Title: The Analysis of the Effect of Weightlifting Shoes and Bare Feet Lifting on the Performance Measures of Back Squat. Objectives: The main goal of this study was to compare speed, power, and depth of the back squat performed both barefoot and in weightlifting shoes using the training protocol 5 × 5 (5 sets with 5 reps) at 70 % one-repetition maximum (1RM). Methods: Ten elite, male participants (27 ± 3.54 years old, 93 ± 10.23 kg of body weight, 179.28 ± 8.54 cm of height) were involved and assessed for the purposes of the study. All participants' 1RM back squat was not lower than 1.5 times of their body weight and they all had many years of experience using weightlifting as a part of their athletic development. The assessment was carried out at the training adaptation lab of the Department of Physiology and Biochemistry, the Faculty of Physical Education and Sport, Charles University in Prague (UK FTVS). Each participant followed the same training protocol during two sessions not less than 48 hours apart; the first one performed barefoot and the second one wearing the weightlifting shoes. Participants were asked to perform three repetitions, first with 20 % of their estimated 1RM, then with 40 % and 60 %, followed by two repetitions with 70 % and 80 % of their estimated 1RM to determine their...

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.

Introduktion: Hastighetsbaserad styrketräning är en metod där rörelsehastighet används för att styra träning, samt monitorera träningsintensitet och volym. Metoden har vuxit fram som ett komplement till traditionellt procentbaserad styrketräning. Syfte: Syftet med litteraturstudien var att undersöka effekterna mellan olika metoder av hastighetsbaserad styrketräning och dess förhållande till traditionell procentbaserad styrketräning. Metod: En strukturerad litteratursökning genomfördes i de vetenskapliga databaserna PubMed och SPORTDiscus med de primära sökorden; velocity-based training, percentage based training och training effect. En ytterligare sökning genomfördes i referenslistorna bland de artiklar som uppfyllde inklusionskriterierna. Resultat: Litteraturstudien visade att hastighetsbaserad styrketräning medförde liknande styrkeökningar som traditionell procentbaserad styrketräning. Hastighetsbaserad styrketräning medförde större ökningar i hopphöjd jämfört med traditionell procentbaserad styrketräning. Ingen av interventionerna medförde träningseffekter på sprintförmåga. Konklusion: Hastighetsbaserad styrketräning verkar vara lika effektivt för att utveckla maximal styrka men effektivare för att utveckla hoppförmåga jämfört med traditionellt procentbaserad styrketräning. Hastighetsbaserad styrketräning med lägre procentuell hastighetsförlust verkar vara fördelaktigt för att utveckla hoppförmåga medan högre procentuell hastighetsförlust verkar vara fördelaktigt för att utveckla muskelhypertrofi. / Introduction: Velocity based training refers to a method where movement velocity is used to regulate strength training and monitor training intensity and volume. In addition, velocity based training could be considered as a complementary method to traditional percentage based training. Purpose: The aim of the literature review was to investigate the effects of different velocity based training methods and their relationship to traditional percentage based training. Method: A structured literature search was conducted in the scientific databases PubMed and SPORTDiscus with the following search terms; velocity-based training, percentage based training and training effect. A further search was conducted in the reference list among articles that met the inclusion criteria. Results: The literature review shows that velocity based training leads to similar gains in maximal strength as traditional percentage based training. However, velocity based training leads to greater gains in jump height compared to traditional percentage based training. Sprint ability showed no clear outcome following any of the interventions. Conclusion: Velocity based training seems to be just as efficient in developing maximal strength but more efficient in developing explosive strength such as jump height compared to traditional percentage based training. In addition, velocity based training with lower velocity loss thresholds may be more beneficial to improve jump height, whilst higher velocity loss threshold may be more beneficial to develop muscle hypertrophy.

Load-velocity relationships may vary between people of different strength levels and across different loads. The purpose of this dissertation was to investigate how external loads influence the velocity characteristics of the back squat exercise, and the influence of strength on these variables. Healthy male students with a history of resistance training completed repetitions at specified intensities of their estimated one-repetition maximum (1RM) until they reached 1RM. Back squat 3D motion analysis was captured using four Vicon T010 cameras (Vicon Motion Systems Ltd.; Oxford, UK) and Vicon Nexus 1.8.5 software. Data were transported into R custom coding statistical analysis software (version 3.5.2; The R Foundation) to calculate velocity analyses which determined mean and peak concentric (MCV, PCV) and eccentric (MEV, PEV) values. Participants were grouped by their relative strength (body mass/1RM) in the back squat, as well as their ability to move often prescribed loads with greater speed (63-70%1RM, 83-87%1RM). Between-groups comparisons were made for MCV at all loading conditions, and correlational relationships between all velocity measures (MEV, PEV, MCV, PCV) were examined for each group. For all subjects, there was a significant effect for relative intensity (%1RM) on MCV, but only for the groups organized by MCV at 63-70%1RM and 83-87%1RM was there a between-subjects effect for group. Correlational analyses between velocity measurements during concentric and eccentric phase of the back squat showed a tendency for high relationships (r = 0.5-0.69) between all phases that weakened as the relative intensity increased. These differences were illustrated uniquely between subject grouping conditions. These results indicate that load-velocity characteristics of the back squat cannot necessarily be positively related to strength level in the movement, and that profiling athletes by their velocities at specific relative intensities could be an effective means of organization.

Aim  The purposes of this study were to investigate if the load-velocity (L-V) profile parameters – force capacity and efficiency - differ between swimmers of different performance level, and to investigate if efficiency is the key performance indicator between international elite and national elite level swimmers.  Method  Fifty-four swimmers (27 female and 27 male) of either regional level, national elite or international elite level, participated in this study. The swimmers performed three 25 m semi- tethered maximum effort swims with ascending loads (1 kg, 5% and 10% of body mass). Mean velocity during three stroke cycles mid-effort was calculated and plotted as a function of the external added load. A linear regression was established, expressing the relationship between load and velocity, with the intercepts between the axes and the regression line being defined as the theoretical maximum velocity (V0) and load (force capacity, L0). The slope of the regression line (slopeLV) serves as an index of efficiency. Results A statistically significant difference was found between the three performance levels for all L- V profile variables for front crawl: V0 (F [2, 51] = 7.76, p<0.001), L0 (F [2, 51] = 5.18, p=0.009), and slopeLV (F [2, 51] = 3.36, p=0.043). A paired t-test revealed no difference in slopeLV between matched international elite and national elite level swimmers (t [9] = 1.42, p=0.188), but a near significant difference in L0 (t [9] = 2.11, p=0.064) . Both slopeLV and L0 for front crawl had a strong correlation with personal best in 100 m front crawl (PB100). Conclusion Efficiency was not found to be the key performance indicator between matched international elite and national elite swimmers in this study, and neither was force capacity. Nevertheless, a significant difference in all front crawl L-V profile parameters was found between performance level groups, but post hoc analyses indicated no difference between adjacent performance levels neither in L0 nor slopeLV. There was however a strong correlation between both slopeLV, and L0, to the swimmers’ PB100. All these findings imply that efficiency and force capacity seem to be of equal importance for high performance, but swimmers use different strategies to reach the high swim velocity. / Longitudinal development of performance determining factors in swimming (NIH)