Hamdi Chtourou

Dr. Hamdi Chtourou

High Institute of Sport and Physical Education of Sfax, University of Sfax, Tunisia
orcid

Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

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

Representative Publications

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28 May 2020 in Nutrients
Verified
Journal Article
Open access
PDF file
Achraf AmmarAchraf Ammar
Achraf Ammar
MBMichael Brach
Michael Brach
Khaled TrabelsiKhaled Trabelsi
Khaled Trabelsi
HCHamdi Chtourou
Hamdi Chtourou
Omar BoukhrisOmar Boukhris
Omar Boukhris
OCOn Behalf of the ECLB-COVID19 Consortium
On Behalf of the ECLB-COVID19 Consortium
Background: Public health recommendations and governmental measures during the COVID-19 pandemic have resulted in numerous restrictions on daily living including social distancing, isolation and home confinement. While these measures are imperative to abate the spreading of COVID-19, the impact of these restrictions on health behaviours and lifestyles at home is undefined. Therefore, an international online survey was launched in April 2020, in seven languages, to elucidate the behavioural and lifestyle consequences of COVID-19 restrictions. This report presents the results from the first thousand responders on physical activity (PA) and nutrition behaviours. Methods: Following a structured review of the literature, the “Effects of home Confinement on multiple Lifestyle Behaviours during the COVID-19 outbreak (ECLB-COVID19)” Electronic survey was designed by a steering group of multidisciplinary scientists and academics. The survey was uploaded and shared on the Google online survey platform. Thirty-five research organisations from Europe, North-Africa, Western Asia and the Americas promoted the survey in English, German, French, Arabic, Spanish, Portuguese and Slovenian languages. Questions were presented in a differential format, with questions related to responses “before” and “during” confinement conditions. Results: 1047 replies (54% women) from Asia (36%), Africa (40%), Europe (21%) and other (3%) were included in the analysis. The COVID-19 home confinement had a negative effect on all PA intensity levels (vigorous, moderate, walking and overall). Additionally, daily sitting time increased from 5 to 8 h per day. Food consumption and meal patterns (the type of food, eating out of control, snacks between meals, number of main meals) were more unhealthy during confinement, with only alcohol binge drinking decreasing significantly. Conclusion: While isolation is a necessary measure to protect public health, results indicate that it alters physical activity and eating behaviours in a health compromising direction. A more detailed analysis of survey data will allow for a segregation of these responses in different age groups, countries and other subgroups, which will help develop interventions to mitigate the negative lifestyle behaviours that have manifested during the COVID-19 confinement.

Achraf AmmarAchraf Ammar
Achraf Ammar
HCHamdi Chtourou
Hamdi Chtourou
Omar BoukhrisOmar Boukhris
Omar Boukhris
Khaled TrabelsiKhaled Trabelsi
Khaled Trabelsi
LMLiwa Masmoudi
Liwa Masmoudi
Leonardo Jose Mataruna-Dos-SantosLeonardo Jose Mataruna-Dos-Santos
Leonardo Jose Mataruna-Dos-Santos
Public health recommendations and governmental measures during the new coronavirusdisease (COVID-19) pandemic have enforced numerous restrictions on daily living including socialdistancing, isolation, and home confinement. While these measures are imperative to mitigatespreading of COVID-19, the impact of these restrictions on psychosocial health is undefined. Therefore,an international online survey was launched in April 2020 to elucidate the behavioral and lifestyleconsequences of COVID-19 restrictions. This report presents the preliminary results from more thanone thousand responders on social participation and life satisfaction. Methods: Thirty-five researchorganizations from Europe, North-Africa, Western Asia, and the Americas promoted the surveythrough their networks to the general society, in 7 languages (English, German, French, Arabic,Spanish, Portuguese, and Slovenian). Questions were presented in a differential format with questionsrelated to responses “before” and “during” confinement conditions. Results: 1047 participations(54% women) from Asia (36%), Africa (40%), Europe (21%), and others (3%) were included in theanalysis. Findings revealed psychosocial strain during the enforced COVID-19 home confinement.Large decreases (p<0.001) in the amount of social activity through family (−58%), friends/neighbors(−44.9%), or entertainment (−46.7%) were triggered by the enforced confinement. These negativeeffects on social participation were also associated with lower life satisfaction (−30.5%) during theconfinement period. Conversely, the social contact score through digital technologies significantlyincreased (p<0.001) during the confinement period with more individuals (+24.8%) being sociallyconnected through digital technology. Conclusion: These preliminary findings elucidate the riskof psychosocial strain during the early COVID-19 home confinement period in 2020. Therefore,in order to mitigate the negative psychosocial effects of home confinement, implementation ofnational strategies focused on promoting social inclusion through a technology-based solution isstrongly suggested.

1 July 2012 in Journal of Strength & Conditioning Research
Verified
Journal Article
Closed access
HCHamdi Chtourou
Hamdi Chtourou
NSNizar Souissi
Nizar Souissi
Chtourou, H and Souissi, N. The effect of training at a specific time of day: A review. J Strength Cond Res 26(7): 1984–2005, 2012—This article focuses on physical performances after training at a specific time of day. To date, although the effect of time of day on aerobic performances appears to be equivocal, during anaerobic exercises, the effect of time of day has been well established with early morning nadirs and peak performances in the late afternoon. These diurnal rhythms can be influenced by several factors such as the regular training at a specific time of day. Indeed, regular training in the morning hours may increase the lower morning performances to the same or even higher level as their normal diurnal peak typically observed in the late afternoon by a greater increase of performance in the evening. However, regular training in the evening hours may increase the morning-evening (i.e., amplitude of the rhythm) difference by a greater increase of performance in the late afternoon. Therefore, adaptations to training are greater at the time of day at which training is regularly performed than at other times. Nevertheless, although modifications in resting hormones concentrations could explain this time-of-day specific adaptations, precise information on the underlying mechanisms is lacking.

1 December 2014 in Journal of Strength & Conditioning Research
Verified
Journal Article
Closed access
JHJamel Halouani
Jamel Halouani
HCHamdi Chtourou
Hamdi Chtourou
TGTim Gabbett
Tim Gabbett
ACAnis Chaouachi
Anis Chaouachi
KCKarim Chamari
Karim Chamari
Small-sided games (SSGs) incorporating skills, sport-specific movements, at intensities sufficient to promote aerobic adaptations, are being increasingly implemented in professional team sport environments. Small-sided games are often employed by coaches based on the premise that the greatest training benefits occur when training simulates the specific movement patterns and physiological demands of the sport. At present, there is relatively little information regarding how SSG can best be used to improve physical capacities and technical and tactical skills in team sports. It is possible that with some modifications (e.g., number of players, pitch size, coach encouragement, and wrestling), such games may be physiologically beneficial for athletes with relatively high initial aerobic fitness levels. For instance, it has been shown that 3-a-side soccer SSG resulted in higher intensity (i.e., greater overall distance, less jogging and walking, higher heart rate, and more tackling, dribbling, goal attempts, and passes) than 5-a-side SSG. Likewise, when player numbers were kept constant, a larger playing area increased the intensity of the SSG with a smaller playing area having the opposite effect. It has also been demonstrated that energy expenditure was similar between badminton and volleyball courts, but lower than that obtained in a basketball court. Moreover, it has been demonstrated in rugby that wrestling can increase the physical demands of SSG. Consistent coach encouragement can also increase training intensity, although most rule changes have trivial or no effect on exercise intensity. Further research is required to examine the optimal periodization strategies of SSG training for the long-term development of physiological capacity, technical skill, and tactical proficiency, while also minimizing the associated risk of injuries.

EBEllen Bentlage
Ellen Bentlage
Achraf AmmarAchraf Ammar
Achraf Ammar
Daniella HowDaniella How
Daniella How
MAMona Ahmed
Mona Ahmed
Khaled TrabelsiKhaled Trabelsi
Khaled Trabelsi
MBMichael Brach
Michael Brach
Diminished volumes of habitual physical activity and increased sedentary levels have been observed as a result of COVID-19 home-confinement. Consequences of inactivity, including a higher mortality rate and poorer general health and fitness, have been reported. This systematic review aimed to provide practical recommendations for maintaining active lifestyles during pandemics. In May 2020, two electronic databases (PubMed; Web of Science) were used to search for relevant studies. A total of 1206 records were screened by two researchers. Thirty-one relevant studies were included in this systematic review, in which the methodological quality was assessed. With regard to six studies, which explicitly dealt with physical activity during COVID-19, the evidence level is classified by three articles to level II, and in the other three to level VI. Regarding the physical activity recommendations in these papers, three of them were classified to a medium, and the same number to a weak evidence base. Of the 25 papers which refer to other pandemics and/or isolation situations, one was classified to evidence level I, four were ranged to level II, three to level III, one to level V, and the others to level VI. This systematic review revealed that reduced physical activity levels are of serious concern during home confinement in pandemic times. The recommendations provided by many international organizations to maintain active lifestyles during these times mainly target the general population, with less consideration for vulnerable populations (e.g., older adults, people with health issues). Therefore, personalized and supervised physical activity programs are urgently needed, with the option to group-play physical activity programs (e.g., exergames). These can be assisted, delivered, and disseminated worldwide through information and communication technology solutions. If it is permitted and safe, being active outside in daylight is advised, with an effort level of mild to moderate using the rating of perceived exertion scale. Relaxation techniques should be integrated into the daily routine to reduce stress levels. On the evidence base and levels of the included articles in this review, the results need to be interpreted with caution. Given that policies are different across regions and countries, further research is needed to categorize recommendations according to different social-distancing scenarios.

27 July 2018 in Frontiers in Physiology
Verified
Journal Article
Open access
PDF file
FEFlorian Engel
Florian Engel
AAAlexander Ackermann
Alexander Ackermann
HCHamdi Chtourou
Hamdi Chtourou
BSBilly Sperlich
Billy Sperlich
Background: High-intensity interval training (HIIT) is as a time-efficient alternative to moderate- or low-intensity continuous exercise for improving variables related to endurance and anaerobic performance in young and adolescent athletes. Objectives: To assess original research about enhancement of endurance and anaerobic exercise performance in young and adolescent athletes performing HIIT. Method: Relevant articles published in peer-reviewed journals were retrieved from the electronic databases PubMed and SPORTDiscus in December 2017. Inclusion criteria were: (i) controlled trials (HIIT vs. alternative training protocol) with pre-post design; (ii) healthy young athletes (≤18 years); (iii) assessing variables related to endurance and exercise performance. Hedges' g effect size (ES), and associated 95% confidence intervals were calculated for comparison of any outcome between experimental (HIIT) and alternative training protocol. Results: Twenty four studies, involving 577 athletes (mean age: 15.5 ± 2.2 years), were included in this review. HIIT exerted no or small positive mean ES on peak oxygen uptake (VO2peak), running performance, repeated sprint ability, jumping performance and submaximal heart rate. Although the mean ES for changes in VO2peak with HIIT is small (mean g = 0.10±0.28), the average increase in VO2peak from pre to post HIIT-interventions were 7.2 ± 6.9% vs. 4.3 ± 6.9% with any other alternative intervention. HIIT largely and positively affected running speed and oxygen consumption at various lactate- or ventilatory-based thresholds, as well as for sprint running performance. Calculations showed negative mean ES for change-of-direction ability (large), and peak blood lactate concentrations (small). Mean duration per training session for HIIT was shorter than for control interventions (28 ± 15 min vs. 38 ± 24 min). Conclusion: The present findings suggest that young athletes performing HIIT may improve certain important variables related to aerobic, as well as anaerobic, performance. With HIIT, most variables related to endurance improved to a higher extent, compared to alternative training protocols. However, based on ES, HIIT did not show clear superiority to the alternative training protocols. Nevertheless, young athletes may benefit from HIIT as it requires less time per training session leaving more time for training sport specific skills.