Effect of Plyometric Jump Training on Skeletal Muscle Hypertrophy in Healthy Individuals: A Systematic Review With Multilevel Meta-Analysis.

Objective: To examine the effect of plyometric jump training on skeletal muscle hypertrophy in healthy individuals. Methods: A systematic literature search was conducted in the databases PubMed, SPORTDiscus, Web of Science, and Cochrane Library up to September 2021. Results: Fifteen studies met the inclusion criteria. The main overall finding (44 effect sizes across 15 clusters median = 2, range = 1-15 effects per cluster) indicated that plyometric jump training had small to moderate effects [standardised mean difference (SMD) = 0.47 (95% CIs = 0.23-0.71); p < 0.001] on skeletal muscle hypertrophy. Subgroup analyses for training experience revealed trivial to large effects in non-athletes [SMD = 0.55 (95% CIs = 0.18-0.93); p = 0.007] and trivial to moderate effects in athletes [SMD = 0.33 (95% CIs = 0.16-0.51); p = 0.001]. Regarding muscle groups, results showed moderate effects for the knee extensors [SMD = 0.72 (95% CIs = 0.66-0.78), p < 0.001] and equivocal effects for the plantar flexors [SMD = 0.65 (95% CIs = -0.25-1.55); p = 0.143]. As to the assessment methods of skeletal muscle hypertrophy, findings indicated trivial to small effects for prediction equations [SMD = 0.29 (95% CIs = 0.16-0.42); p < 0.001] and moderate-to-large effects for ultrasound imaging [SMD = 0.74 (95% CIs = 0.59-0.89); p < 0.001]. Meta-regression analysis indicated that the weekly session frequency moderates the effect of plyometric jump training on skeletal muscle hypertrophy, with a higher weekly session frequency inducing larger hypertrophic gains [ß = 0.3233 (95% CIs = 0.2041-0.4425); p < 0.001]. We found no clear evidence that age, sex, total training period, single session duration, or the number of jumps per week moderate the effect of plyometric jump training on skeletal muscle hypertrophy [ß = -0.0133 to 0.0433 (95% CIs = -0.0387 to 0.1215); p = 0.101-0.751]. Conclusion: Plyometric jump training can induce skeletal muscle hypertrophy, regardless of age and sex. There is evidence for relatively larger effects in non-athletes compared with athletes. Further, the weekly session frequency seems to moderate the effect of plyometric jump training on skeletal muscle hypertrophy, whereby more frequent weekly plyometric jump training sessions elicit larger hypertrophic adaptations.

Effects of high-intensity interval training and plyometric exercise on the physical fitness of junior male handball players.

OBJECTIVE: This study analyzed the effects of high intensity interval training (HIIT) combined with plyometric exercise on the physical fitness of junior male handball players. PATIENTS AND METHODS: Subjects (age ~17 years) were randomly divided between experimental (n=17) and control (n=15) groups. During the 8-week intervention, the experimental group replaced a part of their regular regimen by HIIT, combined with plyometric exercise. Assessments in both groups before and after the intervention included: squat jump (SJ), countermovement jump (CMJ), sprint performance (5 m, 10 m, 20 m and 30 m), change of direction tests (Illinois modified test [Illinois-MT] and T-half test), 20-m shuttle run, and repeated sprint T-test. RESULTS: The two-way analyses of variance revealed significant group-time interactions (all p<0.05), favoring the intervention group in 5 m, 10 m, 20 m and 30 m sprint (d=0.33, 8.3%; d=0.52, 7.6%; d=0.57, 6.8%; and d=0.58, 8.8%, respectively), T-half (d=0.25, 5.1%), Illinois-MT (d=0.47, 4.2%), SJ and CMJ (d=0.34-0.39, 34-4-34.9%), repeated sprint T-test best time, mean time and total time (d=0.83, 6.9%; d=0.62, 7.4%; and d=0.61, 7.2%, respectively), 20 meter shuttle run test aerobic maximum speed and predicted maximal oxygen intake (d=0.36, 7.5%; d=0.19, 9.4%, respectively). CONCLUSIONS: HIIT combined with plyometrics can aid in the development of physical fitness abilities, which are extremely important to junior male handball players.

Home-based exercise programmes improve physical fitness of healthy older adults: A PRISMA-compliant systematic review and meta-analysis with relevance for COVID-19.

This systematic review and meta-analysis aimed to examine the effects of home-based exercise programmes on measures of physical-fitness in healthy older adults. Seventeen randomized-controlled trials were included with a total of 1,477 participants. Results indicated small effects of home-based training on muscle strength (between-study standardised-mean-difference [SMD] = 0.30), muscle power (SMD = 0.43), muscular endurance (SMD = 0.28), and balance (SMD = 0.28). We found no statistically significant effects for single-mode strength vs. multimodal training (e.g., combined balance, strength, and flexibility exercises) on measures of muscle strength and balance. Single-mode strength training had moderate effects on muscle strength (SMD = 0.51) and balance (SMD = 0.65) while multimodal training had no statistically significant effects on muscle strength and balance. Irrespective of the training type, >3 weekly sessions produced larger effects on muscle strength (SMD = 0.45) and balance (SMD = 0.37) compared with ≤3 weekly sessions (muscle strength: SMD = 0.28; balance: SMD = 0.24). For session-duration, only ≤30 min per-session produced small effects on muscle strength (SMD = 0.35) and balance (SMD = 0.34). No statistically significant differences were observed between all independently-computed single-training factors. Home-based exercise appears effective to improve components of health- (i.e., muscle strength and muscular endurance) and skill-related (i.e., muscle power, balance) physical-fitness. Therefore, in times of restricted physical activity due to pandemics, home-based exercises constitute an alternative to counteract physical inactivity and preserve/improve the health and fitness of healthy older adults aged 65-to-83 years.

Association between adiposity levels and cognitive impairment in the Chilean older adult population.

Although both obesity and ageing are risk factors for cognitive impairment, there is no evidence in Chile on how obesity levels are associated with cognitive function. Therefore, the aim of the present study was to investigate the association between adiposity levels and cognitive impairment in older Chilean adults. This cross-sectional study includes 1384 participants, over 60 years of age, from the Chilean National Health Survey 2009-2010. Cognitive impairment was evaluated using the Mini-Mental State Examination. BMI and waist circumference (WC) were used as measures of adiposity. Compared with people with a normal BMI, the odds of cognitive impairment were higher in participants who were underweight (OR 4·44; 95 % CI 2·43, 6·45; P < 0·0001), overweight (OR 1·86; 95 % CI 1·06, 2·66; P = 0·031) and obese (OR 2·26; 95 % CI 1·31, 3·21; P = 0·003). The associations were robust after adjustment for confounding variables. Similar results were observed for WC. Low and high levels of adiposity are associated with an increased likelihood of cognitive impairment in older adults in Chile.

Composición corporal y somatotipo de rugbistas chilenos y su relación con la posición de juego / Body composition and somatotype of chilean rugby players and their relationship with the game position

RESUMEN: El objetivo del estudio fue describir las características morfoestructurales, por posición de juego, en rugbistas de la región de Valparaíso, Chile. La estatura, peso, índice de masa corporal (IMC) y otros 25 parámetros antropométricos fueron obtenidos desde 121 rugbistas competitivos (24,2 ± 4,9 años), siguiendo los estándares de medición de la Sociedad Internacional para el Avance de la Kinantropometría (ISAK). La composición corporal fue descrita en 5 componentes a través del método propuesto por Kerr, estos son masa muscular, adiposa, residual, ósea y piel. El uso del somatotipo descrito por Carter y Heath, permitió describir los componentes de endomorfía, mesomorfía y ectomorfía. Para comparar las características morfoestructurales de los rugbistas por posición de juego, estos fueron separados en forwards y backs. El peso corporal, la estatura sentado y de pie, el IMC y la sumatoria de 8 pliegues fueron mayores en los forwards que los backs (p<0,0001). En relación a las masas corporales, el tejido adiposo y muscular absoluto fueron mayores en los forwards que en los backs (P< 0,01), no así el relativo. El somatotipo evidenció mayor endomorfía y mesomorfía, y menor ectomorfía, en los forwards 4,8-6,9-0,7 (1,8-1,3-0,8) que los backs 3,7-6,1-1,2 (1,8-1,1-0,8) con P<0,01. En conclusión, la posición de juego en el rugby es determinante en la definición de características físicas básicas y morfológicas. El mayor peso corporal de los forwards respecto a los backs se encuentra influenciado por la presencia de más tejido muscular y adiposo. Esto último se relacionó con un mayor componente mesomórfico y endomórfico del somatotipo, y menor del ectomórfico, en los forwards. A pesar de estas diferencias ambos grupos se encuentran en una clasificación de endo-mesomorfo.

SUMMARY: The objective of the study was to describe the morpho-structural characteristics according to playing position, in rugby players from the region of Valparaíso, Chile. Height, weight, body mass index (BMI) and other 25 anthropometric parameters were obtained from 121 competitive rugby players (24.2 ± 4.9 years), following the recommendations of the International Society for the advancement of Kinanthropometry. The body composition was described in 5 components through the method proposed by Kerr, they are muscle, fat, residual, bone and skin. The somatotype described by Carter and Heath, allowed to describe the components of endomorphy, mesomorphy and ectomorphy. To compare the morphostructural characteristics of the rugby players by playing position, these were separated into forwards and backs. Body weight, sitting and standing height, BMI and S 8-fold were higher in the forwards than the backs (p <0.0001). In relation to body mass, adipose tissue and absolute muscle were higher in the forwards than in the backs (P <0.01), but not in the relative. The somatotype showed significant differences in the averages of the three components between forwards 4.8-6.9-0.7 (1.8-1.3-0.8) and backs 3.7-6.1-1, 2 (1.8-1.1-0.8) with P <0.01. In conclusion, the playing position in rugby is decisive in the definition of basic physical and morphological characteristics. A higher body weight of the forwards versus backs is influenced by a greater muscle and adipose tissues. Latter was related to a greater mesomorphic and endomorphic component of the somatotype, and lower ectomorphic in the forwards. Despite these differences, both groups are classified as endo-mesomorph.

Exercise and glucose control in children with insulin resistance: prevalence of non-responders.

BACKGROUND: Exercise training improves cardiometabolic outcomes in 'mean terms', but little information is available in children about the impact of the frequency/week and the wide inter-individual variability to exercise training reported in adults. OBJECTIVES: We compared the effects of resistance training (RT) and high-intensity interval training (HIT), and 'high' and 'low' frequency of training/week, for their effectiveness in decreasing insulin resistance (IR) levels in schoolchildren. A second aim was to decscribe and compare the prevalence of non-responders (NRs) between the different frequencies of training protocol. METHODS: Fifty-three schoolchildren with IR were randomly assigned into four groups: RT at high frequency (three times/week), HIT at high frequency, RT at a low frequency (two times/week) and HIT at low frequency. The intervention lasted 6 weeks. Blood samples and body composition, blood pressure and performance measurements were taken before and after the intervention. RESULTS: The prevalence of NRs was similar between the RTHF and HITHF (25.0% vs. 25.0%, P > 0.05) and RTLF and HITLF groups (20.0% vs. 46.6%, P = 0.174) for decreasing homeostasis model assessment of IR. However, significant differences in the prevalence of NRs were detected between RTHF and HITHF groups in fasting glucose (FGL) (18.7% vs. 58.3%, P < 0.031). CONCLUSIONS: Both RT and HIT improves the glucose control parameters in schoolchildren over 6 weeks, but only HIT is independent of a high or low frequency of training/week. The prevalence of NRs is similar for decreasing homeostasis model assessment of IR comparing each exercise mode in high vs. low frequency/week. However, both high- and low-frequency RT and HIT results in differences in the prevalence of NRs for FGL and other cardiometabolic and performance outcomes.

Interindividual responses to different exercise stimuli among insulin-resistant women.

We aimed to investigate which among 20 cardiometabolic and performance outcomes do and do not respond to high-intensity interval training (HIT), resistance training (RT), or concurrent training (CT) in insulin-resistant adult women. A secondary aim was to report the training-induced changes and the prevalence of non-responders. Forty-five insulin-resistant adult women were randomly assigned to one of the following 4 groups: HIT (39.2 ± 9.5 years [y]; body mass index [BMI], 29.3 ± 3.3; n = 14), RT (33.9 ± 9.3 y; BMI, 29.4 ± 5.5; n = 8), CT (43.3 ± 8.1 y; BMI, 29.1 ± 2.9; n = 10), and a control group (CG, 40.1 ± 11.4 y; BMI, 28.3 ± 3.5; n = 13). Nine body composition, 3 cardiovascular, 3 metabolic, and 5 performance outcomes were assessed at baseline and after 12 weeks of intervention. Considering all outcomes, the lowest number of total non-responses for one or more variables was found in the RT group, followed by the CT and HIT groups. Individuals in the CG group were classified as non-responders for almost all the variables. Moreover, there were several significant changes in body composition and metabolic parameters, including fasting glucose (HIT: -5.7, RT -5.1 mg/d), fasting insulin (HIT: -0.6, RT -0.6 µIU/mL), and HOMA-IR (HIT: -0.3, RT -0.4), in addition to improvements in cardiovascular and performance parameters. Also, there were significant differences among groups in the prevalence of non-responders for the variables where a non-response was detected. Overall, the study suggests that independent of the mode of training including volume and frequency, RT has an important ability to reduce the prevalence of non-response to improve the 20 outcomes of health and performance in insulin-resistant adult women.

Metabolic effects of resistance or high-intensity interval training among glycemic control-nonresponsive children with insulin resistance.

BACKGROUND: Little evidence exists on which variables of body composition or muscular strength mediates more glucose control improvements taking into account inter-individual metabolic variability to different modes of exercise training. OBJECTIVE: We examined 'mediators' to the effects of 6-weeks of resistance training (RT) or high-intensity interval training (HIT) on glucose control parameters in physically inactive schoolchildren with insulin resistance (IR). Second, we also determined both training-induce changes and the prevalence of responders (R) and non-responders (NR) to decrease the IR level. METHODS: Fifty-six physically inactive children diagnosed with IR followed a RT or supervised HIT program for 6 weeks. Participants were classified based on ΔHOMA-IR into glycemic control R (decrease in homeostasis model assessment-IR (HOMA-IR) <3.0 after intervention) and NRs (no changes or values HOMA-IR⩾3.0 after intervention). The primary outcome was HOMA-IR associated with their mediators; second, the training-induced changes to glucose control parameters; and third the report of R and NR to improve body composition, cardiovascular, metabolic and performance variables. RESULTS: Mediation analysis revealed that improvements (decreases) in abdominal fat by the waist circumference can explain more the effects (decreases) of HOMA-IR in physically inactive schoolchildren under RT or HIT regimes. The same analysis showed that increased one-maximum repetition leg-extension was correlated with the change in HOMA-IR (ß=-0.058; P=0.049). Furthermore, a change in the waist circumference fully mediated the dose-response relationship between changes in the leg-extension strength and HOMA-IR (ß'=-0.004; P=0.178). RT or HIT were associated with significant improvements in body composition, muscular strength, blood pressure and cardiometabolic parameters irrespective of improvement in glycemic control response. Both glucose control RT-R and HIT-R (respectively), had significant improvements in mean HOMA-IR, mean muscular strength leg-extension and mean measures of adiposity. CONCLUSIONS: The improvements in the lower body strength and the decreases in waist circumference can explain more the effects of the improvements in glucose control of IR schoolchildren in R group after 6 weeks of RT or HIT, showing both regimes similar effects on body composition or muscular strength independent of interindividual metabolic response variability.

Jump Training in Youth Soccer Players: Effects of Haltere Type Handheld Loading.

The aim of this study was to compare the effects of a jump training program, with or without haltere type handheld loading, on maximal intensity exercise performance. Youth soccer players (12.1±2.2 y) were assigned to either a jump training group (JG, n=21), a jump training group plus haltere type handheld loading (LJG, n=21), or a control group following only soccer training (CG, n=21). Athletes were evaluated for maximal-intensity performance measures before and after 6 weeks of training, during an in-season training period. The CG achieved a significant change in maximal kicking velocity only (ES=0.11-0.20). Both jump training groups improved in right leg (ES=0.28-0.45) and left leg horizontal countermovement jump with arms (ES=0.32-0.47), horizontal countermovement jump with arms (ES=0.28-0.37), vertical countermovement jump with arms (ES=0.26), 20-cm drop jump reactive strength index (ES=0.20-0.37), and maximal kicking velocity (ES=0.27-0.34). Nevertheless, compared to the CG, only the LJG exhibited greater improvements in all performance tests. Therefore, haltere type handheld loading further enhances performance adaptations during jump training in youth soccer players.

Low-Volume High-Intensity Interval Training as a Therapy for Type 2 Diabetes.

Our purpose was to investigate the effects of low-volume, high-intensity interval training (HIT) on cardiometabolic risk and exercise capacity in women with type 2 diabetes mellitus (T2DM). Sedentary overweight/obese T2DM women (age=44.5±1.8 years; BMI=30.5±0.6 kg/m(2)) were randomly assigned to a tri-weekly running-based HIT program (n=13) or non-exercise control follow-up (CON; n=10). Glycemic control, lipid and blood pressure levels, endurance performance, and anthropometry were measured before and after the follow-up (16 weeks) in both groups. Medication intake was also assessed throughout the follow-up. Improvements (P<0.05) on fasting glucose (14.3±1.4%), HbA1c (12.8±1.1%), systolic blood pressure (3.7±0.5 mmHg), HDL-cholesterol (21.1±2.8%), triglycerides (17.7±2.8%), endurance performance (9.8±1.0%), body weight (2.2±0.3%), BMI (2.1±0.3%), waist circumference (4.0±0.5%) and subcutaneous fat (18.6±1.4%) were found after HIT intervention. Patients of HIT group also showed reductions in daily dosage of antihyperglycemic and antihypertensive medication during follow-up. No changes were found in any variable of CON group. The HIT-induced improvements occurred with a weekly time commitment 56-25% lower than the minimal recommended in current guidelines. These findings suggest that low-volume HIT may be a time-efficient intervention to treat T2DM women.

Efecto de 8 semanas de corriente TENS modificada y la corriente rusa, sobre la fuerza muscular y la composición corporal / Efeito de 8 semanas de corrente TENS modificada e corrente russa sobre a força e composição corporal / Effects of 8 weeks of modified TENS current and russian current, on muscle strength and body composition

Objetivo. Comparar el efecto de 2 métodos de electroestimulación en las siguientes variables: fuerza y antropometría. Método. Se realizó una investigación experimental, aleatoria y simple ciego. Se evaluó a 18 sujetos, distribuidos en: Grupo Corriente TENS Modificada (CTM: n = 6), Grupo Corriente Rusa (CR: n = 6) y Grupo Control (TC: n = 6, sometido a corriente TENS Convencional, considerada en la presente investigación como placebo). Resultados. Al cabo de 8 semanas, solo CTM incrementó la fuerza máxima (p < 0.035) y redujo el grosor del pliegue subcutáneo de la pierna derecha (p < 0.03). Conclusiones. La técnica de electroestimulación con corriente TENS Modificada es efectiva para el entrenamiento muscular (AU)

Objetivo. Comparar o efeito de 2 métodos de eletroestimulação nas seguintes variáveis: força e antropometria. Método. Um estudo experimental, randomizado, cego simples. Foram avaliados 18 indivíduos, distribuídos em: grupo de corrente TENS modificada (CTM: n = 6), grupo corrente russa (CR: n = 6) e grupo controle (TC: n = 6, submetido a corrente TENS convencional, considerada nesta investigação como placebo). Resultados. Após 8 semanas, CTM aumentou a força máxima (p < 0,035) e reduziu a espessura de pregas subcutâneas da coxa direita (p < 0,03). Conclusões. A técnica de eletroestimulação com corrente TENS modificada é eficaz para treinamento muscular (AU)

Objective. To compare the effect of two methods of electrostimulation on the following variables: strength and anthropometry. Method. An experimental, randomized, and simple blind investigation was performed. Eighteen subjects were evaluated distributed into a Modified TENS Current Group (CTM: n = 6), Russian Current Group (CR: n = 6), and a Control Group (TC: n = 6, submitted to traditional TENS current, considered as placebo in this research). Results. After 8 weeks, only CTM obtained an increase in maximal strength (p < 0.035), and a reduction in the subcutaneous fat thickness of the right thigh (p < 0.03). Conclusions. A Modified TENS Current is effective for muscular training (AU)

Desgaste protésico en sujetos con reemplazo articular total de tobillo HINTEGRA de origen postraumático en fase funcional / Prosthetic wear in subjects with HINTEGRA total ankle joint replacement secondary to trauma in functional phase

Objetivo: El objetivo de nuestra investigación fue describir en fase funcional, la restauración del comportamiento de las fuerzas articulares de tobillo y sus factores mecánicos durante la marcha en sujetos con reemplazo articular total de tobillo con prótesis HINTEGRA unilateral de origen postraumático. Material y métodos: Dieciséis sujetos de sexo masculino, 8 con prótesis HINTEGRA unilateral de origen postraumático y 8 sujetos sin prótesis HINTEGRA, se sometieron a un análisis de marcha. El comportamiento de las fuerzas articulares de tobillo y sus factores mecánicos fueron obtenidos. Se empleó un análisis de correlación cruzada junto a la prueba U Mann-Whitney no pareada (alfa = 0,05). Resultados: Existió significación estadística con un menor coeficiente de correlación cruzada en la fuerza articular anteroposterior, mediolateral y ambiente articular de cizalla; menor segundo peak compresivo, peak posterior, primer peak anterior, segundo peak anterior, tiempo de segundo peak vertical, peak de momento plantiflexor, y mayor tiempo de primer peak vertical en sujetos con prótesis HINTEGRA. Conclusiones: Los resultados indican que sujetos con prótesis HINTEGRA de origen postraumático presentan alteración del comportamiento de las fuerzas articulares de tobillo durante fase functional, generando una ineficiente función amortiguadora y de propulsión, creando un ambiente patomecánico de cizalla predisponente de un mayor desgaste de la interface en fase funcional

Objective: The objective of our research was to describe the recovery behavior of the ankle joint forces and their mechanical factors during gait in subjects with total ankle replacement with unilateral HINTEGRA prosthesis secondary to trauma during the functional phase. Material and methods: Sixteen male subjects, 8 with unilateral HINTEGRA prosthesis secondary to trauma and 8 subjects without HINTEGRA prosthesis underwent gait analysis. The ankle joint forces behavior and its mechanical factors during gait were obtained. A cross correlation analysis was used with a non-paired Mann-Whitney U test (alfa = 0.05). Results: There was statistical significance with a smaller cross-correlation coefficient in the anteroposterior, mediolateral joint forces and in shear force environment; lesser second compressive peak, posterior peak, first anterior peak, second anterior peak, time of the second vertical peak, plantar flexion moment peak; and a higher first vertical peak time in subjects with HINTEGRA prosthesis. Conclusions: These results suggest that subjects with HINTEGRA prosthesis secondary to trauma have impaired behavior of the ankle joint forces during the functional phase, creating an inefficient damping and propulsion function, this creating a pathomechanic shear environment that predisposes to higher wear of the interface in the functional phase

Effects of general, specific and combined warm-up on explosive muscular performance.

The purpose of this study was to compare the acute effects of general, specific and combined warm-up (WU) on explosive performance. Healthy male (n = 10) subjects participated in six WU protocols in a crossover randomized study design. Protocols were: passive rest (PR; 15 min of passive rest), running (Run; 5 min of running at 70% of maximum heart rate), stretching (STR; 5 min of static stretching exercise), jumping [Jump; 5 min of jumping exercises - 3x8 countermovement jumps (CMJ) and 3x8 drop jumps from 60 cm (DJ60)], and combined (COM; protocols Run+STR+Jump combined). Immediately before and after each WU, subjects were assessed for explosive concentric-only (i.e. squat jump - SJ), slow stretch-shortening cycle (i.e. CMJ), fast stretch-shortening cycle (i.e. DJ60) and contact time (CT) muscle performance. PR significantly reduced SJ performance (p =0.007). Run increased SJ (p =0.0001) and CMJ (p =0.002). STR increased CMJ (p =0.048). Specific WU (i.e. Jump) increased SJ (p =0.001), CMJ (p =0.028) and DJ60 (p =0.006) performance. COM increased CMJ performance (p =0.006). Jump was superior in SJ performance vs. PR (p =0.001). Jump reduced (p =0.03) CT in DJ60. In conclusion, general, specific and combined WU increase slow stretch-shortening cycle (SSC) muscle performance, but only specific WU increases fast SSC muscle performance. Therefore, to increase fast SSC performance, specific fast SSC muscle actions must be included during the WU.

Caracterización del consumo de suplementos nutricionales en población físicamente activa de gimnasios del sur de Chile / Characterization of nutritional supplements consumption in physically active population in gyms of southern Chile

El consumo de suplementos nutricionales (SN) se ha investigado generalmente en relación al rendimiento deportivo. Menos información existe en relación a población no deportista pero físicamente activa. Objetivo y metodología: El objetivo fue conocer las características de los consumidores de SN en 412 usuarios (179 mujeres) de gimnasios de cuatro ciudades del sur de Chile. El instrumento utilizado para recolectar datos correspondió a un cuestionario previamente validado (1), estructurado con preguntas cerradas, alternativas y preguntas abiertas en relación al consumo de SN. Para su interpretación se utilizaron estadísticos descriptivos y de comparación (i.e. Chi cuadrado). El nivel de significancia estadística se estableció en p<0,05. Resultados: los resultados revelan que 22% de los usuarios consumen SN. De los hombres consumidores, 37% lo realiza para aumentar masa muscular y 36% para mejorar el rendimiento físico. Entre las mujeres, 32% los consume por motivos relacionados a salud. Los SN más consumidos fueron: proteínas (36%), vitaminas y minerales (11%), creatina (10%), aminoácidos y carbohidratos (8%). En cuanto al perfil del consumidor, está representado por jóvenes de entre 15 a 25 años, dedicados en su mayoría al estudio y al trabajo, con menos de un año de asistencia al gimnasio y una frecuencia de asistencia ≥ 3 sesiones/semana. Conclusión: un relativamente bajo consumo de SN fue observado,en comparación con deportistas, influenciado por la edad,el género y el uso de dieta o alimentación especial. Varones jóvenes (i.e. 15 a 25 años de edad) que trabajan, con una alta frecuencia de asistencia a gimnasios (≥ 3 sesiones/semana) son los principales consumidores de SN...

Anthropometric characteristics of top-class Brazilian jiu jitsu athletes: role of fighting style / Características antropométricas en atletas de jiu jitsu brasilero de alto nivel: rol del estilo de lucha

Human performance efficiency and effectiveness in different sports depend to a large extent on the size, weight and proportion of the physique of the athlete. The aim of this study was to identify morphological characteristics of Brazilian Jiu-Jitsu (BJJ) athletes. The sample consisted of 25 highly trained male athletes who were classified according to their fighting style; guard fighter (GF) vs. pass fighter (PF). The athletes were assessed for somatotype, body composition and proportionality. For the whole group of athletes the somatotype was 2.23±0.68, 6.33±1.14, and 1.75±0.87 for endomorph, mesomorph and ectomorph components, respectively. Muscle and adipose tissue percentages were 52.34±2.15% and 19.30±2.51%, respectively. PF were significantly more mesomorph (p< 0.05) and less ectomorph (p< 0.05) than GF. Also, PF had significantly higher phantom Z score for bone mass vs. GF (0.51±0.57 vs. 0.01±0.54; p<0.05), and significantly lower muscle mass- bone mass ratio (4.55±0.31 vs. 4.77±0.56; p<0.05), height (1.71±0.06 vs. 1.77±0.07; p<0.05) and height weight ratio (40.58±1.11 vs. 41.84±1.22). Our results show that morphological characteristics are related to different fighting styles in BJJ athletes.

La eficiencia y efectividad del rendimiento humano en diferentes deportes depende en gran medida del tamaño, peso y proporción del físico del atleta. El objetivo de este estudio fue identificar las características morfológicas de atletas jiu-jitsu brasileros. La muestra consintió de 25 atletas varones altamente entrenados, quienes fueron clasificados de acuerdo a su estilo de lucha; guarderos (GF) vs pasadores (PF). Se evaluó en los atletas somatotipo, composición corporal y proporcionalidad. Para el grupo total de atletas el somatotipo fue 2,23±0,68, 6,33±1,14 y 1,75±0,78 para el endomorfismo, mesomorfismo y ectomorfismo, respectivamente. Los porcentajes de tejido muscular y adiposo fueron 52,34±2,15% and 19,30±2,51%, respectivamente. PF fueron significativamente las mesomorfos (p<0,05) y menos ectomorfos (p<0,05) que GF. Además PF tuvieron una significativamente alto Z score para la masa ósea (4,55±0,31 vs. 4,77±0,56; p<0,05), estatura (1,71±0,06 vs. 1,77±0,07; p<0,05) y relación altura peso (40,58±1.11 vs. 41,84±1.22). Nuestros resultados muestran que las características morfológicas están relacionadas a diferentes estilos de lucha en atletas de BJJ.

Efectos agudos y crónicos del entrenamiento aeróbico y el desentrenamiento en la presión arterial de mujeres hipertensas / Acute and chronic effects of aerobic training and detraining on blood pressure of hypertensive women

Introducción: La actividad física es un eficaz tratamiento para la hipertensión, pero el entrenamiento debe ser constante. Objetivo Medir los efectos del entrenamiento aeróbico y el desentrenamiento en la presión arterial de mujeres hipertensas. Materiales y métodos Doce mujeres con hipertensión se sometieron a 2 semanas de entrenamiento aeróbico y a 2 semanas de desentrenamiento. Resultados Los resultados muestran diferencias significativas para la presión arterial sistólica y diastólica 4 h y 3 h posterior al ejercicio. Se encontraron reducciones crónicas en la presión arterial sistólica y diastólica después de 2 semanas de entrenamiento aeróbico p < 0,01 y p < 0,05 respectivamente. No se encontraron diferencias significativas cuando se compararon las presiones arteriales basales y después del desentrenamiento Conclusiones Los efectos positivos del entrenamiento aeróbico desaparecen solo después de 2 semanas de desentrenamiento

Introduction: Physical activity is an effective treatment for hypertension, but the training must be constant to maintain the adaptations. Objective: To measure the effects of aerobic training and detraining on blood pressure of Materials and methods: Twelve hypertensive women underwent 2 weeks of aerobic training and 2 weeks of detraining. Results: The results have shown significant differences regarding systolic and diastolic blood pressure at 4 h and 3 h post-exercise, respectively. Chronic reductions were found for systolic and diastolic blood pressure after 2 weeks of aerobic training: P<.01 and P<.05, respectively. Significant differences were not found when systolic and diastolic blood pressures were compared at baseline versus after detraining

Perfil somatotípico del futbolista profesional chileno / Somatotype profile of professional male soccer Chilean players

El presente estudio pretende describir el somatotipo del futbolista profesional chileno, así como determinar la variabilidad existente en el somatotipo por posición de juego. Cien jugadores profesionales varones (edad 23±4,4 años), participantes del campeonato nacional de fútbol chileno fueron incluidos en el estudio. Se realizó la medición de 10 variables antropométricas según las normas de la International Society for the Advancement of Kinanthropometry (ISAK). Se calcularon los 3 componentes del somatotipo de Heath-Carter por cada posición de juego. El somatotipo grupal de la muestra estudiada presentó una clasificación de mesomorfo­balanceado (2,25-5,32-2,26), siendo los defensas los con mayor predominio de este componente. La posición con menor dispersión en su somatotipo son defensas y arqueros, mientras que volantes y delanteros presentan mayor variabilidad. En conclusión, a pesar de existir un somatotipo en común, las diferencias en las varianzas entre posiciones de juego entregan información sobre la relevancia de la optimización morfológica en una posición específica de juego.

The aim of this study was to describe the somatotype of Chilean professional soccer players, and to determine the variability in the somatotype by playing position. One hundred professional male players (age 23±4.4) participants in the Chilean national soccer championship were included in the study. We performed the measurement of 10 anthropometric variables according to the rules of the International Society for the Advancement of Kinanthropometry (ISAK). We calculated the 3 components of the Heath-Carter somatotype for each playing position. The somatotype of the sample group presents a balanced mesomorph classification (2.25-5.32-2.26),especially among defenders. The positions with less dispersion in their somatotype were the defenses and goalkeepers, while the flyers and forwards show more variability. In conclusion, although there is a common somatotype, differences in the variances between playing positions provide information about the relevance of morphological optimization in a playing position.

Autonomic control of heart rate after exercise in trained wrestlers.

The objective of this study was to establish differences in vagal reactivation, through heart rate recovery and heart rate variability post exercise, in Brazilian jiu-jitsu wrestlers (BJJW). A total of 18 male athletes were evaluated, ten highly trained (HT) and eight moderately trained (MT), who performed a maximum incremental test. At the end of the exercise, the R-R intervals were recorded during the first minute of recovery. We calculated heart rate recovery (HRR60s), and performed linear and non-linear (standard deviation of instantaneous beat-to-beat R-R interval variability - SD1) analysis of heart rate variability (HRV), using the tachogram of the first minute of recovery divided into four segments of 15 s each (0-15 s, 15-30 s, 30-45 s, 45-60 s). Between HT and MT individuals, there were statistically significant differences in HRR60s (p <0.05) and in the non linear analysis of HRV from SD130-45s (p <0.05) and SD145-60s (p <0.05). The results of this research suggest that heart rate kinetics during the first minute after exercise are related to training level and can be used as an index for autonomic cardiovascular control in BJJW.