Intracyclic Variation of Force and Swimming Performance

2018 ◽  
Vol 13 (7) ◽  
pp. 897-902 ◽  
Author(s):  
Pedro G. Morouço ◽  
Tiago M. Barbosa ◽  
Raul Arellano ◽  
João P. Vilas-Boas

Context: In front-crawl swimming, the upper limbs perform alternating movements with the aim of achieving a continuous application of force in the water, leading to lower intracyclic velocity variation (dv). This parameter has been identified as a crucial criterion for swimmers’ evaluation. Purpose: To examine the assessment of intracyclic force variation (dF) and to analyze its relationship with dv and swimming performance. Methods: A total of 22 high-level male swimmers performed a maximal-effort 50-m front-crawl time trial and a 30-s maximal-effort fully tethered swimming test, which were randomly assigned. Instantaneous velocity was obtained by a speedometer and force by a strain-gauge system. Results: Similarity was observed between the tests, with dF attaining much higher magnitudes than dv (P < .001; d = 8.89). There were no differences in stroke rate or in physiological responses between tethered and free swimming, with a high level of agreement for the stroke rate and blood lactate increase. Swimming velocity presented a strong negative linear relationship with dF (r = −.826, P < .001) and a moderate negative nonlinear relationship with dv (r = .734, P < .01). With the addition of the maximum impulse to dF, multiple-regression analysis explained 83% of the free-swimming performance. Conclusions: Assessing dF is a promising approach for evaluating a swimmer’s performance. From the experiments, this new parameter showed that swimmers with higher dF also present higher dv, leading to a decrease in performance.

2020 ◽  
Vol 15 (8) ◽  
pp. 1087-1094
Author(s):  
Jesús J. Ruiz-Navarro ◽  
Pedro G. Morouço ◽  
Raúl Arellano

Purpose: To study the relationship between tethered swimming in a flume at different speeds and swimming performance. Methods: Sixteen regional-level swimmers performed 25-, 50-, and 100-m front-crawl trials and four 30-s tethered-swimming tests at 0, 0.926, 1.124, and 1.389 m·s−1 water-flow velocities. Average and maximum force, average and maximum impulse, and intracyclic force variation (dF) were estimated for each tethered-swimming trial. Swimming velocity and intracyclic velocity variation (dv) were obtained for each free-swimming trial. Stroke rate and rating of perceived exertion (RPE) were registered for all trials. Results: Tethered-swimming variables, both at 1.124 m·s−1 and at 1.389 m·s−1 water-flow velocities, were positively associated with 25-m swimming velocity (P < .05). Average force and maximum impulse in stationary swimming were significantly associated with 25-m swimming velocity (P < .05). A positive relationship between water-flow velocities with dF was observed. Swimming performance was not related to dF or dv. Neither stroke rate nor RPE differed between the 4 tethered conditions and mean 50-m free-swimming velocity (P > .05). Conclusions: Measuring force in a swimming flume at higher water-flow velocities is a better indicator of performance than stationary tethered swimming. It enables assessment of the ability to effectively apply force in the water.


2012 ◽  
Vol 34 (1) ◽  
pp. 112-118 ◽  
Author(s):  
Daniel López-Plaza ◽  
Fernando Alacid ◽  
Pedro A. López-Miñarro ◽  
José M. Muyor

AbstractThe purpose of this study was to determine the influence of different sizes of hand paddles on kinematicparameters during a 100 m freestyle swimming performance in elite swimmers. Nine elite swimmers (19.1 ± 1.9 years)completed three tests of 100 m without paddles, with small paddles (271.27 cm2) and with large paddles (332.67 cm2),respectively. One video camera was used to record the performance during the three trials. The mean swimmingvelocity, stroke rate and stroke length were measured in the central 10 meters of each 50 m length. The results showedthat stroke length tended to increase significantly when wearing hand paddles (p < 0.05) during both the first andsecond 50 m sections whereas the increase in swimming velocity occurred only in the second 50 m (p < 0.05).Conversely, the stroke rate showed a slight decreasing trend with increasing paddle size. During the 100 m freestyletrial the stroke kinematics were changed significantly as a result of the increase in propelling surface size when handpaddles were worn.


Motor Control ◽  
2021 ◽  
pp. 1-12
Author(s):  
Karini Borges dos Santos ◽  
Paulo Cesar Barauce Bento ◽  
Carl Payton ◽  
André Luiz Felix Rodacki

This study described the kinematic variables of disabled swimmers’ performance and correlated them with their functional classification. Twenty-one impaired swimmers (S5–S10) performed 50-m maximum front-crawl swimming while being recorded by four underwater cameras. Swimming velocity, stroke rate, stroke length, intracycle velocity variation, stroke dimensions, hand velocity, and coordination index were analyzed. Kendall rank was used to correlate stroke parameters and functional classification with p < .05. Swimming velocity, stroke length, and submerged phase were positively correlated with the para swimmers functional classification (.61, .50, and .41; p < .05, respectively), while stroke rate, velocity hand for each phase, coordination index, and intracyclic velocity variation were not (τ between −.11 and .45; p > .05). Thus, some objective kinematic variables of the impaired swimmers help to support current classification. Improving hand velocity seems to be a crucial point to be improved among disabled swimmers.


2018 ◽  
Vol 64 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Nicolas Olivier ◽  
Frédéric N. Daussin

Abstract Swimming and throwing are involved in water-polo player performance. These movements have a common biomechanical basis in the use of the internal shoulder rotation and adductor muscles. The aim of the study was to evaluate the relationship between shoulder isokinetic evaluation and throwing velocity as well as swimming performance in female water-polo players. Fifteen high level water-polo players completed two isokinetic shoulder evaluations to determine peak torque of shoulder rotators of the dominant shoulder (concentric and eccentric movements at an angular velocity of 60°·s-1 and concentric movements at an angular velocity of 240°·s-1) and shoulder extensors of both arms (concentric movements at an angular velocity of 60°·s-1 and 240°·s-1). Throwing velocity was measured using a radar gun placed 5 m behind the goal post. Front crawl swimming velocity was determined at 25 m, 100 m and 400 m distances. Concentric peak torque at 60°·s-1 and 240°·s-1 of internal rotators and eccentric peak torque at 60°·s-1 of external rotators were predictors of throwing velocity. The best model to explain the relationship between isokinetic evaluations and throwing velocity was obtained with concentric IR peak torque at 60°·s-1 and eccentric ER peak torque at 60°·s-1 (r2 = 0.52, p = 0.012). Relative total work done and peak torque of shoulder extensors were predictors of 25 m swimming velocity. Shoulder isokinetic evaluations correlate significantly with swimming performance and throwing velocity of female water-polo players. The results may help coaches to develop new strategies such as eccentric dry land training programs to increase both shoulder external rotators strength and throwing velocity.


2013 ◽  
Vol 30 (1) ◽  
pp. 70-84 ◽  
Author(s):  
Inês Marques-Aleixo ◽  
Ana Querido ◽  
Pedro Figueiredo ◽  
João Paulo Vilas-Boas ◽  
Rui Corredeira ◽  
...  

This study examined the differences in intracycle velocity variation and arm coordination in front crawl in swimmers with Down syndrome in three breathing conditions. International swimmers with Down syndrome (N = 16) performed 3 × 20 m front crawl at 50 m race speed: without breathing, breathing to the preferred side, and breathing to the nonpreferred side. A two dimensional video movement analysis was performed using the APASystem. Breathing conditions were compared using Repeated Measures ANOVA. Swimming velocity was higher without breathing and intracyclic velocity variation was higher while breathing. Swimmers tended to a catch up arm coordination mode for both breathing conditions and a superposition mode when not breathing. These data reflect arm coordination compromising swimming performance, particularly when comparing with non disabled swimmers in literature. The physical and perhaps cognitive impairment associated with Down syndrome may result in a disadvantage in both propulsion and drag, more evident when breathing.


Author(s):  
Sam Lowings ◽  
Oliver Michael Shannon ◽  
Kevin Deighton ◽  
Jamie Matu ◽  
Matthew John Barlow

Nitrate supplementation appears to be most ergogenic when oxygen availability is restricted and subsequently may be particularly beneficial for swimming performance due to the breath-hold element of this sport. This represents the first investigation of nitrate supplementation and swimming time-trial (TT) performance. In a randomized double-blind repeated-measures crossover study, ten (5 male, 5 female) trained swimmers ingested 140ml nitrate-rich (~12.5mmol nitrate) or nitrate-depleted (~0.01mmol nitrate) beetroot juice. Three hours later, subjects completed a maximal effort swim TT comprising 168m (8 × 21m lengths) backstroke. Preexercise fractional exhaled nitric oxide concentration was significantly elevated with nitrate compared with placebo, Mean (SD): 17 (9) vs. 7 (3)p.p.b., p = .008. Nitrate supplementation had a likely trivial effect on overall swim TT performance (mean difference 1.22s; 90% CI -0.18–2.6s; 0.93%; p = .144; d = 0.13; unlikely beneficial (22.6%), likely trivial (77.2%), most unlikely negative (0.2%)). The effects of nitrate supplementation during the first half of the TT were trivial (mean difference 0.29s; 90% CI -0.94–1.5s; 0.46%; p = .678; d = 0.05), but there was a possible beneficial effect of nitrate supplementation during the second half of the TT (mean difference 0.93s; 90% CI 0.13–1.70s; 1.36%; p = .062; d = 0.24; possibly beneficial (63.5%), possibly trivial (36.3%), most unlikely negative (0.2%)). The duration and speed of underwater swimming within the performance did not differ between nitrate and placebo (both p > .30). Nitrate supplementation increased nitric oxide bioavailability but did not benefit short-distance swimming performance or the underwater phases of the TT. Further investigation into the effects of nitrate supplementation during the second half of performance tests may be warranted.


Motricidade ◽  
2018 ◽  
Vol 14 (4) ◽  
pp. 103-112 ◽  
Author(s):  
Valdir Junior ◽  
Alexandre Medeiros ◽  
Kelly Jesus ◽  
Nuno Domingos Garrido ◽  
Rui Corredeira ◽  
...  

The evaluation of swimming technique is one of the main aspects to be considered in any training program, with biomechanics being an important source of knowledge. It was our objective to characterize the biomechanical parameters (SL and SF) relating them to the swimming velocity (v) at different intensities and to analyze within each swimming stroke cycle the intra-cyclic velocity variation (IVV) in a group of motor disabled swimmers. Eight disabled male swimmers (25.83 ± 2.93 years old, 72.45 ± 9.26 kg body mass and 1.79 ± 0.11 m of height) of the following functional classes: S6 (n = 1), S8 (n = 2) and S9 (n = 5) participated in this study. Swimmers were evaluated in the kinematic parameters v, stroke frequency (SF) and stroke length (SL) along with an incremental protocol of 6 x 200 m in the the crawl stroke. Data were registered in each step at the distances of 100 and 175 m. With increasing velocity, the mean values of SL decreased while the mean values of SF increased. To achieve higher swimming velocities, swimmers compensated the lack of the propulsive segment increasing SF to increase swimming speed. For the mean values of IVV at 100m distance, a decrease between the first and second levels, followed by a tendency to stabilize from the 2nd to the 6th level is presented. For the 175 m distance, there was a decrease in IVV with an increase in swimming velocity. Stroke frequency is directly related to the magnitude of IVV, which directly influences swimming performance.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Pedro G. Morouço ◽  
Daniel A. Marinho ◽  
Mikel Izquierdo ◽  
Henrique Neiva ◽  
Mário C. Marques

The relative contribution of arm stroke and leg kicking to maximal fully tethered front crawl swimming performance remains to be solved. Twenty-three national level young swimmers (12 male and 11 female) randomly performed 3 bouts of 30 s fully tethered swimming (using the whole body, only the arm stroke, and only the leg kicking). A load-cell system permitted the continuous measurement of the exerted forces, and swimming velocity was calculated from the time taken to complete a 50 m front crawl swim. As expected, with no restrictions swimmers were able to exert higher forces than that using only their arm stroke or leg kicking. Estimated relative contributions of arm stroke and leg kicking were 70.3% versus 29.7% for males and 66.6% versus 33.4% for females, with 15.6% and 13.1% force deficits, respectively. To obtain higher velocities, male swimmers are highly dependent on the maximum forces they can exert with the arm stroke (r=0.77,P<0.01), whereas female swimmers swimming velocity is more related to whole-body mean forces (r=0.81,P<0.01). The obtained results point that leg kicking plays an important role over short duration high intensity bouts and that the used methodology may be useful to identify strength and/or coordination flaws.


Author(s):  
Peterson Silveira ◽  
Soares ◽  
Zacca ◽  
Alves ◽  
Fernandes ◽  
...  

Purpose: to compare different methods to assess the arm stroke efficiency (?F ), whenswimming front crawl using the arms only on the Measurement of Active Drag System (MADSystem) and in a free-swimming condition, and to identify biophysical adaptations to swimming onthe MAD System and the main biophysical predictors of maximal swimming speed in the 200 mfront crawl using the arms only (?200m). Methods: fourteen swimmers performed twice a 5 × 200 mincremental trial swimming the front crawl stroke using the arms only, once swimming freely, andonce swimming on the MAD System. The total metabolic power was assessed in both conditions.The biomechanical parameters were obtained from video analysis and force data recorded on theMAD System. The ?F was calculated using: (i) direct measures of mechanical and metabolic power(power-based method); (ii) forward speed/hand speed ratio (speed-based method), and (iii) thesimplified paddle-wheel model. Results: both methods to assess ?F on the MAD System differed (p< 0.001) from the expected values for this condition (?F = 1), with the speed-based method providingthe closest values (?F~0.96). In the free-swimming condition, the power-based (?F~0.75), speedbased(?F~0.62), and paddle-wheel (?F~0.39) efficiencies were significantly different (p < 0.001).Although all methods provided values within the limits of agreement, the speed-based methodprovided the closest values to the “actual efficiency”. The main biophysical predictors of ?200mwere included in two models: biomechanical (R2 = 0.98) and physiological (R2 = 0.98). Conclusions:our results suggest that the speed-based method provides the closest values to the “actual ?F” andconfirm that swimming performance depends on the balance of biomechanical and bioenergeticparameters


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