Determining Physiological and Energetic Demands during High-Level Pommel Horse Routines Using a Modified Method Based on Heart Rate-Oxygen Uptake Functions.

This study aimed (1) to assess the validity of a modified method (Mmod) based on heart rate (HR)-oxygen uptake (VO2) regression functions to calculate total energy costs (Wtotal) and aerobic (Waer) and anaerobic alactic energy contribution (Wpcr) and (2) to analyse the physiological and energetic demands of high-level pommel horse routines (PH routines). The Mmod was developed because VO2 measurements are limited during high-level PH routines. Answering Part 1, nine male artistic gymnasts performed a PH routine where energy costs were calculated from VO2 measurements and then compared with energy costs determined from the HR- VO2 regressions of Mmod's two additional tests. Using the concordance correlation coefficient (CCC) and Deming regression, Waer (CCC = 0.955), Wpcr (CCC = 0.999), and Wtotal (CCC = 0.990) show substantial to almost perfect validity without constant or proportional bias. Data from eight further gymnasts performing a high-level PH routine and a graded exercise test (GXT), as well as four data sets from Part 1, were used to determine physiological and energetic demands using Mmod. VO2 and HR during PH routines reached 86.1% and 90.4% of the maximal values during GXT. Wpcr was 47.0%, anaerobic lactic energy contribution (Wblc) was 29.7%, and Waer was 23.3% of Wtotal required during PH routines. Summarising the energetic demands of high-level PH routines, they are mainly anaerobic, where Wpcr provides the largest energy share. Waer provides a substantial part of Wtotal and should therefore also be specifically trained.

Variability of time series barbell kinematics in elite male weightlifters.

Introduction: Barbell kinematics are an essential aspect of assessing weightlifting performance. This study aimed at analyzing the total variability of time series barbell kinematics during repeated lifts in the snatch and the clean and jerk at submaximal and maximal barbell loads. Methods: In a test-retest design, seven male weightlifters lifted submaximal [85% planned one-repetition maximum (1RMp)] and maximal (97% 1RMp) loads in the snatch and the clean and jerk during training. Barbell trajectory, vertical velocity, and vertical acceleration were determined using video analysis. Standard error of measurement (SEM), intraclass correlation coefficient (ICC), and smallest real difference (SRD) were used to determine the total variability during the lifts. Hedge's g effect size was used to assess differences in SEM between submaximal and maximal loads. Results: The main findings indicated that variability-in particular for the barbell velocity-was lower at maximal compared to submaximal barbell loads (g = 0.52-2.93). SEM of time series data showed that variability increased in the snatch and the clean and jerk from the 1st pull/dip to the catch position irrespectively of the barbell load. Discussion: This study presents values of total variability of time series barbell kinematics during the snatch, the clean, and the jerk. Further, the SRD can be used to evaluate changes in barbell kinematics in response to training. In addition, when interpreting barbell kinematics, coaches should take into account that the variability of barbell kinematics can vary depending on the exercise and the barbell load.

Optimal barbell force-velocity profiles can contribute to maximize weightlifting performance.

Maximal barbell power output (Pmax) and vertical barbell threshold velocity (vthres) are major determinants of weightlifting performance. Moreover, an optimal force-velocity relationship (FvR) profile is an additional variable that has the potential to maximize sports performance. The aims of this study were (i) to present a biomechanical model to calculate an optimal FvR profile for weightlifting, and (ii) to determine how vthres, Pmax, and the optimal FvR profile influence theoretical snatch performance (snatchth). To address these aims, simulations were applied to quantify the respective influence on snatchth. The main findings confirmed that at constant vthres and Pmax, snatchth is maximized at an optimal FvR profile. With increasing Pmax and decreasing vthres, the optimal FvR profile becomes more force dominated and more effective to enhance snatchth. However, sensitivity analysis showed that vthres and Pmax have a larger effect on snatchth than the optimal FvR profile. It can be concluded that in weightlifting, training protocols should be designed with the goal to improve Pmax and to reduce vthres to ultimately enhance snatchth. Training programs designed to achieve the optimal FvR profile may constitute an additional training goal to further develop weightlifting performance in elite athletes that already present high Pmax levels.

Long-Term Monitoring of Training Load, Force-Velocity Profile, and Performance in Elite Weightlifters: A Case Series With Two Male Olympic Athletes.

ABSTRACT: Sandau, I and Granacher, U. Long-term monitoring of training load, force-velocity profile, and performance in elite weightlifters: a case series with two male Olympic athletes. J Strength Cond Res 36(12): 3446-3455, 2022-The aim of this case series approach was to analyze weekly changes in force-velocity relationship (FvR) parameters (v̅0, F̅0, P̅max) and theoretical snatch performance (snatchth) assessed through a specific snatch pull test in preparation of the European and World Championships in 2 male elite weightlifters. A second aim was to examine associations of training load (volume, volume load, average load), barbell FvR-parameters, and snatchth over a period of 2 macrocycles in preparation of the same competitions. FvR-parameters, snatchth, training load data, and body mass were assessed weekly over 40 weeks. Using the smallest real difference approach, significant (p ≤ 0.05) decreases in v̅0 and increases in F̅0, P̅max, and snatchth were found within macrocycles. However, the large significant loss in body mass (≈11%) in athlete 1 during macrocycle 2 represents most likely a main factor for diminished P̅max, and snatchth in macrocycle 2. Based on cross-correlation analyses, barbell FvR-parameters and snatchth were significantly (p ≤ 0.05) associated with maximal strength, muscle power, and speed training load variables. Moderate correlations (0.31-0.47) were found between training load and P̅max and snatchth in athlete 2. It can be concluded that the applied training loads elicits improvements in P̅max and snatchth because the athlete approached the main competitions. However, because of the large loss in body mass, the relations between training load and barbell FvR-parameters and snatchth were less clear in athlete 1. It seems that a loss in body mass as a result of a change in bodyweight category mitigates P̅max development during the macrocycle and hindered to reach peak snatchth at the main competitions.

Validity and Reliability of a Snatch Pull Test to Model the Force-Velocity Relationship in Male Elite Weightlifters.

ABSTRACT: Sandau, I, Chaabene, H, and Granacher, U. Validity and reliability of a snatch pull test to model the force-velocity relationship in male elite weightlifters. J Strength Cond Res 36(10): 2808-2815, 2022-This study examined the concurrent validity and within-session reliability of parameters describing the force-velocity relationship (FvR) such as maximal force, velocity, power, and the theoretical one repetition maximum snatch performance ( snatchth ) during the snatch pull. The FvR was assessed using the multiple-load (FvR m ) approach and the 2-load (FvR 2 ) approach. Eight male elite weightlifters from the German national team executed the snatch pull in 2 separate experiments. For the concurrent validity assessment (experiment one), during the snatch pull, 7 loads from 70 to 100% were lifted to compute the FvR m , and 2 loads (70 and 100%) were lifted to compute the FvR 2 . For the reliability assessment (experiment 2), a test-retest protocol for the FvR 2 was conducted. Input FvR parameters were determined from video-based barbell tracking. Results indicated no differences (all p > 0.05; all d ≤ 0.07) and extremely large correlations (all r ≥ 0.91) between the FvR m and FvR 2 parameters. The within-session reliability of FvR 2 parameters was excellent (all intraclass correlation coefficient ≥0.97; SEM % ≤1.23%). The percentage smallest real difference (SRD 95 %) of FvR 2 parameters ranged between 1.89 and 3.39%. In summary, using the snatch pull to model FvR 2 parameters is a valid and reliable approach that can easily be integrated into elite weightlifters' daily training routines.

Concurrent validity of barbell force measured from video-based barbell kinematics during the snatch in male elite weightlifters.

This study examined the concurrent validity of an inverse dynamic (force computed from barbell acceleration [reference method]) and a work-energy (force computed from work at the barbell [alternative method]) approach to measure the mean vertical barbell force during the snatch using kinematic data from video analysis. For this purpose, the acceleration phase of the snatch was analyzed in thirty male medal winners of the 2018 weightlifting World Championships (age: 25.2±3.1 years; body mass: 88.9±28.6 kg). Vertical barbell kinematics were measured using a custom-made 2D real-time video analysis software. Agreement between the two computational approaches was assessed using Bland-Altman analysis, Deming regression, and Pearson product-moment correlation. Further, principal component analysis in conjunction with multiple linear regression was used to assess whether individual differences related to the two approaches are due to the waveforms of the acceleration time-series data. Results indicated no mean difference (p > 0.05; d = -0.04) and an extremely large correlation (r = 0.99) between the two approaches. Despite the high agreement, the total error of individual differences was 8.2% (163.0 N). The individual differences can be explained by a multiple linear regression model (R2adj = 0.86) on principal component scores from the principal component analysis of vertical barbell acceleration time-series waveforms. Findings from this study indicate that the individual errors of force measures can be associated with the inverse dynamic approach. This approach uses vertical barbell acceleration data from video analysis that is prone to error. Therefore, it is recommended to use the work-energy approach to compute mean vertical barbell force as this approach did not rely on vertical barbell acceleration.

Predictive Validity of the Snatch Pull Force-Velocity Profile to Determine the Snatch One Repetition-Maximum in Male and Female Elite Weightlifters.

BACKGROUND: The prediction of one repetition-maximum (1RM) performance from specific tests is highly relevant for the monitoring of training in weightlifting. Therefore, this study aimed at examining the predictive validity of the theoretical 1RM snatch (snatchth) computed from the two-point snatch pull force-velocity relationship (FvR2) to determine actual snatch 1RM performance in elite weightlifters. METHODS: Eight (three female, five male) elite weightlifters carried out a 1RM snatch test followed by a snatch pull test with loads of 80% and 110% of the previously determined 1RM snatch. Barbell kinematics were determined for all lifts using video-tracking. From the snatch pull barbell kinematics, the snatch pull FvR2 was modeled and the snatchth was calculated. RESULTS: The main findings indicated a non-significant (p = 0.706) and trivial (d = 0.01) mean difference between the actual 1RM snatch performance and the snatchth. Both measures showed an extremely large correlation (r = 0.99). The prediction accuracy of the actual 1RM snatch from snatchth was 0.2 ± 1.5 kg (systematic bias ± standard deviation of differences). CONCLUSIONS: This study provides a new approach to estimate 1RM snatch performance in elite weightlifters using the snatch pull FvR2. The results demonstrate that the snatchth-model accurately predicts 1RM snatch performance.

Effects of the Barbell Load on the Acceleration Phase during the Snatch in Elite Olympic Weightlifting.

The load-depended loss of vertical barbell velocity at the end of the acceleration phase limits the maximum weight that can be lifted. Thus, the purpose of this study was to analyze how increased barbell loads affect the vertical barbell velocity in the sub-phases of the acceleration phase during the snatch. It was hypothesized that the load-dependent velocity loss at the end of the acceleration phase is primarily associated with a velocity loss during the 1st pull. For this purpose, 14 male elite weightlifters lifted seven load-stages from 70-100% of their personal best in the snatch. The load-velocity relationship was calculated using linear regression analysis to determine the velocity loss at 1st pull, transition, and 2nd pull. A group mean data contrast analysis revealed the highest load-dependent velocity loss for the 1st pull (t = 1.85, p = 0.044, g = 0.49 [-0.05, 1.04]) which confirmed our study hypothesis. In contrast to the group mean data, the individual athlete showed a unique response to increased loads during the acceleration sub-phases of the snatch. With the proposed method, individualized training recommendations on exercise selection and loading schemes can be derived to specifically improve the sub-phases of the snatch acceleration phase. Furthermore, the results highlight the importance of single-subject assessment when working with elite athletes in Olympic weightlifting.

Short-Term Seasonal Development of Anthropometry, Body Composition, Physical Fitness, and Sport-Specific Performance in Young Olympic Weightlifters.

The aim of this study is to monitor short-term seasonal development of young Olympic weightlifters' anthropometry, body composition, physical fitness, and sport-specific performance. Fifteen male weightlifters aged 13.2 ± 1.3 years participated in this study. Tests for the assessment of anthropometry (e.g., body-height, body-mass), body-composition (e.g., lean-body-mass, relative fat-mass), muscle strength (grip-strength), jump performance (drop-jump (DJ) height, countermovement-jump (CMJ) height, DJ contact time, DJ reactive-strength-index (RSI)), dynamic balance (Y-balance-test), and sport-specific performance (i.e., snatch and clean-and-jerk) were conducted at different time-points (i.e., T1 (baseline), T2 (9 weeks), T3 (20 weeks)). Strength tests (i.e., grip strength, clean-and-jerk and snatch) and training volume were normalized to body mass. Results showed small-to-large increases in body-height, body-mass, lean-body-mass, and lower-limbs lean-mass from T1-to-T2 and T2-to-T3 (∆0.7-6.7%; 0.1 ≤ d ≤ 1.2). For fat-mass, a significant small-sized decrease was found from T1-to-T2 (∆13.1%; d = 0.4) and a significant increase from T2-to-T3 (∆9.1%; d = 0.3). A significant main effect of time was observed for DJ contact time (d = 1.3) with a trend toward a significant decrease from T1-to-T2 (∆-15.3%; d = 0.66; p = 0.06). For RSI, significant small increases from T1-to-T2 (∆9.9%, d = 0.5) were noted. Additionally, a significant main effect of time was found for snatch (d = 2.7) and clean-and-jerk (d = 3.1) with significant small-to-moderate increases for both tests from T1-to-T2 and T2-to-T3 (∆4.6-11.3%, d = 0.33 to 0.64). The other tests did not change significantly over time (0.1 ≤ d ≤ 0.8). Results showed significantly higher training volume for sport-specific training during the second period compared with the first period (d = 2.2). Five months of Olympic weightlifting contributed to significant changes in anthropometry, body-composition, and sport-specific performance. However, hardly any significant gains were observed for measures of physical fitness. Coaches are advised to design training programs that target a variety of fitness components to lay an appropriate foundation for later performance as an elite athlete.