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The purpose of this study was to determine whether the critical swimming velocity (Vcri) estimated by the swimming velocity for a distance of 300m at maximal effort breaststroke reflects the maximal lactate steady state (MLSS). Twelve trained swimmers swam 5Dm, 300m and 2000m at maximal effort for determination of Vcri that averaged 1.167 ± 0.045 m·sec-1. Since Vcri was equivalent to 90.5% of the mean swimming velocity over the distance of 300 m at maximal effort, the swimming velocity obtained by multiplying the swimming velocity for the distance of 300 m of each subject by 90.5% was taken to be 100% of the predicted critical swimming velocity (Vcri-pred). Then, in an MLSS test, the subjects were instructed to swim breaststroke 2000m (5x400m) at three constant velocities (98%, 100%, and 102% of Vcri-pred), interrupted by four short rest periods from 30 to 45 seconds for blood sampling and heart rate measurement. As a result, the blood lactate concentration at 100% Vcri-pred showed a higher steady state than the slow velocity, but at high velocity did not show the steady state. In conclusion, we can accurately estimate the Vcri for breaststroke by a one-time 300-m maximal effort swimming test. [ABSTRACT FROM AUTHOR]

The aim of this study was to analyse the kinematics and coordination of the breaststroke start as regards to skill level using a video device. Ten national swimmers were compared with an international swimmer. All swimmers simulated the 100-m pace for 25 m after a grab start. The kinematical analysis assessed the durations of leave block, flight, entry and glide, pull-out, and the swim up to the 15-m mark phases. The coordination analysis assessed the durations of the time spent with the arms close to the thighs after a complete arm pull-push, the time gap between the end of the arm recovery and the beginning of the leg propulsion during the pull-out phase and at the first swim stroke, and the time gap between the end of leg propulsion and the beginning of arm propulsion. The international swimmer had a shorter 15-m start time than the national swimmers due to shorter times in the swim phase, longer times in the underwater phase, longer times spent with the arms close to the thighs and in glide with the body in extension. The whole population showed a negative superposition of leg propulsion with arm recovery at the pull-out phase, which disappeared at the first swim stroke. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the intra-cyclic velocity graphs of breaststroke swimmers at two skill levels in relation to their movement phases. Two groups of nine male swimmers were videotaped underwater at three swimming race paces corresponding to their actual competitive times for the 200-m, 100-m and 50-m breaststroke. Their forward intra-cyclic hip velocity was recorded with a velocity-meter. The breaststroke cycle was divided into four phases: leg propulsion, leg-arm lag phase, arm propulsion, and arm and leg recovery. From the velocity-time data, the following parameters were computed: an index of velocity fluctuations (IVF), the distance covered during each stroke phase, and an acceleration-deceleration time ratio (ADTR). The main results showed that in both groups of swimmers, when the race pace increased, the distance covered during the leg-arm lag phase decreased, while the other swimming phases remained stable. When expressed in relative values, the percentage of distance covered during the leg-arm lag phase decreased. In non-elite swimmers, the percentage of distance covered in the other stroke phases increased significantly, while only a tendency was noted in the elite group. Elite swimmers demonstrated a higher ADTR at the 50-m pace than at their 100-m and 200-m paces. An inter-group comparison showed that elite swimmers had higher values for the IVF and ADTR, which indicated their capacity to accelerate to boost the swim and highlighted the relevancy of these factors to discriminate skill level. [ABSTRACT FROM AUTHOR]

The purpose of this study was to measure and compare the total energy expenditure of the four competitive swimming strokes. Twenty-six swimmers of international level were submitted to an incremental set of 200-m swims (5 swimmers at Breaststroke, 5 swimmers at Backstroke, 4 swimmers at Butterfly and 12 swimmers at Front Crawl). The starting velocity was approximately 0.3 m·s-1 less than a swimmer's best performance and thereafter increased by 0.05 ms-1 after each swim until exhaustion. Cardio-pulmonary and gas exchange parameters were measured breath-by-breath (BxB) for each swim to analyze oxygen consumption (̇O2) and other energetic parameters by portable metabolic cart (K4b², Cosmed, Rome, Italy). A respiratory snorkel and valve system with low hydrodynamic resistance was used to measure pulmonary ventilation and to collect breathing air samples. Blood samples from the ear lobe were collected before and after each swim to analyze blood lactate concentration (YSI 1500 L, Yellow Springs, Ohio, USA). Total energy expenditure (Etot), was calculated for each 200-rn stage. Ėtot differed significantly between the strokes at all selected velocities. At the velocity of 1.0 m·s-1 and of 1.2 m· s-1 the Ėtot was significantly higher in Breaststroke than in Backstroke, in Breaststroke than in Freestyle and in Butterfly than in Freestyle. At the velocity of 1.4 m·s-1, the Ėtot was significantly higher in Breaststroke than in Backstroke, in Backstroke than in Freestyle, in Breaststroke than in Freestyle and in Butterfly than in Freestyle. At the velocity of 1.6m·s-1, the Etot was significantly higher in Breast- stroke and in Butterfly than in Freestyle. As a conclusion, Etot of well-trained competitive swimmers was measured over a large range of velocities utilising a new BxB technique. Freestyle was shown to be the most economic among the competitive swimming strokes, followed by the Backstroke, the Butterfly and the Breaststroke. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the arm-leg coordination in gut breaststroke among four groups of swimmers (elite mules, elite females and non-elite mules, non-elite females) of two different competitive levels. Using a velocity-video system, both forward acceleration and deceleration phases of the hip were first identified. Based on these phases, four temporal gaps indicated the time duration between arm and leg actions throughout three race paces (200, 100, and 50 m). For both groups, a velocity increase was combined with an increase of stroke rate, a decrease of stroke length, and an increase of the propulsive phases and a decrease of the glide phases. However, when the relative duration of one stroke cycle woo considered, the elite swimmers had significant shorter time of the glide phase than lower competitive level swimmers (18.80% vs. 31.04% for females and 11.89% vs. 19.60% for males) combined with a longer stroke length (respectively 2.05 m vs. 1.73 m and 2.03 m vs. 1.82 m). Furthermore, the temporal gaps of the elite swimmers showed a greater continuity in the arm and leg actions, which indicates a better timing than non-elite swimmers. It was concluded that elite breaststroke swimmers are able to optimise their propulsion by reducing their glide phase and using a more continuous timing between arm and leg coordination. [ABSTRACT FROM AUTHOR]