Competitive Weightlifters Research Articles

Elite coaching personality analysis in competitive weightlifting

Elite coaching personality analysis in competitive weightlifting

Acute Endocrine Responses With Long-Term Weight Lifting in a 51-Year-Old Male Weightlifter.

Eserhaut, DA, Fry, AC, Stone, MH, and Kraemer, WJ. Acute endocrine responses with long-term weightlifting in a 51 year old male weightlifter. J Strength Cond Res XX(X): 000-000, 2024-To study the effects of long-term (>35 years) competitive weightlifting on acute endocrine activity, a 51-year-old male two-time Olympian in weightlifting (Subject A) was compared with highly trained young male weightlifters (controls, n = 23; age = 17.7 ± 0.3 years). Between 1400 and 1700 hours, subjects performed 15 maximum effort vertical jumps, a series of single repetitions of the snatch progressing to a maximal effort, and 3 × 10 snatch pulls at 60% 1 repetition maximum. Blood sampling occurred at 0700 hours, pre-exercise, and +5 and +15 minutes postexercise. Exercise performances were comparable between Subject A and controls and elicited similar lactate responses at +5 minutes (mmol·L-1; A = 9.2; controls = 8.1 ± 0.4). Resting testosterone at 0700 hours was lower for Subject A than for the controls (nmol·L-1; A = 13.9; controls = 25.4 ± 2.0), although acute responses at +5 minutes were comparable (A = 21.6; controls 18.3 ± 1.5). Cortisol responses (nmol·L-1; A = 468.4, controls = 540.6 ± 32.3) and testosterone:cortisol ratio (A = 0.0461; controls = 0.0376 ± 0.004) were similar at +5 minutes. Subject A showed no 22 kDa growth hormone response at +5 minutes, while controls exhibited a substantial increase (µg·L-1; A = 0.4; controls = 16.7 ± 2.6). β-endorphin responses were no different at +15 minutes for Subject A relative to controls (pmol·L-1; A = 30.1; controls = 33.8 ± 3.7). Resting and exercise-induced endocrine physiology is partially modified with aging despite long-term participation in competitive weightlifting. Importantly, Subject A's testosterone response was largely preserved.

Validity and Reliability of a Commercially Available Inertial Sensor for Measuring Barbell Mechanics during Weightlifting

This study aimed to assess the validity and reliability of a commercially available inertial measurement unit (Enode) for measuring barbell kinematics and kinetics during a snatch. In order to assess validity and within- and between-session reliability, thirteen competitive weightlifters conducted two snatches on two separate occasions at 85% of their one-repetition maximum. The Enode sensor was attached to the barbell, with each lift recorded via the device’s native application concurrently with an 11-camera motion capture system. Passing–Bablok regression indicated fixed and proportional bias in some horizontal measures of barbell mechanics but showed no bias in all but one vertical variable. Collectively, this suggests that the Enode is a valid tool in the measurement of vertically derived, but not horizontally derived, variables from barbell kinematics. Within- and between-session reliability showed moderate to excellent ICCs, with trivial to small differences between repetitions and between sessions. However, between-session reliability showed lower levels of variability and, thus, may help coaches identify changes in technique over time (between sessions) with good accuracy. Overall the Enode offers a practical and affordable option for coaches seeking to monitor weightlifting technique in training environments.

The accuracy of measuring velocity during weightlifting movements with five velocity-based training devices

The use of weightlifting exercises is prevalent in competitive and recreational environments, as well as sport-specific training. Traditionally, weightlifting coaches prescribe specific training loads based on an individual's maximal ability. Velocity-based training offers an alternative method that promises to quantify strength based on velocity and provides information that increases competitiveness through real-time feedback. Various velocity measurement devices are available on the market. Their precision is critical for the adequate implementation of velocity-based training. The aim of the present study was to compare the concentric peak velocity measurements of five of these devices during two weightlifting movements, the snatch and clean, to data collected with a 12-camera motion capture system, which was considered as gold standard. It was hypothesized that the velocity measurement devices used in this study would vary in accuracy based on their retail prices. Velocity readings associated with light and moderate (40% and 70% of one-repetition max) loads were measured for both the snatch and clean performed by 12 competitive weightlifters. A least products regression was used to assess validity by comparing five devices against a criterion measure. A general linear model showed statistical differences in the velocities measured with these five devices ( p < 0.001). Specifically, the GymAware RS linear position transducer was the most accurate device, demonstrating no fixed or proportional bias when used to quantify velocity during the snatch and clean. The remaining four devices significantly underestimated peak velocity, which would directly impact the daily planning of lifters’ training. Practitioners must consider the error and bias of each device before implementing velocity-based training.

It’s a Balancing Act! Menopausal Symptoms in Competitive Weightlifters

ABSTRACT Introduction Athletes may be unprepared for the onset and duration of menopausal symptoms and how they affect training and competition goals. There are inconsistent results about physical activity and menopausal symptoms, and guidance for athletes is lacking. Purpose We aimed to study the reciprocal association of performance and weekly hours of weightlifting training with menopausal symptoms. Methods Women reported the frequency of weightlifting training and additional physical activities, heaviest weight lifted, and menopausal symptoms using the validated Menopausal Rating Scale. An online survey was distributed by national governing bodies in 30 countries to female master weightlifters (ages 30 to 79 yr) in May 2022. Simultaneous equation models were used to provide reliable estimates in the presence of contemporaneous effects. Results Participants included 868 women, 178 postmenopausal. The proportions of moderate or more severe somato-vegetative symptoms and psychological symptoms were 25.7% and 46.5%, respectively. Better performance, defined as weight lifted relative to age and body weight, was associated with a lower score of menopausal symptoms (−0.51, P < 0.001); worse menopausal symptoms were associated with lower performance (−1.22 for somato-vegetative, −2.19 for psychological; P < 0.001). More hours of weightlifting training were associated with worse menopausal symptoms, whereas more hours of other physical activities were associated with worse somato-vegetative but not with psychological symptoms. Instrumental variables in the model were joint pain and protein tracking. The majority tracked their daily protein intake (62.8%) with a median of 1.9 g·kg−1 body mass. Conclusion Somato-vegetative symptoms were less prevalent in weightlifters than in the general population. There is simultaneous feedback between sport performance and severity of menopausal symptoms. Athletes must balance training intensity and menopausal symptoms to achieve training goals.

The Relationship of Lower-Body, Multijoint, Isometric and Dynamic Neuromuscular Assessment Variables With Snatch, and Clean and Jerk Performance in Competitive Weightlifters: A Meta-Analysis

ABSTRACT The purpose of this meta-analysis was to synthesize the literature and provide a robust estimate of the correlations between lower-body, multijoint, isometric and dynamic neuromuscular assessment variables and snatch (SN) and clean and jerk (C&J) performance in competitive weightlifters. A comprehensive search through 3 electronic databases (PubMed, SPORTDiscus, and Web of Science) returned 12 studies that met the inclusion criteria. Meta-analyses were performed on Pearson's correlations between SN and C&J performance and 15 variables from 5 neuromuscular assessments—countermovement jump (CMJ), squat jump (SJ), isometric midthigh pull (IMTP), back squat (BS), and front squat (FS) one repetition maximum (1RM). The FS and BS 1RM exhibited nearly perfect correlations (r = 0.93 to 0.94), whereas the IMTP peak force exhibited very large correlations (r = 0.83 to 0.85). The IMTP force at 250 ms exhibited very large correlations (r = 0.77 to 0.78), and the CMJ and SJ peak power exhibited very large to nearly perfect correlations (r = 0.88 to 0.92). These findings illustrate the importance of lower-body maximal and time-limited force-producing capabilities in weightlifters. Moreover, each assessment offers at least one variable that exhibits a correlation of >0.70. Therefore, these assessments may be used to gauge weightlifting performance potential.

Modelling Front and Back Squat Record Scores in Long-Term Training of Young Weightlifters

Abstract Introduction. Front and back squats are multi-joint exercises used in sports to develop strength, power and muscle mass. Due to their movement structure and involvement of the main muscle groups, they are training measures that are used in strength training in various sports. A long-term training process leading to sports mastery requires the correct selection of loads as well as objective control of the training effects to date, both short-term and long-term. The aim of this study was to create a statistical model and to determine with it the character of the changes in the record scores in the front and back squat of young weight-lifters over a two-year training cycle. Material and Methods. The study included 17 young athletes training in competitive weightlifting. Recorded scores in the front squat and back squat were measured seven times (every three months over a two-year training cycle). The progression method was used to determine the maximum load, and the repetition with the highest load (1RM) was used in the calculations. Results. The subjects performed better in the back squat, but the difference between the results for both squats was approximately constant over the two-year training cycle. The time courses of both squats were similar over the analysed period. Systematic increases in maximum results were observed. The first statistically non-significant differences between the mean record values in successive measurements were found between the sixth and seventh measurements for both squats. Conclusions. Determining the relationship between front and back squat record scores can contribute to the optimisation of training loads in sports using strength training. Obtaining an analytical form of the course of record scores over time for both squats helps to assess the skill level of athletes and predict their performance in the next training macro-cycle.

The Results of Orthopaedic Medical Examinations in Adolescent Amateur Weightlifters.

Few studies have reported injuries and physical characteristics in adolescent weightlifters. The purpose of this study was to report the results of orthopaedic medical examinations in adolescent amateur weightlifters that were performed cross-sectionally from 2012 to 2019. The orthopaedic medical examination included physical examinations, generalized joint laxity, muscle and joint tightness, static alignment, muscle volume of the lower extremities, and medial longitudinal arch of the foot (the height from the tip of the navicular tubercle to the ground surface). A questionnaire survey regarding pain in the spine and lower extremities was also performed. A total of 99 adolescent weightlifters were included (male/female, 71/28; mean age, 16.2 ± 0.2 years). A total of 9.1% had received orthopaedic treatments, with spine injuries being the most prevalent. Of those who had not received orthopaedic treatments, 31.1% had pain in the spine or lower extremities (for >4 weeks). There were no significant gender differences in the incidence of pain or positive findings of physical examinations. Female weightlifters had a more reduced dorsiflexion of the ankle joint than male weightlifters (p = 0.02). Male weightlifters had a lower flexibility of the quadriceps than female weightlifters. The results of orthopaedic medical examinations in this study may help clinicians and young weightlifters to prevent injuries in competitive weightlifting.

The Tapering Practices of Competitive Weightlifters.

Winwood, PW, Keogh, JW, Travis, SK, and Pritchard, HJ. The tapering practices of competitive weightlifters. J Strength Cond Res 37(4): 829-839, 2023-This study explored the tapering strategies of weightlifting athletes. Weightlifting athletes ( n = 146) (mean ± SD ; age: 29.2 ± 8.7 years, height: 172.5 ± 10.1 cm, body mass: 84.0 ± 17.2 kg, 4.7 ± 3.4 years of weightlifting training experience, and 3.9 ± 3.3 years of competitive weightlifting experience) completed a self-reported 4-page, 39-item internet survey on tapering practices. Subgroup analysis by sex (male and female) and competitive standard (local or regional, national and international level) was conducted. Ninety-nine percent ( n = 144) of weightlifting athletes reported they used a taper. Athletes stated that their typical taper length was 8.0 ± 4.4 days, with the linear (36%) and step tapers (33%) being the most performed. Training volume decreased during the taper by 43.1 ± 14.6%, and athletes ceased all training 1.5 ± 0.6 days out from competition. Muscular strength, light technique work, and aerobic conditioning were the most common types of training performed in the taper. Athletes typically stated that tapering was performed to achieve rest and recovery, physical preparation for peak performance and mental preparation; training intensity and training duration decreased whereas training frequency remained the same or decreased; traditional exercises were performed further out from competition than weightlifting exercises; assistance exercises and some strength work were reduced; nutritional changes, foam rolling, static stretching, and massage were strategies used in the taper; and poor tapering occurred because of training too heavy, too hard, or too light and life-work circumstances. These results may aid athletes and coaches in strength sports to optimize tapering variables leading to improved performances.

How Does Lower-Body and Upper-Body Strength Relate to Maximum Split Jerk Performance?

Soriano, MA, Jiménez-Ormeño, E, Amaro-Gahete, FJ, Haff, GG, and Comfort, P. How does lower-body and upper-body strength relate to maximum split jerk performance? J Strength Cond Res 36(8): 2102-2107, 2022-The aims of this study were to (I) determine the relationships between the maximum dynamic strength of the upper and lower body, measured by overhead press and back squat 1 repetition maximum (1RM) performances, and the split jerk (SJ) performance in trained weightlifters and (II) explore the magnitude of these relationships for men and women to establish sex-specific prediction equations. Twenty men (age: 28.9 ± 6.6 years; height: 1.8 ± 0.1 m; body mass [BM]: 82.5 ± 10.2 kg; weightlifting training experience: 4.2 ± 2.4 years) and 13 women (age: 27.7 ± 4.4 years; height: 1.7 ± 0.1 m; BM: 61.8 ± 5.2 kg; weightlifting training experience: 2.7 ± 1.7 years) competitive weightlifters participated. The 1RM performances of the overhead press, back squat, and SJ were assessed for all subjects. A very strong correlation exists between the back squat and overhead press, with maximum SJ performance for all subjects (r = 0.97; p < 0.001). Similarly, very strong correlations were found for men (r = 0.90, p < 0.001) and women (r = 0.90, p = 0.0002), separately. The coefficient of determination indicates that the prediction equation for the maximum SJ performance is quite accurate (R2 = 0.94) for all subjects and men (R2 = 0.83) and women (R2 = 0.81), separately. These results provide evidence that the maximum strength of the upper and lower body are major contributors to SJ performance. In addition, SJ performance can accurately be predicted from the back squat and overhead press performances.

Intra- and Interday Reliability of Weightlifting Variables and Correlation to Performance During Cleans.

Sorensen, AM, Chavda, S, Comfort, P, Lake, J, and Turner, AN. Intra- and interday reliability of weightlifting variables and correlation to performance during cleans. J Strength Cond Res 36(11): 3008-3014, 2022-The purpose of this investigation was to examine intra- and interday reliability of kinetic and kinematic variables assessed during the clean, assess their relationship to clean performance, and determine their suitability in weightlifting performance analysis. Eight competitive weightlifters performed 3 sets of single repetition cleans with 90% of their 1-repetition maximum (1RM). Force-time data were collected via dual force plates with displacement-time data collected via 3-dimensional motion capture, on 3 separate occasions under the same testing conditions. Seventy kinetic and kinematic variables were analyzed for intra- and interday reliability using intraclass correlation coefficients (ICCs) and the coefficient of variation (CV). Pearson's correlation coefficients were calculated to determine relationships between barbell and body kinematics and ground reaction forces, and for correlations to be deemed as statistically significant, an alpha-level of p ≤ 0.005 was set. Eleven variables were found to have "good" to "excellent" intra- and interday ICC (0.779-0.994 and 0.974-0.996, respectively) and CV (0.64-6.89% and 1.14-6.37%, respectively), with strong correlations ( r = 0.880-0.988) to cleans performed at 90% 1RM. Average resultant force of the weighting 1 (W1) phase demonstrated the best intra- and interday reliability (ICC = 0.994 and 0.996, respectively) and very strong correlation ( r = 0.981) to clean performance. Average bar power from point of lift off to peak bar height exhibited the highest correlation ( r = 0.988) to clean performance. Additional reliable variables with strong correlations to clean performance were found, many of these occurred during or included the W1 phase, which suggests that coaches should pay particular attention to the performance of the W1 phase.

POWER OUTPUT AS A FUNCTION OF BODY MASS AND LEAN BODY MASS IN COMPETITIVE WEIGHTLIFTERS

INTRODUCTION: correlation between body mass (BM), lean body mass (LBM), and peak power output (PPO) in athletes, although the relative contribution of BM and LBM to PPO remains unclear. PURPOSE: We investigated the relationship between PPO (W) assessed in the mid-thigh power clean, BM (W·kg-1), and LBM (W·kg-1) in competitive weightlifters. Results aim to justify the need to further investigate the relationship between performance in sport and body composition in different strength and power athletes. METHODS: 26 competitive weightlifters (age 25 ± 5.8, height 167.8 ± 3.1, body mass 78.7 ± 16.9 kg) performed 4 sets of 3 repetitions of the mid-thigh power clean at 30%, 40%, 50%, and 60% of their clean 1RM. Loads were prescribed based on current evidence for optimal power output in explosive, resistance training exercises in the attempt to define a peak value for each participant. BM and LBM were assessed using bioelectrical impedance analysis (InBody 570 USA, Cerritos, CA). Participants performed each set while standing on a force platform (AMTI, Watertown, MA) sampling at 1,000 Hz interfaced with a laptop. PPO was normalized as a function of BM (PPO/BM) and LBM (PPO/LBM). Descriptive analyses and correlations were examined. RESULTS: The correlation between LBM and BM was .945. To refrain from violating the assumptions, multicollinearity was examined through the implementation of the Variance Inflation Factor (VIF). As a result, LBM was removed from the model. A simple linear regression was performed to predict PPO from BM. The model's result revealed that BM is a statistically significant predictor of PPO, F(1, 24) = 48.013, p < 0.001, R2 = .667. CONCLUSIONS: BM was revealed to be a strong predictor for performance in competitive weightlifters. Future research should examine whether this finding holds true regardless of the sex of the athlete.

The Effect of Coach Gender on Competitive Weightlifting Performance for Men and Women Weightlifters.

Gender of coaches relative to their athletes has recently garnered substantial attention in the public, the media, and academia. Relative to sports engulfed in controversy pertaining to men athletes being coached by women, such as professional baseball, basketball, and football, it is more common to see women coach men in competitive weightlifting, though only a small percent of men weightlifters are coached by women. In competitive weightlifting, coaches are responsible for both physically and mentally training athletes, and with the social barriers faced by women in a sport traditionally perceived as masculine, there may be mental training or communication benefits to training with a coach of a certain gender. Examining the gender of competitive weightlifters and their coaches, total weight lifted in the snatch and clean and jerk events are analyzed using OLS regression. Results indicate that men weightlifters perform better with men coaches. Women weightlifters perform better with men coaches until the age of 43, then they perform better with women coaches. The difference in performance may be due to several factors including historical bias against women in the sport.

Pooled Versus Individualized Load-Velocity Profiling in the Free-Weight Back Squat and Power Clean.

This study compared pooled against individualized load-velocity profiles (LVPs) in the free-weight back squat and power clean. A total of 10 competitive weightlifters completed baseline 1-repetition maximum assessments in the back squat and power clean. Three incremental LVPs were completed, separated by 48 to 72 hours. Mean and peak velocity were measured via a linear-position transducer (GymAware). Linear and nonlinear (second-order polynomial) regression models were applied to all pooled and individualized LVP data. A combination of coefficient of variation (CV), intraclass correlation coefficient, typical error of measurement, and limits of agreement assessed between-subject variability and within-subject reliability. Acceptable reliability was defined a priori as intraclass correlation coefficient > .7 and CV < 10%. Very high to practically perfect inverse relationships were evident in the back squat (r = .83-.96) and power clean (r = .83-.89) for both regression models; however, stronger correlations were observed in the individualized LVPs for both exercises (r = .85-.99). Between-subject variability was moderate to large across all relative loads in the back squat (CV = 8.2%-27.8%) but smaller in the power clean (CV = 4.6%-8.5%). The power clean met our criteria for acceptable reliability across all relative loads; however, the back squat revealed large CVs in loads ≥90% of 1-repetition maximum (13.1%-20.5%). Evidently, load-velocity characteristics are highly individualized, with acceptable levels of reliability observed in the power clean but not in the back squat (≥90% of 1-repetition maximum). If practitioners want to adopt load-velocity profiling as part of their testing and monitoring procedures, an individualized LVP should be utilized over pooled LVPs.

Point-of-care Ultrasound for Suspected Pectoralis Major Rupture: A Case Report

IntroductionPectoralis major muscle injuries are relatively uncommon and occur secondary to weightlifting in nearly 50% of cases. Tendon tears occur almost exclusively in males between 20–40 years old and are heavily associated with anabolic androgenic steroid use. While magnetic resonance imaging is often considered the modality of choice, its availability is often limited in the emergency department (ED). In contrast, point-of-care ultrasound (POCUS) is commonly available in the ED and can be used to help confirm the diagnosis and hasten disposition.Case ReportWe report a case of a 28-year-old male competitive weightlifter with a history of chronic anabolic steroid use who presented to the ED with acute left shoulder pain after weightlifting. History and physical exam were concerning for pectoralis major rupture, and POCUS confirmed the diagnosis.ConclusionPrompt evaluation and radiographic confirmation is key in ensuring good patient outcomes in pectoralis major tears. Therefore, proficiency of emergency physicians in musculoskeletal POCUS as an adjunct to estimate the extent of injury is important for expediting disposition and and promptly involving orthopedic surgery evaluation.

The Reliability and Validity of Current Technologies for Measuring Barbell Velocity in the Free-Weight Back Squat and Power Clean.

This study investigated the inter-day and intra-device reliability, and criterion validity of six devices for measuring barbell velocity in the free-weight back squat and power clean. In total, 10 competitive weightlifters completed an initial one repetition maximum (1RM) assessment followed by three load-velocity profiles (40–100% 1RM) in both exercises on four separate occasions. Mean and peak velocity was measured simultaneously on each device and compared to 3D motion capture for all repetitions. Reliability was assessed via coefficient of variation (CV) and typical error (TE). Least products regression (LPR) (R2) and limits of agreement (LOA) assessed the validity of the devices. The Gymaware was the most reliable for both exercises (CV < 10%; TE < 0.11 m·s−1, except 100% 1RM (mean velocity) and 90‒100% 1RM (peak velocity)), with MyLift and PUSH following a similar trend. Poorer reliability was observed for Beast Sensor and Bar Sensei (CV = 5.1–119.9%; TE = 0.08–0.48 m·s−1). The Gymaware was the most valid device, with small systematic bias and no proportional or fixed bias evident across both exercises (R2 > 0.42–0.99 LOA = −0.03–0.03 m·s−1). Comparable validity data was observed for MyLift in the back squat. Both PUSH devices produced some fixed and proportional bias, with Beast Sensor and Bar Sensei being the least valid devices across both exercises (R2 > 0.00–0.96, LOA = −0.36–0.46 m·s−1). Linear position transducers and smartphone applications could be used to obtain velocity-based data, with inertial measurement units demonstrating poorer reliability and validity.

Plantar Pressure Distribution in Female Olympic-Style Weightlifters.

Background: The aim of this study was to investigate differences in static and dynamic plantar pressure and other foot geometry variables between female Olympic-style weightlifters and an age- and sex-matched control group. Methods: The study involved 24 national-level competitive weightlifters and 24 physical education students. Leg dominance was determined and baropodometry was used to assess plantar pressure and foot posture during quiet standing and walking. For all variables basic descriptive statistics were calculated (mean ± standard deviation). Student’s t test was used to compare the between-group differences. Spearman’s rank correlation coefficients were calculated to determine the association between BMI (Body Mass Index) and average and peak plantar pressure. Results: No significant differences were observed in plantar pressure distribution between the two groups. A moderate correlation was found between BMI and non-dominant limb peak and average plantar pressure in the group of weightlifters in the static condition and in the control group in the dynamic condition. Conclusions: Olympic-style weightlifting may affect plantar pressure distribution and foot posture in female weightlifters. BMI may also correlate with peak and average plantar pressure in this population. Further research is needed to determine if Olympic-style weightlifting may affect plantar pressure distribution and foot posture in female weightlifters.

Inter- and intra-individual variability in the kinematics of the back squat

The purpose of this study was to explore the level of inter- and intra-individual variability in the kinematic profiles of the back squat movement among skilled weightlifters. Ten competitive weightlifters volunteered for participation in this study. Barbell velocity (VBarbell) and angular velocity of the ankle (ωAnkle), knee (ωKnee) and hip joint (ωHip) were obtained by kinematic recording of six trials at 90% of 1RM in the back squat. Inter-individual variability was assessed by analysing inter-individual differences in the velocity curves through the statistical parametric mapping method. Intra-individual variability was assessed through a correlation analysis between the barbell velocity curves of each trial for each participant. Partial least squares regression analysis, was performed to relate changes in intra-individual variability to movement and anthropometric characteristics. Significant inter- and intra-individual differences were identified in VBarbell, ωAnkle, ωKnee, and ωHip (p ≤ 0.05). Having a short trunk and thigh, and a long shin in combination with greater anterior-posterior displacement of the barbell and slower velocities during the acceleration phase increased intra-individual movement consistency over movement variability. The results of the present study clearly demonstrate that skilled weightlifters display both significant inter- and intra-individual variability in the successful execution of the back squat.

Ground Reaction Force Characteristics In Power Cleans With And Without The Double Knee Bend Technique

INTRODUCTION: Muscular power (i.e. muscular force x shortening velocity) is arguably the most important physical quality an athlete can possess. Many athletes use power cleans to improve muscular power but are not taught to use a double knee bend (DKB). The DKB is used by competitive weightlifters to increase muscular power produced in the second pull of the power clean exercise. Thus, athletes using power cleans to improve muscular power without using the DKB may not experience optimal benefit from the exercise. PURPOSE: To determine differences in ground reaction force characteristics between a power clean from the floor both with, and without, the use of a DKB in athletes with weightlifting experience. METHODS: Six participants with weightlifting experience each performed three power cleans with and without a DKB at 80% of their self-reported one-repetition maximum. Ground reaction forces (GRFs) were captured using two force platforms (1200Hz). Commercially available biomechanical analysis software was used to calculate concentric impulse (IMPCON), peak vertical ground reaction force (VGRFPEAK), and rate of force development (RFD) in the second pull for each trial. Paired samples t-tests were used to compare dependent variables in each condition: DKB and NO DKB. Cohen’s d estimates of effects size were used to determine meaningful differences. RESULTS: RFD was greater in the second pull of the power clean when a DKB was used (p <.001, d = 2.25; DKB: 6922±1664; NO DKB: 4710±277 N/s). IMPCON was lower in the DKB condition (p <.001, d = 1.09; DKB: 146±28.8 N•s; NO DKB: 174±36.6 N•s), and no differences were observed in VGRFPEAK (p = 0.375, d = 0.15; DKB: 1607±221 N; NO DKB: 1582±169 N). CONCLUSIONS: Although no differences were observed in VGRFPEAK and IMPCON was reduced, RFD was significantly greater in the second pull with the DKB. These data suggest that DKB may enhance the training stimulus by enabling the athlete to produce comparable peak forces in shorter time periods by increasing muscular shortening velocity. This may be due to a positional optimization of muscular length-tension properties in the hip, knee, and ankle extensor musculature uniquely offered by utilizing a DKB technique.

Relationships between barbell squat strength and weightlifting performance

Weightlifters compete in the snatch, clean and jerk, and total (snatch + clean and jerk). Commonly used assistance exercises for training weightlifters are front barbell squats and back barbell squats. The purpose of this study was to determine relationships between the front barbell squats and back barbell squats one repetition maximum (1 RM) and the snatch, clean and jerk, and total 1 RM. Senior male competitive weightlifters ( n = 72) served as subjects in the survey. Significant correlations were found between front barbell squats and snatch, clean and jerk, or total 1 RM ( r2 = 0.85, 0.88, and 0.87 respectively) and between back barbell squats and snatch, clean and jerk, or total 1 RM ( r2 = 0.83, 0.84, and 0.83 respectively). Regression analyses indicate that 1 RM in the snatch, clean and jerk, and total are linearly related to the 1 RM in the front barbell squats and back barbell squats. Superior lifters appeared to be more efficient in using their back barbell squats strength during weightlifting compared to lower level lifters.