Monem Jemni

Comparison of the Wingate and Bosco anaerobic tests.

The purpose of this study was to compare the Wingate cycling and Bosco repeated jumps anaerobic tests. Eleven men (21.36 ± 1.6 years; 179.1 ± 9.3 cm; 78.7 ± 11.0 kg) and 9 women (21.89 ± 3.66 years; 171.8 ± 10.0 cm; 75.9 ± 21.4 kg), all university athletes, volunteered to participate. Subjects performed each test in random order. The tests consisted of a 30-second Wingate test and a 60-second Bosco test. The Wingate test was conducted using a Monark cycle ergometer and the Bosco test was conducted on a force platform. Following the performance of each test, peak lactate concentrations were determined. Average and peak power values were statistically greater in men and on the Bosco test. Peak lactate values were statistically greater in men but did not differ based on test. Correlations between peak lactate concentrations between tests and lactate values with peak or average power were not statistically significant. The relationship between peak power between tests was statistically significant among men, but not women. The results of the study indicated that the Bosco and Wingate tests, which both measure anaerobic characteristics, appear to measure different aspects of anaerobic power and capacity. The Bosco test also may be inappropriate for athletes who are not well trained in jumping.

The effect of vibration on active and passive range of motion in elite female synchronized swimmers.

Abstract The purpose of this study was to assess the acute effects of vibration and stretching on passive and active forward split range of motion in elite adult female synchronized swimmers. Eleven athletes performed a passive forward split test measuring the height of the anterior superior iliac spine on both sides and an active split test on both sides by adopting an inverted split position. Then athletes were assigned randomly by right or left leg to receive vibration on one leg while stretching. The contralateral leg was stretched but did not receive vibration and served as the control. The treatment involved a 40-s exposure to vibration of the forward leg in a split and 40 s of vibration to the rear leg in a split. The athletes were then post-tested using the same protocols. The results indicated that the vibration had a statistically significant influence on passive forward split flexibility, but not active split flexibility. The results of this study confirm earlier work and further demonstrate the efficacy of vibration in enhancing range of motion in a passive split position. Given that it is often difficult to achieve large changes in range of motion with already highly trained elite athletes, this methodology shows considerable promise. Vibration may not be powerful enough to evoke changes in active range of motion in spite of the changes in passive range of motion.

A systematic review to determine reliability and usefulness of the field-based test batteries for the assessment of physical fitness in adolescents - The ASSO Project.

The aim of the present review is to investigate the main field-based tests, used alone or included in sport or fitness batteries, for the assessment of health- and skill-related physical fitness components in adolescents. Different scientific databases were searched through using the selected key words related to physical fitness and its components for adolescence. The search focused on original articles and reviews/meta-analyses using valid, reproducible and feasible tests that fit within the school environment. A total of 100 scientific manuscripts were included in the qualitative synthesis. The present systematic review pointed out 5 fitness tests that well adapt to the evaluation of the components of physical fitness of adolescents within a school environment: the 20 m shuttle run test for cardio-respiratory endurance; the handgrip strength test for upper body maximal strength; the standing broad jump test for lower body maximal strength; the sit-up test to exhaustion for muscular endurance and the 4×10 m shuttle run test for speed, agility and coordination. These fitness tests have been finally selected and incorporated into the Adolescents and Surveillance System for the Obesity prevention - Fitness Test Battery (ASSO-FTB), and will be adopted within the ASSO Project for evaluation purposes. This instrument could be also provided to teachers and people working in schools in order to assess physical fitness of adolescents over time and prevent obesity and related diseases.

Design, Implementation, and Evaluation of the Adolescents and Surveillance System for the Obesity Prevention Project

AbstractThe Adolescents Surveillance System for Obesity prevention (ASSO) Project aimed at developing standardized and web-based tools for collecting data on adolescents’ obesity and its potential determinants. This has been implemented and piloted in the local area of Palermo city, Italy. The aim of the present study is to provide an overview of the Projects design, implementation, and evaluation, highlighting all the aspects for a potential scale-up of the surveillance system on the whole national territory and abroad, as a sustainable and effective source of data.The overall structure and management, the ASSO-toolkit, the ASSO-NutFit software, and all developed and used procedures for recruiting, training, and data collecting/analyzing are addressed. An interim evaluation has been performed through a feasibility study; a final Project evaluation has been performed reporting the Strengths, Weaknesses, Opportunities, and Threats (SWOT) and the attributes that a surveillance system should have.This article provides a detailed overview of the Project and highlights that ASSO can be considered a valid, logical, coherent, efficient, and sustainable surveillance system that is consistent with countries’ needs and priorities.The system developed by the ASSO Project provides high-quality data and complies with several characteristics typical of a suitable surveillance system. It has a potential of being adopted within the National Health Service and other countries’ Health Services for monitoring adolescents’ obesity and its determinants, such as food intakes, behaviors, physical activity, and fitness profiles.

Plyometric training performance in elite-oriented prepubertal female gymnasts.

Abstract Marina, M and Jemni, M. Plyometric training performance in elite-oriented prepubertal female gymnasts. J Strength Cond Res 28(4): 1015–1025, 2014—We studied the effectiveness of a combined strength and plyometric training program (experimental period) on jumping performance when compared with a training routine on apparatus (control period) over 2 successive gymnastics training seasons. Nine female elite-orientated gymnasts (around 30-hour training per week) were participated in the study. The study was based on a 20-month longitudinal design covering 2 training seasons separated by a competitive period and transition periods. Each season included 1 control and 1 experimental period (Ctrl&Dgr;1 + Ex&Dgr;1 and Ctrl&Dgr;2 + Ex&Dgr;2, respectively). Before and after each control and experimental period, we assessed plyometric performance by means of drop jumps (DJs) from 20, 40, 60, 80, and 100 cm. The jump performance variables considered were flight time (FT), contact time (CT), flight-contact ratio (FC), and estimated mechanical power (also called Bosco expression [BE]), all of which were expressed as raw data and normalized (expressed as a percentage) with respect to the recordings at the beginning of each period of analysis. Flight time was the only variable to increase not only during both experimental periods but also during both controls. Our results confirmed larger relative increments of all the variables (FT, CT, BE, and FC), except for CT at DJs of 80 and 100 cm, during the experimental periods than during their respective previous control periods. Despite the additive effect of growth, development, and maturation, the gymnasts were not able to maintain the DJ performance accomplished during Ex&Dgr;1, thereby confirming detraining during the competitive and transition periods. We conclude that a combination of heavy resistance training with high impact plyometric jumps is effective in prepubertal gymnasts, despite their initial high level of physical conditioning.

Southern Italian teenagers: the older they get, the unfit they become with girls worse than boys

Abstract Italy comprises a high proportion of people who never exercised. Low physical activity levels in adolescents is a risk factor for several disorders. The aim of this cohort epidemiological study was to compare physical fitness profiles between boys and girls with regard to age and gender and to identify health and fitness-related markers that contribute to the make-up of Southern Italian teenagers. Eight hundred eleven teenagers were assessed for anthropometric measurements and completed the 5 ASSO-fitness tests battery. Data were analyzed with a 2-way analysis of variance (ANOVA) for repeated measures to compare the effect of both age and gender on the fitness components. The boys’ anthropometric measurements were superior than the girls as expected [weight, height, body mass index (BMI), and waist circumference]; the overall BMI was found in the normality range. The overall teenagers’ fitness markers were found to be quite poor with the boys outperforming the girls in all fitness tests. The weak cardiorespiratory performance of the female teenagers was remarkable. The under 16 years old (-16 yrs) girls outperformed the over 16 years old (+16yrs) girls. There were less significant differences when comparing (-16) and (+16) yrs old mixed-gender groups. There were no correlations between the (−16) and (+16) yrs when both genders were considered. The trend analysis showed the younger teenagers might be “catching up” the older ones in both contexts. Gender significantly influenced all variables. Although age did not influence cardiorespiratory fitness, the older the teenagers the worse their health and fitness markers become with the older girls worse than their younger peers.

Acute Static Vibration-Induced Stretching Enhanced Muscle Viscoelasticity But Did Not Affect Maximal Voluntary Contractions in Footballers

Abstract Jemni, M, Mkaouer, B, Marina, M, Asllani, A, and Sands, WA. Acute static vibration-induced stretching enhanced muscle viscoelasticity but did not affect maximal voluntary contractions in footballers. J Strength Cond Res 28(11): 3105–3114, 2014—The aim of this study was to compare the effects of acute vibration-enhanced static stretching and/or static stretching alone on the strength and flexibility of the hamstrings and quadriceps muscles. Twenty-one male footballers participated in this study (21.9 ± 1.8 years; 75.54 ± 7.3 kg; 178.7 ± 6.5 cm). The experiment started with 5 minutes standardized warm-up followed by (a) baseline flexibility pretest (Split Test); (b) maximal voluntary flexion and extension (isokinetic strength) of the knee; (c) Treatment or Sham involving 45-second stretch with or without vibration for the hamstring and quadriceps muscle groups with 10-second rest between; and (d) posttest repeating the measures of the pretest. Each player randomly performed both trials on separate occasions. The vibration device operated at 35 Hz with 2 mm amplitude. Stretching with vibration statistically increased hamstring flexibility by 7.8% (p ⩽ 0.05) when compared with stretching without vibration. No statistical differences for hamstring or quadriceps strength were noted between treatment conditions. There was no statistical correlation between flexibility and strength measurements. In conclusion, flexibility increased with vibration-enhanced static stretching; however, no change was evident in the maximal voluntary contractions of the knee flexors and extensors.

Effect of Two Different Types of Olympic Rotation Order on Cardiovascular and Metabolic Variables in Men’s Artistic Gymnastics

Abstract The rotation sequence-order differs from a gymnast to another according to the draw at the time of the qualifying competitions in men’s artistic gymnastics. Only the six best gymnasts start on the floor exercises, the others could start on any of the other five apparatuses. It has been demonstrated that some gymnastics events are physiologically less taxing than others; hence some gymnasts could experience lower and/or higher levels of cardiovascular and metabolic stress compared to others, depending on the apparatus they start with. In this regard, the objective of this investigation was to compare cardiovascular and metabolic variables between two different types of Olympic rotation-order; one began with the floor exercises and the other began with the pommel horse. Six elite male gymnasts took part in this investigation. Heart rates, synchronized with real-time video acquisition, as well as capillary lactate concentration following each apparatus routine were monitored. Cardiovascular and metabolic stresses were significantly higher when gymnasts started their rotation with the pommel horse in all apparatuses except the pommel horse. The floor exercises’ score was significantly affected when gymnasts ended up their competition on this apparatus. As a conclusion, starting gymnastics’ competition on the floor exercises implicates less cardiovascular and metabolic stress associated with better performance compared with the other rotation order. As a matter of fact, best gymnasts who start on this apparatus could have a slight advantage compared with the other athletes.

Profiles of Physical Fitness Risk Behaviours in School Adolescents from the ASSO Project: A Latent Class Analysis

The aim of the present investigation was to describe profiles of adolescents’ fitness level, identify latent classes of fitness-related risk behaviours, and describe their sociodemographic and environmental predictors. In total, 883 adolescents (16.4 ± 1.4 years; 167.3 ± 10.4 cm; 62.8 ± 13.5 kg; 62.2% males) were assessed for personal and lifestyle information and for physical fitness components. Eleven possible fitness determinants and seven predictors were included. Latent class analysis (LCA) was used to determine fitness-related risk behaviours. Logistic regressions predicted class membership and assessed associations with fitness levels and fitness components. Five latent classes were recognised: 1—virtuous, 30.7% of respondents; 2—low physical activity/sport, 18.8%; 3—incorrect alcohol/food habits, 25.8%; 4—health risk/overweight, 15.9%; 5—malaise/diseases, 8.8%. Sex, age, parents’ overweightness/obesity and education, and school type predicted most classes significantly. Compared to class 1, class 2 had higher odds of having all poor fitness components except upper body maximal strength; class 4 had higher risk of low muscular endurance; and class 5 was likely to have lower maximal strength, muscular endurance, and speed/agility. Educating adolescents to reach a sufficient practice of PA/sport could help decreasing the risk of low health-related fitness more than discouraging them from using alcohol, addressing proper food behaviours and habits, and helping them understand their psychophysical malaise symptoms.

A fitness index model for Italian adolescents living in Southern Italy. The ASSO project

BACKGROUND Strong relations between physical fitness and health in adolescents have been established in the last decades. The main objectives of the present investigation were to assess major physical fitness components in a sample of Italian school adolescents, comparing them with international data, and providing a Fitness Index model derived from percentile cut-off values of five considered physical fitness components. METHODS A total of 644 school pupils (15.9±1.1 years; M: N.=399; F: N.=245) were tested using the ASSO-Fitness Test Battery (FTB), a tool developed within the Adolescents and Surveillance System for the Obesity prevention project, which included the handgrip, standing broad-jump, sit-up to exhaustion, 4×10-m shuttle run and 20-m shuttle run tests. Stratified percentile values and related smoothed curves were obtained. The method of principal components analysis (PCA) was applied to the considered five fitness components to derive a continuous fitness level score (the Fit-Score). A Likert-type scale on the Fit-Score values was applied to obtain an intuitive classification of the individual level of fitness: very poor (X<P20), poor (P20≤X<P40), medium (P40≤X<P60), good (P60≤X<P80) and very good (X≥P80). RESULTS Boys had higher fitness levels compared to girls. They also showed an incremental trend amongst fitness levels with age in all physical components. These results could be overlapped with those related to European adolescents. Data revealed high correlations (r>0.5) between the Fit-Score and all the fitness components. The median Fit-Score was equal to 33 for females and 53 for males (in a scale from 0 to 100). CONCLUSIONS The ASSO-FTB allowed the assessment of health-related fitness components in a convenient sample of Italian adolescents and provided a Fitness Index model incorporating all these components for an intuitive classification of fitness levels. If this model is confirmed, the monitoring of these variables will allow early detection of health-related issues in a mass population, thus giving the opportunity to plan appropriate interventions.