest (ROI): quadriceps, tibialis,
hamstrings, and calves before (M0), immediately after (M1) and 10 minutes after
competition (M2). Results: The measures indicate a decrease (p >
0.05) in the temperature of the quadriceps, tibialis, and hamstrings in M1
compared to M0. In M2, a higher temperature than M0 and M1 is observed in the
quadriceps, tibial and calf muscles. Compared to the beginning, competition
resulted in a decrease in temperature immediately after in all regions, except
calves, followed by an increase in the skin temperature of the analyzed ROI and
did not cause asymmetries between dominant and non-dominant members. Conclusion:
Thermography can be used in the analysis of duathletes
and asymmetry between limbs and can help in the planning and organization of
training in this modality.
Keywords: thermography; running; cycling;
competition.
Resumo
Introdução: A termografia contribui para detectar
alterações fisiológicas causadas pelo esporte com o uso da temperatura da pele.
Objetivo: Verificar diferenças na temperatura dos membros inferiores
após uma competição de duathlon sprint. Métodos:
Participaram sete duatletas (37 ± 8 anos, 72,3 ± 6
kg, 15,7 ± 3% e 171 ± 7 cm). Um termovisor FLIR® E8
(sensibilidade ≤ 0,06 °C) foi usado para coletar imagens das regiões de
interesse: quadríceps, tibiais, isquiotibiais e panturrilhas antes (M0),
imediatamente após (M1) e 10 minutos após a competição (M2). Resultados:
Os resultados indicam sensível diminuição da temperatura de quadríceps, tibiais
e isquiotibiais em M1 comparado a M0. Em M2, é observada uma temperatura maior
que em M0 e M1 em quadríceps, tibiais e panturrilhas. A competição resultou em
uma sensível diminuição, seguida de um aumento da temperatura em todas as
regiões, exceto nas panturrilhas, e não causou assimetrias entre membros
dominantes e não dominantes. Conclusão: A termografia pode ser utilizada
na análise de duatletas e assimetria entre membros,
podendo auxiliar no planejamento e organização do treinamento dessa modalidade.
Palavras-chave: termografia; corrida; ciclismo;
competição.
Duathlon is a
high-intensity cyclic modality composed of running-cycling-running. One of the
official distances in competitions is sprint, which consists of 5 km of
running, followed by 20 km of cycling and another 2.5 km of running [1,2],
which depends mostly on the manifestation of skills such as anaerobic
endurance, strength, speed, and coordination [3]. This modality is practiced by
athletes of various levels around the world [4], which increases the need for
an understanding of the organic responses, especially during competition.
Under this
perspective, infrared thermography (IT) has contributed with important
information for detecting physiological changes caused by sports practice
according to skin temperature [5,6,7,8,9]. Radiation emitted by the body is
interpreted as real-time images that identify thermal patterns and can provide
parameters for various physiological processes, as these are almost always
accompanied by an increase in local or systemic temperature. The thermal
sensitivity of the camera is extremely high, often making it difficult to see a
large difference in temperature when viewing images, and for this reason,
careful and cautious singular analysis is required [10,11].
In fact, by
using IT, some studies point toward the understanding of indicators related to
injuries [9], to acute responses of muscles after simulated effort [12,13], to
exercise intensity [14,15], the analysis of possible asymmetries between limbs,
and the difference between muscle groups [7,8,9,13,16]. However, there is a lack
of information related to the analysis of athletes in competition, which, in
the context of training theory and methodology, brings science closer to
practice, and can help to understand the sport and, consequently, the
organization and planning of training.
There is a lack
of information concerning the duathlon, particularly in the case of sprint
distance, about the impact that such a competition has on participants in
relation to changes in skin temperature. Thus, the aim of this study was to
verify the lower limb temperature after a sprint duathlon competition.
Sample
Seven Brazilian
trained male duathletes (37 ± 8 years, 72.3 ± 6 kg,
15.7 ± 3% and 171 ± 7 cm) participated in this study during an official stage
of duathlon sprint. The weekly training frequency of six days and an average of
seven sessions divided between running (38 ± 5 km), cycling (110 ± 25 km) and
gym weight training with a predominance of strength and power development (92 ±
13 minutes long; eight exercises per training session with four sets of five to
eight repetitions with 75–85% of the maximum). Inclusion criteria were: practicing the modality for at least two years, not
having any osteomioarticular lesion established
within 30 days prior to collection, not to be a smoker and not to ingest any
substance that changes the metabolism. This study was approved by the Research
Ethics Committee under the protocol CAEE: 00348818.1.0000.5404.
Data collection procedure
The athletes
were subjected to the thermographic evaluation protocol before the competition
(M0), immediately after (M1) and 10 minutes after (M2).
Infrared images
were obtained with a FLIR® thermal imager, model E8, integrated resolution of
320 × 240 pixels, which allows to measure temperatures between -20°C and 250°C,
with thermal sensitivity ≤ 0.06°C, accuracy of ± 2°C or ± 2% of reading
and thermal sensitivity/NETD <30 mK at 30°C.
The athletes
were instructed not to consume caffeine or alcohol, not to use any type of skin
product, not to use any medication and not to exercise in the last 24 hours
before collection. This care had a verbal confirmation immediately before the
beginning of the evaluations. They were also instructed not to press, rub or scratch the skin at any time until the entire data
collection process was completed [17]. All measurements were performed in the
morning.
The
thermographic camera was positioned in the assessment room and turned on 20
minutes before the start of data collection for stabilization. After that, the
athletes stayed for 20 minutes in this room (temperature 21 ± 0.3°C and
humidity 75 ± 4.9%) for the thermal balance to occur [12]. All participants
remained in anatomical position before the evaluator on a carpet and at two
meters from the camera which was maintained perpendicular to the regions of
interest (ROI). Two images were captured, one anterior and one posterior, and
were considered as ROI: quadriceps (A), tibialis (B), hamstrings (C) and calves
(D), as shown in Figure 1. All images were processed using an emissivity factor
of 0.98 to obtain human skin temperatures. The Rainbow pallet was used with
scale fix to 21°C-34°C. The thermogram processing software FlirTools®
was used for image storage, processing and analysis.
All images were analyzed by an experienced and qualified professional.
Figure 1 - Regions of Interest (ROI)
considered for analysis: A = Quadriceps; B = Tibialis; C = Hamstrings; D = Calves
Statistical analysis
After data
collection, information was initially processed with mean and standard
deviation values, and normality was verified with the Shapiro-Wilk test.
Pearson Correlation was then used for analysis between muscle groups and ANOVA
One-Way repeated measures for comparison of variables according to assessment
moments. A value of p < 0.05 was adopted as level of significance.
The results are
presented in two moments. In the first moment (Table I), the average
temperature of the ROI and the difference between the three assessment moments,
and next (Table II), the relation between temperature and the dominance of
limbs during the three assessment moments.
Table I
shows the mean and standard deviation of ROI temperature in Celsius and the
respective difference between the three assessment moments. There was a
sensitive decrease in temperature for M1 compared to M0 in all regions except
calves. In M2, a higher temperature is observed compared to M0 and M1 in
quadriceps, tibialis and calves (p < 0.05).
Table I - Mean and
standard deviation of ROI temperature according to each assessment moment and
difference between moments
Table II
presents mean and standard deviation values of temperature (°C) and the
differences between dominant and non-dominant limbs for each assessment moment.
There is a thermal equilibrium in all ROI and moments, except for the tibialis
musculature in M0, where there is a higher temperature in the dominant limb.
Table II - Mean
and standard deviation of temperature in ROI and difference in °C between
dominant and non-dominant limbs according to the moments
*p < 0.05
Based on the
proposed objective, which aimed to analyze the effect of an official
competition on the skin temperature of the duathletes
lower limbs, this discussion points in two directions: 1) the temperature
behavior of the skin between the ROI, and 2) the asymmetries between dominant
and non-dominant limbs at the moments assessed.
Particularly in
the first moment, the percentage variation (D%) stands out, with a decrease in temperature in M1 (p
> 0.05), compared to M0 in the quadriceps, tibial and hamstring muscle
groups, and soon afterwards in M2, a sensitive increase (p > 0.05) in the
temperature of the same muscle groups. This behavior seems to corroborate the
detailed review by Marins et al. [18] on the
application of thermography in this sport, as well as the findings by Tanda
[5], who analyzed middle runners in two types of treadmill competitioning,
with gradual and constant loading, and noted that in both situations skin
temperature showed a slight decrease during the first minutes of exercise and
soon thereafter a significant increase. The conclusion is that the decrease in
temperature was related to the effort-induced skin vasoconstriction, and the
subsequent increase to vasodilation caused by the thermoregulation process. These
results are like those found in the present study. Korman
et al. [6] analyzed elite sprinters before, during and after a speed
endurance training session and found similar results, noting a decline in lower
limb skin temperature in the early moments of the session, followed by
stabilization and sensitivity increase in the following minutes.
Another
highlight in this context is the temperature of the muscle groups of the
resting duathletes. Other findings in the literature
[6,18,19] have lower scores compared to the data presented here. According to Marins et al. [20], reference values for active men
while resting indicate: 29.7°C for quadriceps, 30.2°C for tibialis, 30.2°C for
hamstrings and 29.9°C for calves, which puts the values shown in the present
study above the expected in all muscle groups, suggesting that athletes have
already started the race with prior physiological alteration. Sillero-Quintana et al. [10], who evaluated more
than 200 athletes, show that temperatures equal to or higher than 31.9°C while
resting indicate the presence of an inflammatory process and/or possible
injury. It should be noted that out of the four ROI analyzed in this sample,
three were close to or above this value (tibialis = 31.6°C; hamstrings = 32.0°C;
calves = 32.1°C).
A high volume
regarding the distance of the competition can be seen when considering the
information on the training performed. When it comes to running, Bourdon et
al. [21] and Rios et al. [22] state that high training volumes are directly
associated with inflammation or injury.
As for the
asymmetry between dominant and non-dominant limbs, only one situation -
tibialis while resting (M0) - was found in which the dominant limb showed
higher temperature (0.5°C), which should lead to a more thorough follow-up as
this asymmetry may be an early sign of lesion or overload [18]. Regarding the
remaining three ROI, no asymmetry was found at any of the three assessment
moments, as it is considered a normal condition according to Marins et al. [18] and Corte et al. [9], who
state that asymmetries lower than 0.4°C as not being clinically important.
Other studies that analyzed the thermal asymmetry between dominant and
non-dominant limbs in modalities such as professional soccer [9,19], sub13 and
sub15 soccer [16], women's soccer [23], futsal [7], volleyball [13] and
handball [8] also observed asymmetries lower than 0.4°C, which allowed them to
consider clinically normal conditions for their respective athletes.
The lack of
monitoring of some factors that can influence changes in skin temperature, such
as weather conditions and sample number, can be considered as limitations of
this study.
The duathlon
sprint competition resulted in a decrease in temperature immediately after the
competition in all regions except the calves, followed by an increase in the
skin temperature of the analyzed ROI, in addition to not causing asymmetries
between dominant and non-dominant limbs. Thus, the thermography can be used in
the analysis of duathletes, specifically regarding
the asymmetry between the dominant and non-dominant limbs, giving clues about
information that can help in the planning and organization of the training of
athletes in this modality.
Conflict of interest
No conflict of interest
with relevant potential.
Financing source
This study was financed
in part by the Coordenadoria de Esporte
e Lazer da Prefeitura
Municipal de São Pedro/SP.
Author’s contributions
Conception and design
of study: Tuono AT, Borin
JP; Acquisition, analysis and/or interpretation of data: Tuono AT, Pinheiro AM, Padovani
CR, Borin, JP; Drafting the manuscript: Tuono AT, Pinheiro AM; Revising the manuscript critically
for important intellectual content: Tuono AT,
Pinheiro AM, Vieira NA, Rezende T, Borin SH, Hartz
CS, Padovani CR, Borin JP.
Acknowdgements
The authors thank Espaço da Escrita, Pró-Reitoria de Pesquisa, UNICAMP
for the language services. Thanks to the athletes and the municipal
administration of São Pedro, São Paulo, Brazil.