Dimitrios Bourdas

Dr. Dimitrios Bourdas

Department of Sports Medicine & Biology of Exercise, National and Kapodistrian University of Athens, Athens, Greece
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Research Focus & Metrics

Academic Career Length

26Years (2001-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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21 October 2020 in Sports
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DBDimitrios Bourdas
Dimitrios Bourdas
EZEMMANOUIL ZACHARAKIS
EMMANOUIL ZACHARAKIS
It is well known that physical inactivity increases the risk of global death; however, the impact of the coronavirus disease 2019 (COVID-19) lockdown strategy on physical activity (PA) remains unclear. This study compared PA—i.e., daily occupation, transportation to and from daily occupation, leisure time activities, and regular sporting activities—prior (PRE) and during (POST) the on-going COVID-19 outbreak in the Greece lockdown environment. A Greek version of the web-based Active-Q questionnaire was used to access PA. The questionnaire was filled out twice (once each for the PRE and POST conditions) by 8495 participants (age = 37.2 ± 0.2 years (95% confidence interval (CI), 36.9–37.5); males = 38.3% (95%CI, 36.7–40.0); females = 61.7% (95%CI, 60.4–63.0). The relative frequency of overall sporting activities, which, prior to lockdown, occurred at least once per month, and overall participation in competitive sports was significantly reduced (8.6% (95%CI, 7.9–9.3) and 84.7% (95%CI, 82.9–86.6) respectively). With the exception of overall leisure time activities, which were significantly increased in the POST condition, daily occupational, transportation, and sporting activities significant reduced (p < 0.05). Overall PA was reduced in all genders, age, body mass index (BMI) and PA level subgroups in the POST condition, and an interaction between the males and High PA subgroups was observed. The change in overall PA (from PRE to POST conditions) was −16.3% (95%CI, −17.3 to −15.4), while in daily occupational, transportation, and sporting activities, it was −52.9% (95%CI, −54.8–51.0), −41.1% (95%CI, −42.8–39.5) and −23.9% (95%CI, −25.1–22.8), respectively. Thus, the lockdown period is highly associated with a negative change in overall PA. During lockdown, inactivity increased dramatically, with males and the high PA population affected significantly more. The decline in PA is a great concern due to possible long-term consequences on public health and healthcare system.

1 October 2020 in Data in Brief
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DBDimitrios Bourdas
Dimitrios Bourdas
EZEmmanouil D. Zacharakis
Emmanouil D. Zacharakis
There is a worldwide interest in how lockdown affects physical activity (PA) during the COVID-19 pandemic. Although it has been shown that the mandated stay-at-home restrictions and self-isolation measures applied in different countries were accosiated with a reduction in physical exercise and activity, such results derive from studying only specific periods of lockdown. However, in order for this hypothesis to be tested, consecutive lockdown periods need to be examined separately. In this study we focus on PA change in Greek adults over time, during each of the last four weeks of lockdown in Greece. The web-based Active-Q questionnaire (see Supplementary file 1_Active-Q) was used to collect data prior to the COVID-19 crisis (PRE condition) and during lockdown measures (POST condition). The period of data collection (5 April to 3 May 2020) was divided into four phases (Ph-I, Ph-II, Ph-III, Ph-V), corresponding to the 3rd, 4th, 5th and 6th lockdown week respectively (out of a six-week total lockdown). There were four independent groups of respondents (G-I, G-II, G-III, G-V) who reported their age, weight, height and usual PA habits. Energy expenditure (EE) was calculated (MET-min/week; see Supplementary file 2_Data) in four main different domains (daily occupation activities, means of transportation to and from daily occupation, leisure time and regular sporting activities; see Supplementary file 3_Corresponding MET values). Each group's dataset corresponded to one of the aforementioned phases (G-I to Ph-I, G-II to Ph-II, and so on). Overall PA change (from PRE to POST condition) ranged from -21.50% in G-I (Ph-I) to -5.03 in G-V (Ph-V); PA change in male subgroups ranged from -26.10% in Ph-I to -13.64 in Ph-V; in female subgroups it ranged from -17.42% in Ph-I to -1.39 in Ph-V. Although the decline in overall PA is evident in all groups during each lockdown phase (p<0.05), the combination of our data demonstrates that towards the end of lockdown this decline showed a gradual decreasing tendency.

24 November 2021 in Nutrients
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DBDimitrios Bourdas
Dimitrios Bourdas
ASAthanasios Souglis
Athanasios Souglis
EZEMMANOUIL ZACHARAKIS
EMMANOUIL ZACHARAKIS
NGNickos D Geladas
Nickos D Geladas
ATAntonios K. Travlos
Antonios K. Travlos
Carbohydrate (CHO) supplementation during prolonged exercise postpones fatigue. However, the optimum administration timing, dosage, type of CHO intake, and possible interaction of the ergogenic effect with athletes’ cardiorespiratory fitness (CRF) are not clear. Ninety-six studies (from relevant databases based on predefined eligibility criteria) were selected for meta-analysis to investigate the acute effect of ≤20% CHO solutions on prolonged exercise performance. The between-subject standardized mean difference [SMD = ([mean post-value treatment group–mean post-value control group]/pooled variance)] was assessed. Overall, SMD [95% CI] of 0.43 [0.35, 0.51] was significant (p < 0.001). Subgroup analysis showed that SMD was reduced as the subjects’ CRF level increased, with a 6–8% CHO solution composed of GL:FRU improving performance (exercise: 1–4 h); administration during the event led to a superior performance compared to administration before the exercise, with a 6–8% single-source CHO solution increasing performance in intermittent and ‘stop and start’ sports and an ~6% CHO solution appearing beneficial for 45–60 min exercises, but there were no significant differences between subjects’ gender and age groups, varied CHO concentrations, doses, or types in the effect measurement. The evidence found was sound enough to support the hypothesis that CHO solutions, when ingested during endurance exercise, have ergogenic action and a possible crossover interaction with the subject’s CRF.

1 December 2023 in Journal of Sports Science and Medicine
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IMIoannis Mitrousis
Ioannis Mitrousis
DBDimitrios Bourdas
Dimitrios Bourdas
SKStylianos Kounalakis
Stylianos Kounalakis
EBEvangelos Markos Bekris
Evangelos Markos Bekris
MMMichael Mitrotasios
Michael Mitrotasios
EZEmmanouil Zacharakis
Emmanouil Zacharakis
Soccer is a complex sport, and balance appears to play a crucial role in the quality execution of technical skills, which are mostly performed while standing on one foot. Nevertheless, in younger ages, when learning still affects soccer performance, the effect of a balance-training program on the player’s balance and technical skills remains unexplored. This research examined the effect of a balance-training program (BTP) on balance and technical skills of adolescent soccer players. Τhe participating volunteers were thirty-two soccer players (12-13 years old with 3.84 ± 0.95 years of practice), randomly separated into two groups: an experimental (EXP, n1 = 17) and a control group (CON, n2 = 15). Both groups were evaluated in static and dynamic balance and in technical skills (dribbling, passing, juggling, and shooting with dominant and non-dominant legs) before (Pre-condition) and after the intervention (Post-condition) which was an eight-week BTP for the EXP group and a placebo-training program for the CON group. Α 2 by 2 (groups×condition) mixed analysis of variance (ANOVA) with repeated measures on the condition factor was used to assess possible differences between groups. A significant groups × condition interaction effect was found in dynamic balance (p = 0.008), static (p = 0.042), and shooting (p = 0.022) with dominant leg performance. The EXP group improved (p = 0.007) its static balance by 37.82% and also significantly improved its dynamic balance and shooting accuracy with dominant leg in Post condition by 24.98% (p = 0.006) and 83.84% (p = 0.006) respectively. No significant improvement of other variables was detected in the EXP group Post condition. Dynamic and static balance, and shooting with dominant leg skills can be improved in adolescent soccer players through a specialized 8-week BTP. Balance-training program may contribute to technical skill improvement in soccer training.

20 February 2024 in Sports
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DBDimitrios Bourdas
Dimitrios Bourdas
ATAntonios K. Travlos
Antonios K. Travlos
ASAthanasios Souglis
Athanasios Souglis
DGDimitrios Gkofas
Dimitrios Gkofas
DSDimitrios Stavropoulos
Dimitrios Stavropoulos
PBPanteleimon Bakirtzoglou
Panteleimon Bakirtzoglou
This study investigated the impact of basketball-induced fatigue on 3-point jump shooting accuracy, the ball’s entry angle (EA) into the hoop, shot release time (RT), their relationship with player positions in high-level basketball, and the correlation between cardiorespiratory fitness markers and potential shooting performance changes. Guards (n = 13), forwards (n = 13), and centers (n = 12) underwent physiological assessments. Sequentially, they performed 15 jump shots (PRE), a basketball exercise simulation (BEST) involving 24 × 30 s circuit activities, and a repeated shooting test (POST). The study design was double-blind. The results revealed significant differences (p ≤ 0.05) in RT, EA, and successful shots (SSs) between PRE and POST in each group. The percentage changes from PRE to POST conditions across guards, forwards, and centers were for RT: 25.34% [95%CI: 1.7–48.98], 19.73% [95%CI: −1.9–41.36], 14.95% [95%CI: −5.23–35.13]; for EA: −3.89% [95%CI: −14.82–7.04], −3.13% [95%CI: −12.9–6.64], −3.47% [95%CI: −14.19–7.25]; and for SS: −14.42% [95%CI: −36.5–7.66], −16.76% [95%CI: −40.81–7.29], −19.44% [95%CI: −46.7–7.82], respectively. Post-test differences (p ≤ 0.05) highlighted greater fatigue impact on RT, EA, and SS from guards to centers. Additionally, significant correlations (p ≤ 0.05) were found between the ventilatory threshold, mean HR during BEST, and changes in RT, EA, and SS. This study highlights the substantial impact of basketball-induced fatigue on 3-point shooting parameters across player positions and the interplay with cardiorespiratory factors post-fatigue. Tailored training, considering heart rate, is crucial to optimizing shooting performance.

29 June 2023 in Sports
Verified
Journal Article
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ASAthanasios Souglis
Athanasios Souglis
DBDimitrios Bourdas
Dimitrios Bourdas
AGAristotelis Gioldasis
Aristotelis Gioldasis
IIIoannis Ispirlidis
Ioannis Ispirlidis
Anastassios PhilippouAnastassios Philippou
Anastassios Philippou
ATAntonios K. Travlos
Antonios K. Travlos
Background: Our aims were to investigate the time-course effects of a futsal match on performance, oxidative stress, and muscle damage markers, as well as inflammatory and antioxidant responses during a 6-day post-match period. Methods: Thirty-four female high-level futsal players were assessed on several oxidative stress, inflammation, subjective muscle soreness, subjective rate perceived exertion, and performance tests before a futsal match, immediately after, and 24 h to 144 h after. Results: Counter movement jump, 20 m, and 10 m sprints performance significantly decreased immediately after the match (p < 0.05) and returned to baseline 72 h post-match (p > 0.05). Delayed onset muscle soreness peaked 24 h post-match and rate perceived exertion peaked post-match (p < 0.05) and returned to baseline 96 h post-match (p > 0.05). Inflammatory biomarkers peaked at 24 h (p < 0.05) and remained significantly elevated for 72 h after the match (p < 0.05). Muscle damage biomarkers peaked at 24 h (p < 0.05) and remained significantly (p < 0.05) elevated for at least 72 h after the match. Oxidative stress markers peaked at 24 h–48 h (p < 0.05) and returned to baseline 120 h post-match (p > 0.05). In respect to antioxidant responses, these peaked at 24 h–48 h post-match (p < 0.05) and returned to baseline 120 h after the match (p > 0.05). Conclusions: A single futsal match induces short/mid-term changes in performance, inflammation, oxidative stress, and muscle damage markers for about 72 h–96 h post-match.