Showing papers by "Karim Chamari published in 2020"
University of Sfax1, University of Münster2, German Center for Neurodegenerative Diseases3, Otto-von-Guericke University Magdeburg4, University of Gafsa5, Rio de Janeiro State University6, University of Twente7, Catholic University of the Sacred Heart8, Estácio S.A.9, American University in the Emirates10, Imam Khomeini International University11, University of Paris12, University of Genoa13, University of Arkansas14, Stanford University15, University of Toulouse16, Assiut University17, Karlsruhe Institute of Technology18, Georgia Southern University19, Government of Extremadura20, University Medical Center Groningen21, University of Ulm22, Yarmouk University23, University of Jordan24, University of Porto25, Loughborough University26, Paris West University Nanterre La Défense27
TL;DR: Results indicate that isolation is a necessary measure to protect public health, but results indicate that it alters physical activity and eating behaviours in a health compromising direction.
Abstract: 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.
1,275 citations
Norwegian School of Sport Sciences1, Stellenbosch University2, University of Calgary3, Edith Cowan University4, Linköping University5, University of British Columbia6, University of North Carolina at Chapel Hill7, McMaster University8, University of Sydney9, Wellington Management Company10, University of Chicago11, University of Pretoria12, International Olympic Committee13, University of Bath14
TL;DR: The objective was to further strengthen consistency in data collection, injury definitions and research reporting through an updated set of recommendations for sports injury and illness studies, including a new Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist extension.
Abstract: Injury and illness surveillance, and epidemiological studies, are fundamental elements of concerted efforts to protect the health of the athlete. To encourage consistency in the definitions and methodology used, and to enable data across studies to be compared, research groups have published 11 sport-specific or setting-specific consensus statements on sports injury (and, eventually, illness) epidemiology to date. Our objective was to further strengthen consistency in data collection, injury definitions and research reporting through an updated set of recommendations for sports injury and illness studies, including a new Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist extension. The IOC invited a working group of international experts to review relevant literature and provide recommendations. The procedure included an open online survey, several stages of text drafting and consultation by working groups and a 3-day consensus meeting in October 2019. This statement includes recommendations for data collection and research reporting covering key components: defining and classifying health problems; severity of health problems; capturing and reporting athlete exposure; expressing risk; burden of health problems; study population characteristics and data collection methods. Based on these, we also developed a new reporting guideline as a STROBE Extension-the STROBE Sports Injury and Illness Surveillance (STROBE-SIIS). The IOC encourages ongoing in- and out-of-competition surveillance programmes and studies to describe injury and illness trends and patterns, understand their causes and develop measures to protect the health of the athlete. Implementation of the methods outlined in this statement will advance consistency in data collection and research reporting.
373 citations
Otto-von-Guericke University Magdeburg1, University of Sfax2, University of Münster3, German Center for Neurodegenerative Diseases4, University of Gafsa5, Rio de Janeiro State University6, University of Twente7, Estácio S.A.8, Canadian University of Dubai9, Imam Khomeini International University10, University of Paris11, University of Genoa12, York University13, Paris West University Nanterre La Défense14, University of Thessaly15, Loughborough University16, Stanford University17, University of Toulouse18, Assiut University19, Karlsruhe Institute of Technology20, Georgia Southern University21, Government of Extremadura22, University Medical Center Groningen23, University of Ulm24, Yarmouk University25, University of Jordan26, University of Porto27, ISCTE – University Institute of Lisbon28, Catholic University of the Sacred Heart29, Józef Piłsudski University of Physical Education in Warsaw30, University of Sousse31, University of Arkansas32, Manouba University33
TL;DR: The preliminary findings elucidate the risk of psychosocial strain during the early COVID-19 home confinement period in 2020 and suggest implementation of national strategies focused on promoting social inclusion through a technology-based solution is strongly suggested.
Abstract: Public health recommendations and governmental measures during the new coronavirus disease (COVID-19) pandemic have enforced numerous restrictions on daily living including social distancing, isolation, and home confinement. While these measures are imperative to mitigate spreading 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 lifestyle consequences of COVID-19 restrictions. This report presents the preliminary results from more than one thousand responders on social participation and life satisfaction. Methods: Thirty-five research organizations from Europe, North-Africa, Western Asia, and the Americas promoted the survey through 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 questions related 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 the analysis. 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 negative effects on social participation were also associated with lower life satisfaction (−30.5%) during the confinement period. Conversely, the social contact score through digital technologies significantly increased (p < 0.001) during the confinement period with more individuals (+24.8%) being socially connected through digital technology. Conclusion: These preliminary findings elucidate the risk of 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 of national strategies focused on promoting social inclusion through a technology-based solution is strongly suggested.
284 citations
Paris West University Nanterre La Défense1, Otto-von-Guericke University Magdeburg2, German Center for Neurodegenerative Diseases3, University of Sfax4, University of Münster5, University of Gafsa6, Rio de Janeiro State University7, University of Twente8, Catholic University of the Sacred Heart9, Estácio S.A.10, Canadian University of Dubai11, Imam Khomeini International University12, University of Paris13, University of Genoa14, York University15, University of Arkansas16, Stanford University17, University of Toulouse18, University of Thessaly19, Assiut University20, Karlsruhe Institute of Technology21, Loughborough University22, Government of Extremadura23, University Medical Center Groningen24, University of Ulm25, Yarmouk University26, University of Jordan27, University of Porto28, Józef Piłsudski University of Physical Education in Warsaw29, Georgia Southern University30, Qatar Airways31, Manouba University32
TL;DR: The ECLB-COVID19 survey revealed an increased psychosocial strain triggered by the home confinement, and a crisis-oriented interdisciplinary intervention is urgently needed to mitigate this high risk of mental disorders.
Abstract: 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-COVID19) was launched on April 6, 2020 in seven languages to elucidate the impact of COVID-19 restrictions on mental health and emotional wellbeing. METHODS: The ECLB-COVID19 electronic survey was designed by a steering group of multidisciplinary scientists, following a structured review of the literature. The survey was uploaded and shared on the Google online-survey-platform and was promoted by thirty-five research organizations from Europe, North-Africa, Western-Asia and the Americas. All participants were asked for their mental wellbeing (SWEMWS) and depressive symptoms (SMFQ) with regard to "during" and "before" home confinement. RESULTS: Analysis was conducted on the first 1047 replies (54% women) from Asia (36%), Africa (40%), Europe (21%) and other (3%). The COVID-19 home confinement had a negative effect on both mental-wellbeing and on mood and feelings. Specifically, a significant decrease (p < .001 and Δ% = 9.4%) in total score of the SWEMWS questionnaire was noted. More individuals (+12.89%) reported a low mental wellbeing "during" compared to "before" home confinement. Furthermore, results from the mood and feelings questionnaire showed a significant increase by 44.9% (p < .001) in SMFQ total score with more people (+10%) showing depressive symptoms "during" compared to "before" home confinement. CONCLUSION: The ECLB-COVID19 survey revealed an increased psychosocial strain triggered by the home confinement. To mitigate this high risk of mental disorders and to foster an Active and Healthy Confinement Lifestyle (AHCL), a crisis-oriented interdisciplinary intervention is urgently needed.
194 citations
University of Sfax1, German Center for Neurodegenerative Diseases2, Rio de Janeiro State University3, University of Twente4, Catholic University of the Sacred Heart5, Universidade Federal do Estado do Rio de Janeiro6, American University in the Emirates7, Imam Khomeini International University8, University of Paris9, University of Genoa10, University of Arkansas11, Stanford University12, National Polytechnic Institute of Toulouse13, Assiut University14, Karlsruhe Institute of Technology15, Drexel University16, Georgia Southern University17, University Medical Center Groningen18, University of St Andrews19, University of Ulm20, Yarmouk University21, University of Jordan22, University of Porto23, University of Oxford24, University of Waterloo25, Loughborough University26, Otto-von-Guericke University Magdeburg27
TL;DR: The results indicate that isolation is a necessary measure to protect public health, but it alters physical activity and eating behaviours in a direction that would compromise health.
Abstract: Background Public health recommendations and governmental measures during the COVID-19 pandemic have enforced 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 lifestyle at home is undefined. Therefore, an international online survey was launched in April 2020 in seven languages to elucidate the behavioral and lifestyle consequences of COVID-19 restrictions. This report presents the preliminary results from the first thousand responders on physical activity (PA) and nutrition behaviours. Methods Thirty-five research organisations from Europe, North-Africa, Western Asia and the Americas promoted the survey through their networks to the general society, in English, German, French, Arabic, Spanish, Portugese, 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 into a general analysis. The COVID-19 home confinement had a negative effect on all intensities of PA (vigorous, moderate, walking and overall). Conversely, daily sitting time increased from 5 to 8 hours per day. Additionally, food consumption and meal patterns (the type of food, eating out of control, snacks between meals, number of meals) were more unhealthy during confinement with only alcohol binge drink decreasing significantly. Conclusion While isolation is a necessary measure to protect public health, our results indicate that it alters physical activity and eating behaviours in a direction that would compromise health. 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 bespoke interventions to mitigate the negative lifestyle behaviors manifest during the COVID-19 confinement.
86 citations
TL;DR: The available scientific evidence is analyzed in order to recommend a practical approach, focusing on nutrition, intermittent fasting or caloric restriction, vitamin D insufficiency, sleep pattern, exercise, and psychodynamic aspects as factors impacting the immune system and human health in general.
Abstract: On January 31, 2020, the World Health Organization (WHO) declared the outbreak of a novel coronavirus responsible for an infection termed COVID-19 as a global public health emergency. To slow the spread of the coronavirus, countries around the world have been implementing various measures, including school and institutional closures, lockdown and targeted quarantine for suspected infected individuals. More than a third of the world's population have been home confined less than 4 months after the start of the outbreak. The present article aims to advise healthy individuals and athletes who are in lockdown regarding their lifestyle in order to keep healthy, safe and fit. The advice contained in the present article could apply to anyone aiming at remaining in good physical and mental health while forced to undergo lockdown, quarantine, or limited movement (movement control order). Boosting the immune system is crucial during such periods for confined people and especially for confined athletes. Specific recommendations must be followed concerning boosting the immune system through physiological and psychological management. This article analyses the available scientific evidence in order to recommend a practical approach, focusing on nutrition, intermittent fasting or caloric restriction, vitamin D insufficiency, sleep pattern, exercise, and psychodynamic aspects as factors impacting the immune system and human health in general.
76 citations
Otto-von-Guericke University Magdeburg1, German Center for Neurodegenerative Diseases2, Rio de Janeiro State University3, University of Twente4, Catholic University of the Sacred Heart5, Universidade Federal do Estado do Rio de Janeiro6, American University in the Emirates7, Imam Khomeini International University8, University of Genoa9, University of Arkansas10, Stanford University11, University of Toulouse12, Assiut University13, Karlsruhe Institute of Technology14, Georgia Southern University15, University Medical Center Groningen16, University of Ulm17, Yarmouk University18, University of Jordan19, University of Porto20, ISCTE – University Institute of Lisbon21, University of Waterloo22, Loughborough University23, Paris West University Nanterre La Défense24
TL;DR: The findings elucidate the risk of psychosocial strain during the current home confinement period and provide a clear remit for the urgent implementation of technology-based intervention to foster an Active and Healthy Confinement Lifestyle (AHCL).
Abstract: Background Although recognised as effective measures to curb the spread of the COVID-19 outbreak, social distancing and self-isolation, have been suggested to generate burden throughout the population. To provide scientific data to help identify risk-factors for the psychosocial strain during the COVID-19 outbreak, an international cross-disciplinary online survey was circulated in April 2020. This report outlines the mental, emotional and behavioural consequences of COVID-19 home confinement. Method Thirty-five research organisations from four continents promoted the survey through their networks to the general society, in Ten different languages. Questions were presented in a differential format with questions related to responses “before” and “during” confinement period. Results 1047 replies (54% women) from Western-Asia (36%), North-Africa (40%), Europe (21%) and other countries (3%) were analysed. The COVID-19 home confinement evoked a negative effect on mental wellbeing and emotional status (P Conclusion These findings elucidate the risk of psychosocial strain during the current home confinement period and provide a clear remit for the urgent implementation of technology-based intervention to foster an Active and Healthy Confinement Lifestyle (AHCL).
53 citations
TL;DR: Napping could be preventive against performance degradation caused by sleep loss and a short nap opportunity could be more beneficial when the subsequent effort is brief and requires frequent decision making.
Abstract: PURPOSE To investigate the effects of napping after partial sleep deprivation (PSD) on reaction time, mood, and biochemical response to repeated-sprint exercise in athletes. METHODS Nine male judokas performed 4 test sessions in a counterbalanced and randomized order. Participants accomplished 1 control session after a normal sleep night (NSN) and 3 after PSD with (1) no nap, (2) ∼20-min nap (N20), and (3) ∼90-min nap (N90) opportunities. Test sessions included the running-based anaerobic sprint test, reaction time, Hooper index, and Epworth Sleepiness Scale. Muscle-damage biomarkers and antioxidant status were evaluated before and after exercise. RESULTS PSD decreased maximum (P < .001, d = 1.12), mean (P < .001, d = 1.33), and minimum (P < .001, d = 1.15) powers compared with NSN. However, N20 and N90 enhanced maximum power compared with PSD (P < .05, d = 0.54; P < .001, d = 1.06, respectively). Minimum power and mean power increased only after N90 (P < .001, d = 1.63; P < .001, d = 1.16, respectively). Epworth Sleepiness Scale increased after PSD (P < .001, d = 0.86) and decreased after N20 (P < .001, d = 1.36) and N90 (P < .001, d = 2.07). N20 reduced multiple-choice reaction time (P < .001, d = 0.61). Despite performance decrement, PSD increased postexercise aspartate aminotransferase (P < .001, d = 4.16) and decreased glutathione peroxidase (P < .001, d = 4.02) compared with NSN. However, the highest performances after N90 were accompanied with lesser aspartate aminotransferase (P < .001, d = 1.74) and higher glutathione peroxidase (P < .001, d = 0.86) compared with PSD. CONCLUSIONS Napping could be preventive against performance degradation caused by sleep loss. A short nap opportunity could be more beneficial when the subsequent effort is brief and requires frequent decision making. However, a longer nap opportunity could be preventive against muscle and oxidative damage, even for higher performances.
30 citations
TL;DR: Extra, school-based recreational soccer for adolescents was accompanied by a significant improvement in physical fitness, compared toPhysical education classes only, and the implementation of recreational soccer into regular physical education classes seems to be a potentially appropriate stimulus for reducing aggression in high-school students.
Abstract: School-based programmes have shown promising results in the reduction of aggressive behaviour, but the effectiveness of physical activity modalities among adolescents remains to be determined. The aim of this study was to determine the effects of a school-based soccer programme on physical fitness and aggression in adolescent students. One hundred and five high school students were randomized to a small-sided soccer training group (SG) or a control group (CG). In addition to the regular physical education classes performed as part of a curriculum, the SG completed eight months of small-sided soccer training twice a week after school. Aerobic fitness (YYIR1), vertical jump (VJ), backward overhead medicine ball throw (BOMBT), and Buss and Perry's aggression questionnaire were evaluated before and after eight months of training. Greater improvements were observed in the SG than in the CG in the BOMBT (%diff=4.3, ŋp2=.308) and YYIR1 tests (%diff=2.2, ŋp2=.159), and physical aggression subscale (%diff=-12.1, ŋp2=.144). Extra, school-based recreational soccer for adolescents was accompanied by a significant improvement in physical fitness, compared to physical education classes only. Moreover, the implementation of recreational soccer into regular physical education classes seems to be a potentially appropriate stimulus for reducing aggression in high-school students.
21 citations
Otto-von-Guericke University Magdeburg1, German Center for Neurodegenerative Diseases2, Rio de Janeiro State University3, University of Twente4, Catholic University of the Sacred Heart5, Universidade Federal do Estado do Rio de Janeiro6, American University in the Emirates7, Imam Khomeini International University8, University of Paris9, University of Genoa10, Loughborough University11, Stanford University12, University of Toulouse13, Assiut University14, Karlsruhe Institute of Technology15, Georgia Southern University16, University Medical Center Groningen17, University of Ulm18, Yarmouk University19, University of Jordan20, University of Porto21, ISCTE – University Institute of Lisbon22, University of Waterloo23, University of Arkansas24
TL;DR: Preliminary findings revealed psychosocial strain during the enforced COVID-19 home confinement, and implementation of national strategies focused on promoting social inclusion through technology-based solution is urgently needed to mitigate the negative psychossocial effects of home confinement.
Abstract: Background Public health recommendations and governmental measures during the COVID-19 pandemic have enforced numerous restrictions on daily living including social distancing, isolation and home confinement. While these measures are imperative to mitigate spreading of COVID-19, the impact of these restrictions on psychosocial health is undefined. Therefore, an international online survey was launched in April 2020 in seven languages to elucidate the behavioral and lifestyle consequences of COVID-19 restrictions. This report presents the preliminary results from the first thousand responders on social participation and life satisfaction. Methods Thirty-five research organisations from Europe, North-Africa, Western Asia and the Americas promoted the survey through their networks to the general society, 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. Preliminary findings revealed psychosocial strain during the enforced COVID-19 home confinement. In particular, large decreases in the amount of social activity through family (58%), friends/neighbors (44.9%) or entertainment (46.7%) were triggered by the enforced confinement. These negative effects on social participation were also associated with lower satisfaction (−30.5%) during the confinement period. Conversely, social contact score through digital technologies has significantly increased (p Conclusion These preliminary findings elucidate the risk of psychosocial strain during the current home confinement period. Therefore, in order to mitigate the negative psychosocial effects of home confinement, implementation of national strategies focused on promoting social inclusion through technology-based solution is urgently needed.
19 citations
TL;DR: It is suggested that sports medicine journals should adopt minimum reporting standards and perhaps checklists could be a useful step forward after injury and exposure data were collected among professional male players from the Qatar Stars League from the 2008-2009 season to the 2017-2018 season.
Abstract: To examine if and how adjustments in injury surveillance recording methodology may have influenced injury rates. Injury and exposure data were collected among professional male players from the Qatar Stars League from the 2008-2009 season to the 2017-2018 season. There have been four iterations of our data collection methods. In the first five seasons, participation in the programme was voluntary. For seasons 6-7, additional dedicated researchers were tasked with contacting the medical teams every month. At the start of season 8, an electronic recording method was instituted. In the final two seasons, injury surveillance participation was further boosted by reinforced encouragement from institutional management. Overall injury incidence increased from season 5 to season 8. Severe injuries have fallen steadily, but slightly over the ten seasons, whereas mild injuries increased dramatically from seasons 5 to 8. The current data suggest that along with the standard metrics (e.g. injury incidence, injury burden) we also need to clearly report the methods by which data were collected and verified in as much detail as possible. We suggest that sports medicine journals should adopt minimum reporting standards and perhaps checklists could be a useful step forward.
Otto-von-Guericke University Magdeburg1, German Center for Neurodegenerative Diseases2, Rio de Janeiro State University3, University of Twente4, Catholic University of the Sacred Heart5, Universidade Federal do Estado do Rio de Janeiro6, American University in the Emirates7, Imam Khomeini International University8, University of Paris9, University of Genoa10, Stanford University11, University of Toulouse12, Assiut University13, Karlsruhe Institute of Technology14, Loughborough University15, University Medical Center Groningen16, University of Ulm17, Yarmouk University18, University of Jordan19, University of Porto20, ISCTE – University Institute of Lisbon21, University of Waterloo22, Georgia Southern University23
TL;DR: The ECLB-COVID19 survey revealed an increased psychosocial strain triggered by the enforced home confinement, and a crisis-oriented interdisciplinary intervention is urgently needed to mitigate this high risk of mental disorders.
Abstract: Background Public health recommendations and government measures during the COVID-19 pandemic have enforced restrictions on daily living, which may include social distancing, remote work/school, and home confinement. 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 was launched on April 6, 2020 in seven languages to elucidate the impact of COVID-19 restrictions on mental health and emotional well-being. This report presents the preliminary results from the first thousand responders on mental wellbeing and mood and feelings questionnaires. Methods The ECLB-COVID19 electronic survey was designed by a steering group of multidisciplinary scientists and academics, following a structured review of the literature. The survey was uploaded and shared on the Google online survey platform. Thirty-five research organizations from Europe, North-Africa, Western Asia and the Americas promoted the multi-languages survey through their networks to general society. Of the 64 questions, 7 were from the Short Warwick-Edinburgh Mental Well-being Scale (SWEMWBS), and 13 were from the Short Mood and Feelings Questionnaire (SMFQ), which are both validated instruments. Results Analysis was conducted on the first 1047 replies (54% women) from Asia (36%), Africa (40%), Europe (21%) and other (3%). The COVID-19 home confinement had a negative effect on both mental wellbeing and on mood and feelings. Specifically, a significant decrease (p Conclusion The ECLB-COVID19 survey revealed an increased psychosocial strain triggered by the enforced home confinement. To mitigate this high risk of mental disorders and to foster an Active and Healthy Confinement Lifestyle (AHCL), a crisis-oriented interdisciplinary intervention is urgently needed.
TL;DR: The impact of RT on maximal strength (isometric and isokinetic strength), the power of both lower and upper limbs, and throwing velocity, in handball players is investigated to design conditioning protocols and programs based on the results.
Abstract: Purpose: Handball (Team Handball) is an intermittent and strenuous contact sport, the successful performance of which depends on frequent body contacts, and the ability to make repeated explosive muscular contractions required for jumping, acceleration, sprinting, turning, changing pace, and throwing a ball. Many studies have investigated the effect of resistance training (RT) in handball players, however with conflicting results. Therefore, our objective was to investigate the impact of RT on maximal strength (isometric and isokinetic strength), the power of both lower and upper limbs, and throwing velocity, in handball players. Methods: A comprehensive literature search yielded a pool of 18 studies, which were retained in the systematic review and meta-analysis. Results: A total of 275 handball players were included. The overall effect size (ES) of RT was 0.996 ([95%CI 0.827–1.165], p = 0.0000). At the multivariate meta-regression, the effect of publication year was significant, as well as the effects of country, gender, and level. The impact of RT on isokinetic strength was not significant (ES 0.079 [95%CI −0.060–0.219], p = 0.265), whereas the impact of RT on throwing (ES 1.360 [95%CI 0.992–1.728], p = 0.000) was significant, as well as the effects of RT on isometric strength (ES 0.398 [95%CI 0.096–0.700], p = 0.010), on maximal strength (ES 1.824 [95%CI 1.305–2.343], p = 0.000), and on power (ES 0.892 [95%CI 0.656–1.128], p = 0.000). Conclusions: RT has a significant impact in handball players. Handball coaches could design conditioning protocols and programs based on our results. However, due to a number of shortcomings, including the high, statistically significant heterogeneity among studies and the evidence of publication bias, further high-quality investigations are needed.
TL;DR: In conclusion, incorporating MPT into the in-season regimen of under 21 soccer players improved performance of various indices related to soccer activity (i.e., CMJ, CODS, and DPC) and has the potential to be appealing to coaches.
Abstract: The aim of the study was to assess the effects of multi-directional plyometric training (MPT) on vertical jump height, change of direction speed (CODS), and dynamic postural control (DPC) of soccer players under 21 year (U-21). Twenty-seven male soccer players were randomly allocated to either an experimental group (EG; n = 14; age: 19.0 ± 0.9 years) or a control group (CG; n = 13; age: 19.0 ± 0.7 years). The EG introduced 6 weeks MPT, 2 days per week into their in-season training, while CG continued training without change. Measurements of vertical jump height, CODS and DPC were completed at the beginning and end of the 6 week MPT. ANOVA demonstrated a significant group × time interaction for SJ (F = 6.03, p = 0.021), CMJ (F = 9.10, p = 0.006), and T-Test (F = 10.46, p = 0.002). The Bonferroni Post Hoc test demonstrated significant increase for the three tests in both group (EG and CG). For SJ (EG: p < 0.001; CG: p < 0.001), CMJ (EG: p < 0.001; CG: p = 0.005) and T-Test (EG: p < 0.001; CG: p = 0.02). For DPC on the dominant leg, there was a significant group × time interaction for four axes [anterior (F = 5.48, p = 0.028), antero-lateral (F = 4.82, p = 0.038), postero-lateral (F = 4.82, p = 0.038), and medial (F = 6.77, p = 0.015)]. The Bonferroni Post Hoc test demonstrated significant increase in EG (p < 0.001), but no significant change in CG in four axes (anterior, antero-lateral, postero-lateral and medial). Furthermore DPC on the non-dominant leg, there was a significant group × time interaction for three axes [lateral (F = 8.09, p = 0.009), postero-lateral (F = 11.92, p = 0.002), and medial (F = 5.84, p = 0.023)]. The Bonferroni Post Hoc test demonstrated significant increase in EG (p < 0.001), but no significant change in CG in three axes (lateral, postero-lateral, and medial). In conclusion, incorporating MPT into the in-season regimen of under 21 soccer players improved performance of various indices related to soccer activity (i.e., CMJ, CODS, and DPC). MPT has the potential to be appealing to coaches, as it requires little time while yielding valuable results in the physical preparation of soccer players.
TL;DR: Novel exploratory evidence is provided that the volume of sprinting during competitive soccer match-play has a harmful association with muscle injury occurrence and an increment in sprinting distance covered over a 1-min period increased the odds of muscle injury.
TL;DR: Implementing a NHE prevention program has a positive effect on the injury rate in a soccer team; however, the compliance of players with such interventions may be critical for its success.
Abstract: Chebbi, S, Chamari, K, Van Dyk, N, Gabbett, T, and Tabben, M. Hamstring injury prevention for elite soccer players: A real-world prevention program showing the effect of players' compliance on the outcome. J Strength Cond Res XX(X): 000-000, 2020-The aim of this study was to determine the effect of implementing the Nordic hamstring exercise (NHE) to prevent hamstring injuries in soccer. A professional team was followed by the same medical team during 5 successive seasons (2012/2013 through 2016/2017). During the first and last seasons (2012/2013 and 2016/2017), no hamstring preventive action was implemented. For the seasons 2013/2014, 2014/2015, and 2015/2016, a noncompulsory (few players refusing to participate) NHE prevention program was implemented with accurate recording of the players' training and match exposure and attendance to the prevention sessions. The first 10 weeks of the season were used to progressively increase the volume and intensity of the NHE exercises, and at the end of the season, players were split in low-, moderate-, and high-attendance groups to the prevention sessions. Overall, 35 time-loss hamstring strain injuries were accounted for. The injury incidence was 0.30 per player per season, and the injury rate was 0.95 injury/1000 hour of exposure. A nonstatistically significant higher risk of hamstring injury was observed in the control, low, and moderate attendance groups compared with the high-attendance group. The greatest risk of hamstring injury was observed in the low-attendance group (odds ratio 1.77, confidence interval 0.57-5.47, p = 0.32). Implementing a NHE prevention program has a positive effect on the injury rate in a soccer team; however, the compliance of players with such interventions may be critical for its success.
TL;DR: It is concluded that an early return to “full participation to training” is not recommended in participants who have undergone an ACLR with patellar tendon grafts.
Abstract: The aim of this study was to examine performance in hopping tests in male athletes after anterior cruciate ligament reconstruction (ACLR) in the 4-to-6 months post-surgery period. A total of 36 athletes (24 ACLR and 12 controls) participated in this study. The ACLR group consisted of athletes who had undergone an ACLR on their dominant side (ACL DG n=16) or non-dominant side (ACL NDG n=8). Participants completed the following functional tests: a single-leg hop (SLH), single-leg triple hop (SL3H) and single-leg counter movement jump (SLCMJ), then the limb symmetry index (LSI) was calculated. There were no significant differences between the dominant and the non-dominant legs for all functional tests when comparing the ACL DG and the ACL NDG at 6 months after surgery. At 6 months after ACLR, the LSI of the two legs was within acceptable values, whether the athlete had the operation on their dominant or non-dominant leg (except the mean LSI for the ACL DG in the SLCMJ test). Furthermore, the control group showed higher performances as compared to the ACL group for all variables at 6 months after surgery, despite acceptable LSI. We concluded that an early return to "full participation to training" is not recommended in participants who have undergone an ACLR with patellar tendon grafts.
TL;DR: To develop a 6‐minute walk‐distance (6MWD) reference equation for children and adolescents with obesity, and to assess its determinant factors.
Abstract: Aim To develop a 6-minute walk-distance (6MWD) reference equation for children and adolescents with obesity, and to assess its determinant factors. Methods A cross-sectional study using mixed linear and multiple regression models was conducted in 497 children (235 girls and 262 boys) aged 6-18 years with a body mass index (BMI) greater than 97th percentile. Anthropometrics and a 6-minute walk test (6MWT) were performed. Results Mean 6MWD was 547 ± 86 m for girls and 575 ± 96 m for boys, which averaged ~80% of a reference normal-weight population matched for age and ethnicity. Age, weight and BMI were positively correlated with 6MWD whereas waist and hip circumferences (WC and HC, respectively) were negatively correlated with 6MWD for both genders. The combination of age, height, BMI and HC explained 69% of the 6MWD variability in the equation for the whole population. Moreover, the combination of age, height, HC as well as the combination of age, height, BMI and WC explained 67% and 75% of the variability in the girls' and boys' equations, respectively. Conclusion This 6MWD reference equation, which was influenced by abdominal obesity markers in a gender-specific way, extends and enhances scientific knowledge and provides useful predictive tools for the care of obese children.
TL;DR: The PCA model demonstrated a great predictive power in accounting for GRF-based parameters of explosive push-up exercises, allowing for stronger logical and ecological validity as tests of upper-body power.
Abstract: Zalleg, D, Ben Dhahbi, A, Dhahbi, W, Sellami, M, Padulo, J, Souaifi, M, Beslija, T, and Chamari, K. Explosive push-ups: From popular simple exercises to valid tests for upper-body power. J Strength Cond Res 34(10): 2877-2885, 2020-The purpose of this study was to assess the logical and ecological validity of 5 explosive push-up variations as a means of upper-body power assessment, using the factorial characterization of ground reaction force-based (GRF-based) parameter outputs. Thirty-seven highly active commando soldiers (age: 23.3 ± 1.5 years; body mass: 78.7 ± 9.7 kg; body height: 179.7 ± 4.3 cm) performed 3 trials of 5 variations of the explosive push-up in a randomized-counterbalanced order: (a) standard countermovement push-up, (b) standard squat push-up, (c) kneeling countermovement push-up, (d) kneeling squat push-up, and (e) drop-fall push-up. Vertical GRF was measured during these exercises using a portable force plate. The initial force-supported, peak-GRF and rate of force development during takeoff, flight time, impact force, and rate of force development impact on landing were measured. A significant relationship between initial force-supported and peak-GRF takeoff was observed for the countermovement push-up (CMP) exercises (standard countermovement push-up, kneeling countermovement push-up, and drop-fall push-up) and squat push-up (SP) exercises (standard squat push-up and kneeling squat push-up) (r = 0.58 and r = 0.80, respectively; p < 0.01). Furthermore, initial force supported was also negatively correlated to a significant degree with flight time for both CMP and SP (r = -0.74 and r = -0.80; p < 0.01, respectively). Principal component analysis (PCA) showed that the abovementioned 6 GRF-based variables resulted in the extraction of 3 significant components, which explained 88.9% of the total variance for CMP, and 2 significant components, which explained 71.0% of the total variance for SP exercises. In summary, the PCA model demonstrated a great predictive power in accounting for GRF-based parameters of explosive push-up exercises, allowing for stronger logical and ecological validity as tests of upper-body power. Furthermore, it is possible to adjust the intensity level of the push-up exercise by altering the starting position (i.e., standard vs. kneeling).
TL;DR: The exploratory findings suggest its role for type‐specific injury risk determination appears empirically unsupported, and limited exploratory evidence regarding the value of perceived exertion and session duration as etiological factors of hamstring injury in Middle‐East professional football is found.
Abstract: Training and competition loads have emerged as modifiable composite risk factors of non‐contact injury. Hamstring strains are the most common injuries in football with substantial burden on the individual player and club. Nevertheless, robust evidence of a consistent load‐hamstring injury relationship in professional football is lacking. Using available data from the Qatar Stars League over three competitive seasons, this study investigated the separate and combined effects of perceived exertion and session duration on hamstring injury occurrence in a sample of 30 outfield football players. Load variables were calculated into 7‐day, 14‐day, 21‐day, 28‐day periods of data, and week‐to‐week changes for average ratings of perceived exertion (RPE; au) score and session‐RPE (s‐RPE; session‐duration urn:x-wiley:09057188:media:sms13591:sms13591-math-0001 score), plus the cumulative training and match minutes and s‐RPE, respectively. Conditional logistic regression models estimated load‐injury relationships per 2‐within‐subject standard deviation increments in each candidate variable. Associations were declared practically important based on the location of the confidence interval in relation to thresholds of 0.90 and 1.11 defining small beneficial and harmful effects, respectively. The uncertainty for the corrected odds ratios show that typically high within‐subject increments in each candidate variable were not practically important for training‐ and match‐related hamstring injury (95% confidence intervals range: 0.85 to 1.16). We found limited exploratory evidence regarding the value of perceived exertion and session duration as etiological factors of hamstring injury in Middle‐East professional football. Monitoring remains valuable to inform player load management strategies, but our exploratory findings suggest its role for type‐specific injury risk determination appears empirically unsupported.
TL;DR: Age group, gender, the used phenolic compounds, their human bioavailability rate, and the supplementation dose as the primary moderator variables relating to the beneficial effects of (poly)phenol consumption on cognitive and brain function in humans are suggested.
Abstract: Background: Recent anti-aging interventions have shown contradictory impacts of (poly)phenols regarding the prevention of cognitive decline and maintenance of brain function. These discrepancies have been linked to between-study differences in supplementation protocols. This subgroup analysis and meta-regression aimed to (i) examine differential effects of moderator variables related to participant characteristics and supplementation protocols and (ii) identify practical recommendations to design effective (poly)phenol supplementation protocols for future anti-aging interventions. Methods: Multiple electronic databases (Web of Science; PubMed) searched for relevant intervention published from inception to July 2019. Using the PICOS criteria, a total of 4303 records were screened. Only high-quality studies (n = 15) were included in the final analyses. Random-effects meta-analysis was used, and we calculated standard differences in means (SDM), effect size (ES), and 95% confidence intervals (CI) for two sufficiently comparable items (i.e., psychomotor function and brain-derived neurotrophic factor (BDNF)). When significant heterogeneity was computed (I2 > 50%), a subgroup and meta-regression analysis were performed to examine the moderation effects of participant characteristics and supplementation protocols. Results: The reviewed studies support the beneficial effect of (poly)phenols-rich supplementation on psychomotor functions (ES = −0.677, p = 0.001) and brain plasticity (ES = 1.168, p = 0.028). Subgroup analysis revealed higher beneficial impacts of (poly)phenols (i) in younger populations compared to older (SDM = −0.89 vs. −0.47 for psychomotor performance, and 2.41 vs. 0.07 for BDNF, respectively), (ii) following an acute compared to chronic supplementation (SDM = −1.02 vs. −0.43 for psychomotor performance), and (iii) using a phenolic compound with medium compared to low bioavailability rates (SDM = −0.76 vs. −0.68 for psychomotor performance and 3.57 vs. 0.07 for DBNF, respectively). Meta-regressions revealed greater improvement in BDNF levels with lower percentages of female participants (Q = 40.15, df = 6, p < 0.001) and a skewed scatter plot toward a greater impact using higher (poly)phenols doses. Conclusion: This review suggests that age group, gender, the used phenolic compounds, their human bioavailability rate, and the supplementation dose as the primary moderator variables relating to the beneficial effects of (poly)phenol consumption on cognitive and brain function in humans. Therefore, it seems more advantageous to start anti-aging (poly)phenol interventions in adults earlier in life using medium (≈500 mg) to high doses (≈1000 mg) of phenolic compounds, with at least medium bioavailability rate (≥9%).
TL;DR: Sports played outdoors involving close contact between athletes represent a limited risk for SARS-CoV-2 infection and severe illness when preventive measures are in place.
Abstract: Objectives: The risk of viral transmission associated with contact sports such as Football during the COVID-19 pandemic is unknown. The aim of this study was to describe the development of infective and immune status of professional football players, team staff and league officials over a truncated football season resumed at the height of the Covid-19 pandemic in a country with high infection rates and to investigate the clinical symptoms related to Covid-19 infection in professional football players.
Methods: Prospective cohort study of 1337 football players, staff and officials during a truncated football season (9 weeks) with a tailored infection control program based on preventive measures and regular SarS-CoV-2 PCR swab testing (every 3-5 days) combined with serology testing for immunity (every 4 weeks). Clinical symptoms in positive participants were recorded using a 26-item, Likert-scale-based scoring system.
Results: During the study period, 85 subjects returned positive (cycle threshold (cT)<30) or reactive (30
TL;DR: Compared with NS, DS tended to affect the pattern of improvement of COD performance during play by intensifying and accelerating it, and it is recommended that DS be incorporated to the warm-up preceding the match.
Abstract: PURPOSE To explore the immediate (15-s post-warm-up) and the delayed (after 20 and 40 min of simulated volleyball play) effects of 2 different warm-up protocols-a stretching-free volleyball warm-up (NS) and a warm-up incorporating dynamic stretching (DS)-on subsequent change of direction (COD) performance in young elite volleyball players. METHODS Sixteen male players (age 16.88 [0.34] y, body mass 75.81 [5.41] kg, body height 1.91 [0.05] m, body mass index 20.84 [1.79] kg·m-2, and body fat percentage 9.48 [1.83]%) from the U-17 national volleyball team performed NS and DS on 2 different nonconsecutive days. During each testing session (NS and DS), half T-test performance measurements were performed after 5 minutes of a general warm-up (ie, baseline), immediately post-warm-up (after 15 s), and after 20 and 40 minutes of simulated volleyball play. RESULTS For DS, a significant improvement in COD performance (2.08%, P < .001) was observed after 20 minutes of play compared with the baseline values. In addition, COD performance recorded after 40 minutes of play was better than after 15-second post-warm-up (5.85%, P = .001). Inferential statistics showed better COD performance in the DS condition after 20 minutes of play (2.32%, likely negative, d = 0.61). CONCLUSIONS Compared with NS, DS tended to affect the pattern of improvement of COD performance during play by intensifying and accelerating it. Consequently, to enhance COD performance for up to 40 minutes into the game, it is recommended that DS be incorporated to the warm-up preceding the match.
01 Dec 2020
TL;DR: In this paper, the authors investigated the anthropometric and physical fitness profiles of Tunisian female soccer players in relation to field position, and concluded that, in a north African sample, anthropometric profiles vary by playing position, while positional differences can be found when testing physical fitness components.
Abstract: Background: There is a lack of descriptive data available regarding the characteristics of female soccer players from the African continent or the Arab world. Objective: This study investigated the anthropometric and physical fitness profiles of Tunisian female soccer players in relation to field position. Methods: In all, 75 Tunisian sub-elite female soccer players, with an average of 4.3 ± 1.6 years of playing experience, including goalkeepers (GK; n = 11), central defenders (CD; n = 13), external defenders (ED; n = 15), central midfielders (CM; n = 10), external midfielders (EM; n = 14), and attackers (AT; n = 12), underwent anthropometric evaluations (body height, body mass, and body fat percentage) and physical fitness tests (flexibility, countermovement jump [CMJ], 20-m sprint, and Yo-Yo intermittent recovery test level 1 [YoYoIR1]). Results: GK had significantly higher body mass (67.3 ± 2.4 kg), body height (169.3 ± 1.7 m) and fat percentage (24 ± 2.6%) compared to all field positions. AT were significantly faster (3.64 ± 0.10 s) than GK (3.75 ± 0.09 s) in the 20-m sprint (p < .01), but there were no significant differences among the other field positions. GK had a significantly lower Yo-YoIR1 performance (625 ± 84 m) than other field position players (p < .001), but no significant difference was found among other field positions. GK and AT showed significantly better CMJ performance (GK: 31.3 ± 2.6 cm, AT: 30.4 ± 2.4 cm) compared to other groups. GK had higher flexibility (21.6 ± 2.7 cm in the the sit-and-reach test) than all other positions (p < .05), but no significant difference was observed among players in the field. Conclusions: Overall, we can conclude that, in a north African sample of female soccer players, anthropometric profiles vary by playing position. As well, positional differences can be found when testing physical fitness components. This information could help coaches design more effective training programs to achieve success in modern soccer.
TL;DR: Analysis of variance tests showed that no significant differences were found between the three moon phases in all analyzed variables, and showed that the different lunar cycle phases did not have significant effects on the selected physical performances and psychological indices in trained athletes.
Abstract: BACKGROUND Fascination with the moon has spanned millennia. It has recently been asserted that the moon cycle affects endurance performance in untrained individuals. The present study aimed at investigating the effects of the lunar cycle on intermittent endurance physical performance, balance and reaction-time capabilities, and selected physiological and psychological parameters in trained athletes. METHODS Twelve male Taekwondo athletes (age, 22.3±0.8 years; height, 178.8±6.5 cm; body mass, 72.75±7.28 kg; %body fat, 13.9±3.6%) performed the Yo-Yo intermittent recovery test level-1 (YYIRT), the Y-balance test (YBT), and a reaction-time test (RT) during different lunar cycle phases (new moon (NM), full moon (FM), and half-moon). Participants' psychological profiles and well-being indices (i.e. a profile of mood state (POMS) and Hooper Index) were also taken during each moon phase. The testing sessions during the different moon phases were performed in a counterbalanced order. The tests order remained the same (POMS, then Hooper index, RT, YBT, YYIRT and rating of perceived exertion scale (RPE)), and all sessions were performed at noon (11:00 to 13:00 h) during the first day of each evaluated lunar phase. RESULTS Analysis of variance tests showed that no significant differences were found between the three moon phases in all analyzed variables. CONCLUSIONS This study showed that the different lunar cycle phases did not have significant effects on the selected physical performances and psychological indices in trained athletes.
TL;DR: This study showed that U-19 elite-female basketball is a moderate to high- intensity activity, with the Yo-Yo-IR1 test being a good-predictor of physical game- performance.
Abstract: BACKGROUND Understanding the physical activity, the physiological profile and the repeated sprint bouts (RS) nature of U-19 female basketball during official games could help coaches to plan their training. However, they are not extensively researched, as well as, the ecological validity of the Yo-Yo Intermittent-Recovery Test level-1 (YoYo-IRT1). The aims of this study were to determine: 1) the physical and physiological demands of U-19 elite-female basketball; 2) the relationship between the YoYo-IRT1 and game physical-activity; 3) and the RS nature in U-19 basketball. METHODS Computerized motion-analysis, heart-rate (HR) and blood lactate concentration [La] were measured in 30 players during eight U-19 games (the play-off stage of Tunisian league). They performed YoYo-IRT1. A RS was defined as a minimum of 3-sprints, with recovery of less than 21-sec in-between any of sprints' set. RESULTS Players spent ~13%, ~29.2% and ~25.2% of total live-time in high, moderate to low-intensity activities, whereas in-between efforts' recovery corresponded to ~32.6%. They spent ~57% of playing-time in high HR-zone (85-95%HRmax). Players performed an average of 6.4 RS per-player per-game, each bout including 3 to 5-sprints. The mean of sprint duration was 2.1±0.4 sec, with a mean recovery time equal to ~8.8-sec. A significant correlation was also observed between [La] and the time spent in high-intensity activity for the 5-min of play prior to blood sampling (r=0.52, P<0.05). A significant correlation was found between YoYo-IRT1 performance and the %time spent in sprint and total high-intensity activities (r=0.67, P=0.001 and r=-0.72, P<0.001, respectively). CONCLUSIONS This study showed that U-19 elite-female basketball is a moderate to high-intensity activity, with the Yo-Yo-IR1 test being a good-predictor of physical game-performance.