Background: At present, most runners use conventional sports shoes to protect and absorb the impacts that may cause overloading of the feet and joints. On the other hand, some runners tend to run almost barefoot or in minimalist footwear that may lead to foot strike pattern changes. Objective: The aim of this study was to analyse and to compare the foot strike pattern and foot loading when running in conventional running shoes (CRS) and minimalist running shoes (MRS) in a group of recreational women runners. Methods: A group of 14 experienced recreational women runners participated in this research. A Pedar-X system (Novel, Munich, Germany) was used to analyse the interaction of the foot with the ground while running in different type of shoes from as it relates to vertical force and plantar pressure distribution. The participants ran over a distance of 100 m with their habitual foot strike pattern in minimalist and also in conventional running shoes and data was always obtained while running along a straight 50 m long section (v = 3.33 ± 0.2 m ⋅ s -1 ). For assessment of the temporal and kinetics variables differences, the Wilcoxon test and the unpaired t-tests were used. Results: Recreational women runners showed statistically significant shift of the plantar pressures towards the forefoot when running in MRS compared to CRS (p = .047). Duration of swing phase in MRS and in CRS was similar (p = .291). When running in MRS, foot loading during initial contact was significantly higher than when running in CRS. Loading in the area of midfoot and forefoot was significantly higher in MRS too. Conclusions: Runners shifted their foot strike pattern forward when running in MRS; running in MRS may increase the foot loading and we recommend the use of minimalist footwear only after adequate foot strengthening and adaptation to avoid possible risk of foot injuries.
{"title":"Comparison of foot loading and foot strike pattern in women running in minimalist and conventional sports shoes","authors":"S. Jandova, J. Charousek, M. Janura","doi":"10.5507/AG.2019.003","DOIUrl":"https://doi.org/10.5507/AG.2019.003","url":null,"abstract":"Background: At present, most runners use conventional sports shoes to protect and absorb the impacts that may cause overloading of the feet and joints. On the other hand, some runners tend to run almost barefoot or in minimalist footwear that may lead to foot strike pattern changes. Objective: The aim of this study was to analyse and to compare the foot strike pattern and foot loading when running in conventional running shoes (CRS) and minimalist running shoes (MRS) in a group of recreational women runners. Methods: A group of 14 experienced recreational women runners participated in this research. A Pedar-X system (Novel, Munich, Germany) was used to analyse the interaction of the foot with the ground while running in different type of shoes from as it relates to vertical force and plantar pressure distribution. The participants ran over a distance of 100 m with their habitual foot strike pattern in minimalist and also in conventional running shoes and data was always obtained while running along a straight 50 m long section (v = 3.33 ± 0.2 m ⋅ s -1 ). For assessment of the temporal and kinetics variables differences, the Wilcoxon test and the unpaired t-tests were used. Results: Recreational women runners showed statistically significant shift of the plantar pressures towards the forefoot when running in MRS compared to CRS (p = .047). Duration of swing phase in MRS and in CRS was similar (p = .291). When running in MRS, foot loading during initial contact was significantly higher than when running in CRS. Loading in the area of midfoot and forefoot was significantly higher in MRS too. Conclusions: Runners shifted their foot strike pattern forward when running in MRS; running in MRS may increase the foot loading and we recommend the use of minimalist footwear only after adequate foot strengthening and adaptation to avoid possible risk of foot injuries.","PeriodicalId":51894,"journal":{"name":"Acta Gymnica","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2019-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44760044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: A few studies have shown that different types of court surfaces can have different effects on tennis match performance in different age groups, however, no studies have researched on tennis match performance responses in young tennis players. Objective: The purpose of this study was to evaluate the effect of different court surfaces on psychophysiological responses, time-motion and match characteristics of young tennis players. Methods: Twenty-six young male tennis players (age 13.0 ± 0.3 years, body height 158 ± 8 cm, body mass 48 ± 7 kg) volunteered to participate in the study. Heart rate was monitored along with total distance covered in four different speed zones-walking, low-intensity running, moderate-intensity running and high-intensity running, using two portable multivariable integrated 10 Hz GPS monitoring devices over twenty-six outdoor tennis matches; ratings of perceived exertion and enjoyment level were also determined at the end of the matches. Variables describing the characteristics of the matches determined from video recordings were: strokes per rally, rally duration, effective playing time, work-to-rest ratio and rest time between rallies. Differences between hard and clay courts were assessed by a paired t-test. Results: The results showed that clay court surfaces induced significantly more perceived enjoyment scores (29.4 ± 2.8 vs. 26.0 ± 3.2) with lower perceived exertion level (13.4 ± 2.7 vs. 14.4 ± 2.9) compared to hard courts. Moreover, a clay court surface is also more effective at improving physiological responses, time-motion and match characteristics compared to hard court. Conclusions: If a coach strives to improve their young tennis players' tennis-specific performance with greater physical enjoyment, clay court surfaces should be specially used in their tennis training season.
{"title":"Playing tennis matches on clay court surfaces are associated with more perceived enjoyment response but less perceived exertion compared to hard courts","authors":"Bülent Ki̇li̇t, Erşan Arslan","doi":"10.5507/AG.2018.021","DOIUrl":"https://doi.org/10.5507/AG.2018.021","url":null,"abstract":"Background: A few studies have shown that different types of court surfaces can have different effects on tennis match performance in different age groups, however, no studies have researched on tennis match performance responses in young tennis players. Objective: The purpose of this study was to evaluate the effect of different court surfaces on psychophysiological responses, time-motion and match characteristics of young tennis players. Methods: Twenty-six young male tennis players (age 13.0 ± 0.3 years, body height 158 ± 8 cm, body mass 48 ± 7 kg) volunteered to participate in the study. Heart rate was monitored along with total distance covered in four different speed zones-walking, low-intensity running, moderate-intensity running and high-intensity running, using two portable multivariable integrated 10 Hz GPS monitoring devices over twenty-six outdoor tennis matches; ratings of perceived exertion and enjoyment level were also determined at the end of the matches. Variables describing the characteristics of the matches determined from video recordings were: strokes per rally, rally duration, effective playing time, work-to-rest ratio and rest time between rallies. Differences between hard and clay courts were assessed by a paired t-test. Results: The results showed that clay court surfaces induced significantly more perceived enjoyment scores (29.4 ± 2.8 vs. 26.0 ± 3.2) with lower perceived exertion level (13.4 ± 2.7 vs. 14.4 ± 2.9) compared to hard courts. Moreover, a clay court surface is also more effective at improving physiological responses, time-motion and match characteristics compared to hard court. Conclusions: If a coach strives to improve their young tennis players' tennis-specific performance with greater physical enjoyment, clay court surfaces should be specially used in their tennis training season.","PeriodicalId":51894,"journal":{"name":"Acta Gymnica","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47314597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The role of the YMCA in shaping modern sport and the Olympic Movement in Germany","authors":"T. Tlustý","doi":"10.5507/ag.2018.022","DOIUrl":"https://doi.org/10.5507/ag.2018.022","url":null,"abstract":"","PeriodicalId":51894,"journal":{"name":"Acta Gymnica","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70741618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: Dehydration is the most common fluid and electrolyte problem among elderly people. The elderly leading an active lifestyle may be a risk group vulnerable to dehydration. Objective: The goals of the study were: to assess hydration status and the fluid intake, to determine gender differences in hydration status and fluid intake, and to determine the role of physical activity on hydration status in free-living elderly people. Methods: The research sample included 105 participants aged 67.2 ± 3.7 years (52% women) living independently in their own homes. Urine specific gravity (USG) was used to evaluate the hydration status (dehydration was defined as USG ≥ 1.020 and serious dehydration as USG > 1.030). A 4-day food record was used to monitor fluid intake, and the International Physical Activity Questionnaires - Short Form was used to assess physical activity. Results: The prevalence of dehydration was 45.7% with a lower prevalence in women. Serious dehydration was prevalent in two participants. Average daily beverage intake was 1144.4 ± 445.2 ml. There was no gender difference in total fluid intake. However, only 27.3% of women and 4.0% of men fulfilled the recommended daily fluid intake. Participants with moderate or high levels of physical activity had a better hydration status compared to their low-physical activity peers. Conclusions: These results indicate that almost half of elderly adults are dehydrated. The study suggests that being physically active can contribute to better fluid replenishment.
{"title":"Hydration status in Czech elderly adults: Gender and physical activity differences","authors":"I. Klimešová, Julie Wittmannová, L. Kováčová","doi":"10.5507/AG.2018.023","DOIUrl":"https://doi.org/10.5507/AG.2018.023","url":null,"abstract":"Background: Dehydration is the most common fluid and electrolyte problem among elderly people. The elderly leading an active lifestyle may be a risk group vulnerable to dehydration. Objective: The goals of the study were: to assess hydration status and the fluid intake, to determine gender differences in hydration status and fluid intake, and to determine the role of physical activity on hydration status in free-living elderly people. Methods: The research sample included 105 participants aged 67.2 ± 3.7 years (52% women) living independently in their own homes. Urine specific gravity (USG) was used to evaluate the hydration status (dehydration was defined as USG ≥ 1.020 and serious dehydration as USG > 1.030). A 4-day food record was used to monitor fluid intake, and the International Physical Activity Questionnaires - Short Form was used to assess physical activity. Results: The prevalence of dehydration was 45.7% with a lower prevalence in women. Serious dehydration was prevalent in two participants. Average daily beverage intake was 1144.4 ± 445.2 ml. There was no gender difference in total fluid intake. However, only 27.3% of women and 4.0% of men fulfilled the recommended daily fluid intake. Participants with moderate or high levels of physical activity had a better hydration status compared to their low-physical activity peers. Conclusions: These results indicate that almost half of elderly adults are dehydrated. The study suggests that being physically active can contribute to better fluid replenishment.","PeriodicalId":51894,"journal":{"name":"Acta Gymnica","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46454285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: Physically active people present overall accelerated bone turnover. However, less is known about the effects of different types of resistance training on bone metabolism markers among adolescent weightlifters. Objective: The purpose of this study was to investigate the effects of isokinetic training versus isotonic training of rotator cuff muscles and one month of cessation of training on blood bone metabolism markers among adolescent advanced level weightlifters. Methods: Sixteen adolescent male weightlifters (age 14.88 ± 1.31 years) who represented their state in Malaysia were weight-matched and randomly assigned into two training groups: isokinetic training (FIT, n = 7) and isotonic training (TON, n = 9) groups. The experiment was conducted during the preparatory phase of the training cycle for a total of 24 sessions with three sessions per week for eight weeks using dynamometer or dumbbells. Blood samples were collected before the commencement of training, after training and one month following the cessation of training and analyzed for determining blood metabolism markers of serum osteocalcin, serum C-telopeptide of type 1 collagen (CTX-1), and serum total calcium. Results: Total calcium concentrations were not different between groups at any time, as indicated by a non-significant main effect of time (F = 1.89, p = .166) and no condition Ă time interaction effect (F = 0.64, p = .533). Serum osteocalcin concentrations were not different between groups at any time, as indicated by a non-significant main effect of time (F = 2.10, p = .162) and no condition Ă time interaction effect (F = 0.024, p = .912). Serum CTX-1 concentrations were not different between groups at any time, as indicated by a non-significant main effect of time (F = 3.12, p = .059) and no condition Ă time interaction effect (F = 1.59, p = .221). Conclusions: No significant changes were observed in serum total calcium, osteocalcin and CTX-1 following either eight weeks of isokinetic or isotonic additional training among advanced level of adolescent weightlifters.
{"title":"Changes of bone metabolism markers following additional isokinetic and isotonic training and its subsequent cessation in advanced level adolescent weightlifters","authors":"Mohamad Rahizam Abdul Rahim, S. Shaharudin","doi":"10.5507/ag.2018.024","DOIUrl":"https://doi.org/10.5507/ag.2018.024","url":null,"abstract":"Background: Physically active people present overall accelerated bone turnover. However, less is known about the effects of different types of resistance training on bone metabolism markers among adolescent weightlifters. Objective: The purpose of this study was to investigate the effects of isokinetic training versus isotonic training of rotator cuff muscles and one month of cessation of training on blood bone metabolism markers among adolescent advanced level weightlifters. Methods: Sixteen adolescent male weightlifters (age 14.88 ± 1.31 years) who represented their state in Malaysia were weight-matched and randomly assigned into two training groups: isokinetic training (FIT, n = 7) and isotonic training (TON, n = 9) groups. The experiment was conducted during the preparatory phase of the training cycle for a total of 24 sessions with three sessions per week for eight weeks using dynamometer or dumbbells. Blood samples were collected before the commencement of training, after training and one month following the cessation of training and analyzed for determining blood metabolism markers of serum osteocalcin, serum C-telopeptide of type 1 collagen (CTX-1), and serum total calcium. Results: Total calcium concentrations were not different between groups at any time, as indicated by a non-significant main effect of time (F = 1.89, p = .166) and no condition Ă time interaction effect (F = 0.64, p = .533). Serum osteocalcin concentrations were not different between groups at any time, as indicated by a non-significant main effect of time (F = 2.10, p = .162) and no condition Ă time interaction effect (F = 0.024, p = .912). Serum CTX-1 concentrations were not different between groups at any time, as indicated by a non-significant main effect of time (F = 3.12, p = .059) and no condition Ă time interaction effect (F = 1.59, p = .221). Conclusions: No significant changes were observed in serum total calcium, osteocalcin and CTX-1 following either eight weeks of isokinetic or isotonic additional training among advanced level of adolescent weightlifters.","PeriodicalId":51894,"journal":{"name":"Acta Gymnica","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46220907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bojan MeÄedoviÄ, R. Romanov, V. Zubanov, DuĹĄan PeriÄ, DuĹĄan Stupar, Zlatko AhmetoviÄ
Background: Various field tests can be used to evaluate children's motor skills. Because of the complexity of their motor skills, which at their age are still in a very intensive stage of development, it is inadequate to use the same test protocol as in the adult population, as children receive and process information in a different way. Some evidence showed that familiarization with test protocols is important in children's motor skills evaluation process. Objective: The purpose of this study was to examine the influence of familiarization on motor test results for the assessment of motor skills in preschool children population. A controlled research study design was conducted. Methods: The sample included 40 children, 20 boys and 20 girls (age 5.89 ± 0.42 years). Subjects underwent two testing sessions with two weeks between the trials, performed 6 motor skills: leg power, flexibility, abdominal muscles endurance, shoulder muscles endurance, agility, and running speed. Before the second testing session, subjects underwent a period of familiarization with motor tasks in 3 sessions, with 3 trials every 3 days. Results: Significantly better results in the second testing session were observed in countermovement jump (with both fixed and free arms), curl-ups, speed and agility test. The present study indicates that children significantly improved the results in the motor test of explosive strength, muscle endurance, speed and agility, being influenced by familiarization. Conclusions: The results of this study indicate that familiarization with the test procedures prior to testing affect the results of the motor test, and represent an important part of the evaluation of motor skills of preschool children.
{"title":"Influence of familiarization on preschool children's motor tests results","authors":"Bojan MeÄedoviÄ, R. Romanov, V. Zubanov, DuĹĄan PeriÄ, DuĹĄan Stupar, Zlatko AhmetoviÄ","doi":"10.5507/ag.2018.020","DOIUrl":"https://doi.org/10.5507/ag.2018.020","url":null,"abstract":"Background: Various field tests can be used to evaluate children's motor skills. Because of the complexity of their motor skills, which at their age are still in a very intensive stage of development, it is inadequate to use the same test protocol as in the adult population, as children receive and process information in a different way. Some evidence showed that familiarization with test protocols is important in children's motor skills evaluation process. Objective: The purpose of this study was to examine the influence of familiarization on motor test results for the assessment of motor skills in preschool children population. A controlled research study design was conducted. Methods: The sample included 40 children, 20 boys and 20 girls (age 5.89 ± 0.42 years). Subjects underwent two testing sessions with two weeks between the trials, performed 6 motor skills: leg power, flexibility, abdominal muscles endurance, shoulder muscles endurance, agility, and running speed. Before the second testing session, subjects underwent a period of familiarization with motor tasks in 3 sessions, with 3 trials every 3 days. Results: Significantly better results in the second testing session were observed in countermovement jump (with both fixed and free arms), curl-ups, speed and agility test. The present study indicates that children significantly improved the results in the motor test of explosive strength, muscle endurance, speed and agility, being influenced by familiarization. Conclusions: The results of this study indicate that familiarization with the test procedures prior to testing affect the results of the motor test, and represent an important part of the evaluation of motor skills of preschool children.","PeriodicalId":51894,"journal":{"name":"Acta Gymnica","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44580341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Katarzyna Stronska, P. Bojacz, A. Gołaś, A. Maszczyk, A. Zając, P. Stastny
Background: The incline machine shoulder press (IMSP) is an alternative resistance exercise to the bench press associated with throwing performance. The muscle activity during IMSP has not yet been described in females and at different exercises intensities. Objectives: The aim of this present study was to investigate changes in the activity of prime movers during the IMSP in relation to the exercise intensity in female athletes. Methods: Eight female athletes experienced in resistance training were screened for peak electromyography amplitude normalized for maximum voluntary isometric contraction during the IMSP with increasing loads of 40%, 60%, 80% and 100% of 1 repetition maximum (1RM). The selected muscles were the anterior deltoid (AD), pectoralis major (PM), triceps brachii long head (TBlong) and triceps brachii lateral head (TBlat). Results: The results of Friedman ANOVA showed increased muscle activity along with exercise intensity in all prime movers (p < .001). The Kruskal-Wallis ANOVA showed inter-muscle differences at exercise intensity of 40% 1RM (p = .004, ηp2 = .52), 60% 1RM (p = .005, ηp2 = .55), 80% 1RM (p = .035, ηp2 = .46) and 100% 1RM (p = .002, ηp2 = .52), where TBlat showed lower activity than other muscle groups at each exercise intensity. The TBlong showed lower activity than the PM and AD at 40% 1RM, and the PM activity was lower than that of AD and TBlong at 100% 1RM. Conclusions: The IMSP is an exercise which activated AD and TBlong more than PM and TBlat during maximal lifting effort. Therefore, the IMSP should be understood as the exercise which might substantially overload the AD and TBlong during maximal lifts. Coaches should use the IMSP if they desire to activate TBlong more than TBlat during upper limb pressing.
{"title":"Muscle activity during the incline shoulder press in relation to the exercise intensity","authors":"Katarzyna Stronska, P. Bojacz, A. Gołaś, A. Maszczyk, A. Zając, P. Stastny","doi":"10.5507/ag.2018.019","DOIUrl":"https://doi.org/10.5507/ag.2018.019","url":null,"abstract":"Background: The incline machine shoulder press (IMSP) is an alternative resistance exercise to the bench press associated with throwing performance. The muscle activity during IMSP has not yet been described in females and at different exercises intensities. Objectives: The aim of this present study was to investigate changes in the activity of prime movers during the IMSP in relation to the exercise intensity in female athletes. Methods: Eight female athletes experienced in resistance training were screened for peak electromyography amplitude normalized for maximum voluntary isometric contraction during the IMSP with increasing loads of 40%, 60%, 80% and 100% of 1 repetition maximum (1RM). The selected muscles were the anterior deltoid (AD), pectoralis major (PM), triceps brachii long head (TBlong) and triceps brachii lateral head (TBlat). Results: The results of Friedman ANOVA showed increased muscle activity along with exercise intensity in all prime movers (p < .001). The Kruskal-Wallis ANOVA showed inter-muscle differences at exercise intensity of 40% 1RM (p = .004, ηp2 = .52), 60% 1RM (p = .005, ηp2 = .55), 80% 1RM (p = .035, ηp2 = .46) and 100% 1RM (p = .002, ηp2 = .52), where TBlat showed lower activity than other muscle groups at each exercise intensity. The TBlong showed lower activity than the PM and AD at 40% 1RM, and the PM activity was lower than that of AD and TBlong at 100% 1RM. Conclusions: The IMSP is an exercise which activated AD and TBlong more than PM and TBlat during maximal lifting effort. Therefore, the IMSP should be understood as the exercise which might substantially overload the AD and TBlong during maximal lifts. Coaches should use the IMSP if they desire to activate TBlong more than TBlat during upper limb pressing.","PeriodicalId":51894,"journal":{"name":"Acta Gymnica","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46780852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eliška Štefanová, T. Baška, Zuzana Boberova, Daniela Husárová, Z. Veselska, H. Hudeckova
Background: Understanding opinions, attitudes and knowledge of schoolchildren regarding eating habits is essential to develop effective preventive measures in this target group. Objective: The aim of the study was to find opinions and attitudes of schoolchildren regarding nutrition and related behaviour. Methods: Data were collected in selected elementary schools from April to June 2015. Pupils of 5th (7 girls, 7 boys), 7th (4 girls, 4 boys) and 9th (8 girls, 10 boys) grades debated their opinions and attitudes regarding eating habits during sessions in classrooms and recorded them into worksheets. Qualitative content analysis of the obtained data was performed. Results: Pupils expressed adequate knowledge on healthy eating habits. Attractiveness of sweets is much stronger in comparison to fruits and vegetables. 11 years olds complained about absence of their parents during family mealtime. The main reasons for drinking soft and energy drinks included taste and social motives. Girls were concerned about their body image and mentioned vomiting as a method to reduce body weight. Conclusions: Children possess general principles of healthy eating habits, but they do not implement them in their life. Prevention in nutrition to avoid social-health problems related to unhealthy diet, particularly obesity, should be focused both on children and their parents as role models in development of eating habits.
{"title":"\"Voice of Children\": Qualitative analysis of children's interpretations regarding nutritional behaviour","authors":"Eliška Štefanová, T. Baška, Zuzana Boberova, Daniela Husárová, Z. Veselska, H. Hudeckova","doi":"10.5507/ag.2018.017","DOIUrl":"https://doi.org/10.5507/ag.2018.017","url":null,"abstract":"Background: Understanding opinions, attitudes and knowledge of schoolchildren regarding eating habits is essential to develop effective preventive measures in this target group. Objective: The aim of the study was to find opinions and attitudes of schoolchildren regarding nutrition and related behaviour. Methods: Data were collected in selected elementary schools from April to June 2015. Pupils of 5th (7 girls, 7 boys), 7th (4 girls, 4 boys) and 9th (8 girls, 10 boys) grades debated their opinions and attitudes regarding eating habits during sessions in classrooms and recorded them into worksheets. Qualitative content analysis of the obtained data was performed. Results: Pupils expressed adequate knowledge on healthy eating habits. Attractiveness of sweets is much stronger in comparison to fruits and vegetables. 11 years olds complained about absence of their parents during family mealtime. The main reasons for drinking soft and energy drinks included taste and social motives. Girls were concerned about their body image and mentioned vomiting as a method to reduce body weight. Conclusions: Children possess general principles of healthy eating habits, but they do not implement them in their life. Prevention in nutrition to avoid social-health problems related to unhealthy diet, particularly obesity, should be focused both on children and their parents as role models in development of eating habits.","PeriodicalId":51894,"journal":{"name":"Acta Gymnica","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2018-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48455150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Polakovičová, Miroslav Vavák, R. Ollé, M. Lehnert, M. Sigmund
Background: Vertical jump is one of the most prevalent activities performed in volleyball. During adolescence, boys and girls undergo substantial changes in physiological and anthropometric characteristics that influence vertical jump performance. Objective: The purpose of this study was to examine and quantify sex and age-related differences in vertical jump performance assessed as vertical jumps height (VJH) and ground contact time (Tc) during repeated vertical jump tests within the Czech and Slovak population of elite adolescent volleyball players. Further aims were to compare the obtained results to non-athletic adolescent national normative data and investigate the relationship between basic anthropometric measures and VJH. Methods: The cross-sectional study was conducted on 203 females and 180 males from 13 to 19 years old. Statistical analysis of VJH differences between sex and age categories was performed using two-way ANOVA with Tukey's post hoc test. The relationship between basic anthropometric parameters and VJH were examined by Pearson's correlation analysis. Results: ANOVA showed statistically significant differences in VJH between males and females (p .05). Volleyball players have significantly higher VJH than non-athletes across all age categories and sex differences in volleyball players were smaller than the sex differences among non-athletic adolescents. A correlation analysis revealed only weak sex specific correlations of VJH with body height, body mass and BMI. Conclusions: The presented study showed significant sex differences in VJH between elite male and female volleyball players from the age of 15. VJH increases continually with increasing age in males. In females the effect of age on VJH was insignificant.
{"title":"Vertical jump development in elite adolescent volleyball players: Effects of sex and age","authors":"M. Polakovičová, Miroslav Vavák, R. Ollé, M. Lehnert, M. Sigmund","doi":"10.5507/ag.2018.016","DOIUrl":"https://doi.org/10.5507/ag.2018.016","url":null,"abstract":"Background: Vertical jump is one of the most prevalent activities performed in volleyball. During adolescence, boys and girls undergo substantial changes in physiological and anthropometric characteristics that influence vertical jump performance. Objective: The purpose of this study was to examine and quantify sex and age-related differences in vertical jump performance assessed as vertical jumps height (VJH) and ground contact time (Tc) during repeated vertical jump tests within the Czech and Slovak population of elite adolescent volleyball players. Further aims were to compare the obtained results to non-athletic adolescent national normative data and investigate the relationship between basic anthropometric measures and VJH. Methods: The cross-sectional study was conducted on 203 females and 180 males from 13 to 19 years old. Statistical analysis of VJH differences between sex and age categories was performed using two-way ANOVA with Tukey's post hoc test. The relationship between basic anthropometric parameters and VJH were examined by Pearson's correlation analysis. Results: ANOVA showed statistically significant differences in VJH between males and females (p .05). Volleyball players have significantly higher VJH than non-athletes across all age categories and sex differences in volleyball players were smaller than the sex differences among non-athletic adolescents. A correlation analysis revealed only weak sex specific correlations of VJH with body height, body mass and BMI. Conclusions: The presented study showed significant sex differences in VJH between elite male and female volleyball players from the age of 15. VJH increases continually with increasing age in males. In females the effect of age on VJH was insignificant.","PeriodicalId":51894,"journal":{"name":"Acta Gymnica","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2018-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44784856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Hojka, J. Tufano, T. Malý, P. Stastny, R. Jebavy, Jan Feher, F. Zahálka, T. Gryc
Background: Previous research has determined the validity and reliability of accelerometer-based devices, but the findings are not consistent. Objective: The purpose of this study was to determine the validity of an accelerometer (Myotest PRO) for measuring explosive strength indicators (jump height, peak force, peak velocity, and peak power) during the countermovement jump. Methods: Thirty-three university students (22 males and 11 females; 178.6 ± 5.6 cm, 69.3 ± 6.5 kg, 21.8 ± 1.7 years) performed five individual countermovement jumps. Jump height was derived from an accelerometer (Myotest, frequency 200 Hz), optic timing system (Optojump) and from a force plate (Kistler, frequency 800 Hz) using both flight time and force impulse algorithms. Peak force, peak velocity, and peak power were calculated by the accelerometer and force plate. Results: The Myotest resulted in systematic bias, overestimating jump height by 8.0 ± 2.1 cm (p < .001) compared to force impulse algorithm; flight time algorithm by 5.5 ± 2.0 cm (p < .001) using the force plate and by 5.9 ± 2.0 cm (p < .001) using the Optojump. The Myotest also underestimated peak force by 167 ± 182 N (p < .001). Compared to force impulse algorithm, the Myotest displayed less agreement for peak velocity (r2 = .245) and peak power (r2 = .557). Conclusion: Accelerometers are valid and may be used consistently to evaluate countermovement jump height. However, they are not valid, and should neither be used to measure peak force, velocity, or power nor be compared against other methods due to a bias.
{"title":"Concurrent validity of Myotest for assessing explosive strength indicators in countermovement jump","authors":"V. Hojka, J. Tufano, T. Malý, P. Stastny, R. Jebavy, Jan Feher, F. Zahálka, T. Gryc","doi":"10.5507/AG.2018.013","DOIUrl":"https://doi.org/10.5507/AG.2018.013","url":null,"abstract":"Background: Previous research has determined the validity and reliability of accelerometer-based devices, but the findings are not consistent. Objective: The purpose of this study was to determine the validity of an accelerometer (Myotest PRO) for measuring explosive strength indicators (jump height, peak force, peak velocity, and peak power) during the countermovement jump. Methods: Thirty-three university students (22 males and 11 females; 178.6 ± 5.6 cm, 69.3 ± 6.5 kg, 21.8 ± 1.7 years) performed five individual countermovement jumps. Jump height was derived from an accelerometer (Myotest, frequency 200 Hz), optic timing system (Optojump) and from a force plate (Kistler, frequency 800 Hz) using both flight time and force impulse algorithms. Peak force, peak velocity, and peak power were calculated by the accelerometer and force plate. Results: The Myotest resulted in systematic bias, overestimating jump height by 8.0 ± 2.1 cm (p < .001) compared to force impulse algorithm; flight time algorithm by 5.5 ± 2.0 cm (p < .001) using the force plate and by 5.9 ± 2.0 cm (p < .001) using the Optojump. The Myotest also underestimated peak force by 167 ± 182 N (p < .001). Compared to force impulse algorithm, the Myotest displayed less agreement for peak velocity (r2 = .245) and peak power (r2 = .557). Conclusion: Accelerometers are valid and may be used consistently to evaluate countermovement jump height. However, they are not valid, and should neither be used to measure peak force, velocity, or power nor be compared against other methods due to a bias.","PeriodicalId":51894,"journal":{"name":"Acta Gymnica","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2018-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47560101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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