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Konstantina Karatrantou has a total of 79 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    A Combined Workplace Intervention Including Exercise and Nutrition for Health Promotion in Obese Office Workers: A Randomized Controlled Study

    by Konstantina Karatrantou, Elisavet Efthymiou, Christos Batatolis, Konstantinos Pappas, Theodora Vasilopoulou, Anastasia Melissopoulou, Vassilis Gerodimos

    Background: During the last decades, the office workplace setting has increasingly become an inherently “obesogenic” environment, promoting unhealthy behaviors. The main objective of this study was to investigate the efficacy of a 6-month workplace combined (exercise and nutrition) intervention in obese office workers, using a randomized controlled study. An additional objective of this study was to evaluate the individual responses per participant following the program. Methods: In total, 36 obese office workers (BMI: ≥30) were randomly assigned to two equal groups: intervention (IG; age: 48.06 ± 6.60 yrs; BMI: 33.57 ± 1.58 kg/m2) and control (CG; age: 47.95 ± 5.95 yrs; BMI: 33.54 ± 1.74 kg/m2). The IG participated in a daily supervised 6-month workplace program (during working hours), including (a) exercise (flexibility, balance, strength, and aerobic) and (b) counseling and educational activities for healthy diet and hydration. The CG did not participate in any intervention. Before and after the 6-month period, the following were measured: (a) health indices (body fat, body circumferences, blood pressure, respiratory function, and lipidemic profile), (b) functional capacity indices (flexibility, balance, handgrip strength, and cardiovascular fitness), and (c) adherence to the Mediterranean diet (MedDietScore) and daily water consumption. Results: All the participants of the IG reduced body mass, body fat, and circumferences (−4.47 to −18.95%), blood pressure (−4.08 to −46.15%), lipidemic profile indicators (−2.50 to −212.67%), and heart rate recovery (−9.62 to −57.33%), while increased respiratory function (1.82–20.26%), flexibility (5.13–50%), balance (15.38–88.83%), handgrip strength (5–25%), MedDietScore (12.5–56%), and water consumption (23.08–50%). In CG, all aforementioned indices remained unchanged (p = 0.16–0.99). Conclusions: A combined workplace intervention (exercise and nutrition) constitutes an effective approach for health promotion in obese office workers.

  • Open Access

    Flexibility in Wrestlers, Taekwondoists, and Non-Athletes During the Developmental Ages: The Effects of Sport, Age, and Sex

    by Vassilis Gerodimos, Nikolaos Tsiakaras, Konstantina Karatrantou

    Objectives: Flexibility may be influenced by several factors, including age, sex, and physical activity or sport. This study simultaneously investigated the effect of sport (wrestling vs. taekwondo vs. no participation in sports activities), age (children vs. adolescents), and sex (boys vs. girls) on lower and upper body flexibility during the developmental ages. Methods: A total of 120 wrestlers, 120 taekwondoists, and 120 non-athletes (60 boys: 30 children and 30 adolescents; 60 girls: 30 children and 30 adolescents, per group) participated in the present study and performed two flexibility tests (sit and reach, back scratch). Results: ANOVAs and ANCOVAs (using anthropometric characteristics as covariates) analyses showed greater (p = 0.000–0.005) flexibility values in wrestlers and taekwondoists than non-athletes (except for the sit and reach in children girls, and flexibility of the right hand in children boys and girls, where no differences were observed). However, no differences (p = 0.672–0.992) were presented between wrestlers and taekwondoists (except for the flexibility of the left hand, where wrestlers showed greater values). Within the wrestlers and taekwondoists groups, children exhibited lower (p = 0.01–0.04) values than adolescents; while, in non-athletes, no age-related differences were observed (p = 0.263–0.995). Additionally, girls demonstrated higher values than boys, and the right hand demonstrated higher flexibility values than the left hand (p = 0.000–0.04). The difference between hands was greater (p = 0.000–0.01) in non-athletes (69.14–96.22%) vs. athletes (23.73–58.85%), taekwondoists (41.01–58.85%) vs. wrestlers (23.73–47%), and boys (44.68–96.22%) vs. girls (23.73–70.44%). Conclusions: It seems that engaging in wrestling and taekwondo sports affects the growth pattern of flexibility in boys and girls during the developmental ages.


  • Open Access

    Intrasession and Intersession Reliability of Flexibility Tests During Developmental Years: The Effects of Sport, Age, and Sex

    by Nikolaos Tsiakaras, Konstantina Karatrantou, Christos Batatolis, Konstantinos Papavasileiou, Fenia Tzeli, Vassilis Gerodimos

    Flexibility plays an important role in both daily life and performance in various sports. This study evaluated the intrasession and the intersession reliability of flexibility measurements, examining the effects of sport, age, and sex. The sample included 80 wrestling athletes (40 boys: 20 children/20 adolescents; 40 girls: 20 children/20 adolescents), 80 taekwondo athletes (40 boys: 20 children/20 adolescents; 40 girls: 20 children/20 adolescents), and 80 non-athletes (40 boys: 20 children/20 adolescents; 40 girls: 20 children/20 adolescents). The participants performed two assessment sessions, which included two tests (back scratch/sit and reach). The results showed high intrasession and intersession reliability for boys and girls among wrestling and taekwondo athletes (children: ICC = 0.988–0.998, SEM% = 2.31–7.44; adolescents: ICC = 0.993–0.999, SEM% = 1.13–5.19). Additionally, the results demonstrated good/high intrasession and intersession reliability for boys and girls among non-athletes (children: ICC = 0.992–0.997, SEM% = 3.40–9.98; adolescents: ICC = 0.996–0.998, SEM% = 2.81–8.94). The SEM% values were slightly higher in non-athletes vs. athletes (wrestling, taekwondo), as well as in children vs. adolescents, indicating that athletes and adolescents present better reliability than non-athletes and children, respectively. No differences in reliability were observed between boys and girls. In conclusion, the sit and reach and the back scratch are reliable tests in assessing flexibility during the developmental ages. It seems that age and engagement in sports affect the reliability of measurements.


  • Open Access

    Physiological Responses to Repeated Maximum Intensity Efforts in Surface and Underwater Fin Swimming

    by Ioannis D. Kostoulas, Gregory Kalaitzoglidis, George Tsalis, Konstantina Karatrantou, Argyris Toubekis, Vassilis Gerodimos

    The purpose of the study was to compare physiological and performance responses during surface and underwater fin swimming. Thirteen male, elite fin swimmers performed four repetitions of 50-m sprints using a monofin (4 x 50 m) either on surface (S) or underwater with apnea (U). Performance time and the number of lower body kicks were recorded during 4 x 50-m sprints. Lactate was evaluated before the start, after the second and the fourth sprint and five minutes into recovery. The heart rate was measured continuously and respiratory function was recorded before and after each condition. Performance time was shorter and kicking frequency was higher in U compared to S (17.73 ± 1.18 vs. 19.94 ± 1.41 s, 135 ± 18 vs. 121 ± 15 kicks∙min−1, p < 0.05). Lactate concentration was no different between conditions. Forced expiratory volume in 1 s and peak expiratory flow were no different before and after the sprints and between conditions (p > 0.05). Forced vital capacity and maximal voluntary ventilation were increased after sprints under both conditions (p < 0.05). The heart rate was decreased in U compared to S during both sprints (167–177 vs. 183–185 b∙min−1) and the recovery period (141–151 vs. 166–174 b∙min−1). Underwater and surface repeated sprint swimming present maximal dynamic and physiological responses that should be considered during fin swimming training.


  • Open Access

    Test–Retest Reliability of Cervical Strength Testing Protocols with Handheld Dynamometer in Prepubertal and Pubertal Untrained Boys

    by Christos Batatolis, Konstantina Karatrantou, Theodora Vasilopoulou, Konstantina Chanou, Nikolaos Tsiakaras, Vassilis Gerodimos

    Background: The cervical spine plays an important role in several daily activities of children and adolescents, and thus, its evaluation using reliable protocols is of crucial importance. This study examined the test–retest reliability of cervical strength protocols using indices of absolute (standard error of measurement—SEM and 95% limits of agreement—LOA) and relative reliability (intraclass correlation coefficient—ICC). Methods: Twenty prepubertal (9.10 ± 0.61 years old) and twenty pubertal boys (13.6 ± 0.6 years old) participated in two assessment sessions separated by 48 h. During both sessions, maximal isometric strength (forward flexion, extension, and right–left lateral flexion) was assessed using a handheld dynamometer, and then, the cervical flexion-to-extension ratio (cervicalF/E ratio) was calculated. Results: According to our data analysis, good absolute and relative reliability was denoted for prepubertal boys in all cervical movements (ICC = 0.81–0.90; SEM% = 5.82–8.62); conversely, pubertal boys denoted high relative and absolute reliability in all directions of movements (ICC = 0.90–0.96; SEM% = 3.8–5.5). The cervicalF/E ratio showed moderate reliability in prepubertal (ICC = 0.71; SEM% = 9.11) and pubertal boys (ICC = 0.78; SEM% = 7). Conclusions: In conclusion, the isometric strength of cervical muscles, using a handheld dynamometer, showed acceptable reliability in prepubertal and pubertal boys; however, prepubertal boys demonstrated slightly lower reliability. Additionally, the assessment of the cervical F/E ratio should be interpreted with caution. However, it would be important to carry out future studies to strengthen the findings of the present study.


  • Open Access

    Measurement and Evaluation of Health, Functional Capacity, Physical Fitness, and Daily Habits of Greek Female Healthcare Professionals Working in a Hospital Environment

    by Anastasia Chasandra, Konstantina Karatrantou, Kyriaki Papazeti, Anastasia Melissopoulou, Christos Batatolis, Maria Mourounoglou, Rafaela-Varvara Sioupi, Vassilis Gerodimos

    Background/Objectives: The wellness profile of healthcare professionals is of crucial importance since it can affect the quality of healthcare services. This study created a comprehensive profile of health, functional capacity, physical fitness, and lifestyle behaviours in hospital healthcare professionals. Methods: A hundred female (age: 45.53 ± 2 yrs) professionals underwent assessments of their health (respiratory function/blood pressure/body circumference/body fat/body mass index/musculoskeletal pains), functional capacity (flexibility/balance), physical fitness (strength/aerobic capacity), and daily habits (smoking/alcohol/caffeinated beverages/screen time/physical activity). Results: According to data analysis (descriptive statistics, paired t-tests to analyze possible differences between the right and left sides), (a) 39% of the participants were overweight and 28% obese, (b) 40–44% of the participants showed higher values than normal in waist circumference and systolic blood pressure, and (c) 96% of the participants showed musculoskeletal pains. Functional capacity and physical fitness demonstrated significant differences in balance and flexibility (p < 0.05) between sides (right/left) and low levels of strength and dynamic balance-agility. Moreover, 67% of the sample did not participate in physical activities, while a significant percentage showed increased screen time on weekdays (44%) and weekends (61%). Finally, 36% of the sample smoked, 62% consumed alcohol, and 92% consumed caffeinated beverages (the majority were within permissible limits). Conclusions: In conclusion, this study contributes valuable insights into the wellness profile of healthcare professionals to ensure optimal care for this population.

  • Open Access

    Individuality Affects the Efficiency of Basketball Pre-Game Warm-Up on Players’ Performance

    by Grigoris Papagiannis, Konstantina Karatrantou, Christos Batatolis, Panagiotis Ioakimidis, Vassilis Gerodimos

    Pre-game warm-up is integral to athletes’ preparation before a basketball game. The main objectives of this study were to compare specific performance indicators before and immediately after a basketball pre-game warm-up, and examine the individualized players’ responses. The impact of rest intervals after warm-up (9–23 min) was also examined. A total of 20 male basketball players (age: 21.15 ± 2.2 years; body mass: 82.23 ± 10.78 kg; body height: 184.18 ± 7.9 cm) performed a pre-game warm-up and were assessed in selected indicators such as heart rate (HR), flexibility, running speed, and countermovement jump with arm swing (CMJAS) before, immediately after, 9 min and 23 min after warm-up. Immediately after warm-up, HR increased to all players (mean change: 69.78%), while flexibility (mean change: 20.14%) and CMJAS (mean change: 4.95%) increased to the majority of players (except one and two players, respectively). The individualized results regarding speed were conflicting, showing a decrease or increase. However, 9 and 23 min after warm-up, there was a decrease in HR, speed, and CMJAS (p < 0.5), while flexibility remained stable (p > 0.5) in the total sample, with great change variations among players. In conclusion, it seems that each player’s individuality may affect the warm-up’s efficiency. Thus, it is important to carefully design the pre-game warm-up so that all players will be in the most suitable condition to meet the demands of their competition.


  • Open Access

    Tennis Coaches’ Self-Determined Motivation and Achievement Goals: Links between Coach-Created Motivational Climate, Work Engagement, and Well-Being

    by Aristea Kiamouri, Maria Angeli, Charalampos Krommidas, Nikolaos Digelidis, Konstantina Karatrantou

    Tennis coaches display significant influence, catalyzing changes in athlete performance, motivation, and overall well-being. Research on coaches’ motivations and their impact on coaching style, work, and well-being is limited, especially in individual sports like tennis. Based on self-determination (SDT) and achievement goal (AGT) theories, the aim of the present study was to examine the relationships of coaches’ self-determined motivation (intrinsic, extrinsic, and amotivation), basic psychological needs satisfaction (autonomy, relatedness, and competence), and achievement goals (self-improvement—SI, self-enhancement—SE, self-transcendence—ST) with their coach-created empowering-disempowering motivational climate, work engagement, and well-being (subjective vitality). Participants were 106 tennis coaches from Greece (66 males and 40 females), with an average age of 41.30 ± 12.54 years and coaching experience ranging from six months to 40 years. Data was collected through online questionnaires. Correlation analysis revealed that intrinsic and extrinsic motivation, satisfaction of the three basic psychological needs, and achievement goals were found to be positively related to an empowering climate, work engagement, and subjective vitality. Coaches’ amotivation was positively related to a disempowering climate. Multiple regression analyses showed that autonomy and ST achievement goals significantly predicted tennis coaches’ empowering motivational climate, while none of the independent variables were significant predictors of the disempowering motivational climate. Additionally, intrinsic motivation and ST goal significantly predicted tennis coaches’ work engagement, while autonomy and ST goal significantly predicted their subjective vitality. It is advisable for forthcoming coach education initiatives to consider these findings as an additional justification for tennis coaches to incorporate multiple perspectives into their coaching methodologies.


  • Open Access

    A 3-Month Modified Basketball Exercise Program as a Health-Enhancing Sport Activity for Middle-Aged Individuals

    by Konstantina Karatrantou, Konstantinos Pappas, Christos Batatolis, Panagiotis Ioakimidis, Vassilis Gerodimos

    Recreational team sports have received great acceptance lately, in different populations, indicating encouraging results in health-related quality of life. This study examined the efficacy of a 3-month basketball exercise program on selected indices of health (body mass—BM, body fat—BF, blood pressure—BP), functional capacity (flexibility of lower and upper limbs, balance), and physical fitness (maximum strength of lower limbs, trunk and handgrip, aerobic capacity) in middle-aged individuals. Forty middle-aged individuals (males and females; 40–55 years old) were randomly divided into (a) exercise (EG; n = 20) and (b) control groups (CG; n = 20). The EG followed a 3-month modified basketball exercise program (2 times/week; 24 training units), including different basketball drills with and without the ball (dribbling, passing, pivot, stops, etc.), to improve participants’ health and physical fitness. Repeated measures ANOVA showed that the EG significantly increased their flexibility (17.23–74.88%; p < 0.001), static balance (44.76–54.69%; p < 0.001), and strength of lower limbs and trunk (11.67–13.13%; p < 0.001), while reducing BP (7.31–12%; p < 0.001), heart rate and RPE (5.30–34.37%; p < 0.001), and time during time-up-and-go test (−10.91%; p < 0.001). Handgrip strength, BM, and BF did not change following the program in the EG (p > 0.05). In the CG, the above variables remained stable. In conclusion, this program may be used to eliminate the detrimental effects of aging on health, functional capacity, and physical fitness parameters.


  • Open Access

    A Comprehensive Workplace Exercise Intervention to Reduce Musculoskeletal Pain and Improve Functional Capacity in Office Workers: A Randomized Controlled Study

    by Konstantina Karatrantou, Vassilis Gerodimos

    The high levels of musculoskeletal pain, in conjunction with the low levels of functional capacity, may negatively affect workers’ health, efficiency, and productivity. This randomized controlled study investigated the efficacy of a 6-month comprehensive workplace exercise program on musculoskeletal pain and functional capacity in office workers. Seventy male and female office workers with musculoskeletal pain in any body area were randomly assigned to either an intervention (IG; n = 35) or a control group (CG; n = 35). The IG participated every working day (during working hours) in a 6-month supervised combined (flexibility, strength, and balance) exercise program (120 training sessions; five times/week) for the total body. The CG did not participate in any intervention. Musculoskeletal pains in nine body areas and functional capacity (flexibility, balance, and strength) of the lower and upper body were measured before and following the intervention. The IG significantly reduced duration and intensity of pain (43.1–70%; p = 0.000) as well as days of work absenteeism (84.6%; p = 0.000), while improving work capacity (87.1%; p = 0.000). Furthermore, the IG significantly increased cervical, handgrip, back, and leg maximal strength (10.3–27.1%; p = 0.000) and flexibility and balance (12.3–73.7%; p = 0.000). In CG, all musculoskeletal pain and functional capacity indices remained unchanged. In conclusion, this program may be effectively used to reduce musculoskeletal pain and improve functional capacity.