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Relationship Between Freestyle Swimming Speed and Stroke Mechanics to Isokinetic Muscle Function
Abstract
Maximal swimming performance is determined, at least in part, by the maximal water resistance a swimmer can overcome. Previous work has suggested that increased strength may allow the swimmer to overcome more resistance and, therefore, go faster. The purpose of the present study was to relate isokinetic muscle function to swimming speed, VO^2 max and stroke mechanics. Fifteen male university swimmers, competing in freestyle events, were studied. Isokinetic measurements of the shoulder, elbow, wrist, knee and ankle were determined, along with the maximal distance per stroke, peak speed, stroke frequency and distance per stroke at peak speed. When the swimmers were separated into high and low speed groups, there were no significant difference (p<=0.05) in isokinetic strength, work or power. However, the high speed group showed difference in technical ability, as represented by an increased distance per stroke at peak speed. This suggests that other factors, such as skill of the swimmer and speed of the contraction, are of more importance than muscular strength in swimming fast.
... Results obtained in our investigation by means of the Wingate test confirm the aforementioned data, showing that IHT improves anaerobic performance of landbased exercises that were performed in an upright positon with a predominant involvement of lower body muscles in exercise execution. However, the present study extends these findings to whole-body exercise performed in a prone position during freestyle swimming, where the arms provide 70-85% of the propulsive forces [29,30]. Moreover, swimming has been shown to be more energy demanding per unit of distance than locomotion on land and both internal and external work in water is elevated compared to land-based conditions, because of water density [31]. ...
... The study with longer high-intensity IHT exercise bouts revealed the effectiveness of this method in improving VO 2max [3,11,12,60]. The lack of improvement in VO 2max observed in our study may be, at least partially, attributed to a predominate engagement of a rather small mass of upper body muscles that provide 70-85% of the propulsive forces during front crawl swimming [29]. Moreover, in relation to land-based exercise, swimming involves more technique-dependent breathing, with respiration being synchronized with swimming strokes [61], and the prone position implies venous return, which results in an increase in stroke volume (SV) and lowered HR during swimming [62]. ...
The main objective of this research was to evaluate the efficacy of intermittent hypoxic training (IHT) on anaerobic and aerobic capacity and swimming performance in well-trained swimmers. Sixteen male swimmers were randomly divided into a hypoxia (H) group (n = 8), which trained in a normobaric hypoxia environment, and a control (C) group (n = 8), which exercised under normoxic conditions. However, one participant left the study without explanation. During the experiment group H trained on land twice per week in simulated hypoxia (FiO2 = 15.5%, corresponding to 2,500 m a.s.l); however, they conducted swim training in normoxic conditions. Group C performed the same training program under normoxic conditions. The training program included four weekly microcyles, followed by three days of recovery. During practice sessions on land, the swimmers performed 30 second sprints on an arm-ergometer, alternating with two minute high intensity intervals on a lower limb cycle ergometer. The results showed that the training on land caused a significant (p
... Inicialmente os nadadores começavam o nado lentamente até o cabo estar em extensão total, de modo a evitar movimentos bruscos e valores enviesados de força. A partir deste momento o avaliador emitia um sinal sonoro para início do nado à intensidade máxima o qual terminava após 30s; procedimento previamente utilizado por outros investigadores (Reilly et al., 1990;) (Figura 2). A Performance foi calculada através do registo do tempo após um sprint de 50m crol, em piscina de 25m coberta (27ºC), em situação de nado real. ...
... Relativamente às correlações entre variáveis de força isocinética e nado amarrado (Tabelas 6 e 7), foram obtidas correlações fortes e moderadas entre as variáveis de PT (RI e RE) e de Wt (Wt-RI e Wt-RE) com as variáveis de F.máx e F.min no nado amarrado, no membro dominante e não dominante, contrariando os resultados obtidos em investigações anteriores (Reilly et al., 1990). Num outro estudo (Loturco et al., 2015), também foram encontradas correlações entre variáveis de força fora de água (supino e agachamento) e variáveis de força dentro de água (nado amarrado) reforçando que efetivamente a força realizada nos exercícios feitos fora de água parecem ter um transfere positivo para a força realizada dentro de água. ...
... The above outcomes are in accordance with the study that reported an inverse relationship between isokinetic knee extension force and mono-fin swimming 100 m time [25]. However, some studies indicated that isokinetic force variables were not associated with swimming performance [26][27][28]. These last studies used dryland tests that employed different movements types than those used in swimming (different muscular groups and patterns). ...
Although performance and biomechanical evaluations are becoming more swimming-specific, dryland testing permits monitoring of a larger number of performance-related variables. However, as the degree of comparability of measurements conducted in-water and on land conditions is unclear, we aimed to assess the differences between force production in these two different conditions. Twelve elite swimmers performed a 30 s tethered swimming test and four isokinetic tests (shoulder and knee extension at 90 and 300°/s) to assess peak force, peak and average torque, and power symmetry index. We observed contralateral symmetry in all the tests performed, e.g., for 30 s tethered swimming and peak torque shoulder extension at 90°/s: 178 ± 50 vs. 183 ± 56 N (p = 0.38) and 95 ± 37 vs. 94 ± 35 N × m (p = 0.52). Moderate to very large direct relationships were evident between dryland testing and swimming force production (r = 0.62 to 0.96; p < 0.05). Swimmers maintained similar symmetry index values independently of the testing conditions (r = −0.06 to −0.41 and 0.04 to 0.44; p = 0.18–0.88). Asymmetries in water seems to be more related to technical constraints than muscular imbalances, but swimmers that displayed higher propulsive forces were the ones with greater force values on land. Thus, tethered swimming and isokinetic evaluations are useful for assessing muscular imbalances regarding propulsive force production and technical asymmetries.
... The tests' objective is to provide information not only about the isolated muscles' peak torque, power and endurance values, but also informing about muscular asymmetry. The latter can be useful for preventing injuries such as the "swimmers shoulder" which consists the most common musculoskeletal problem in competitive swimming (Beach et al., 1992) The assumption that greater isokinetic peak torque values would conclude to greater propulsive force and, as a consequence, to greater velocity values, seems not to be accepted (Miyashita & Kanehisa, 1983;Reilly et al., 1990), due to the lack of specific reproducing of the swimming movements (Cardone et al., 1999) and the fact that the arm-pull phase during swimming is not an isokinetically action with constant velocity (Swaine & Reilly, 1983). Differences in peak torque values of upper extremities of elite compared with non-elite group of swimmers have been observed (Cardone et al., 1999). ...
Dalamitros, A.A., Manou, V., & Pelarigo, J.G. (2014). Laboratory-based tests for swimmers: methodology, reliability, considerations and relationship with front-crawl performance. J. Hum. Sport Exerc., 9(1), pp.172-187. Monitoring training process in swimming is essential for providing valuable information for both coaches and athletes. Among a large variety of laboratory-based tests used for the quantification of swimmers abilities and evaluation of fitness status, the most representative and easy to apply ones are chosen to be presented in this review. Furthermore, these tests reliability, methodology, referred considerations and relationship with front-crawl swimming performance are reported. Based on the previous mentioned criteria, the assessment of aerobic, anaerobic power and muscular strength, are analyzed. From the data examined, it is concluded that despite their reliability and efficacy in determining adaptations after a training period, as well as, detecting differences between athletes’ training status, laboratory-based tests assessing aerobic, anaerobic power and muscular strength for swimmers does not meet the criterion of specificity and disregard the crucial role of technique.
Key words: Aerobic power, anaerobic power, muscular strength, dry-land testing, swimming.
Strength characteristics were studied in 12 members of the University men's swimming team, aged 19 to 23 years, and in 22 students, not engaged in competitive sports (control group). In each subject, isometric and isokinetic (at 1 rad/s) torques were measured for 8 muscle groups of upper and lower extremities by using a Merac isokinetic dynamometer. The sums of torques of 8 muscle groups in swimmers did not differ significantly from those in controls. Hovewer, mean values of absolute isometric strength of individual muscle groups (elbow flexors, shoulder extensors, knee flexors and hip flexors) were significantly higher in swimmers than in controls and the same was true for isokinetic torques in relation to joint angle and range of movement in swimming strokes at certain angle values.
Performance is the time (t) to cover a given distance (d), i. e.
speed of swimming (v = d / t). In turn, v is the product of
stroke rate (SR), and distance per stroke (d/S). Maximal v is
set by maximal metabolic power (E’
max
) and energy cost of
swimming (C
s
). Drag (D), efficiency (
h
) and v set the metabol-
ic requirements. D can be partitioned in friction (22%), pres-
sure (55%) and wave (23%) drag. D reduction can be achieved
by training and swim suit design. _ and C
s
are influenced by D,
by the energy wasted to water and by the internal work. E’
tot
is
a combination of aerobic and anaerobic power: it increases
monotonically with the speed, is highly variable and, it
decreases with training. Aerobic, anaerobic lactic and alactic
energy supply 38, 43, and 19% in 200 yd and 19, 54, and 26%
in 50 yds. At competitive v, C
s
is lowest in front crawl and
higher in backstroke, butterfly and breaststroke (in that order).
The above mentioned factors are highly variable, but even
among elite swimmers each is highly trainable.
Key Words: biomechanics, swimming, aerobic, anaerobic, drag,
efficiency, training.
Swimming fast is a complex skill that requires physical attributes to maximize propulsive force whilst minimizing drag forces. The models that have historically been used to explain the incidence of shoulder pain in swimmers have been very mechanical in nature. The interplay between the requirement of the sport, the shoulder's mechanical restraints, the biomechanical effect of the kinetic chain, and the powerful influence of the neuromuscular system must be appreciated in pathological and rehabilitation models. The interaction between flexibility, strength, fatigue, muscle inhibition, proprioception, muscle patterning and pain is complicated and poorly understood. It is, however, in these complex intertwining relationships that the origin of shoulder pain in swimming must lay and therefore where the conservative management of that pain must have its effect.
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