Development, implementation and evaluation of a seven-day clinical pharmacy service in a tertiary referral teaching hospital during surge-2 of the COVID-19 pandemic.

BACKGROUND: Seven-day clinical pharmacy services in the acute sector of the National Health Service are limited. There is a paucity of evidential patient benefit. This limits investment and infrastructure, despite United Kingdom wide calls. AIM: To optimise medicines seven-days a week during surge-2 of the COVID-19 pandemic through implementation of a seven-day clinical pharmacy service. This paper describes service development, evaluation and sustainability. SETTING: A tertiary-referral teaching hospital, London, United Kingdom. DEVELOPMENT: The seven-day clinical pharmacy service was developed to critical care, acute and general medical patients. Clinical leads developed the service specification and defined priorities, targeting complex patients and transfer of care. Contributing staff were briefed and training materials developed. IMPLEMENTATION: The service was implemented in January 2021 for 11 weeks. Multidisciplinary team communication brought challenges; strategies were employed to overcome these. EVALUATION: A prospective observational study was conducted in intervention wards over two weekends in February 2021. 1584 beds were occupied and 602 patients included. 346 interventions were reported and rated; 85.6% had high or moderate impact; 56.7% were time-critical. The proportion of medicines reconciliation within 24-h of admission was analysed across the hospital between November 2020 and May 2021. During implementation, patients admitted Friday-Sunday were more likely to receive medicines reconciliation within 24-h (RR 1.41 (95% CI 1.34-1.47), p < 0.001). Rostered services were delivered sustainably in terms of shift-fill rate and medicines reconciliation outcome. CONCLUSION: Seven-day clinical pharmacy services benefit patient outcome through early medicines reconciliation and intervention. Investment to permanently embed the service was sustained.

Anatomia do sistema reprodutor feminino de Alouatta belzebul (Linnaeus, 1766) / [Anatomy of the female reproductive system of the Alouatta belzebul (Linnaeus, 1766)]

O conhecimento da anatomia de qualquer animal silvestre é de fundamental importância para sua preservação e proteção. Neste contexto, o presente estudo objetivou descrever a morfologia do sistema reprodutor feminino de Alouatta belzebul. Foram utilizados seis espécimes de A. belzebul, fêmeas, adultas, e livres de lesões. Observou-se macroscopicamente que os ovários têm características morfológicas em formato ovoides, com superfície lisa, e, na análise histológica na região de córtex, evidenciou-se folículos ovarianos em diferentes estágios de desenvolvimento. As tubas uterinas anatomicamente são finas e curvilíneas, apresentando uma camada mucosa, uma muscular e outra serosa. O útero possui formato simples, com fundo globoso, com um miométrio altamente vascularizado, sendo organizado em feixes de fibras musculares lisas. A estrutura anatômica da vagina apresentou-se como um tubo muscular longo de paredes finas, onde, na região vestibular, o óstio externo da uretra é marcado por uma papila uretral bilobada e, na região de vulva, em sua porção caudal, contatou-se um clitóris bem desenvolvido. No que concerne à análise histológica da vagina, verificou-se, em região de mucosa vaginal, um extrato basal composto por epitélio estratificado pavimentoso não queratinizado atrófico. As descrições morfológicas fornecem, de forma inédita, informações importantes relativas à anatomia macroscópica e microscópica do sistema reprodutor feminino dessa espécie.(AU)

Knowledge of the anatomy of any wild animal is of fundamental importance for its preservation and protection. In this context the present study aimed to describe the morphology of the female reproductive system of A. belzebul. We used 6 specimens of A. belzebul, female, adult and free of lesions. It was macroscopically observed that the ovaries are ovoid with smooth surface and the histological analysis in cortical region showed ovarian follicles in different stages of development. The fallopian tubes are anatomically thin and curvilinear, with one mucous layer, one muscular and one serous layer. The uterus was presented in a simple format with a globular fundus, with a highly vascularized myometrium, being organized in bundles of smooth muscle fibers. The anatomical structure of the vagina presented itself as a long thin-walled muscular tube where in the vestibular region the external orifice of the urethra is marked by a bilobed urethral papilla and in the caudal portion in its caudal portion a well-developed clitoris. Regarding the histological analysis of the vagina, a basal extract composed of atrophic non-keratinized stratified squamous epithelium was found in the vaginal mucosa region. The morphological descriptions provide important information regarding the macroscopic and microscopic anatomy of the female reproductive system of this species in an unprecedented way.(AU)

Behavioural variability and motor performance: Effect of practice specialization in front crawl swimming.

The aim was to examine behavioural variability within and between individuals, especially in a swimming task, to explore how swimmers with various specialty (competitive short distance swimming vs. triathlon) adapt to repetitive events of sub-maximal intensity, controlled in speed but of various distances. Five swimmers and five triathletes randomly performed three variants (with steps of 200, 300 and 400m distances) of a front crawl incremental step test until exhaustion. Multi-camera system was used to collect and analyse eight kinematical and swimming efficiency parameters. Analysis of variance showed significant differences between swimmers and triathletes, with significant individual effect. Cluster analysis put these parameters together to investigate whether each individual used the same pattern(s) and one or several patterns to achieve the task goal. Results exhibited ten patterns for the whole population, with only two behavioural patterns shared between swimmers and triathletes. Swimmers tended to use higher hand velocity and index of coordination than triathletes. Mono-stability occurred in swimmers whatever the task constraint showing high stability, while triathletes revealed bi-stability because they switched to another pattern at mid-distance of the task. Finally, our analysis helped to explain and understand effect of specialty and more broadly individual adaptation to task constraint.

AquaTrainer® Snorkel does not Increase Hydrodynamic Drag but Influences Turning Time.

Our purpose was to verify if the use of the new AquaTrainer(®) respiratory snorkel lead to an increase of front crawl hydrodynamic drag and whether the constraint of using an adapted turning technique influences its corresponding turning time. 12 swimmers performed 2 (without and with snorkel) 12×25 front crawl repetitions from low to maximal velocity on the measuring active drag system. Complementarily, 3 swimming turns were compared: open turn with snorkel, tumble turn and open turn without snorkel. Drag values were similar without vs. with snorkel at 0.9, 1.1, 1.3, 1.5 and 1.7 m.s(-1) velocities: 15.84 ±5.32 vs. 16.18±4.81, 25.60±6.69 vs. 26.03±6.17, 38.37±8.04 vs. 38.88±7.56, 54.64±10.06 vs. 55.08±9.55, 74.77±14.09 vs. 74.92±13.14 N, (respectively, p≥0.05), and high agreement between conditions was observed (p<0.01). Front crawl swimming with snorkel using the open turn implied an increase in turning time of 14.2 and 5.1% than the tumble turn and open turn without the apparatus (p<0.01). AquaTrainer(®) snorkel does not lead to an increase in active drag during front crawl performed at a large range of velocities and, consequently, the metabolic energy necessary to overcome total drag will not be affected. However, turning with it requires an additional time that should be taken into account in scientific research and training conditions.

Computational fluid dynamics vs. inverse dynamics methods to determine passive drag in two breaststroke glide positions.

Computational fluid dynamics (CFD) plays an important role to quantify, understand and "observe" the water movements around the human body and its effects on drag (D). We aimed to investigate the flow effects around the swimmer and to compare the drag and drag coefficient (CD) values obtained from experiments (using cable velocimetry in a swimming pool) with those of CFD simulations for the two ventral gliding positions assumed during the breaststroke underwater cycle (with shoulders flexed and upper limbs extended above the head-GP1; with shoulders in neutral position and upper limbs extended along the trunk-GP2). Six well-trained breaststroke male swimmers (with reasonable homogeneity of body characteristics) participated in the experimental tests; afterwards a 3D swimmer model was created to fit within the limits of the sample body size profile. The standard k-ε turbulent model was used to simulate the fluid flow around the swimmer model. Velocity ranged from 1.30 to 1.70 m/s for GP1 and 1.10 to 1.50 m/s for GP2. Values found for GP1 and GP2 were lower for CFD than experimental ones. Nevertheless, both CFD and experimental drag/drag coefficient values displayed a tendency to jointly increase/decrease with velocity, except for GP2 CD where CFD and experimental values display opposite tendencies. Results suggest that CFD values obtained by single model approaches should be considered with caution due to small body shape and dimension differences to real swimmers. For better accuracy of CFD studies, realistic individual 3D models of swimmers are required, and specific kinematics respected.

Autonomic adaptation after traditional and reverse swimming training periodizations.

The objective of the present study was to analyze the autonomic response of trained swimmers to traditional and reverse training periodization models. Seventeen swimmers were divided in two groups, performing a traditional periodization (TPG) or a reverse periodization (RPG) during a period of 10 weeks. Heart rate variability and 50 m swimming performance were analyzed before and after the training programs. After training, the TPG decreased the values of the high frequency band (HF), the number of differences between adjacent normal R-R intervals longer than 50 ms (NN50) and the percentage of differences between adjacent normal R-R intervals more than 50 ms (pNN50), and the RPG increased the values of HF and square root of the mean of the sum of the squared differences between adjacent normal R-R intervals (RMSSD). None of the groups improved significantly their performance in the 50-m test. The autonomic response of swimmers was different depending on the periodization performed, with the reverse periodization model leading to higher autonomic adaption. Complementary, the data suggests that autonomic adaptations were not critical for the 50-m swimming performance.

Metabolic and ventilatory thresholds assessment in front crawl swimming.

AIM: The purpose of this study was to assess and characterize the ventilatory anaerobic threshold in swimming, and to verify if the anaerobic metabolic threshold could be accurately estimated using ventilatory parameters. METHODS: Twenty-eight national-level male swimmers performed a n x 200 m front crawl individualized intermittent incremental protocol, with 30 s rest intervals, until exhaustion. The ventilatory variables and heart rate were continuously measured using a telemetric portable gas analyser. The capillary blood samples for lactate concentration analysis were collected from the earlobe at rest, during rest intervals, and at the end of exercise. RESULTS: No significant differences were observed between the ventilatory and metabolic thresholds for lactate concentration, heart rate and velocity (P=0.62, 0.80 and 0.78, respectively). The Bland-Altman plot revealed higher agreement between both methods for heart rate and velocity values. Ventilatory anaerobic threshold occurred at a swimming velocity corresponding to 88% of maximal oxygen uptake and lactate concentration mean values at ventilatory and metabolic thresholds were lower than 3 mmol.L(-1). CONCLUSION: Swimming anaerobic metabolic threshold could be accurately estimated using ventilatory parameters. Moreover, ventilatory anaerobic threshold occurred at similar %VO2max than in other sports. The lactate concentration mean values at ventilatory and metabolic thresholds were lower than the reference value of 4 mmol.L(-1) evidencing that, in highly trained swimmers, individualized values of anaerobic threshold should be used instead of general references.

Which are the best VO2 sampling intervals to characterize low to severe swimming intensities?

Cardiorespiratory response in swimming has been used to better understand aerobic performance, especially by assessing oxygen uptake (VO2). The current study aimed to compare different VO2 time-averaging intervals throughout low to severe swimming intensities, hypothesizing that VO2 values are similar for different time averages at low to moderate and heavy swimming intensities, but not for the severe domain. 20 male trained swimmers completed an incremental protocol of 7×200 m until exhaustion (0.05 m/s increments and 30 s intervals). VO2 was measured by a portable gas analyser connected to a snorkel system. 6 time average intervals (breath-by-breath, 5, 10, 15, 20 and 30 s) were compared for all the protocol steps. Breath-by-breath and 5 s average exhibited higher VO2 values than averages≥10 s for all swimming intensities (P≤0.02; partial η(2)≤0.28). VO2 values did not differ between 10, 15, 20 and 30 s averages throughout the incremental protocol (P>0.05; partial η(2)≤0.05). Furthermore, 10 and 15 s averages showed the lowest VO2 mean difference (0.19 mL( · )kg(-1 · )min(-1)). For the 6 time average intervals analysed, 10 and 15 s averages were those that showed the lowest changes on VO2 values. We recommended the use of 10 and 15 s time averaging intervals to determine relevant respiratory gas exchange parameters along a large spectrum of swimming intensities.

CNS myelin induces regulatory functions of DC-SIGN-expressing, antigen-presenting cells via cognate interaction with MOG.

Myelin oligodendrocyte glycoprotein (MOG), a constituent of central nervous system myelin, is an important autoantigen in the neuroinflammatory disease multiple sclerosis (MS). However, its function remains unknown. Here, we show that, in healthy human myelin, MOG is decorated with fucosylated N-glycans that support recognition by the C-type lectin receptor (CLR) DC-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) on microglia and DCs. The interaction of MOG with DC-SIGN in the context of simultaneous TLR4 activation resulted in enhanced IL-10 secretion and decreased T cell proliferation in a DC-SIGN-, glycosylation-, and Raf1-dependent manner. Exposure of oligodendrocytes to proinflammatory factors resulted in the down-regulation of fucosyltransferase expression, reflected by altered glycosylation at the MS lesion site. Indeed, removal of fucose on myelin reduced DC-SIGN-dependent homeostatic control, and resulted in inflammasome activation, increased T cell proliferation, and differentiation toward a Th17-prone phenotype. These data demonstrate a new role for myelin glycosylation in the control of immune homeostasis in the healthy human brain through the MOG-DC-SIGN homeostatic regulatory axis, which is comprised by inflammatory insults that affect glycosylation. This phenomenon should be considered as a basis to restore immune tolerance in MS.

Is the new AquaTrainer® snorkel valid for VO2 assessment in swimming?

The Cosmed AquaTrainer® snorkel, in connection with the K4b2 analyzer, is the most recent instrument used for real time gas analysis during swimming. This study aimed to test if a new AquaTrainer® snorkel with 2 (SV2) or 4 (SV4) valves is comparable to a standard face mask (Mask) being valid for real time gas analysis under controlled laboratory and swimming pool conditions. 9 swimmers performed 2 swimming and 3 cycling tests at 3 different workloads on separate days. Tests were performed in random order, at constant exercise load with direct turbine temperature measurements, breathing with Mask, SV4 and SV2 while cycling, and with SV2 and SV4 while swimming. A high agreement was obtained using Passing - Bablok regression analysis in oxygen consumption, carbon dioxide production, tidal volumes, pulmonary ventilation, expiratory fraction of oxygen and carbon dioxide, and heart rate comparing different conditions in swimming and cycling. Proportional and fixed differences were always rejected (95% CI always contained the value 1 for the slope and the 0 for the intercept). In conclusion, the new SV2 AquaTrainer® snorkel, can be considered a valid device for gas analysis, being comparable to the Mask and the SV4 in cycling, and to the SV4 in swimming.

Kinematic and electromyographic changes during 200 m front crawl at race pace.

The purpose of this study was to analyse eventual kinematic and electromyographic changes during a maximal 200 m front crawl at race pace. 10 male international level swimmers performed a 200 m maximal front crawl test. Images were recorded by 2 above and 4 under water cameras, and electromyographic signals (EMG) of 7 upper and lower limbs muscles were analysed for 1 stroke cycle in each 50 m lap. Capillary blood lactate concentrations were collected before and after the test. The variables of interest were: swimming speed, stroke length, stroke and kick frequency, hand angular velocity, upper limb and foot displacement, elbow angle, shoulder and roll angle, duration of stroke phases, and EMG for each muscle in each stroke phase. Generally, the kinematic parameters decreased, and a relative duration increased for the entry and pull phases and decreased for the recovery phase. Muscle activation of flexor carpi radialis, biceps brachii, triceps brachii, peitoral major and upper trapezius increased during specific stroke phases over the test. Blood lactate concentration increased significantly after the test. These findings suggest the occurrence of fatigue, characterised by changes in kinematic parameters and selective changes in upper limbs muscle activation according to muscle action.

Different VO2max time-averaging intervals in swimming.

We aimed to determine the effect of sampling interval strategy on VO(2max) assessment to establish a standard time averaging method that allows a better identification of the VO(2) plateau incidence in swimming. To this end, 3 incremental protocols utilizing different step lengths for each sampling interval were used to compare VO(2max)measurements. 11 trained male swimmers performed 3 repetitions of a front crawl intermittent incremental protocol until exhaustion (increments of 0.05 m.s(-1), with 30 s and 24-48 h intervals between steps and tests, respectively) with 200, 300 and 400-m step lengths. VO(2) was directly measured, and 6 sampling intervals were compared: bxb and averages of 5, 10, 15, 20 and 30 s. Shorter sampling intervals (≤ 15 s) allowed the highest incidence of the VO(2) plateau, independent of the step lengths used; the 200 and 300-m step protocols accounted for higher percentage of VO(2) plateau incidence, and higher VO(2max) values, compared to the 400-m step protocol. As an optimal sampling interval should be used for the validation of the research findings, and considering that swimmers and coaches prefer less time-consuming protocols, the use of the 10 s time-average interval (once bxb and 5 s samplings present high variability) in a 200-m step incremental protocol for VO(2max) assessment in swimming is suggested.

Gross efficiency and energy expenditure in kayak ergometer exercise.

We purposed to study energy expenditure, power output and gross efficiency during kayak ergometer exercise in 12 elite sprint kayakers. 6 males (age 24.2±4.8 years, height 180.4±4.8 cm, body mass 79.7±8.5 kg) and 6 females (age 24.3±4.5 years, height 164.5±3.9 cm, body mass 65.4±3.5 kg), performed an incremental intermittent protocol on kayak ergometer with VO2 and blood lactate concentration assessment, a non-linear increase between power output and energy expenditure being observed. Paddling power output, energy expenditure and gross efficiency corresponding to VO2max averaged 199.92±50.41 W, 75.27±6.30 ml.kg - 1.min - 1, and 10.10±1.08%. Male kayakers presented higher VO2max, power output and gross efficiency at the VO2max, and lower heart rate and maximal lactate concentration than females, but no differences were found between genders regarding energy expenditure at VO2max. Aerobic and anaerobic components of energy expenditure evidenced a significant contribution of anaerobic energy sources in sprint kayak performance. Results also suggested the dependence of the gross efficiency on the changes in the amount of the aerobic and anaerobic contributions, at heavy and severe intensities. The inter-individual variance of the relationship between energy expenditure and the corresponding paddling power output revealed a relevant tracking for females (FDγ=0.73±0.06), conversely to the male group (FDγ=0.27±0.08), supporting that some male kayakers are more skilled in some paddling intensities than others.

Intracycle velocity variation of the body centre of mass in front crawl.

Our aim was to determine the 3-dimensional intracycle velocity variation (IVV) of the body centre of mass during a 200-m front crawl event, and to analyse its relation with the segmental hand kinematics and the velocity (v) changes. 10 high-level male swimmers performed a 200-m front crawl swim at maximal intensity. 2 above- and 4 underwater cameras were used to record one complete non-breathing cycle for each 50-m lap, and APASystem was used for imaging processing. The coefficient of variation was calculated to assess the IVV in the horizontal (x), vertical (y), and lateral (z) axes; hand kinematics was also computed. IVV remained stable across the 200 m, and significant correlations were found between vx and vmaxx (r=0.55), vminx (r = 0.68), IVVx (r = -0.45), and IVVz (r = -0.45) (all p≤0.01). In addition, IVVx was correlated with the backward horizontal amplitude normalized to stroke length (r = 0.54), IVVy with hand angular velocity (r = -0.40), and IVVz with the elbow angle range in the pull phase (r = - 0.37) (all p<0.05). This study shows the stability of the IVV (x,y,z), the inverse relation of the IVV (x, z) with v, the direct relation of the vmaxx and vminx with v, and the influence of the hand kinematics in the IVV.

Effect of increasing energy cost on arm coordination in elite sprint swimmers.

The purpose of this study was to analyze the changes in stroke parameters, motor organization and swimming efficiency with increasing energy cost in aquatic locomotion. Seven elite sprint swimmers performed a 6×300-m incremental swimming test. Stroke parameters (speed, stroke rate and stroke length), motor organization (arm stroke phases and arm coordination index), swimming efficiency (swimming speed squared and hand speed squared) and stroke index were calculated from aerial and underwater side-view cameras. The energy cost of locomotion was assessed by measuring oxygen consumption and blood lactate. Results showed that the increase in energy cost of locomotion was correlated to an increase in the index of coordination and stroke rate, and a decrease in stroke length (p<.05). Furthermore, indicators of swimming efficiency and stroke index did not change significantly with the speed increments (p<.05), indicating that swimmers did not decrease their efficiency despite the increase in energy cost. In parallel, an increase in the index of coordination IdC and stroke rate were observed, along with a decrease in stroke length, stroke index and hand speed squared with each increment, revealing an adaptation to the fatigue within the 300m.

Step length and individual anaerobic threshold assessment in swimming.

Anaerobic threshold is widely used for diagnosis of swimming aerobic endurance but the precise incremental protocols step duration for its assessment is controversial. A physiological and biomechanical comparison between intermittent incremental protocols with different step lengths and a maximal lactate steady state (MLSS) test was conducted. 17 swimmers performed 7×200, 300 and 400 m (30 s and 24 h rest between steps and protocols) in front crawl until exhaustion and an MLSS test. The blood lactate concentration values ([La-]) at individual anaerobic threshold were 2.1±0.1, 2.2±0.2 and 1.8±0.1 mmol.l - 1 in the 200, 300 and 400 m protocols (with significant differences between 300 and 400 m tests), and 2.9±1.2 mmol.l - 1 at MLSS (higher than the incremental protocols); all these values are much lower than the traditional 4 mmol.l - 1 value. The velocities at individual anaerobic threshold obtained in incremental protocols were similar (and highly related) to the MLSS, being considerably lower than the velocity at 4 mmol.l - 1. Stroke rate increased and stroke length decreased throughout the different incremental protocols. It was concluded that it is valid to use intermittent incremental protocols of 200 and 300 m lengths to assess the swimming velocity corresponding to individual anaerobic threshold, the progressive protocols tend to underestimate the [La-] at anaerobic threshold assessed by the MLSS test, and swimmers increase velocity through stroke rate increases.

VO2 kinetics in 200-m race-pace front crawl swimming.

Studies that aim to characterize oxygen uptake kinetics in efforts above maximal oxygen consumption intensity are scarce. Our aim was to analyze the oxygen kinetics in a maximal 200-m front crawl, all measurements being conducted in swimming pool conditions. 10 high-level male swimmers performed a maximal 200-m bout and oxygen uptake was directly measured through breath-by-breath gas analysis. Mean (±SD) peak oxygen uptake was 68.58 (±5.79) ml.kg(-1).min(-1), evidencing a fast component phase. As expected, peak oxygen uptake presented a direct relationship with mean swimming speed of the first 50-m lap and with the 200-m effort, and was also correlated with the amplitude of the fast component (r=0.75, r=0.72, r=0.73, p<0.05, respectively). The observed mean amplitude value was higher than those observed in the literature for other exercise intensity domains. However, the time for its onset, as well as the duration for attaining the steady state, was shorter, as the peak oxygen uptake was not correlated with these 2 components. Moreover, as previously described for swimming at high intensities, the slow component phenomenon was not observed. Aerobic metabolic pathway accounted for 78.6%, confirming the high aerobic contribution in middle distance swimming events.

Biomechanical analysis of backstroke swimming starts.

The relationships between the start time and kinematic, kinetic and electromyographic data were examined in order to establish the common features of an effective backstroke swimming start. Complementarily, different starting positions were analysed to identify the parameters that account for the fastest backstroke start time under different constraints. 6 high-level swimmers performed 4×15 m maximal trials of each start variants with different feet position: parallel and entirely submerged (BSFI) and above water surface (BSFE), being monitored with synchronized dual-media image, underwater platform plus handgrip with a load cell, and eletromyographic signal of RECTUS FEMORIS and GASTROCNEMIUS MEDIALIS. Mean and SD values of start time for BSFI and BSFE were 2.03 ± 0.19 and 2.14 ± 0.36 s, respectively. In both starts, high associations (r > =0.75, p < 0.001) were observed between start time and centre of mass resultant average velocity at glide phase and horizontal impulse at take-off for BSFI, and centre of mass horizontal position at the start signal for BSFE. It was concluded that the greater impulse during the take-off and its transformation into a fast underwater movement are determinant to decrease the start time at BSFI. Regarding BSFE, a greater centre of mass pool-wall approximation might imply a flatter take-off angle, compromising underwater velocity and starting performance.

Anaerobic critical velocity in four swimming techniques.

The aim of this study was to assess critical velocity in order to control and evaluate anaerobic swimming training. 51 highly trained male swimmers performed maximal 15, 25, 37.5 and 50 m in the 4 swimming techniques to determine critical velocity from the distance-time relationship. Anaerobic critical velocity was compared with 100 m swimming performance and corresponding partials. Complementarily, 9 swimmers performed a 6×50 m (4 min interval) training series at front crawl individual anaerobic critical velocity, capillary blood lactate concentrations being assessed after each repetition. The mean±SD values of anaerobic critical velocity and its relationship with the 100 m event were: 1.61±0.07 (r=0.60, p=0.037), 1.53±0.05 (r=0.81, p=0.015), 1.33±0.05 (r=0.83, p=0.002), and 1.75±0.05 (r=0.74, p=0.001), for butterfly, backstroke, breaststroke and front crawl, respectively. However, differences between anaerobic critical velocity and performance were observed (with exception of the second half of the 100 m swimming events in breaststroke and butterfly). Lactate concentration values at the end of the series were 14.52±1.06 mmol.l (-1), which suggests that it was indeed an anaerobic training set. In this sense, anaerobic critical velocity can be used to prescribe anaerobic training intensities.

Comparison of grab start between elite and trained swimmers.

This study analysed motor control during front crawl swimming starts by elite and trained swimmers, based on comparisons of: 1) kinematic and kinetic parameters of the start and 2) variability of these parameters across 3 trials per swimmer. Given that the start time to the 15-m mark is greatly influenced by the swimming phase, the study also compared the stroking and coordinative parameters from water entry to 25-m in the 2 skill groups. The swimmers performed 3 x 25-m at the 50-m race-pace and used their preferential start technique (grab start). The elite swimmers showed better start organization as reflected by higher impulse values in the direction of intended displacement despite similar block phase durations. They then spent more time in the water entry, gliding and leg kicking phases, with shorter swimming phase duration and 15-m start time than the trained swimmers (p<0.05). The trained swimmers showed significantly lower values for stroke length and velocity (p<0.05) during the swimming phase. Analysis revealed low intra-subject variability (across the 3 trials) but high inter-subject variability, indicating that both elite and trained swimmers had mastered distinct, though different, motor patterns.