Sprint Interval Training Attenuates Neuromuscular Function and Vagal Reactivity Compared With High-Intensity Functional Training in Real-World Circumstances.

ABSTRACT: Benítez-Flores, S, de S. Castro, FA, Lusa Cadore, E, and Astorino, TA. Sprint interval training attenuates neuromuscular function and vagal reactivity compared with high-intensity functional training in real-world circumstances. J Strength Cond Res 37(5): 1070-1078, 2023-The aim of this study was to compare the acute cardiovascular and neuromuscular effects of 3 time-matched sessions of high-intensity training. Eighteen moderately active adults (9 women and 9 men [age: 23 ± 2.9 years; maximum oxygen consumption (V̇ o2 max): 47.6 ± 4.1 ml·kg -1 ·min -1 ]) performed three low-volume (∼9 minutes) sessions in a randomized order: sprint interval training (SIT), burpee interval training (BIT) (10 × 5 seconds efforts × 35 seconds recovery), and vigorous intensity continuous training (VICT) (6 minutes 5 seconds of running at ∼85% of peak heart rate [HR peak ]). Indices related to heart rate (HR), neuromuscular performance (counter movement jump height [CMJ height ] and squat and bench press power), and autonomic balance (heart rate recovery and heart rate variability [HRR and HRV] )were monitored during exercise. Sprint interval training and VICT elicited a higher HR mean (171.3 ± 8.4 and 166.5 ± 7.5 vs. 150.5 ± 13.6 b·min -1 , p < 0.001) and time of ≥90%HR peak (133.3 ± 117.4 and 110 ± 128.9 vs. 10 ± 42.4 seconds, p < 0.01) than BIT. Sprint interval training exhibited a slower HRR and lower HRV than BIT and VICT ( p < 0.05) postsession. Moreover, only SIT resulted in a significant decline ( p < 0.01) in CMJ height (34.7 ± 7.2 to 33.5 ± 7.2 cm), relative squat mean power (25.5 ± 4.5 to 23.8 ± 4.9 W·kg -1 ), and relative bench press peak power (6.9 ± 2.4 to 6.2 ± 2.5 W·kg -1 ). Results revealed that SIT diminishes the sympathovagal reactivation and neuromuscular performance compared with work-matched BIT and VICT.

Oxygen Uptake of Wave Surfers and Complementary Parameters in Front Crawl and Surfing-Paddling Tests.

ABSTRACT: Godoy, DF, Cadore, EL, Feitosa, WG, Correia, RdA, and Castro, FAdS. Oxygen uptake of wave surfers and complementary parameters in front crawl and surfing-paddling tests. J Strength Cond Res 35(9): 2645-2650, 2021-The aim of this study was to assess the reliability of the oxygen uptake and complementary parameters (heart rate [HR], blood lactate concentration, and rate of perceived exertion [RPE]) obtained from surfers swimming and paddling in a swimming pool. Fourteen recreational male surfers (37.7 ± 4.7 years old) were evaluated in (a) a maximal 300-m front crawl test and (b) paddling in a surfboard test, both at the same intensity and for the same duration. Peak oxygen uptake (V̇o2peak) during the tests (direct method), HR, blood lactate concentration (LA), and RPE were assessed. Two-way analysis of variance, a simple Student t test, effect size calculation, intraclass correlation coefficient, and limits of agreement were applied. In general, the tests presented similar results (except for HR), with low agreement, high intraclass correlation, and average to large effect sizes between swimming and paddling. The results suggest that surfers training in a swimming pool should not simply be swimming. Front crawl swimming and surf paddling are 2 distinct actions that should be practiced and tested on their own merits rather than assumed to be interchangeable.

Relação entre o desempenho no teste de salto vertical em água e a velocidade de arremesso da bola em jogadores de polo aquático / Relationship between water vertical jump test and ball speed in the throw to the goal in water polo players

Considerando as técnicas fundamentais do polo aquático (PAq), o objetivo deste estudo foi verificar a existência de relação entre a velocidade da bola após o arremesso à gol (VB) e a altura alcançada em teste vertical realizado dentro da água (HEB) por jogadores recreacionais de PAq. Participaram 13 jogadores de PAq do sexo masculino (idade: 30,4 ± 6,5 anos, massa corporal de 81,4 ± 9,9 kg, estatura de 1,78 ± 0,05 m e envergadura de 1,81 ± 0,06 m). VB foi mensurada com radar e HEB com videogrametria. Resultados: VB foi de 15,8 ± 1,4 m∙s -1 e HEB foi de 128,0 ± 12,0 cm. Encontrou-se correlação positiva, forte e significativa (r = 0,71 e p = 0,004) entre a VB e a HEB. Jogadores recreacionais adultos de polo aquático tem desempenho no teste de velocidade da bola e no de salto vertical na água próximos ou abaixo daquele apresentado por jogadoras de elevado nível de desempenho e atletas mais jovens de bom desempenho.(AU)

Considering the fundamental techniques of water polo (WP), the aim of this study was to verify the existence of a relationship between the speed of the ball in the throw to the goal (SB) and the height reached in vertical test performed in water (HEB) by WP players. Thirteen WP male players participated (age: 30.4 ± 6.5 years, body mass 81.4 ± 9.9 kg, height 1.78 ± 0.05 m and wingspan of 1.81 ± 0, 06 m). SB was measured with radar and HEB with videogrammetry. Results: SB was 15.8 ± 1.4 m∙s -1 and HEB was 128.0 ± 12.0 cm. Positive, strong and significant correlation (r = 0.71 and p = 0.004) between SB and HEB was found. Adult male recreational water polo players perform the throw to the goal and the vertical jump near or below that of high-performance female players and younger but high-level athletes.(AU)

Monitoring Age-Group Swimmers Over a Training Macrocycle: Energetics, Technique, and Anthropometrics.

Zacca, R, Azevedo, R, Chainok, P, Vilas-Boas, JP, Castro, FAdS, Pyne, DB, and Fernandes, RJ. Monitoring age-group swimmers over a training macrocycle: energetics, technique, and anthropometrics. J Strength Cond Res 34(3): 818-827, 2020-The aim of this study was to quantify changes and contributions of energetic, technique, and anthropometric profiles across the first training macrocycle (16-week) in a traditional 3-peak swimming season. Twenty-four age-group swimmers (10 boys and 14 girls age 14.4 ± 0.9 years) of equal maturational stage were monitored through a 400-m test in front crawl (T400). Energetic, technique, and anthropometric characteristics were compared before (experimental testing 1, E1) and after the preparatory (E2), specific (E3), and competitive (E4) training periods. Sex interaction was not significant for any variable. Multiple linear regressions and principal component analysis were used to identify the most influential variables and the relative contribution of each domain (energetics, technique, and anthropometrics) to changes in swimming performance of T400. The relative contributions for performance of T400 at E1, E2, E3, and E4 were 15, 12, 6, and 13% for energetics, 78, 85, 75, and 70% for technique, and 7, 3, 19 and 17% for anthropometrics, respectively. Technique played the main role during the first 16-week macrocycle in a competitive season, regardless of small fluctuations in the influence of energetics and anthropometrics. Changes and influence of energetics, technique, and anthropometric on age-group swimmers' performance could be described by the T400 swimming test, providing a comprehensive biophysical overview of the main contributors to swimming performance.

Is V̇O2peak a Valid Estimation of V̇O2max in Swimmers with Physical Impairments?

Purpose: Peak and maximal oxygen uptake ([Formula: see text] and [Formula: see text], respectively) are used in assessing aerobic power. For swimmers with physical impairments, it is unclear whether the physiological variables obtained in 200-m and Nx200-m tests are similar. The objective of this study is to assess the validity of [Formula: see text] as an estimator of [Formula: see text] and complementary physiological variables, in particular, carbon dioxide production ([Formula: see text]), respiratory exchange ratio (RER), minute-ventilation ([Formula: see text] and absolute (HR) and relative (%HRmax) heart rates-which were obtained in a time trial test (200-m) and an incremental intermittent test (Nx200-m) performed by swimmers with physical impairments. Methods: Eleven well-trained swimmers with physical impairments performed 200-m all-out and Nx200-m from low to all-out (controlled by a visual pacer), both with a respiratory valve system and a portable gas analyzer. Results: A paired Student's t-test showed no statistical difference (p > .05) for all comparisons. The intraclass correlation coefficient (ICC) was 0.97 and 0.98 for [Formula: see text] in l/min and ml/kg/min, respectively; ICC = 0.75 to 0.9 for [Formula: see text] (l/min and ml/kg/min),[Formula: see text] (in l/min) and HR (beats/min); ICC = 0.5 and 0.75 for %HRmax; and ICC < 0.5 for RER. Passing-Bablok regression showed that the dispersions were acceptable, considering the proportionality, except for HR and %HRmax. Bland-Altman method showed a high level of agreement for all variables. Conclusions: The [Formula: see text] and [Formula: see text], as well as the physiological variables [Formula: see text] and HR obtained, respectively, by 200-m and Nx200-m tests in swimmers with physical impairment were not different.

Effects of detraining in age-group swimmers performance, energetics and kinematics.

Changes in performance, energetics and kinematics during age-group swimmers off-season inform the prescription of training for the following season. Age-group swimmers (n = 15, age 14.3 ± 0.7 years) of equal maturational stage performed a 400-m front crawl (T400) before and after a four-weeks training cessation period. Performance-related energetic and kinematic variables were obtained controlling for anthropometric changes and non-swimming specific physical activities during off-season. T400 time decreased 3.8% (95%CI 1.4 to 6.1%; p < 0.01; d = 0.90) with non-specific physical activities (1814 ± 1989 MET-min·wk-1) accounting for ~40% of the underlying variance (p = 0.01; η2 = 0.40). Stroke rate and stroke index decreased despite similar stroke length and index of coordination values. Although mean response time, amplitude, maximal oxygen uptake, heart rate, total energy expenditure, metabolic power and energy cost were similar, aerobic contribution decreased by ~1.8% (-2.7 to -0.9%; p < 0.01; d = -1.19) and anaerobic lactic contribution increased by ~1.6% (0.8 to 2.5%; p < 0.01; d = 1.08) over the off-season. Impaired performance was mainly associated with a decreased stroke rate (r = -0.85 to -0.61; p ≤ 0.02), increased peak blood lactate (r = -0.52; p = 0.05) and fewer non-swimming specific physical activities performed during the off-season (r = -0.58; p = 0.03). The end-of-season cessation of training yielded moderate impairments in age-group swimmers performance-related energetic and kinematic factors, however non-specific physical activities can minimise fitness losses.

VO2FITTING: A Free and Open-Source Software for Modelling Oxygen Uptake Kinetics in Swimming and other Exercise Modalities.

The assessment of oxygen uptake (VO2) kinetics is a valuable non-invasive way to evaluate cardiorespiratory and metabolic response to exercise. The aim of the study was to develop, describe and evaluate an online VO2 fitting tool (VO2FITTING) for dynamically editing, processing, filtering and modelling VO2 responses to exercise. VO2FITTING was developed in Shiny, a web application framework for R language. Validation VO2 datasets with both noisy and non-noisy data were developed and applied to widely-used models (n = 7) for describing different intensity transitions to verify concurrent validity. Subsequently, we then conducted an experiment with age-group swimmers as an example, illustrating how VO2FITTING can be used to model VO2 kinetics. Perfect fits were observed, and parameter estimates perfectly matched the known inputted values for all available models (standard error = 0; p < 0.001). The VO2FITTING is a valid, free and open-source software for characterizing VO2 kinetics in exercise, which was developed to help the research and performance analysis communities.

Comparison of Incremental Intermittent and Time Trial Testing in Age-Group Swimmers.

Zacca, R, Azevedo, R, Peterson Silveira, R, Vilas-Boas, JP, Pyne, DB, Castro, FAdS, and Fernandes, RJ. Comparison of incremental intermittent and time trial testing in age-group swimmers. J Strength Cond Res 33(3): 801-810, 2019-The aim of this study was to compare physiological and biomechanical characteristics between an incremental intermittent test and a time trial protocol in age-group swimmers. Eleven national level age-group swimmers (6 men and 5 women) performed a 7 × 200-m incremental intermittent protocol (until exhaustion; 30-second rest) and a 400-m test (T400) in front crawl on separate days. Cardiorespiratory variables were measured continuously using a telemetric portable gas analyzer. Swimming speed, stroke rate, stroke length, and stroke index were assessed by video analysis. Physiological (oxygen uptake, heart rate, and lactate concentrations) and biomechanical variables between seventh 200-m step (in which the minimal swimming speed that elicits maximal oxygen uptake-vV[Combining Dot Above]O2max was identified) and T400 (time trial/fixed distance) were compared with a paired student's t test, Pearson's product-moment correlation, Passing-Bablok regression, and Bland-Altman plot analyses. There were high level of agreement and high correlations (r-values ∼0.90; p ≤ 0.05) for all physiological variables between the seventh 200-m step and T400. Similarly, there were high level of agreements and high correlations (r-values ∼0.90; p ≤ 0.05) for all biomechanical variables and only trivial bias in swimming speed (0.03 m·s; 2%). Primary physiological and biomechanical responses between incremental intermittent and representative time trial protocols were similar, but best practice dictates protocols should not be used interchangeably to minimize errors in prescribing swimming training speeds. The T400 is a valid, useful, and easier to administer test for aerobic power assessment in age-group swimmers.

Cinemática do nado crawl em velocidade sustentada até a exaustão / Kinematics of the front crawl in sustained speed to exhaustion

O objetivo deste estudo foi verificar as respostas da frequência média de ciclos de braçadas (FB) e da distância média percorrida por ciclo de braçada (DC) no nado crawl ao longo de série de natação na intensidade de 95% da velocidade média dos 400 m (V400), até a exaustão. Onze nadadores realizaram 400 m em máxima intensidade para determinação da V400, e, posteriormente, uma série a 95% da V400 (95v) com média de 2,88 ± 1,37 repetições de 400 m e intervalos de 40 s de repouso passivo, quarenta e oito horas após a V400. A duração da série a 95% da V400 foi normalizada a 100%, de modo individual, e posteriormente, foi dividida em cinco momentos (0, 25, 50, 75 e 100%) para a análise de FB e DC, que foram comparadas ao longo da série. Resultados: houve manutenção dos parâmetros cinemáticos apenas entre os momentos 0 e 25%. Ocorreram aumento da FB e diminuição da DC nos últimos momentos (75 e 100%) em comparação aos demais momentos da série 95v. Ao nadar nesta intensidade, que está situada o domínio de intensidade severa, nadadores não são capazes de manter a técnica constante ao longo da duração total da série...(AU)

The objective of this study was to investigate the stroke rate (SR) and the stroke length (SL) responses in front crawl along swimming training series in the intensity of 95% of the average velocity of 400 m (V400) until exhaustion. Eleven swimmers performed 400 m at maximum intensity for determining V400, and subsequently, a series of 95% the V400 (95v) with average 2.88 ± 1.37 trials of 400 m and intervals of 40 s of passive rest, 48 hours after the V400. The duration of the 95V was normalized to 100%, individually, and, later, it was divided into five moments (0, 25, 50, 75, and 100%) for the SR and SL analysis, which were compared over the series. Results: there was maintenance of kinematic parameters only between moments 0 and 25%, The SR increased and the SL decreased in the end of the series (75 and 100%) compared to other moments. When swimming at this intensity, which is situated in severe intensity domain, swimmers are not able to keep constant the technique over the entire duration of the series...(AU)

Validity of a portable force platform for assessing biomechanical parameters in three different tasks.

The aim of this study was to determine the precision and accuracy of the vertical and anterior-posterior force components of the portable PASCO PS-2142 force plate. Impulse, peak force, and time to peak force were assessed and compared to a gold standard force plate in three different tasks: vertical jump, forward jump, and sprint start. Two healthy male participants performed ten trials for each task, resulting in 60 trials. Data analyses revealed good precision and accuracy for the vertical component of the portable force plate, with relative bias and root mean square (RMS) error values nearly the same in all tasks for the impulse, time to peak force, and peak force parameters. Precision and accuracy of the anterior-posterior component were lower for the impulse and time to peak force, with relative bias and RMS error values nearly the same between tasks. Despite the lower precision and accuracy of the anterior-posterior component of the portable force plate, these errors were systematic, reflecting a good repeatability of the measure. In addition, all variables presented good agreement between the portable and gold standard platforms. Our results provide a good perspective for using the aforementioned portable force plate in sports and clinical biomechanics.