Cardiorespiratory and aerobic demands of squat exercise.

Squatting, a traditional resistance exercise classified as strength training, relies on anaerobic pathways, but its aerobic aspects remain unclear. We examined heart rate and oxygen demand during squats, exploring variations across different strength statuses. It fills gaps in understanding the cardiorespiratory effects of squatting, especially during multiple sets. Twenty-two young healthy resistance trained men (age: 28 ± 4 years) participated. Maximal oxygen consumption (V̇O2max) and 1 repetition maximum (RM) of squat were measured. Participants performed 5 sets of squat exercises at 65% of 1RM for 10 repetitions with 3-min rest intervals. Heart rate and pulmonary gas exchange were measured during the squat exercise. Participants were divided into high strength (HS; upper 50%) and low strength (LS; lower 50%) groups based on a median split of their 1 RM squat values (normalized to their body weight). During 5 sets of squat exercise, oxygen consumption (V̇O2) increased up to 47.8 ± 8.9 ml/kg/min, corresponding to 100.6% of predetermined V̇O2max. The HS group achieved a greater highest point of V̇O2 in relation to V̇O2max than the LS group (108.0 vs. 93.7%). During the exercise intervals, V̇O2 exceeded V̇CO2, while during the rest intervals, V̇CO2 surpassed V̇O2. Our findings suggest that the oxygen demand during squatting is notably substantial, which may vary according to the training status.

Postural control during the back squat at different load intensities in powerlifters and weightlifters.

BACKGROUND: The movement of the barbell has been detected as success factor for the snatch and the clean and jerk events. As the barbell's movement has been shown to be related to the athlete's body movement, we hypothesized that the latter could be a success factor also for the back squat (BS) event. Hence, this study aimed to investigate postural control during the execution of the BS at different load intensities in powerlifters and weightlifters. METHODS: Seventeen powerlifters and weightlifters were enrolled and the one-repetition maximum (1-RM) of the BS of each participant was measured. Afterwards, the assessment of postural control during the execution of the BS at different load intensities (i.e. 60%, 70%, 80%, 90%, 100%) of the 1-RM of each participant was carried out through a posturographic platform to measure the displacement of the centre of pressure (CoP). The following parameters were considered: sway path length (SPL), sway ellipse surface (SES), length/surface (LFS ratio), sway mean speed (SMS), CoP coordinates along X and Y planes. RESULTS: We found a significant increase in SPL and LFS ratio, and a significant decrease in SMS as the load intensity increased. In detail, we detected a significant difference in: (a) SPL between the BS at 60% and 80%, 60% and 90%, 60% and 100%; between the BS at 70% and 90%, 70% and 100%; between the BS at 80% and 100%; and between the BS at 90% and 100%; (b) SMS between the BS at 60% and 80%, 60% and 90%; (c) LFS ratio between the BS at 60% and 90%, 60% and 100%. CONCLUSIONS: These results suggest that powerlifters and weightlifters adopt different postural control strategies depending on the load intensity when performing the BS. Our findings showed that higher effort could affect postural control during the BS. Thus, postural control could be considered a success factor for the BS.

EmpowerHER: A Pilot Study to Increase Physical Activity and Strength Through Powerbuilding.

Engaging in empowering exercise develops movement competency (MC) and strength and supports physical health, mental well-being, and quality of life. Powerbuilding combines powerlifting and bodybuilding to increase physical activity (PA), MC, and strength. To our knowledge, powerbuilding has not been explored as an exercise intervention. This pilot study investigated the impact of an eight-week powerbuilding intervention on women's PA, MC, strength, and empowerment. Eighteen women aged 25.1±9.8 with no powerbuilding experience participated in the intervention, meeting three times weekly for one hour. PA and MC were assessed pre- and post-intervention. Three-repetition maximum (3-RM) tests in the squat, bench press, and deadlift were completed in weeks one and eight of the intervention. Data were checked for normality; the Wilcoxon signed-rank test was used for non-normally distributed data. The McNemar test was used to analyze differences in dichotomous variables. Effect size was calculated and interpreted as follows small (r=0.1, d=0.2, ω=0.1), medium (r=0.3, d=0.5, ω=0.3), and large (r=0.5, d=0.8, ω=0.5) Total PA ([t(17)=3.52, p=0.003, d=0.83]) and participants who met the PA guidelines (Z=6.13, p=0.008, ω=0.82) increased significantly from pre- to post-intervention. Participants' MC scores improved significantly from pre- (24.3±3.5) to post-intervention (29.5±2.5; [t(17)=10.04, p<0.001; d=2.37]). Significant increases in strength were observed (squat [Z=-3.73, p<0.001, r=0.88], bench press [Z=-3.73, p<0.001, r=0.88], and deadlift [t(17)=16.41, p<0.001; d=3.87]). Empowerment in exercise scores averaged 56.3±6.6 (on a scale of 5-65). The intervention significantly increased total PA, improved MC, increased strength, and facilitated empowerment. Women's participation in powerbuilding may enhance their quality of life.

Role of the Flexion Relaxation Phenomenon in the Analysis of Low Back Pain Risk in the Powerlifter: A Proof-of-Principle Study.

INTRODUCTION: Unlike the most common training approaches for bodybuilding, powerlifting programs are generally based on maximum and submaximal loads, putting enormous stresses on the lumbar spine. The flexion relaxation phenomenon evaluation is a clinical tool used for low back pain (LBP) assessment. This study aimed to evaluate the role of the flexion relaxation phenomenon in the analysis of LBP in the powerlifters. METHODS: Healthy professional powerlifters participated in the study. In fact, we divided the participants into a LBP-low-risk group and a LBP-high-risk group, based on a prior history of LBP. Outcome measures included flexion relaxation ratio (FRR) and trough surface electromyography collected during trunk maximum voluntary flexion; furthermore, during a bench press lifting, we measured the height of the arched back (ARCH), using a camera and the Kinovea video editing software, to consider a potential correlation with the risk of LBP. RESULTS: We included a group of 18 male (aged 24-39 y) powerlifters of 93 kg category. We measured a nonsignificant mean difference of ARCH between low-risk LBP group and high-risk LBP subjects. Curiously, maximum voluntary flexions were both above the threshold of 3.2 µV; therefore, with an absence of appropriate myoelectric silence, on the contrary, the FRR ratios were higher than 9.5, considering the presence of the phenomenon, exclusively for the low-risk group. The lumbar arched back measurement data did not report any association with the LBP risk, regarding the maximum voluntary flexion value, and even more than the FRR there is a relationship with the presence or the absence of LBP risk. CONCLUSIONS: FRR could be considered as a useful parameter for studying the risk of LBP in powerlifting. The FRR index not only refers to the possible myoelectric silence of the lumbar muscles in trunk maximum forward flexion but also takes into account the energy value delivered by the lumbar muscles during the flexion. Furthermore, we can indicate that the size of the powerlifter ARCH may not be a determining factor in the occurrence of LBP.

Comparison of Neuromuscular Fatigue in Powerlifting Paralympics in Different Training Methods.

Mean propulsive velocity (MPV) has been associated with neuromuscular fatigue; however, its suitability for strength training in Paralympic powerlifting (PP) remains uncertain. The objective of this work was to evaluate the MPV in two training methods (traditional-TRAD and eccentric-ECC). Eleven PP athletes were evaluated pre, during the intervention and post intervention at a load of 80% of the 1RM for TRAD and 110%-80% of 1 RM for ECC. The results demonstrated that there was no significant neuromuscular fatigue for the TRAD (~5% performance loss), as well as no significant decline in MPV during the intervention. For the ECC, there is a significant reduction in MPV before and after training (~12% loss of performance). A difference between TRAD and ECC after the intervention was also identified (0.87 m/s±0.22, 95% CI 0.72-1.02 vs. 0.72±0.20, 95% CI 0.59-0.86 p=0.042, F(3.30)=10.190, η2p=0.505 - very high effect). During the intervention for ECC, no significant decline in MPV was observed. The results of this study suggest that the mechanical indices of MPV do not seem to be effective indicators of neuromuscular fatigue in the sample studied or in the context of this specific training regime, being more indicated as a control of training volume.

Fueling for and recovering from resistance training: The periworkout nutrition practices of competitive powerlifters.

PURPOSE: Nutrient timing is a concept that emphasizes the intentional ingestion of whole or fortified foods, and dietary supplements, to adequately fuel for, and recover from, acute and chronic exercise. The nutrition strategies used by powerlifters around training sessions have not, to our knowledge, been previously investigated. This study explored the self-reported periworkout (before, during, and after) nutrition practices of competitive powerlifters, including what, why, and information source that informed practice, with comparison to current sport nutrition guidelines. METHODS: Actively competing male (n = 240) and female (n = 65) powerlifters completed a cross-sectional online survey of self-reported periworkout nutrition practices in the pre-, intra-, and postexercise periods, fasted training, and supplementation. Data are presented as the number (n) and percentage (%) of all powerlifters practicing a given strategy followed by a % of responses reporting various practices or beliefs within this strategy. Categorical subgroups (sex, age, and weight class; and competitive caliber) were analyzed with a chi-square test or Fisher's exact test and denoted where significant (P ≤ 0.05). RESULTS: Most powerlifters reported paying specific attention to nutrition practices in the pre-exercise period (n = 261; 85.6%) by ingesting more carbohydrate (CHO) rich foods (n = 234; 89.6%) for the purpose of assisting in training performance (n = 222; 85.1%). Most powerlifters reported intraexercise nutrition strategies (n = 211; 69.2%), of which most included ingesting more CHO rich foods (n = 159; 74.5%) for the purpose of feeling less hungry and/or boosting energy levels during training (n = 129; 61.1%). Most powerlifters reported paying attention to postexercise nutrition (n = 244; 80%), by ingesting more protein rich foods (n = 182; 74.6%) for the purpose of recovering better for the whole day (n = 152; 62.3%) and enhancing the benefits of training (n = 149; 61.1%). Most powerlifters did not complete training sessions in the fasted state (n = 262; 85.9%). Most powerlifters reported paying attention to supplementation before training (n = 237; 77.7%), of which preworkout formulas (n = 137; 57.8%), energy drinks (n = 101; 42.6%), creatine (n = 88; 37.1%), and caffeine pills (n = 70; 29.5%) were most reported. Supplementation was used to assist in training performance (n = 197; 83.1%) and increase wakefulness/alertness (n = 183; 77.2%). Males reported more often than females that they informed multiple elements of their nutrition practices with the information they read or watched somewhere (P = 0.002-0.012). CONCLUSION: The periworkout nutrition practices used by competitive powerlifters followed current sport nutrition guidelines, by using CHO sources to fuel for training and ensuring the provision of protein postexercise. Competitive powerlifters may wish to exert caution with supplementation, as there is a risk of harm or inadvertent doping.

The magnitude of correlation between deadlift 1RM and jumping performance is sports dependent.

Introduction: Based on the assumption of maximal strength as a basic ability, several studies show a high influence of maximum strength on jumping performance in several sport athletes. However, there is a wide range of correlations from r = 0.17-0.9 between squat 1RM and jumping performance in different sports. Additionally, there are only a few studies investigating the influence of deadlift one repetition maximum (1RM) on jumping performance. Thus, this study aimed to investigate the correlations between 1RM in the deadlift on jumping performance using the countermovement jump height (CMJ) and squat jump height (SJ) considering different sports. Methods: 103 athletes with experience in the deadlift from soccer, basketball, American football, powerlifting as well as participants from different sports without any deadlift experience (control group) were included to this study. Results: Overall statistics showed a significant moderate influence of deadlift 1RM (r = 0.301-0.472) on jumping performance. However, subgroup analysis showed no significant correlation between deadlift 1RM and jumping performance in control participants, while moderate correlations could be detected in powerlifters (r = 0.34-0.39), soccer players (r = 0.437-0.46), American football players (0.584-0.62) and high correlations in basketball players (r = 0.809-0.848) showing significant influence of type of sport on correlations between deadlift maximum strength and jumping performance. Discussion: Presented results underline movement velocity- and task specificity of strength training routines which is discussed in the light of the respective sports.

Lumbopelvic movement control in powerlifters with and without low back pain.

OBJECTIVES: To measure lumbopelvic movement control in powerlifters with and without low back pain (LBP). DESIGN: Quantitative Cross-sectional. PARTICIPANTS: Twelve powerlifters with LBP and 28 powerlifters without LBP. SETTING: Powerlifters were recruited in nine different cities and filmed while performing a movement control test battery. MAIN OUTCOME MEASURES: Lumbopelvic movement control test battery consisting of seven tests, with a possible score between 0 and 13. The tests were rated by a physical therapist blinded to the group allocation and comparisons of the frequency of current/incorrect tests between groups were calculated. RESULTS: There was no statistically significant difference in the movement control test battery between the powerlifters with LBP (Median = 7.0, (2-11)) and powerlifters without LBP (Median = 6.0, (1-10)) (P = 0.59). There were no statistically significant differences between groups when the individual movement control tests were analyzed separately. CONCLUSIONS: The lack of significant differences between groups indicates that performance in lumbopelvic movement control test might not be associated with LBP in powerlifters. More studies on associations between LBP and movement control and other body functions are needed to guide assessment and treatment of powerlifters with LBP and for investigation of possible risk factors for LBP in powerlifters.

Prevalence and incidence of health problems and their characteristics in Brazilian para athletes: A one-season single-center prospective pilot study.

BACKGROUND: Para athletes experience high prevalence and incidence of health problems related to sport. Despite this, there are few longitudinal studies. OBJECTIVE: To describe the characteristics, prevalence, incidence, and severity of health problems in para athletes from one of the Brazilian Paralympic Reference Centers during a sports season and to compare the prevalence of health problems between para athletics, para powerlifting, and para swimming. METHODS: This prospective pilot study was conducted from October 2019 to March 2020. The Oslo Sports Trauma Research Center Questionnaire on Health Problems was used to record injuries and illnesses every week for 24 weeks. The characteristics, prevalence, incidence, and severity of health problems were described for each modality. The prevalence of health problems was compared among the three sport modalities. RESULTS: Thirty-five para athletes participated. Most of the injuries occurred in the shoulder, and most illnesses caused respiratory and gastrointestinal symptoms. The average weekly prevalence and the incidence rate of health problems were 40.6% (95% CI 17.0-64.4) and 12.7 (95% CI 9.6-15.9) per 1000 athlete hours, respectively. Para powerlifting had the highest prevalence of all and substantial health problems; para swimming had the lowest prevalence of injuries; and para athletics had the lowest prevalence of illnesses. CONCLUSIONS: This group of Brazilian para athletes showed a high prevalence and incidence of health problems throughout the season. Para athletics, para powerlifting, and para swimming each had a different prevalence of injuries and illnesses.

Variability analysis of muscle activation symmetry to identify indicators of individual motor strategy: a case series on elite Paralympic powerlifters.

Introduction: In Paralympic powerlifting competitions, movement execution symmetry is a technical requirement influenced by individual athlete characteristics and motor strategies. Identifying the elements associated with individual motor strategies can offer valuable insight for improving sport performance. Therefore, this case series study aimed to explore muscle activation symmetry and its intra- and inter-individual variability to determine the muscles mostly related to individual motor strategies in elite Paralympic powerlifters. Methods: Bilateral electromyographic activation of the anterior deltoid (AD), pectoralis major (PM), latissimus dorsi (LD), triceps (TRI) and external oblique (EO) muscles were analysed in five elite Paralympic powerlifters while performing four sets of one-repetition maximum of Paralympic bench press. Muscle activation symmetry indexes (SI) were obtained and transformed to consider individual-independent evaluation. The coefficient of variation (CV), variance ratio (VR), and mean deviation (MD) were computed to assess inter- and intra-individual variability in electromyographic waveforms and SI. Results: Both transformed and non-transformed SI indicated overall symmetric activation in DA, PM, TRI, and LD. Transformed SI revealed asymmetrical muscle activation of EO when grouping data (mean bilateral difference: 10%). Athletes exhibited low intra-individual SI variability in all analysed muscles (CV < 10%) and low inter-individual variability in DA, PM, LD, and TRI (CV < 10%; VR: 4%-11%; MD: 29%-43%). In contrast, higher inter-individual variability was observed in EO (CV: 23%; VR: 23%; MD: 72%-81%). Conclusion: The highest variability and asymmetry in abdominal muscle activation among athletes emphasize the importance of personalized training approaches for targeting these muscles due to their role in individualizing motor strategies.

A comparison of rapid weight loss practices within international, national and regional powerlifters.

Background: Rapid weight loss (RWL) practices are common amongst strength-sport athletes to 'make weight' for a chosen weight class. Aim: This study compared the RWL practices of International Powerlifting Federation (IPF) powerlifters from Great Britain. Methods: Participants (n = 69, male = 36, female = 33) were recruited from IPF lifting populations (mandatory <2-hour competition weigh-in). Participants were categorised based on highest level of competition (regional, national and international) and also sex (male and female). The previously validated 'Rapid Weight Loss Questionnaire' established RWL practices, however also included an open-ended question regarding thoughts, feeling and mood during RWL. Results: Nearly all participants (97%) had purposely acutely reduced body mass to compete, with an average typical pre-competition loss of 4.2%. Regional competitors reported a higher 'typical' body mass loss compared to international competitors (5.5% vs 3.3%, p = 0.004). Females reported a greater 'highest' body mass loss than males (6.7% vs 5.3%, p = 0.028). Fluid restriction (86.5%), water loading (67.2%) and increased exercise (49.2%) were the RWL methods most commonly used 'always' or 'sometimes'. Content analysis revealed a predominance of negative perceptions during RWL with the emergence of codes; fatigue, sensations, anxiety, low mood and irritation, accounting for ∼70% of responses. Conclusion: Prevalence of RWL is high amongst competitive powerlifters, with many competitors attributing negative perceptions during the weight-cutting process. The magnitude of reported acute RWL within regional lifters was beyond where performance decrements are commonly seen (>5%), this should be cautioned against given the IPF's mandatory <2-hour competition weigh-in.

The general nutrition practices of competitive powerlifters vary by competitive calibre and sex, weight, and age class.

PURPOSE: To characterise self-reported nutrition practices and beliefs of powerlifters. METHODS: Actively competing male (n = 240) and female (n = 65) powerlifters completed a cross-sectional online survey of self-reported nutrition practices across the competitive cycle, within specific competitive phases, and hard and easy training days. Data are presented as number (n) and percentage (%) of all powerlifters practicing a given strategy followed by a % of responses reporting various practices or beliefs within this strategy. Differences in categorical sub-groups (sex, age, and weight class; and competitive calibre) were analysed with a chi-square test and denoted where significant (p ≤ 0.05). RESULTS: Most powerlifters reported following a specific diet long-term (n = 203, 66.6%) of which If It Fits Your Macros (IIFYM)/flexible dieting was most common (n = 159, 78.3%). Over half reported introducing a special diet for a competitive phase (n = 162, 53.1%), of which IIFYM/flexible dieting was most followed for competition preparation (n = 80, 63%) and off-season (n = 48, 71.6%). Compared to normal dietary intake, most reported eating more on harder training days (n = 219, 71.8%) and refraining from eating less on easier training days (n = 186, 61%). CONCLUSIONS: IIFYM/flexible dieting is commonly followed by powerlifters to support performance and body composition goals. Females seemed to report more often restricting energy and dieting for body composition reasons than males. Powerlifters tailor their energy intake on harder training days to the higher training demands but refrain from reducing energy intake on rest/easier training days.

Thoracolumbar and Lumbopelvic Spinal Alignment During the Barbell Back Squat: A Comparison Between Men and Women.

Background: Maintaining neutral spinal alignment is considered important when performing the barbell back squat exercise. Since male and female lifters may differ in injury location it is important to examine whether they differ in spinal alignment during the back squat. Objectives: The study aimed to quantify the spinal alignment in the upper and lower lumbar spine during the barbell back squat exercise in male and female lifters. Secondary aims were to compare alignment during the back squat to standing habitual lumbar spine alignment and determine whether male and female lifters differ in these aspects. Study Design: Observational, Cross-sectional. Methods: Competitive power- and weightlifters were recruited and performed three repetitions of the barbell back squat exercise using a load equivalent to 70% of their one-repetition maximum. Spinal alignment and range of motion were measured using inertial measurement units placed on the thoracic, lumbar and sacral spine. Data was presented descriptively and comparisons between men and women as well as spinal alignment in four different positions were done with a factorial repeated measures analysis of variance. Results: Twenty-three (14 males, 9 females) were included. During execution of the squat, spinal alignment adjustments in the lumbar spine were made in all three planes of movement, compared to the start position, in both male and female lifters. Compared to their standing habitual posture, all lifters adjusted their upper lumbar spine to a less lordotic position when in the start position of the back squat (standing upright with the barbell on their back). Only male lifters assumed a less lordotic alignment in their lower lumbar spine in the start position compared their habitual posture. Conclusions: Adjustments of spinal alignment, predominantly in the sagittal plane, are made during execution of the back squat in both male and female lifters. Further, lifters adopt a less lordotic alignment with a heavy barbell on their upper back, more so in male than female lifters. In conclusion, it seems that spinal alignment changes noticeably during the barbell back squat. Level of Evidence: 3©The Author(s).

Injury epidemiology in competing and non-competing spanish crossfit® practitioners / Epidemiología lesional en practicantes de crossfit® competidores y no competidores españoles

La falta de estudios sobre lesiones en Crossfit® en España, motiva la realización de este estudio epidemiológico descriptivo, observacional y retrospectivo, analizando la incidencia y las características de las lesiones sufridas por practicantes de Crossfit® competidores y no competidores. Se registraron las lesiones sufridas por 434 deportistas entre el 1 de enero y el 31 de diciembre de 2019. Se registraron datos sobre el número de lesiones, lesiones más frecuentes, distribución, tipo, ubicación, el momento en que ocurrieron y la causa de las lesiones que afectan el sistema musculoesquelético. La tasa de lesiones en esta población fue de 3,48 lesiones por 1000 horas de exposición al riesgo. El hombro y la zona lumbar fueron las zonas anatómicas más frecuentemente lesionadas, siendo el musculo y el tendón el tejido de asiento más habitual de las lesiones. El Powerlifting fue la actividad más lesiva. (AU)

The lack of studies on Crossfit® injuries in Spain, motivates the realization of this descriptive, observational and retrospective epidemiological study, analyzing the incidence and characteristics of injuries suffered by Crossfit® competitors and non-competitors.The injuries suffered by 434 athletes between from January 1st to December 31st 2019 were recorded. We collected data on the number of injuries, the most frequent injuries, their distribution, type, location, the moment at which these occurred and the cause of the injuries affecting the musculoeskeletal system. We found that the injury rate in this population was 3,48 injuries per 1000 hours of risk. The shoulder and lumbar area were the most frequently injured anatomical areas, with muscle and tendon being the most common seat tissue of injuries. Powerlifting was the most damaging activity. (AU)

Ischemic Preconditioning Improves the Bench-Press Maximal Strength in Resistance-Trained Men.

We investigated whether acute ischemic preconditioning (IPC) would affect upper limb maximal strength performance in resistance-trained men. Using a counterbalanced randomized crossover design, fifteen men (29.9 ± 5.9 yrs.; 86.3 ± 9.6 kg; 8.0 ± 5.0 yrs. resistance training experience) performed one-repetition maximum (1-RM) bench press tests on three different occasions: control, 10 min post-IPC or 10 min post-placebo (SHAM). One-way analysis of variance showed that the post-IPC condition increased (P < 0.0001) 1-RM loads compared to both control and post-SHAM (control 113.3 ± 15.9 kg vs. SHAM 113.9 ± 15.8 kg vs. IPC 115.7 ± 15.6 kg), while control and SHAM did not differ (P > 0.05). Individual results showed that 13 participants (~87%) improved their performance post-IPC compared to control, and 11 participants (~73%) performed better post-IPC compared to post-SHAM. Reported session rating of perceived exertion (RPE) was lower (P < 0.0001) post-IPC (8.5 ± 0.6 arb.u) compared to control (9.3 ± 0.5 arb.u) and post-SHAM (9.3 ± 0.5 arb.u). Therefore, we conclude that IPC acutely improves upper limb maximal strength performance and reduces session-RPE in resistance-trained men. These results suggest an acute ergogenic effect of IPC for strength and power sports such as powerlifting.

Análisis biomecánico de la sentadilla libre en el levantamiento de potencia en Quito

El análisis de la técnica deportiva desde el punto de vista biomecánico posibilita controlar los supuestos que conforman la técnica deportiva específica para su futuro perfeccionamiento, esto es esencial en la toma de decisiones como parte del proceso de dirección deportiva, sobre todo en deportes poco estudiados como es el powerlifting. En tal sentido, se determinó como objetivo de la investigación analizar biomecánicamente la técnica de sentadilla libre en el levantamiento de potencia por géneros. La investigación fue de tipo descriptiva-correlacional. Se estudiaron a 42 levantadores con rango etario entre 17-28 años, clasificados en dos grupos independientes según el género. Se estudió la técnica de la sentadilla libre en cuatro variables de análisis. No se evidenciaron diferencias significativas en ninguna de las variables analizadas. Se incluyó el ángulo de la rodilla (p=0.845), el pico de velocidad máxima (p=0.095) y la trayectoria del movimiento en su eje X (p=0.979) y su eje Y (p=0.845). No se evidenciaron diferencias entre los rangos etarios de los géneros estudiados (p=0.237). La técnica de sentadilla libre analizada, en su comparación por géneros, no evidenció diferencias significativas, aspecto que permitió deducir un nivel técnico similar entre los géneros estudiados. Se concluyó que, si es correcta la ejecución motriz específica en el deporte estudiado, el componente técnico del entrenamiento deportivo en powerlifting se cumple satisfactoriamente e independientemente del género entrenado.

SÍNTESE A análise da técnica esportiva do ponto de vista biomecânico permite controlar as suposições que compõem a técnica esportiva específica para seu futuro aperfeiçoamento, isto é essencial na tomada de decisões como parte do processo de gestão esportiva, especialmente em esportes pouco estudados, como o powerlifting. Neste sentido, o objetivo da pesquisa era analisar biomecanicamente a técnica de agachamento livre no powerlifting por gênero. A pesquisa foi descritivo-correlacional. Foram estudados 42 elevadores com idades entre 17-28 anos, classificados em dois grupos independentes de acordo com o gênero. A técnica do agachamento livre foi estudada em quatro variáveis de análise. Não foram encontradas diferenças significativas em nenhuma das variáveis analisadas. Foram incluídos o ângulo do joelho (p=0,845), a velocidade máxima de pico (p=0,095) e a trajetória do movimento em seu eixo X (p=0,979) e eixo Y (p=0,845). Não foram evidentes diferenças entre as faixas etárias dos gêneros estudados (p=0,237). A técnica de agachamento livre analisada, em sua comparação por gênero, não mostrou diferenças significativas, um aspecto que nos permitiu deduzir um nível técnico semelhante entre os gêneros estudados. Concluiu-se que, se a execução motora específica no esporte estudado estiver correta, o componente técnico do treinamento esportivo em powerlifting é cumprido satisfatoriamente e independentemente do gênero treinado.

The analysis of the sports technique from the biomechanical point of view makes it possible to control the assumptions that make up the specific sports technique for its future improvement, this is essential in decision-making as part of the sports management process, especially in sports little studied as It's powerlifting. In this sense, the research objective was to biomechanically analyze the free squat technique in power lifting by gender. The research was descriptive-correlational. Forty-two lifters with an age range between 17-28 years were studied, classified into two independent groups according to gender. The free squat technique was studied in four analysis variables. No significant differences were found in any of the variables analyzed. The knee angle (p=0.845), the maximum speed peak (p=0.095) and the trajectory of the movement in its X axis (p=0.979) and its Y axis (p=0.845) were included. No differences were found between the age ranges of the genders studied (p=0.237). The analyzed free squat technique, in its comparison by gender, did not show significant differences, an aspect that allowed us to deduce a similar technical level between the genders studied. It was concluded that, if the specific motor execution in the sport studied is correct, the technical component of sports training in powerlifting is satisfactorily fulfilled and regardless of the gender trained.

The rates of null and valid movements in parapowerlifting in international competitions / As taxas de movimentos nulos e válidos no parapowerlifting em competições internacionais / Tasa de levantamientos validos y nulos en competiciones internacionales de parapowerlifting

ABSTRACT The Paralympic system adapted the press modality, allowing the participation of people with physical disabilities called para-powerlifting (PPL). The purpose was to establish the rates of valid and invalid movements; identify if factors such as the weight category, gender, or athletes 'country have an influence on the results; A retrospective study was elaborated in which the results of the null and valid movements made in 12 international events of the 2013-2016 Paralympic cycle were recovered from the official page of the international paralympic committee The results indicate that in these twelve events a total of 6,759 movements were performed, of which 3,264 moves were valid and 2,991 were rated as null, with no significant differences in null movements between men and women. These results indicate the need to review the judging system or the use of visual technologies to reduce the rate of null movements.

RESUMO O sistema paraolímpico adaptou ama modalidade de supino, permitindo a participação de pessoas com deficiências físicas, denominada parapowerlifting (PPL). O objetivo foi estabelecer as taxas de movimentos válidos e inválidos; identificar se fatores como a categoria de peso, o gênero ou o país dos atletas influenciam os resultados; Foi elaborado um estudo retrospectivo no qual os resultados dos movimentos nulos e válidos realizados em 12 eventos internacionais do ciclo paraolímpico 2013-2016 foram recuperados da página oficial do Comitê Paraolímpico Internacional. Os resultados indicam que nesses doze eventos foi realizado um total de 6.759 movimentos, dos quais 3.264 movimentos foram válidos e 2.991 foram classificados como nulos, sem diferenças significativas nos movimentos nulos entre homens e mulheres. Esses resultados indicam a necessidade de revisar o sistema de julgamento ou o uso de tecnologias visuais para reduzir a taxa de movimentos nulos.

RESUMEN El sistema paralímpico, adaptó la modalidad de press plano, para permitir la participación de personas con discapacidad física, denominándola como para-powerlifting (PPL). El objetivo de este estudio fue establecer los índices de movimientos válidos y no válidos; identificar si factores como la categoría de peso, el sexo o el país de los atletas influyen en los resultados; se elaboró un estudio retrospectivo en el que se recuperaron de la página oficial del Comité Paralímpico Internacional los resultados de los movimientos nulos y válidos realizados en 12 eventos internacionales del ciclo paralímpico 2013-2016. Los resultados indican que en estos doce eventos se realizaron un total de 6.759 movimientos, de los cuales 3.264 movimientos fueron válidos y 2.991 fueron calificados como nulos, sin diferencias significativas en los movimientos nulos entre hombres y mujeres. Estos resultados demuestran que es necesario revisar el sistema de juzgamiento o implementar el uso de video para reducir la tasa de movimientos nulos.

Does Caffeine Supplementation Associated with Paralympic Powerlifting Training Interfere with Hemodynamic Indicators?

Exercise, including resistance exercise with high loads, has positive hemodynamic responses such as reduced systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), Pressure Product Rate (PPR), and estimated myocardial oxygen volume (MVO2). Caffeine (CA), used to improve performance, tends to interfere with BP and HR. This study aimed to analyze the effects of CA supplementation on hemodynamic indicators in Paralympic weightlifting (PP). The exercise was performed on 14 male athletes (32.4 ± 8.5 years; 81.7 ± 21.9 kg) for three weeks. Two conditions were evaluated: supplementation with CA Anhydrous 9 mg/kg and with placebo (PL). The adapted bench press was used, with 5 × 5 at 80% 1RM. We evaluated BP, HR, PPR, and MVO2, before, after, 5, 10, 20, 30, 40, 50, 60 min, and 24 h later. The CA presented higher absolute values in the pressure indicators than the PL, and after 24 h there was an inversion. The HR was higher in the CA and showed a reduction after 10 min. The PPR and MVO2 in the CA presented absolute values greater than the PL, and 24 h later there was an inversion. There was no hypotensive effect, but the use of CA did not present risks related to PPR and MVO2, demonstrating the safe use of this supplement in adapted strength sports.

Validation of an Automatic Inertial Sensor-Based Methodology for Detailed Barbell Velocity Monitoring during Maximal Paralympic Bench Press.

Current technologies based on inertial measurement units (IMUs) are considered valid and reliable tools for monitoring barbell velocity in strength training. However, the extracted outcomes are often limited to a few velocity metrics, such as mean or maximal velocity. This study aimed at validating a single IMU-based methodology to automatically obtain the barbell velocity full profile as well as key performance metrics during maximal Paralympic bench press. Seven Paralympic powerlifters (age: 30.5 ± 4.3 years, sitting height: 71.6 ± 6.8 cm, body mass: 72.5 ± 16.4 kg, one-repetition maximum: 148.4 ± 38.6 kg) performed four attempts of maximal Paralympic bench press. The barbell velocity profile and relevant metrics were automatically obtained from IMU linear acceleration through a custom-made algorithm and validated against a video-based reference system. The mean difference between devices was 0.00 ± 0.04 m·s−1 with low limits of agreement (<0.09 m·s−1) and moderate-to-good reliability (ICC: 0.55−0.90). Linear regression analysis showed large-to-very large associations between paired measurements (r: 0.57−0.91, p < 0.003; SEE: 0.02−0.06 m·s−1). The analysis of velocity curves showed a high spatial similarity and small differences between devices. The proposed methodology provided a good level of agreement, making it suitable for different applications in barbell velocity monitoring during maximal Paralympic bench press.