Acta Kinesiologica

Associations between skinfold thickness, body mass index and waist-to-height ratio in elite national dance sport athletes

Tamara Despot, Lovro Štefan, Davor Plavec — Tue, 08 Jul 2025 00:00:00 +0200

Purpose: The main purpose of the study was to investigate the associations between fat mass percentage (%) assessed by
skinfold thickness with body mass index (BMI) and waist-to-height ratio (WHtR).
Methods: For this observational study, we recruited 33 young dancer sport athletes who competed at international level (age
= 18.70 ± 5.00 yrs, height = 172.43 ± 7.85 cm, weight = 61.88 ± 10.60 kg, BMI = 20.70 ± 2.43 kg/m2, 48.50% women). The
sum of seven skinfold thicknesses (triceps, chest, subscapular, midaxillary, suprailia, abdominal, and thigh) were measured
using the Harpenden® skinfold caliper on the right side of the body. Body fat % was estimated with the Jackson & Pollock
equations for men and women. BMI and WHtR were calculated as weight in kg divided by height in meters squared and the
ratio between waist circumference and height in cm.
Results: In men, the average values in body fat %, BMI and WHtR were 10.17±4.28%, 21.34±2.31 kg/m2 and .43±.03. Body
fat % was positively and strongly correlated with BMI (R = .71, P= .002) and WHtR (R = .76, P< .001). In women, the average
values in body fat %, BMI and WHtR were 12.94±3.92%, 20.02±2.45 kg/m2 and .43±.04. In comparison to men, body fat
% exhibited somewhat stronger correlations with BMI (R = .83, P< .001) in women, yet the correlation with WHtR yielded
lower scores (R = .69, P= .003). In the total sample, body fat % remained positively and moderately correlated with BMI (R =
.60, P< .001) and WHtR (R = .68, P< .001).
Conclusions: This study shows that both BMI and WHtR are valid measures to estimate body fat % in elite dance sport
athletes.

The intensity of health behaviors and health satisfaction among physically active paramedics and professional firefighters

Tue, 08 Jul 2025 00:00:00 +0200

Purpose: Physical activity positively influences lifestyle changes in society. This study aimed to examine the relationship
between the intensity of health behaviours, physical activity, and health satisfaction among paramedics and professional
firefighters.
Methods: The study included 172 participants aged 19–50 years. Physically active paramedics (P1) comprised 32.6% of
the sample, professional firefighters (F1) 31.4%, non-exercising paramedics (P2) 25%, and non-exercising firefighters (F2)
11%. The standardized Health Behaviour Inventory (HBI) questionnaire and a proprietary questionnaire were used. Both
parametric and non-parametric statistical analyses were employed.
Results: Significant differences were found in the intensity of health behaviours (IHB) among the participants within the IHB
point score, correct eating habits (CEH), preventive behaviours (PB), positive mental attitude (PMA), and health practices
(HP) (P< .001 for the F-test in each case; ω²= .65–.74). The highest overall intensity of health behaviours (IHB) point score
(82.54) was observed among physically active paramedics (P1), who also achieved better results in preventive behaviours
(PB), positive mental attitude (PMA), and health practices (HP) compared to inactive firefighters (F2) (P< .001 for the t-test
in each case; d= .51–.59). A significant overall variation was confirmed (P< .001 for the H-test; E²R= .11–.18, strong effect)
between the Health Behaviour Inventory (HBI) and its categories and participants' health satisfaction. The respondents
with the highest IHB point scores, correct eating habits (CEH), preventive behaviours (PB), positive mental attitude (PMA),
health practices (HP), were more satisfied with their health (D) compared to those with lower health behaviour scores (A,
B, C) (rg= -.40 to -.83).
Conclusions: The demonstrated relationship between the intensity of health behaviours, physical activity and health
satisfaction underscores the need to further promote these behaviours to enhance overall quality of life and improve safety
in the professional practice of paramedics and firefighters.

Reliability of manual marker placement in twodimensional kinematic analysis of single-leg landing, countermovement jump, and broad jump movement techniques

Ažbe Ribič, Darjan Spudić, Nejc Šarabon, Primož Pori — Tue, 08 Jul 2025 00:00:00 +0200

Purpose: Manual two-dimensional (2D) kinematic analysis is widely used in research settings to evaluate jump techniques.
However, a gap remains in the literature regarding the reliability and validity of analyzing single-leg jumps. This study
examines a previously overlooked source of variability in manual 2D kinematic analysis, specifically: (a) the impact of manual
marker placement on anatomical landmarks and (b) the precision of visually identifying key movement time points in singleleg
countermovement jumps, single-leg broad jump push-off and landing phases, and single-leg drop landings.
Methods: Eighty professional handball players (age: 21.8±3.9 years; mass: 92.0±9.6 kg; stature: 1.90±.06 m) were video
recorded from lateral and frontal planes, and the analysis was manually performed using Kinovea software. The study
examined 2D kinematic variables, including the inclinations of the shin, thigh, and trunk segments relative to a vertical
reference line, as well as the joint angles between these segments during single-leg jumps. Reliability was assessed by
comparing (a) three repetitions of manual marker placement (MP) on anatomical landmarks and (b) three repetitions of
visual identification of key movement positions (KPs) during single-leg countermovement jumps, broad jump push-offs and
landings, and drop landings. KPs were defined by two criteria, based on either the lowest vertical position of the greater
trochanter (subjective) or peak vertical ground reaction force data (objective).
Results: The main findings of our study indicate that the reliability of marker placement and key position determination,
regardless of the test, plane of motion, leg, and criteria of key position determination is acceptable (ICC= .883–.999; CV<10
%).
Conclusions: These findings confirm that manual 2D kinematic analysis reliably evaluates movement techniques during
jumps and landings across different KP definitions and variable conditions.

The Importance of Physical Activity and Eating Behaviours for Fat and Muscle Mass in Young Men and Women

Dorota Łoboda, Jarosław Ocalewski , Beata Ziółkowska , Szymon Kulis — Thu, 10 Jul 2025 00:00:00 +0200

Purpose: The aim of the study was to determine the relationships between the level of physical activity and eating-related
behaviors (such as emotional eating, habitual eating, and dietary restraint) and the amount of fat and muscle tissue in the
bodies of young adults.
Methods: The study was conducted among 202 university students (103 women - age 21.44 ±2.14 years, stature 167.91
±6.13 cm, body mass 62.08 ±12.11 kg; 99 men - age 21.48 ±1.93 years, stature 179.12±7.11 cm, body mass 77.31±15.32
kg) from two higher education institutions. Self-report questionnaires were used: the IPAQ (International Physical Activity
Questionnaire) and the KZZJ (Eating Behavior Questionnaire). Anthropometric measurements and body composition
analyses were also performed. Data were analyzed using Pearson's r correlations, Mann–Whitney U tests, Pearson's χ² tests,
and structural equation modeling (SEM).
Results: Strong positive correlations were observed between emotional eating and the level of body fat. It was found that
only individuals with high-intensity physical activity (over 1500 MET-min/week) had body fat levels within the normal
range. For smaller adipose tissue, only the following correlations were statistically significant: intensive exercise around the
house (R=- .143, P= .043), intensive physical activity in free time (R= -.268, P< .001) and moderate physical activity in free
time (R= - .188, P= .008). For larger muscle tissue, the following correlations were statistically significant: intensive exercise
around the house (R=. 140, P= .048), intensive physical activity in free time (R= .198, P= .005). SEM models showed that
psychological and physical activity-related variables explained 48% of the variance in body fat and 32% of the variance in
muscle mass.
Conclusions: Physical activity, especially at a high intensity, plays a crucial role in maintaining a healthy body composition.
At the same time, emotional eating contributes to increased body fat, particularly in women. The findings have practical
applications for the prevention of overweight, obesity, and eating disorders among young adults.

Neuromuscular Profile of Top-Level Youth Taekwondo Competitors Assessed Through Tensiomyography - Croatian National Youth Taekwondo Team Example

Nino Sladic, Drazen Cular, Matej Babic, Ana Kezic, Toni Tomas, Damir Zubac — Thu, 19 Jun 2025 00:00:00 +0200

Purpose: This study aimed to investigate the neuromuscular profile of elite youth Taekwondo (TKD) athletes using
tensiomyography (TMG) to assess lower-limb muscle contractile properties and estimate muscle fiber composition.
Methods: Seventeen members of the Croatian national junior TKD team (10 males, 7 females) participated in this crosssectional
study. Anthropometric characteristics and age at peak height velocity (APHV) were assessed, and TMG measurements
were performed bilaterally on the vastus lateralis (VL) muscle to obtain contraction time (Tc), delay time (Td), sustain time
(Tr), and estimated percentage of type I muscle fibers (MHC-I%). The average chronological age of participants was 16.3 ±
0.9 years, with an average APHV of 13.4 ± 0.7 years.
Results: Males were taller and heavier than females, and females showed earlier biological maturation. No significant
differences were found between the left and right VL for Tc (21.5 ± 2.6 ms vs. 22.2 ± 2.8 ms; P = .29) or MHC-I% (15.4 ± 9.5%
vs. 14.4 ± 11.7%; P = .69). However, a significant side-to-side difference was observed in Td (t = 2.43, P = .03), suggesting
asymmetries in neuromuscular activation onset. Substantial intra-individual variability in MHC-I% distribution was also
observed.
Conclusions: These findings provide novel insight into the contractile characteristics of adolescent TKD athletes and highlight
the utility of TMG as a non-invasive profiling tool. The results may inform individualized training design, injury prevention
strategies, and athlete development models in youth combat sports.

Comparison of the effects of isometric and dynamic training on strength and body composition in recreational athletes

Artur Kruszewski, Marek Kruszewski, Kamil Zawadka, Rafał Tabęcki — Thu, 10 Jul 2025 00:00:00 +0200

Purpose: The aim of this study was to compare the effectiveness of isometric and dynamic contractions of equal duration in
terms of strength development and changes in body composition.
Methods: Recreational strength-trained men (n=20) were divided into two subgroups that performed an isometric and
dynamic contraction protocol. Isometric and dynamic contraction protocols were performed 14 times over a 7-week period
and preceded and followed by measurements of maximal weight (1RM – one repetition maximum) using the weightlifting
method, MVIC (maximal voluntary isometric contraction) measured on an LR2-P upper limb flexor and extensor torques and
body composition made using electrical bioimpedance (BIA)
Results: MVIC values increased significantly measured in the angle settings of 30º P= .009, 60º P= .016, 90º P= .048. after
isometric training, and after training in dynamic conditions only for the joint angle value of 60º P= .016. MVIC differences
between the effects of training in isometric conditions and in dynamic conditions, were significant for angles of 90º P= .044
and 30º P= .002. The 1RM values did not change significantly after both types of training (pre-post isometric vs dynamic).
There were no significant changes in active body mass and body fat of the whole body and segmentally of the upper limbs.
Conclusions: Given the limited scope and limitations of the study, the use of isometric contractions appears to promote an
increase in MVIC values in all angular settings (30, 60, 90°), although the greatest differences between static and dynamic
training effects were obtained at 30 and 90°. The lack of significant changes in strength (1RM), active body mass and body
fat after the application of both types of training, may indicate an inadequate conversion of the selected loading modality to
fitness in these characteristics.

Reaction time analysis in professional table tennis: gender differences and key determinants

Marcin Szczepański, Monika Lopuszanska-Dawid, Paulina Kubot — Tue, 08 Jul 2025 00:00:00 +0200

Purpose: The purpose of study was to identify the factors influencing the visuomotor reaction time of elite male and female
players and to assess the magnitude of sex-based differences in reaction times.
Methods: The study involved 64 participants: 44 elite Polish table tennis players (female n=17, male n=27) athletes;
female and male students as the control group (n=20). Data on socioeconomic status, physical activity and subjective
physiological state were collected using an author-designed questionnaire. Anthropometric data were collected. Reaction
time was measured using the Piórkowski’s apparatus. The analyses included Chi2 tests, Student’s t-tests for independent
samples, Spearman’s rank correlation and multiple regression analyses.
Results: Significant differences were found in the number of points scored between female table tennis players and female
students (137 vs 126 P= .013) and between female and male table tennis players (137 vs 129, P= .023), while no significant
differences were observed among male participants. Gender differences were identified in the urbanization of residence
(P= .034), participation in additional sports disciplines (P= .013), and anthropometric features such as body height, body
mass and Waist to Hip Ratio (P= .001). Among female athletes, moderate negative correlations were found between speed of
reaction and training session duration (R= -.559) and body height (R= -.489), suggesting shorter training sessions and lower
body height may enhance reaction time. No significant associations between reaction time and the analyzed variables were
observed among male athletes.
Conclusions: The analyses revealed differences in place of residence, participation in additional sports disciplines, hunger
perception, and somatic build between female and male athletes. The study demonstrated that certain factors influence
reaction time. Appropriate training duration combined with adequate intensity can improve the reaction time of athletes.
The obtained results may serve as a foundation for further research and observations of table tennis players.

Development and Internal Validation of a Field-Based Equation for Predicting Half-Squat One-Repetition Maximum in Youth Soccer Players Using Standing Long Jump Performance and Body Mass

Tue, 08 Jul 2025 00:00:00 +0200

Purpose: This study aimed to examine the validity of field-based tests, specifically the 5-Jump Test (5JT) and Standing Long
Jump (SLJ), combined with anthropometric measures for predicting one-repetition maximum (1RM) half-squat performance
in U-13 male soccer players.
Methods: Forty-one male youth soccer players (age: 12.77±.25 years; body-mass (BM): 46.54±7.86 kg; body-height:
157.70±9.58 cm) participated in this investigation. Following a one-week familiarization session that included practice
trials of all testing procedures and movement pattern instruction, participants completed three testing sessions comprising
anthropometric measurements, 1RM half-squat assessment, and field tests (5JT and SLJ). Multiple linear regression analysis
was employed to develop prediction equations, with model validation including assessments of normality, homoscedasticity,
and multicollinearity.
Results: The final prediction model incorporating only BM and SLJ explained 70% of the variance in 1RM half-squat
performance (R²=.696, P<.001). The resulting equation (1RM=-114.503+ 1.953×BM+71.468×SLJ) demonstrated robust
statistical properties, with both predictors showing significant contributions (BM: β=1.953, 95% CI [1.3-2.5], P<.001;
SLJ: β=71.468, 95% CI [45.3-97.6], P<.001). The model satisfied assumptions of normality (Shapiro-Wilk: P=.06) and
homoscedasticity (Breusch-Pagan: P=.521), with acceptable multicollinearity indices (VIF<4.0). While initially considered,
age, standing height, and 5JT did not significantly improve prediction accuracy.
Conclusions: This study validates a practical equation for estimating maximal half-squat strength in youth soccer players
using readily available field measures. The combination of SLJ performance and BM provides coaches with a time-efficient,
low-risk method for strength assessment in young athletes. This approach provides coaches with an accessible, time-efficient
tool for strength monitoring that requires minimal equipment while maintaining scientific validity.

Determinants of Life Satisfaction Among Marathon Runners

Paweł F. Nowak, Tuğba Gültekin, Dariusz S. Bajkowski, Thomas Casale — Tue, 08 Jul 2025 00:00:00 +0200

Purpose: This study aimed to assess life satisfaction and health behaviors among marathon runners and explore the
determinants of higher satisfaction levels. The hypothesis was that marathon participation leads to pro-health behaviors
and increased life satisfaction.
Methods: A cross-sectional survey was conducted with 506 Polish marathon runners. Participants were recruited through
a social network for runners. Health behaviors were measured using the Health Behavior Inventory (HBI), while life
satisfaction was assessed using the Satisfaction with Life Scale (SWLS). Statistical analyses included regression models to
identify predictors of life satisfaction.
Results: The analysis revealed that marathon runners exhibited a high level of life satisfaction, with 45% of women and
37% of men reporting high satisfaction. Significant differences were found in training distances and marathon participation
between genders. The regression model identified three key predictors of life satisfaction: training experience, number of
marathons completed, and the overall health behavior index (HBI). Additionally, when health behavior categories were
further analyzed, the Positive Mental Attitude (PMA) category showed the strongest association with life satisfaction. The
final model explained 18% of the variability in life satisfaction, with the number of completed marathons and PMA being
significant predictors.
Conclusions: Marathon participation fosters pro-health behaviors, particularly a positive mental attitude, which contributes
to higher life satisfaction. This highlights the importance of mental well-being alongside physical activity in long-distance
running. Promoting running as an accessible form of exercise, with a focus on health education and psychological support,
could significantly improve participants' quality of life.

Changes in body composition and handgrip strength of sports science students in the context of summer break

Grzegorz Bielec, Aneta Omelan — Thu, 10 Jul 2025 00:00:00 +0200

Purpose: The phenomenon of reduced physical activity during the summer holidays and the resulting adverse changes in
body composition is addressed in the public health literature. This phenomenon in relation to university students has not yet
been thoroughly investigated. The aim of this study was to investigate the effect of summer break on body composition and
handgrip strength in sports science students.
Methods: Forty-seven male students of the Faculty of Sports Science participated in the first examination conducted in mid-
June. Thirty-eight students aged 21.2± .6 years participated in the second examination in early October. Body composition
was determined with bioelectrical impedance analysis (Tanita BC 418 MA). Handgrip strength was assessed with a bulb
dynamometer. Students were also questioned about physical activity undertaken during the academic year and during
summer holidays.
Results: None of the body composition parameters changed significantly in examined students after the summer break
(P> .05). Handgrip strength increased significantly after summer holidays (P= .01, d= .423). Body weight, muscle mass, and
basal metabolic rate were strongly correlated with handgrip strength after the summer break (R>. 50, P< .05). Number of
days devoted to intensive and moderate physical activity decreased substantially during the summertime compared with
academic year (P< .00, d= .620 and P< .00, d= .771, respectively).
Conclusions: Despite a reduction in physical activity levels during the summer break, body composition parameters did not
change significantly in sports science students. Further research should consider more detailed characteristics of students'
physical activity during the summer break.