Boro Štrumbelj

Relationship between different push-off variables and start performance in experienced swimmers

Abstract The objective of this study was to determine the relationship between different variables measured with a force plate during the swimming start push-off phase and start performance presented by times to 5, 10 and 15 m. Twenty-one women from the Slovenian national swimming team performed two different swim starts (freestyle and undulatory) on a portable force plate to a distance further than 15 m. Correlations between push-off variables and times to 5, 10 and 15 m were quantified through Pearsons product-moment correlation coefficient (r). The variables that significantly correlated (p < .05) to all times measured in the two starts performed were: average horizontal acceleration (freestyle: r = −0.58 to −0.71; and undulatory: r = −0.55 to −0.66), horizontal take-off velocity (freestyle: r = −0.56 to −0.69; and undulatory: r = −0.53 to −0.67) and resultant take-off velocity (freestyle: r = −0.53 to −0.65; and undulatory: r = −0.52 to −0.61). None of the variables derived from the vertical force were correlated to swimming start performance (p > .05). Based on the results of this study, we can conclude that horizontal take-off velocity and average horizontal acceleration (calculated as the average horizontal force divided by swimmers body mass) are the variables most related to swimming start performance in experienced swimmers, and therefore could be the preferred measures to monitor swimmers’ efficiency during the push-off phase.

The Effect of an Altitude Training Camp on Swimming Start Time and Loaded Squat Jump Performance

This study evaluated the influence of an altitude training (AT) camp on swimming start time and loaded squat jump performance. To accomplish this goal, 13 international swimmers (8 women, 5 men) were allocated to both the control (Sea Level Training, SLT) and experimental conditions (AT, 2320 m above sea level) that were separated by a one year period. All tests (15 m freestyle swimming start and loaded squat jumps with additional loads of 25%, 50%, 75%, and 100% of swimmers’ body weight) were performed before and after a concurrent 3-week strength and endurance training program prescribed by the national coach. Following the SLT camp, significant impairments in swimming start times to 10 (+3.1%) and 15 m (+4.0%) were observed (P < 0.05), whereas no significant changes for the same distances were detected following the AT camp (-0.89%; P > 0.05). Trivial changes in peak velocity were obtained during the loaded squat jump after both training periods (effect sizes: < 0.20). Based on these results we can conclude that a traditional training high—living high strategy concurrent training of 3 weeks does not adversely affect swimming start time and loaded squat jump performance in high level swimmers, but further studies are necessary to assess the effectiveness of power-oriented resistance training in the development of explosive actions.

The Relationship Between the Lower-Body Muscular Profile and Swimming Start Performance

Abstract This study aimed to examine the correlation of different dry land strength and power tests with swimming start performance. Twenty international level female swimmers (age 15.3 ± 1.6 years, FINA point score 709.6 ± 71.1) performed the track freestyle start. Additionally, dry land tests were conducted: a) squat (SJ) and countermovement jumps (CMJ), b) squat jumps with additional resistance equivalent to 25, 50, 75 and 100% of swimmers’ body weight [BW]), and c) leg extension and leg flexion maximal voluntary isometric contractions. Correlations between dry land tests and start times at 5, 10 and 15 m were quantified through Pearson’s linear correlation coefficients (r). The peak bar velocity reached during the jumps with additional resistance was the variable most correlated to swimming start performance (r = -0.57 to -0.66 at 25%BW; r = -0.57 to -0.72 at 50%BW; r = -0.59 to -0.68 at 75%BW; r = -0.50 to - 0.64 at 100%BW). A few significant correlations between the parameters of the SJ and the CMJ with times of 5 and 10 m were found, and none with the isometric variables. The peak velocity reached during jumps with external loads relative to BW was found a good indicator of swimming start performance.

The Influence of Reduced Breathing During Incremental Bicycle Exercise on Some Ventilatory and Gas Exchange Parameters

The purpose of this study was to examine the ventilatory, gas exchange, oxygen saturation and heart rate response to reduced breathing frequency during an incremental bicycle exercise. Eight healthy male subjects performed an incremental bicycle exercise test on an electromagnetically braked cycle ergometer twice: first with continuous breathing (CB), and second with reduced breathing frequency (B10), which was defined as 10 breaths per minute. As work rates increased, significantly higher VE, Vco2 and R were measured during the exercise with SB than during the exercise with B10. Consequently, PETco2 and PETo2 were higher and lower, respectively, during the exercise with B10 than during the exercise with SB at 150 W. In addition, HR was greater during the exercise with SB than during the exercise with B10; significant differences were achieved at 90, 120 and 150W. However, Vo2 showed no significant difference between the exercises in two different breathing conditions. In summary, reduced breathing frequency during the incremental bicycle exercise decreased VE and consequently decreased So2 and increased PETco2. However, it seemed that this degree of breathing reduction did not influence on aerobic metabolism due to unchanged Vo2.

Graded shuttle run performance by playing positions in elite female basketball

Abstract Štrumbelj, B, Vučković, G, Jakovljević, S, Milanović, Z, James, N, and Erčulj, F. Graded shuttle run performance by playing positions in elite female basketball. J Strength Cond Res 29(3): 793–799, 2015—A graded shuttle run test was used to assess differences in physiological parameters between playing positions in elite female basketball players. Twenty-four female basketball players (8 guards, 8 forwards, and 8 centers) who played for the senior national teams of Slovenia and Serbia were tested with the 30-15 intermittent fitness test. During the shuttle run, the following physiological parameters were measured: oxygen consumption ( ), carbon dioxide production ( ), pulmonary ventilation (VE) breath by breath, respiratory quotient, oxygen pulse as the vs. HR ratio and [LA−]. No significant differences were found for any of the measures between the 3 playing positions. Although this finding was surprising, future studies should try to determine whether the tactics used in female basketball determine that the interpositional differences seen in male basketball are not evident.