Achraf Ammar

Achraf Ammar
Johannes Gutenberg-Universität Mainz | JGU · Institute of Sports Science

Doctor of Sports Science
Post-doctoral researcher

About

136
Publications
86,664
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Introduction
Achraf Ammar doctor of Sports Science. Achraf does research in Nutritional Biochemistry, Sports Medicine and Physiology and biomechanics. Their current projects are "Effects of Home Confinement on Multiple Lifestyle Behaviours During the COVID-19 Outbreak (ECLB-COVID19)", ''Pomegranate juice and physical exercise', Polyphenols and brain health', 'Kinetic and Kinematic analysis of Olympic Clean and Jerk Movement in elite weightlifters.'
Additional affiliations
October 2013 - December 2015
Otto-von-Guericke-Universität Magdeburg
Position
  • Researcher

Publications

Publications (136)
Article
Full-text available
The effect of 40-min nap (NAP) opportunity on psycho-physiological outcomes and technical performance during small-sided basketball game (SSG) was examined in ten professional basketball players. Nocturnal sleep and naps were monitored by actigraphic recording and sleep diaries. Nocturnal total sleep time (TST), time in bed (TIB), sleep efficiency...
Article
Full-text available
This study examined the effects of a six-week preparatory training program on physical performance and physiological adaptations in junior soccer players. Additionally, we investigated whether a relationship existed between external and internal loads. Youth soccer players (aged 16 years old) from a youth football academy participated in six weeks...
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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Purpose: To investigate differences in athletes' knowledge, beliefs, and training practices during COVID-19 lockdowns with reference to sport classification and sex. This work extends an initial descriptive evaluation focusing on athlete classification. Methods: Athletes (12,526; 66% male; 142 countries) completed an online survey (May-July 2020...
Article
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Post-COVID19 patients suffer from persistent respiratory, cardiovascular, neurological, and musculoskeletal health complaints such as dyspnea, chest pain/ discomfort, and fatigue. In Tunisia, the potential benefits of a cardiorespiratory rehabilitation program (CRRP) after COVID19 remain unclear. The main aim of this study was to evaluate the impac...
Preprint
Full-text available
Religious fasting is practiced by people of all faiths, including Christianity, Islam, Buddhism, Jainism, as well as Hinduism, Judaism, and Taoism. Individual/clinical, public, global, and planetary health has traditionally been studied as separate entities. Nevertheless, religious fasting, in conjunction with other religious health assets, can pro...
Article
As laterality of the lower limbs is regarded as a relevant influence on soccer performance, we assessed whether a bilateral training program for both the preferred leg (PL) and non-preferred leg (NPL) would improve soccer players’ lateral asymmetry, agility, and accuracy. Sixty right-foot-dominant young soccer players were randomly assigned to eith...
Article
Systematic reviews and meta-analyses examining the effects of Ramadan observance on athletes’ mood states are lacking. Thus, this systematic review and meta-analysis aimed to identify the impact of Ramadan observance on athletes’ mood states assessed using validated scales. Six electronic databases (PubMed, Web of Science, Scopus, Wiley, Taylor & F...
Article
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Older adults with amnestic mild cognitive impairment (aMCI) who in addition to their memory deficits also suffer from frontal-executive dysfunctions have a higher risk of developing dementia later in their lives than older adults with aMCI without executive deficits and older adults with non-amnestic MCI (naMCI). Handgrip strength (HGS) is also cor...
Article
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The COVID-19 outbreak resulted in the shutdown of athletic training facilities. Although the effects of these restrictions on daily activity and sleep patterns have been widely analyzed, the employed tools often lacked accuracy, and were based on subjective measures. This study assessed the effects of home confinement on objective physical activity...
Article
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Although the effects of caffeine supplementation on combat sports performance have been extensively investigated, there is currently no consensus regarding its ergogenic benefits.This systematic review with meta-analysis aimed to summarize the studies investigating the effects of caffeine supplementation on different aspects of performance in comba...
Article
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The human microbiota is comprised of more than 10-100 trillion microbial taxa and symbiotic cells. Two major human sites that are host to microbial communities are the gut and the skin. Physical exercise has favorable effects on the structure of human microbiota and metabolite production in sedentary subjects. Recently, the concept of “athletic mic...
Article
Background: There has been increasing evidence and support for the use of digital technology in the cognitive health field. Despite the growing use of innovative digital technology to assess cognitive function, such technology remains scarce in Arabic countries, particularly in Tunisia. Objective: To investigate the effectiveness of a digitally...
Article
Full-text available
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
Full-text available
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
Full-text available
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
This study aimed to examine the impact of 40-min and 90-min naps on performance in the 5-m shuttle run test (5mSRT) and on various physiological and perceptual measures. Sixteen male athletes (20 ± 3 years, 173 ± 7 cm, 67 ± 7 kg) performed the 5mSRT after a 40-min nap (N40), after a 90-min nap (N90), and in a no-nap, control condition (N0). The 5mS...
Article
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This study aimed to investigate the effect of a walking football (WF) program during Ramadan fasting (RF) on heart rate variability (HRV) indices, body composition, and physical fitness in middle-aged males. Thirty-one healthy sedentary men were randomized to WF ( n = 18) and control ( n = 13) groups. Both groups participated in RF. The WF group we...
Article
Full-text available
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...
Conference Paper
Objectif Les sportifs souffrent du manque de sommeil de façon chronique. L’objectif de cette revue systématique était d’évaluer l’efficacité des opportunités de sieste diurne sur les performances physiques et cognitives des sportifs. Méthodes Conformément aux recommandations pour les revues systématiques et les méta-analyses (PRISMA), les bases de...
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
Full-text available
Older adults with amnestic mild cognitive impairment (aMCI) who in addition to their memory deficits also suffer from frontal-executive dysfunctions have a higher risk of developing dementia later in their lives than older adults with aMCI without executive deficits and older adults with non-amnestic MCI (naMCI). Handgrip strength (HGS) is also cor...
Article
Full-text available
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
IntroductionNitric oxide (NO) is a vasodilator that plays an important role in blood pressure control. The purpose of the present study was to compare the effect of 8 weeks of resistance-interval and endurance-resistance trainings on plasma levels of adropin and NO in males with hypertension.Method Forty-five patients with hypertension were recruit...
Article
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This study examined the effect of time of day (TOD) on physical performance, and physiological and perceptual responses to a 10-km cycling time trial (TT10km). Twelve physically trained subjects (20.3 ± 1.2 years, 74.3 ± 7.4 kg, 179.7 ± 5.5 cm) completed, in a randomized order, a TT10km in the morning and in the evening. Intra-aural temperature (IA...
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
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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Sleep problems can be caused by psychological stress but are also related to cardiovascular and neurodegenerative diseases. Improving lifestyle behaviors, such as good sleep hygiene, can help to counteract the negative effects of neurodegenerative diseases and to improve quality of life. The purpose of this cross-sectional study was to investigate...
Conference Paper
Introduction: Athletes often experience chronic sleep disturbance. Napping is widely recommended as a safe and non-invasive intervention to counteract the negative effects of partial sleep deprivation. The aim of this systematic review was to evaluate the effectiveness of diurnal napping opportunities on athletes physical and cognitive performance,...
Article
The purpose of this study was to examine the effect of a 40-min nap opportunity (N40) on performance during, markers of muscle damage and inflammation, and the perception of fatigue and recovery, in response to a 5-m shuttle run test (5msrt). Fifteen male amateur athletes performed the 5msrt under two conditions: N40 and no-nap condition (NN). Bloo...
Article
Full-text available
Although napping is commonly used as a strategy to improve numerous physical and cognitive performances, the efficacy of this strategy for improving postural balance has not yet been elucidated. Thus, the aim of this study was to conduct a comprehensive examination of the effect of a 60min nap opportunity (N60) on different components of postural c...
Article
Full-text available
Objective: (i) To evaluate the effectiveness of diurnal napping opportunities on athletes’ physical and cognitive performance and (ii) to outline how aspects of the study design (i.e., nap duration, exercise protocol, participants’ fitness level and previous sleep quantity) can influence the potential effects of napping through a systematic apprais...
Article
Full-text available
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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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
Full-text available
The aim of the present study is to evaluate the effect of Ramadan observance (RAM) on decision-making in Kung-Fu athletes. Fourteen male Kung-Fu athletes (mean age = 19 ± 3 years) completed two test sessions: before Ramadan (BR) and at the end of Ramadan (ER). In the afternoon of each session (between 16:00 h and 18:00 h), participants completed: E...
Article
Objectives The objectives of this study were to evaluate the duration and the quality of sleep, as well as daytime sleepiness, among different levels of Arab athletes (i.e., amateur, elite) and to compare sleep quality and duration and daytime sleepiness in athletes and sedentary individuals. Material and methods A total of 409 participants, chara...
Article
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The specifics of short-term physical exercise are similar to the immediate reaction demands placed on police officers. Identifying the physiological predisposition to short-term high-intensity exercise in male law enforcement officers will assist in understanding their metabolism and make a significant contribution to a much more personal and indiv...
Article
The aim of the present study was to evaluate the impact of Ramadan fasting on sleep quality and daytime sleepiness in team sport referees. Seventy-eight male amateur team sport referees (age: 31.1 ± 10.8 years) participated in this study. Participants responded to the Arabic version of the Pittsburgh Sleep Quality Index (PSQI) and the Epworth sleep...
Article
Full-text available
Physical training is considered as a low-cost intervention to generate cardioprotective benefits and to promote physical and mental health, while reducing the severity of acute respiratory in-fection symptoms in older adults. However, lockdown measures during COVID-19 have limited people’s opportunity to exercise regularly. The aim of this study wa...
Data
Figure S1: Individual responsiveness scores to 8 weeks Dance-training training program, Figure S2. Individual responsiveness scores to 4 weeks Covid-19 induced detraining
Article
The effect of a 40-min nap opportunity was investigated during the day following a late evening simulated soccer match. Twelve male amateur soccer players (23 ± 3 years; 77.3 ± 5.3 kg; 1.76 ± 0.04 m) performed the Loughborough-intermittent-shuttle test at 21h00 and the following day they completed the sleepiness scale after either a nonap (N0) or 4...
Article
Full-text available
BACKGROUND The impact of intermittent circadian fasting (ICF) on skin disorders is far to be plenty deciphered. However, the circadian rhythm seems to exert a modulation on dermatoses severity, drug‐response and drug‐related side effects. OBJECTIVES To evaluate ICF effect in the daily management of dermatoses. METHODS In this multicenter, prospec...
Article
Full-text available
Our aim in this study was to examine, via technical performance analysis and speed of execution, whether information processing and technical knowledge help explain learning benefits of self-controlled video feedback in children’s weightlifting performance. We randomized 24 children (aged 10 to 12 years) into self-controlled (SC) and yoked (YK) fee...
Article
Full-text available
Changes and relationships between cycling performance indicators following a one-year strength and conditioning training have not been totally clarified. The aims of this study are to investigate (i) the effect of a combined strength and conditioning training programme on performance indicators and the possible relationships between these indicator...
Article
Full-text available
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
Several studies report sleep deprivation negatively impacts post-cognitive and physical performance, and other functions. Recent findings indicate ingestion of melatonin prior to exercise enhances tolerance to training and improves competition. We investigated the effects of melatonin supplementation on psychomotor performance and selected physical...
Article
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Objectives: Changes in hematological parameters are becoming evident as important early markers of COVID-19. Type 2 Diabetes Mellitus (T2DM) has been shown to be associated with increased severity of COVID-19. In this study, we aim to explore the various hematological variables in COVID-19 positive patients with T2DM, so as to act early and improve...
Article
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The purpose of the present study was to investigate which of two strategies, Video Feedback with Pedagogical Activity (VF-PA) or Video Feedback (VF), would be more beneficial for the remote error correction of the snatch weightlifting technique during the confinement period. Thirty-five school aged children with at least three months of weightlifti...
Article
Full-text available
COVID-19 home confinement has led to a stressful situation for children around the world and affected their lifestyle. The present study aimed to investigate the effect of these restrictions on sleep quality, screen time (ST) and physical activity (PA) in Tunisian children with a special focus on gender differences. An online survey was launched in...
Article
Full-text available
(1) Background: The COVID-19 pandemic forced people from all around the globe to strongly modify their daily routines, putting a significant strain on the social aspects of daily lives. While the first wave of the pandemic was a very challenging time in all countries, it is still uncertain whether various lockdown intensities and infection rates di...
Article
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Drowsiness detection (DD) has become a relevant area of active research in biomedical signal processing. Recently, various deep learning (DL) researches based on the EEG signals have been proposed to detect fatigue conditions. The research presented in this paper proposes an EEG classification system for DD based on DL networks. However, the propos...
Article
Objectif Examiner l’effet de la privation partielle de sommeil (PPS) en début et en fin de nuit sur les fluctuations diurnes des réponses psycho-cognitives chez des coureurs de demi-fond. Méthodes Vingt-huit coureurs de demi-fond (21,1 ± 1,6 ans, 69,8 ± 4,5 kg, 174,3 ± 3,9 cm) ont réalisé volontairement, d’une manière randomisée, deux sessions exp...
Article
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on December 31, 2019 first case of an unex-plained low respiratory infection detected in Wuhan (China) was reported to the WHO Country Office in China. The WHO Director Dr. Tedros Adhanom Ghebreyesus, announced that the disease caused by a new coronavirus (CoV), called “COVID-19”, which is the acronym of “coronavirus disease 2019”. (PDF) COVID-19...
Article
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AimsThe study investigated the influence of hydrotherapy method–based McKenzie and Williams among patients with non-specific low back pain (NSLBP).Methods Semi-experimental pretest-posttest with a control group design trial was conducted at Health Service Center, Qazvin, Iran. Twenty-eight NSLBP patients (16 men and 12 women, age: 42.5 ± 7 years) w...
Article
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Symptoms of psychological distress and disorder have been widely reported in people under quarantine during the COVID-19 pandemic; in addition to severe disruption of peoples' daily activity and sleep patterns. This study investigates the association between physical-activity levels and sleep patterns in quarantined individuals. An international Go...
Article
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Background: Maximal strength-speed exercise is a powerful stimulus to acutely increase concentrations of circulating steroid hormones and homocysteine [Hcy]. There is some evidence that antioxidant beverages rich in polyphenols can attenuate [Hcy] levels and modulate endocrine responses in favor of an anabolic environment. Polyphenols-rich pomegra...
Article
Full-text available
Background Public health recommendations and government measures during the COVID-19 pandemic have enforced restrictions on daily-living. While these measures are imperative to abate the spreading of COVID-19, the impact of these restrictions on mental health and emotional wellbeing is undefined. Therefore, an international online survey (ECLB-COVI...
Article
We investigated the effect of exergames and aquatic exercises on lung function and weight-loss in obese children. Sixty-one obese male primary school children were randomly allocated to video game, aquatic exercise and control groups. Lung functions and anthropometric variables were measured before and after the intervention and after one month (fo...