Karim Chamari

Karim Chamari
Aspetar - Qatar Orthopaedic and Sports Medicine Hospital | aspetar · Athlete Health and Performance Research Centre

Ph.D.

About

579
Publications
763,238
Reads
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22,030
Citations
Introduction
I grew in a sport environment. Studied sport and physical education (ISSEP ksar-saïd, Tunisia) and then did a Ph.D. in Exercise physiology (Fac Medicine, Montpellier France, Pr Christian Préfaut as tutor. Back in Tunisia, teaching, fitness coaching in professional football, and obviously Research. Now in Doha, Qatar at Aspetar as Research Scientist. Working with ASPREV (Aspetar Sport injury and illness prevention program).
Additional affiliations
April 2013 - October 2020
Aspetar - Qatar Orthopaedic and Sports Medicine Hospital
Position
  • Head of Department
December 2010 - March 2013
Université de la Manouba
Position
  • Professor
January 2005 - March 2013
Institut Supérieur du Sport et de l’Education Physique de Ksar-Said
Position
  • University Teacher
Education
July 1995 - September 2004
Université de la Manouba
Field of study
  • Exercise Physiology
September 1990 - June 1995
Université de Montpellier 1, Faculté de Médecine
Field of study
  • Exercise Physiology

Publications

Publications (579)
Article
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This study aimed to examine the effects of Ramadan on judokas' performances in specific and non-specific tasks performed in the afternoon. Twelve male black belt judokas voluntarily participated in this study. The experimental design consisted of two testing phases: the fourth week of Ramadan (FWR), and five weeks after Ramadan (AR). At each phase,...
Article
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Ramadan intermittent fasting during the COVID-19 lockdown (RIFL) may present unique demands. We investigated training practices (i.e., training load and training times) of athletes, using pre-defined survey criteria/questions, during the ‘first’ COVID-19 lockdown, comparing RIFL to lockdown-alone (LD) in Muslim athletes. Specifically, a within-subj...
Article
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Hamstring injuries constitute the single largest cause of lost playing time in professional football. While restoring high‐speed running ability is paramount for rehabilitation from these injuries, little evidence exists regarding the extent of return to sport running performance after hamstring injury in football. We examined medical and match per...
Article
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To assess the mechanisms of ACL injury in male professional football players in Qatar across multiple seasons using systematic video analysis. 15 ACL injuries occurred in competition among the professional football teams that participated in an injury Surveillance Programme during 6 seasons (2013/2014 to 2018/2019). High-definition broadcast videos...
Article
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Objective Disrupted sleep and training behaviors in athletes have been reported during the COVID-19 pandemic. We aimed at investigating the combined effects of Ramadan observance and COVID-19 related lockdown in Muslim athletes. Methods From an international sample of athletes ( n = 3,911), 1,681 Muslim athletes (from 44 countries; 25.1 ± 8.7 year...
Article
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Objective: Disrupted sleep and training behaviors in athletes have been reported during the COVID-19 pandemic. We aimed at investigating the combined effects of Ramadan observance and COVID-19 related lockdown in Muslim athletes. Methods: From an international sample of athletes (n = 3,911), 1,681 Muslim athletes (from 44 countries; 25.1 ± 8.7 yea...
Article
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Objective: To investigate the effect of 1) lockdown duration and 2) training intensity on sleep quality and insomnia symptoms in elite athletes. Methods: 1,454 elite athletes (24.1 ± 6.7 years; 42% female; 41% individual sports) from 40 countries answered a retrospective, cross-sectional, web-based questionnaire relating to their behavioral habits...
Article
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Objective In a convenience sample of athletes, we conducted a survey of COVID-19-mediated lockdown (termed ‘lockdown’ from this point forward) effects on: (i) circadian rhythms; (ii) sleep; (iii) eating; and (iv) training behaviors. Methods In total, 3911 athletes [mean age: 25.1 (range 18–61) years, 1764 female (45%), 2427 team-sport (63%) and 14...
Article
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The objective of the present study was to investigate the selected performance adaptations of amateur soccer players to 2 different running-based sprint interval training (SIT) protocols with different recovery intervals and work-rest ratios (1:5 & 1:1). Twenty-three subjects (age 21.4±1.1 years; height 175.4±4.7 cm; body mass 69±6.4 kg) participat...
Article
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In hypertonic muscles of patients with upper motor neuron syndrome (UMNS), investigation with surface electromyography (EMG) with the muscle in a shortened position and during passive muscle stretch allows to identify two patterns underlying hypertonia: spasticity and spastic dystonia. We recently observed in Para swimmers that the effect of fatigu...
Article
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Background The second-to-fourth digit ratio (2D:4D) has been calculated for individual athletes and sports, but it has not been investigated in futsal performance. Therefore, the aim of this study was to investigate any relationships between 2D:4D of the dominant and non-dominant hands and physical capacity performances, selected functional variabl...
Article
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Objectives: Explore training-related knowledge, beliefs and practices of athletes and the influence of COVID-19-related lockdowns. Methods: Athletes [n = 12,526 classified: world-class (13%), international (21%), national (36%), state (24%), and recreational (6%)] completed an online survey (50 d; 17th May to 5th July 2020) exploring their trainin...
Article
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Purpose: To survey elite athletes and practitioners to identify (1) knowledge and application of heat acclimation/acclimatization (HA) interventions, (2) barriers to HA application, and (3) nutritional practices supporting HA. Methods: Elite athletes (n = 55) and practitioners (n = 99) completed an online survey. Mann-Whitney U tests (effect siz...
Article
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Objectives This study aims to investigate the impact of combined exercise training on selected health status measures and quality of life in patients with AIDSMaterial and methodsThirty AIDS patients were randomly divided into two groups of combined exercise training on one hand and control on the other. Combined training consisted of aerobic and r...
Article
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Background Metabolomics is a field of omics science that involves the comprehensive measurement of small metabolites in biological samples. It is increasingly being used to study exercise physiology and exercise-associated metabolism. However, the field of exercise metabolomics has not been extensively reviewed or assessed.Objective This review on...
Article
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Background The month of Ramadan will intersect with many football leagues’ schedules over the next decade. Understanding the effects of Ramadan intermittent fasting (RIF) on physical performance is necessary to guide considerations for football players. Objective The aim of this systematic review was to investigate the effects of RIF on physical f...
Article
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The purpose of this study was to examine the effects of non-resisted (NRS) and partner-towing resisted (RS) sprint training on legs explosive force, sprint performance and sprint kinematic parameters. Sixteen young elite soccer players (age 16.6 ± 0.2 years, height 175.6 ± 5.7 cm, and body mass 67.6 ± 8.2 kg) were randomly allocated to two training...
Article
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Drafting in swimming is a tactic in which an athlete (drafter) swims in the wave of another athlete (leader). Our aim was to compare the effects of this tactic on the drafter, as far as muscle fatigue, muscle activity, and swimming efficiency are concerned. Fifteen drafters performed three 200 m front crawl trials at a controlled submaximal pace in...
Article
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The COVID-19 pandemic has impacted the global international sports calendar, causing the first-ever postponement of the 2020 Tokyo Summer Olympic Games (OG) and Paralympic Games (PG) until 2021. Several scientists and sports organisations were strongly opposed to the organisation of these OG and PG. Variable vaccination rates, waning immunity and t...
Article
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Preparation for the FIFA World Cup 2022 (WC2022) comes in the time of the COVID-19 pandemic. This study aims were to (i) provide a brief overview of the 2020 Tokyo Olympic and Paralympic games in the context of the COVID-19 pandemic, and (ii) highlight the potential challenges and opportunities central to the hosting of the FIFA WC2022. The organis...
Article
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The aim of this research was to evaluate the effect of Ramadan observance on dietary intake and body composition in adult athletes. This was a systematic review and meta-analysis. Data sources used were PubMed, Web of Science, Scopus, and Taylor and Francis. Eligibility criteria for selecting studies were as follows: single-group, pre-/post-Ramadan...
Article
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It is well-documented that changes in the rhythm of life during Ramadan affect sleep schedules (i.e., interruption of night sleep patterns) and are likely to have negative effects on physical and cognitive performances. The aim of the present study was to examine the effect of different naps opportunities’ durations during Ramadan on performance of...
Article
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Intermittent fasting (IF) is an increasingly popular dietary practice, and its implementation is found throughout human civilisation in various cultural, spiritual and religious traditions. Emerging evidence has shown that the health benefits of IF stretch beyond calorie restriction and weight loss. These benefits include metabolic shifts in energy...
Article
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Carbohydrate mouth-rinsing has been reported to benefit endurance performance in athletes intermittently fasting; however, in the fasted state, the effects of combined caffeine and carbohydrate (CAF-CHO) mouth-rinsing on sprint-endurance performance are unknown. We determined the effects of CAF-CHO mouth-rinsing on kinetics, kinematics, and percept...
Article
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Introduction Physeal injuries have been overlooked in epidemiological research in youth sports. Our prospective study investigated the incidence, severity, and burden of physeal injuries in a youth elite football academy. Methods 551 youth male football players from Under-9 to Under-19 were included and observed over four consecutive seasons. Inju...
Article
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The COVID-19 pandemic has affected the lifestyles and training of elite athletes around the world. The detrimental effects of lockdown periods may vary among individuals, as well as among sports and sexes. This study investigated the changes in dietary habits, and the predictors of perceived stress during lockdown and a “bubble” training camp. This...
Article
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To investigate the effect of 20 min nap opportunity (N20), 5 mg · kg-1 of caffeine (CAF) and their combination (CAF+N20) on the biochemical response (energetic biomarkers, biomarkers of muscle damage and enzymatic antioxidants) to the running-based anaerobic sprint test. Fourteen highly trained male athletes completed in a double-blind, counterbala...
Article
This study aimed at comparing the efficiency of two viewing control strategies, total control versus partial control, in correcting the snatch technique in school-aged boys (10–12 years old). Thirty-nine participants, with 2 months of weightlifting training experience, were divided into three groups: total control, partial control, or a control gro...
Article
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Study the effect of Adipose derived stromal cells (ASCs) injection as therapeutic procedure on the common extensor tendinopathy. Eighteen Tennis players with chronic, recalcitrant LET (who have previously been unsuccessfully treated with nonoperative treatments) underwent clinical evaluation and magnetic resonance imaging (MRI) before intervention....
Conference Paper
Background While effective programmes to prevent anterior cruciate ligament (ACL) injury have been established, it is important that programme design, consistent with the van Mechelen model, is based on the specific injury mechanisms, representative of the region and playing conditions. Presently, no such data exist for professional football player...
Conference Paper
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Background Adolescent athletes have different injury patterns to those of adults, and their growing bones are susceptible to overuse injuries. Evidence of growth-related injuries in relation to growth and maturation in youth elite soccer players remains sparse. Objective 1) to investigate lower-limb apophyseal injuries (LL-AI) and 2) their relatio...
Research Proposal
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Dear students We would like to kindly ask you to do your best to answer all questions, if possible, because this will allow us to anonymously process and analyze the data, and thus, improve the knowledge in the field. The estimated time to complete the survey is of about 20 minutes English: https://forms.gle/hDNwU8bYmS2HbESC7 Arabic: https://...
Article
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Background Muslims around the world practice intermittent fasting during the month of Ramadan each year. We hypothesized that daily physical activity could be reduced among Muslims due to the inability to refuel and rehydrate in the fasting state. Methods A cohort study design among adults registered with national physical activity community progr...
Article
The purpose of this systematic review and meta‐analysis is to provide an accurate description of the effect of Ramadan observance on sleep duration, sleep quality, daily nap duration, and daytime sleepiness in athletes and physically active individuals. Five electronic databases (PubMed, Web of Science, Scopus, Wiley, and Taylor and Francis) were u...
Article
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Prolonged exercise induces cardiovascular drift, which is characterized by decreasing mean arterial pressure (MAP), stroke volume and heart rate increase. Cardiovascular drift has been debated for a long time. Although the exact mechanisms underlying cardiovascular drift are still unknown, two theories have been proposed. The first is that increase...
Article
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Parental vaccine hesitancy (VH) remains a barrier to full population inoculation, hence herd immunity against the SARS-CoV-2 virus. We aimed to determine parental VH rate, subgroups and influencing factors related to the BNT162b2 COVID-19 vaccine among their young adolescents (12–15 years old) in Qatar. A retrospective, cross-sectional study was co...
Article
This study aimed to determine if sleep quality and psychological factors were associated with time to meet the discharge criteria to return to sport (RTS) following anterior cruciate ligament reconstruction (ACL-R) among athletes. A cohort-study design included 89 athletes following ACL-R. Each participant completed a battery of questionnaires at 6...
Article
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Purpose: To investigate the effects of placebo (PLA), 20 min nap opportunity (N20), 5mg·kg ⁻¹ of caffeine (CAF), and their combination (CAF+N20) on sleepiness, mood and reaction-time after partial sleep deprivation (PSD; 04h30 of time in bed; study 1 ) or after normal sleep night (NSN; 08h30 of time in bed; study 2 ). Methods: Twenty-three highly t...
Article
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Intermittent fasting (IF) has recently gained popularity, and has been used for centuries in many religious practices. The Ramadan fasting is a mandatory form of IF practiced by millions of healthy adult Muslims globally for a whole lunar month every year. In Islam, the “Sunna” also encourages Muslims to practice IF all along the year (e.g.; two da...
Article
Individual Effect Of Post-Activation Performance Enhancement After A Re-Warm-Up: Statistically Not Significant But Clinically Meaningful. Monoem Haddad1, Zied Abbes1, Montassar Tabben2, Khalid W Bibi1, Cyril Martin3, Karim Chamari2. 1Qatar University, Doha, Qatar. 2ASPETAR, Doha, Qatar. 3University of Lyon – University Claude Bernard Lyon 1, Lyon,...
Article
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Purpose: Effect of ultrasound guided injections of autologous ASCs in chronic recalcitrant patellar tendinopathy. Methods: Fourteen patients (16 knees, 12/2 males/females) with chronic, recalcitrant (unsuccessfully treated with nonoperative treatments) insertional PT underwent clinical evaluation and magnetic resonance imaging (MRI) before inter...
Article
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Background: We assessed SARS CoV2 contamination of random surfaces in football training facilities in an environment with a high prevalence of infections. Methods: In six clubs of the Qatar Stars League, surfaces of random locations (high touch areas, ventilation systems, toilets, cleaning tools, freezers, pantries) in routinely cleaned training fa...
Article
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The combined effect of Ramadan fasting and the time of theday on the physical performance of team-handball players has not yet been fully investigated. This study investigated the effects of Ramadan fasting on the morning–evening difference in team-handball-related short-term maximal physical performance. With acounterbalanced study design, 15 elit...
Article
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Purpose: To survey soccer practitioners' recovery strategy: (1) use, (2) perceived effectiveness, and (3) factors influencing their implementation in professional soccer. Methods: A cross-sectional convenience sample of professional soccer club/confederation practitioners completed a web-based survey (April to July 2020). Pearson chi-square and...
Article
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Purpose: The current study compared metabolic profiles and movement patterns between different player positions and explored relationships between indicators of internal and external loads during elite male basketball games. Methods: Five main players from 14 basketball teams ( n = 70) were selected as subjects and defined as backcourt (positions 1...
Article
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The novel pandemic called “Coronavirus Disease 2019” (COVID-19), as a global public health emergency and global threat, has affected many countries in unpredictable ways and impacted on physical activity (PA) behaviors to various extents. Specific populations including refugees, asylum seekers, and prisoners, are vulnerable groups with multiple com...
Article
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The COVID-19 pandemic has had severe effects on communities globally, leading to significant restrictions on all aspects of society, including in sports. Several significant decisions were made to postpone or cancel major swimming events by FINA (Fédération Internationale de Natation). Swimmers were no longer allowed to continue their usual trainin...
Experiment Findings
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1.1 Objectives and Purpose of the Guideline The primary aim of this guideline is to define the appropriate management of healthy, adolescent and adult athletes, who are exercising during the month of Ramadan. The objective is to enhance the prescription of appropriate exercise guidelines during the holy month of Ramadan. The second aim is to follo...
Article
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Background: The COVID-19 lockdown could engender disruption to lifestyle behaviors, thus impairing mental wellbeing in the general population. This study investigated whether sociodemographic variables, changes in physical activity, and sleep quality from pre- to during lockdown were predictors of change in mental wellbeing in quarantined older ad...
Article
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The aim of the present study was to analyse the influence of congested periods of matches on the acceleration (Acc) and deceleration (Dec) profiles of elite soccer players. Twenty-three elite male professional soccer players participated in the study across 31 official matches. Assessed periods included: (i) congested periods (three to four days be...
Article
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Adiponectin (a protein consisting of 244 amino acids and characterized by a molecular weight of 28 kDa) is a cytokine that is secreted from adipose tissues (adipokine). Available evidence suggests that adiponectin is involved in a variety of physiological functions, molecular and cellular events, including lipid metabolism, energy regulation, immun...