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Herbert Gustavo Simoes - One of the best experts on this subject based on the ideXlab platform.

  • an integrative perspective of the Anaerobic Threshold
    Physiology & Behavior, 2017
    Co-Authors: Marcelo Magalhaes Sales, Caio Victor Sousa, Samuel Da Silva Aguiar, Beat Knechtle, Pantelis T Nikolaidis, Polissandro Mortoza Alves, Herbert Gustavo Simoes
    Abstract:

    The concept of Anaerobic Threshold (AT) was introduced during the nineteen sixties. Since then, several methods to identify the Anaerobic Threshold (AT) have been studied and suggested as novel 'Thresholds' based upon the variable used for its detection (i.e. lactate Threshold, ventilatory Threshold, glucose Threshold). These different techniques have brought some confusion about how we should name this parameter, for instance, Anaerobic Threshold or the physiological measure used (i.e. lactate, ventilation). On the other hand, the modernization of scientific methods and apparatus to detect AT, as well as the body of literature formed in the past decades, could provide a more cohesive understanding over the AT and the multiple physiological systems involved. Thus, the purpose of this review was to provide an integrative perspective of the methods to determine AT.

  • noninvasive method to estimate Anaerobic Threshold in individuals with type 2 diabetes
    Diabetology & Metabolic Syndrome, 2011
    Co-Authors: Marcelo Magalhaes Sales, Carmen Silvia Grubert Campbell, Pâmella Karoline De Morais, Carlos Ernesto, Lucio Flavio Soarescaldeira, Paulo Russo, Daisy F Motta, Sergio Rodrigues Moreira, Fabio Yuzo Nakamura, Herbert Gustavo Simoes
    Abstract:

    Background While several studies have identified the Anaerobic Threshold (AT) through the responses of blood lactate, ventilation and blood glucose others have suggested the response of the heart rate variability (HRV) as a method to identify the AT in young healthy individuals. However, the validity of HRV in estimating the lactate Threshold (LT) and ventilatory Threshold (VT) for individuals with type 2 diabetes (T2D) has not been investigated yet.

  • acute exercise performed close to the Anaerobic Threshold improves cognitive performance in elderly females
    Brazilian Journal of Medical and Biological Research, 2009
    Co-Authors: Claudio Cordova, Herbert Gustavo Simoes, V C Silva, Clayton Franco Moraes, Otavio De Toledo Nobrega
    Abstract:

    The objective of the present study was to compare the effect of acute exercise performed at different intensities in relation to the Anaerobic Threshold (AT) on abilities requiring control of executive functions or alertness in physically active elderly females. Forty-eight physically active elderly females (63.8 ± 4.6 years old) were assigned to one of four groups by drawing lots: control group without exercise or trial groups with exercise performed at 60, 90, or 110% of AT (watts) and submitted to 5 cognitive tests before and after exercise. Following cognitive pretesting, an incremental cycle ergometer test was conducted to determine AT using a fixed blood lactate concentration of 3.5 mmol/L as cutoff. Acute exercise executed at 90% of AT resulted in significant (P < 0.05, ANOVA) improvement in the performance of executive functions when compared to control in 3 of 5 tests (verbal fluency, Tower of Hanoi test (number of movements), and Trail Making test B). Exercising at 60% of AT did not improve results of any tests for executive functions, whereas exercise executed at 110% of AT only improved the performance in one of these tests (verbal fluency) compared to control. Women from all trial groups exhibited a remarkable reduction in the Simple Response Time (alertness) test (P = 0.001). Thus, physical exercise performed close to AT is more effective to improve cognitive processing of older women even if conducted acutely, and using a customized exercise prescription based on the Anaerobic Threshold should optimize the beneficial effects.

  • hypotensive effects of exercise performed around Anaerobic Threshold in type 2 diabetic patients
    Diabetes Research and Clinical Practice, 2008
    Co-Authors: L C J Lima, Carmen Silvia Grubert Campbell, Vilmar Baldissera, Gabrielle V Assis, Wolysson Hiyane, W S Almeida, Gisela Arsa, Herbert Gustavo Simoes
    Abstract:

    Abstract Aim To verify the occurrence of post-exercise hypotension (PEH) in type 2 diabetics (DM2) and the effects of exercise intensity on post-exercise blood pressure (BP). Methods Eleven men and women with DM2 (58.5 ± 10.2 years; 160 ± 0.1 cm; 80.6 ± 13.5 kg; 31.2 ± 3.8 kg/m2, 19 ± 3.2 mL kg min−1 of VO2 max, 155.0 ± 39.2 mg dL−1 of fasting blood glucose and 126 ± 10/75 ± 7 mmHg of resting BP) performed an incremental test (IT) for cardiovascular evaluation and Anaerobic Threshold (AT) determination. Then, participants randomly underwent 2 exercise sessions (90% and 110% AT) and a control session (CON). In all sessions, BP was measured at resting, during 20 min of exercise/control and at each 15 min through 120 min of post-exercise recovery (R15–R120). Results The mean results of systolic BP (SBP)/diastolic BP (DBP) over the 120 min of recovery were 125 ± 16/76 ± 7 mmHg, 122 ± 13/75 ± 6 mmHg and 129 ± 16/78 ± 7 mmHg, respectively for 90%, 110% and CON. Significant reductions of SBP occurred after 90% (R15–R45) and 110% (R15–R90), while only after 110% there were reductions of DBP (R15, R45) and MAP (R15, R45, R75, R90, R105). Conclusions Both exercise intensities evoked reductions in SBP while DBP and MAP were reduced only after 110%. Despite the higher intensity exercise to be more effective in promoting BP reductions, we suggest caution while prescribing exercise for DM2.

  • blood glucose responses in humans mirror lactate responses for individual Anaerobic Threshold and for lactate minimum in track tests
    European Journal of Applied Physiology, 1999
    Co-Authors: Herbert Gustavo Simoes, Carmen Silvia Grubert Campbell, Eduardo Kokubun, Benedito Sergio Denadai, Vilmar Baldissera
    Abstract:

    The equilibrium point between blood lactate production and removal (La−min) and the individual Anaerobic Threshold (IAT) protocols have been used to evaluate exercise. During progressive exercise, blood lactate [La−]b, catecholamine and cortisol concentrations, show exponential increases at upper Anaerobic Threshold intensities. Since these hormones enhance blood glucose concentrations [Glc]b, this study investigated the [Glc] and [La−]b responses during incremental tests and the possibility of considering the individual glucose Threshold (IGT) and glucose minimum (Glcmin) in addition to IAT and La−min in evaluating exercise. A group of 15 male endurance runners ran in four tests on the track 3000 m run (v3km); IAT and IGT – 8 × 800 m runs at velocities between 84% and 102% of v3km; La−min and Glcmin– after lactic acidosis induced by a 500-m sprint, the subjects ran 6 × 800 m at intensities between 87% and 97% of v3km; endurance test (ET) – 30 min at the velocity of IAT. Capillary blood (25 μl) was collected for [La−]b and [Glc]b measurements. The IAT and IGT were determined by [La−]b and [Glc]b kinetics during the second test. The La−min and Glcmin were determined considering the lowest [La−] and [Glc]b during the third test. No differences were observed (P 0.05). We concluded that for these subjects it was possible to evaluate the aerobic capacity by IGT and Glcmin as well as by IAT and La−min.

Jonida Bejko - One of the best experts on this subject based on the ideXlab platform.

  • lvad pump speed increase is associated with increased peak exercise cardiac output and vo2 postponed Anaerobic Threshold and improved ventilatory efficiency
    International Journal of Cardiology, 2017
    Co-Authors: Carlo Vignati, Alberico Del Torto, Vincenzo Tarzia, Stefania Farina, Anna Apostolo, Gino Gerosa, Tomaso Bottio, Gaia Cattadori, S. Scuri, Jonida Bejko
    Abstract:

    Abstract Backgrounds Peak exercise cardiac output (CO) increase is associated with an increase of peak oxygen uptake (VO 2 ), provided that arteriovenous O 2 difference [Δ(Ca−Cv)O 2 ] does not decrease. At Anaerobic Threshold, VO 2 , is related to CO. We tested the hypothesis that, in heart failure (HF) patients with left ventricular assistance device (LVAD), an acute increase of CO obtained through changes in LVAD pump speed is associated with peak exercise and Anaerobic Threshold VO 2 increase. Methods Fifteen of 20 patients bearing LVAD (Jarvik 2000) enrolled in the study successfully performed peak exercise evaluation. All patients had severe HF as shown by clinical evaluation, laboratory tests, echocardiography, spirometry with alveolar-capillary diffusion, and maximal cardiopulmonary exercise testing (CPET). CPETs with non-invasive CO measurements at rest and peak exercise were done on 2days at LVAD pump speed set randomly at 2 and 4. Results Increasing LVAD pump speed from 2 to 4 increased CO from 3.4±0.9 to 3.8±1.0L/min (ΔCO 0.4±0.6L/min, p =0.04) and from 5.3±1.3 to 5.9±1.4L/min (ΔCO 0.6±0.7L/min, p 2 increased from 788±169 to 841±152mL/min (ΔVO 2 52±76mL/min, p =0.01) and from 568±116 to 619±124mL/min (ΔVO 2 69±96mL/min, p =0.02) at peak exercise and at Anaerobic Threshold, respectively. Δ(Ca−Cv)O 2 did not change significantly, while ventilatory efficiency improved (VE/VCO 2 slope from 39.9±5.4 to 34.9±8.3, ΔVE/VCO 2 −5.0±6.4, p Conclusions In HF, an increase in CO with a higher LVAD pump speed is associated with increased peak VO 2 , postponed Anaerobic Threshold, and improved ventilatory efficiency.

  • lvad pump speed increase is associated with increased peak exercise cardiac output and vo2 postponed Anaerobic Threshold and improved ventilatory efficiency
    International Journal of Cardiology, 2017
    Co-Authors: Carlo Vignati, Alberico Del Torto, Vincenzo Tarzia, Stefania Farina, Anna Apostolo, Gino Gerosa, Tomaso Bottio, Gaia Cattadori, S. Scuri, Jonida Bejko
    Abstract:

    Abstract Backgrounds Peak exercise cardiac output (CO) increase is associated with an increase of peak oxygen uptake (VO 2 ), provided that arteriovenous O 2 difference [Δ(Ca−Cv)O 2 ] does not decrease. At Anaerobic Threshold, VO 2 , is related to CO. We tested the hypothesis that, in heart failure (HF) patients with left ventricular assistance device (LVAD), an acute increase of CO obtained through changes in LVAD pump speed is associated with peak exercise and Anaerobic Threshold VO 2 increase. Methods Fifteen of 20 patients bearing LVAD (Jarvik 2000) enrolled in the study successfully performed peak exercise evaluation. All patients had severe HF as shown by clinical evaluation, laboratory tests, echocardiography, spirometry with alveolar-capillary diffusion, and maximal cardiopulmonary exercise testing (CPET). CPETs with non-invasive CO measurements at rest and peak exercise were done on 2days at LVAD pump speed set randomly at 2 and 4. Results Increasing LVAD pump speed from 2 to 4 increased CO from 3.4±0.9 to 3.8±1.0L/min (ΔCO 0.4±0.6L/min, p =0.04) and from 5.3±1.3 to 5.9±1.4L/min (ΔCO 0.6±0.7L/min, p 2 increased from 788±169 to 841±152mL/min (ΔVO 2 52±76mL/min, p =0.01) and from 568±116 to 619±124mL/min (ΔVO 2 69±96mL/min, p =0.02) at peak exercise and at Anaerobic Threshold, respectively. Δ(Ca−Cv)O 2 did not change significantly, while ventilatory efficiency improved (VE/VCO 2 slope from 39.9±5.4 to 34.9±8.3, ΔVE/VCO 2 −5.0±6.4, p Conclusions In HF, an increase in CO with a higher LVAD pump speed is associated with increased peak VO 2 , postponed Anaerobic Threshold, and improved ventilatory efficiency.

Gaia Cattadori - One of the best experts on this subject based on the ideXlab platform.

  • lvad pump speed increase is associated with increased peak exercise cardiac output and vo2 postponed Anaerobic Threshold and improved ventilatory efficiency
    International Journal of Cardiology, 2017
    Co-Authors: Carlo Vignati, Alberico Del Torto, Vincenzo Tarzia, Stefania Farina, Anna Apostolo, Gino Gerosa, Tomaso Bottio, Gaia Cattadori, S. Scuri, Jonida Bejko
    Abstract:

    Abstract Backgrounds Peak exercise cardiac output (CO) increase is associated with an increase of peak oxygen uptake (VO 2 ), provided that arteriovenous O 2 difference [Δ(Ca−Cv)O 2 ] does not decrease. At Anaerobic Threshold, VO 2 , is related to CO. We tested the hypothesis that, in heart failure (HF) patients with left ventricular assistance device (LVAD), an acute increase of CO obtained through changes in LVAD pump speed is associated with peak exercise and Anaerobic Threshold VO 2 increase. Methods Fifteen of 20 patients bearing LVAD (Jarvik 2000) enrolled in the study successfully performed peak exercise evaluation. All patients had severe HF as shown by clinical evaluation, laboratory tests, echocardiography, spirometry with alveolar-capillary diffusion, and maximal cardiopulmonary exercise testing (CPET). CPETs with non-invasive CO measurements at rest and peak exercise were done on 2days at LVAD pump speed set randomly at 2 and 4. Results Increasing LVAD pump speed from 2 to 4 increased CO from 3.4±0.9 to 3.8±1.0L/min (ΔCO 0.4±0.6L/min, p =0.04) and from 5.3±1.3 to 5.9±1.4L/min (ΔCO 0.6±0.7L/min, p 2 increased from 788±169 to 841±152mL/min (ΔVO 2 52±76mL/min, p =0.01) and from 568±116 to 619±124mL/min (ΔVO 2 69±96mL/min, p =0.02) at peak exercise and at Anaerobic Threshold, respectively. Δ(Ca−Cv)O 2 did not change significantly, while ventilatory efficiency improved (VE/VCO 2 slope from 39.9±5.4 to 34.9±8.3, ΔVE/VCO 2 −5.0±6.4, p Conclusions In HF, an increase in CO with a higher LVAD pump speed is associated with increased peak VO 2 , postponed Anaerobic Threshold, and improved ventilatory efficiency.

  • lvad pump speed increase is associated with increased peak exercise cardiac output and vo2 postponed Anaerobic Threshold and improved ventilatory efficiency
    International Journal of Cardiology, 2017
    Co-Authors: Carlo Vignati, Alberico Del Torto, Vincenzo Tarzia, Stefania Farina, Anna Apostolo, Gino Gerosa, Tomaso Bottio, Gaia Cattadori, S. Scuri, Jonida Bejko
    Abstract:

    Abstract Backgrounds Peak exercise cardiac output (CO) increase is associated with an increase of peak oxygen uptake (VO 2 ), provided that arteriovenous O 2 difference [Δ(Ca−Cv)O 2 ] does not decrease. At Anaerobic Threshold, VO 2 , is related to CO. We tested the hypothesis that, in heart failure (HF) patients with left ventricular assistance device (LVAD), an acute increase of CO obtained through changes in LVAD pump speed is associated with peak exercise and Anaerobic Threshold VO 2 increase. Methods Fifteen of 20 patients bearing LVAD (Jarvik 2000) enrolled in the study successfully performed peak exercise evaluation. All patients had severe HF as shown by clinical evaluation, laboratory tests, echocardiography, spirometry with alveolar-capillary diffusion, and maximal cardiopulmonary exercise testing (CPET). CPETs with non-invasive CO measurements at rest and peak exercise were done on 2days at LVAD pump speed set randomly at 2 and 4. Results Increasing LVAD pump speed from 2 to 4 increased CO from 3.4±0.9 to 3.8±1.0L/min (ΔCO 0.4±0.6L/min, p =0.04) and from 5.3±1.3 to 5.9±1.4L/min (ΔCO 0.6±0.7L/min, p 2 increased from 788±169 to 841±152mL/min (ΔVO 2 52±76mL/min, p =0.01) and from 568±116 to 619±124mL/min (ΔVO 2 69±96mL/min, p =0.02) at peak exercise and at Anaerobic Threshold, respectively. Δ(Ca−Cv)O 2 did not change significantly, while ventilatory efficiency improved (VE/VCO 2 slope from 39.9±5.4 to 34.9±8.3, ΔVE/VCO 2 −5.0±6.4, p Conclusions In HF, an increase in CO with a higher LVAD pump speed is associated with increased peak VO 2 , postponed Anaerobic Threshold, and improved ventilatory efficiency.

  • deceptive meaning of oxygen uptake measured at the Anaerobic Threshold in patients with systolic heart failure and atrial fibrillation
    European Journal of Preventive Cardiology, 2015
    Co-Authors: Damiano Magri, Gaia Cattadori, Ugo Corrà, Piergiuseppe Agostoni, Marco Metra, Claudio Passino, Domenico Scrutinio, Pasquale Perronefilardi, Michele Correale, Davide Girola
    Abstract:

    BackgroundOxygen uptake at the Anaerobic Threshold (VO2AT), a submaximal exercise-derived variable, independent of patients’ motivation, is a marker of outcome in heart failure (HF). However, previous evidence of VO2AT values paradoxically higher in HF patients with permanent atrial fibrillation (AF) than in those with sinus rhythm (SR) raised uncertainties.DesignWe tested the prognostic role of VO2AT in a large cohort of systolic HF patients, focusing on possible differences between SR and AF.MethodsAltogether 2976 HF patients (2578 with SR and 398 with AF) were prospectively followed. Besides a clinical examination, each patient underwent a maximal cardiopulmonary exercise test (CPET).ResultsThe follow-up was analysed for up to 1500 days. Cardiovascular death or urgent cardiac transplantation occurred in 303 patients (250 (9.6%) patients with SR and 53 (13.3%) patients with AF, p = 0.023). In the entire population, multivariate analysis including peak oxygen uptake (VO2) showed a prognostic capacity (C-...

  • prognostic value of indeterminable Anaerobic Threshold in heart failure
    Circulation-heart Failure, 2013
    Co-Authors: Piergiuseppe Agostoni, Gaia Cattadori, Ugo Corrà, Fabrizio Veglia, Elisa Battaia, Rocco La Gioia, Angela Beatrice Scardovi, Michele Emdin, Marco Metra, Gianfranco Sinagra
    Abstract:

    Background—In patients with heart failure (HF), during maximal cardiopulmonary exercise test, Anaerobic Threshold (AT) is not always identified. We evaluated whether this finding has a prognostic m...

Carlo Vignati - One of the best experts on this subject based on the ideXlab platform.

  • lvad pump speed increase is associated with increased peak exercise cardiac output and vo2 postponed Anaerobic Threshold and improved ventilatory efficiency
    International Journal of Cardiology, 2017
    Co-Authors: Carlo Vignati, Alberico Del Torto, Vincenzo Tarzia, Stefania Farina, Anna Apostolo, Gino Gerosa, Tomaso Bottio, Gaia Cattadori, S. Scuri, Jonida Bejko
    Abstract:

    Abstract Backgrounds Peak exercise cardiac output (CO) increase is associated with an increase of peak oxygen uptake (VO 2 ), provided that arteriovenous O 2 difference [Δ(Ca−Cv)O 2 ] does not decrease. At Anaerobic Threshold, VO 2 , is related to CO. We tested the hypothesis that, in heart failure (HF) patients with left ventricular assistance device (LVAD), an acute increase of CO obtained through changes in LVAD pump speed is associated with peak exercise and Anaerobic Threshold VO 2 increase. Methods Fifteen of 20 patients bearing LVAD (Jarvik 2000) enrolled in the study successfully performed peak exercise evaluation. All patients had severe HF as shown by clinical evaluation, laboratory tests, echocardiography, spirometry with alveolar-capillary diffusion, and maximal cardiopulmonary exercise testing (CPET). CPETs with non-invasive CO measurements at rest and peak exercise were done on 2days at LVAD pump speed set randomly at 2 and 4. Results Increasing LVAD pump speed from 2 to 4 increased CO from 3.4±0.9 to 3.8±1.0L/min (ΔCO 0.4±0.6L/min, p =0.04) and from 5.3±1.3 to 5.9±1.4L/min (ΔCO 0.6±0.7L/min, p 2 increased from 788±169 to 841±152mL/min (ΔVO 2 52±76mL/min, p =0.01) and from 568±116 to 619±124mL/min (ΔVO 2 69±96mL/min, p =0.02) at peak exercise and at Anaerobic Threshold, respectively. Δ(Ca−Cv)O 2 did not change significantly, while ventilatory efficiency improved (VE/VCO 2 slope from 39.9±5.4 to 34.9±8.3, ΔVE/VCO 2 −5.0±6.4, p Conclusions In HF, an increase in CO with a higher LVAD pump speed is associated with increased peak VO 2 , postponed Anaerobic Threshold, and improved ventilatory efficiency.

  • lvad pump speed increase is associated with increased peak exercise cardiac output and vo2 postponed Anaerobic Threshold and improved ventilatory efficiency
    International Journal of Cardiology, 2017
    Co-Authors: Carlo Vignati, Alberico Del Torto, Vincenzo Tarzia, Stefania Farina, Anna Apostolo, Gino Gerosa, Tomaso Bottio, Gaia Cattadori, S. Scuri, Jonida Bejko
    Abstract:

    Abstract Backgrounds Peak exercise cardiac output (CO) increase is associated with an increase of peak oxygen uptake (VO 2 ), provided that arteriovenous O 2 difference [Δ(Ca−Cv)O 2 ] does not decrease. At Anaerobic Threshold, VO 2 , is related to CO. We tested the hypothesis that, in heart failure (HF) patients with left ventricular assistance device (LVAD), an acute increase of CO obtained through changes in LVAD pump speed is associated with peak exercise and Anaerobic Threshold VO 2 increase. Methods Fifteen of 20 patients bearing LVAD (Jarvik 2000) enrolled in the study successfully performed peak exercise evaluation. All patients had severe HF as shown by clinical evaluation, laboratory tests, echocardiography, spirometry with alveolar-capillary diffusion, and maximal cardiopulmonary exercise testing (CPET). CPETs with non-invasive CO measurements at rest and peak exercise were done on 2days at LVAD pump speed set randomly at 2 and 4. Results Increasing LVAD pump speed from 2 to 4 increased CO from 3.4±0.9 to 3.8±1.0L/min (ΔCO 0.4±0.6L/min, p =0.04) and from 5.3±1.3 to 5.9±1.4L/min (ΔCO 0.6±0.7L/min, p 2 increased from 788±169 to 841±152mL/min (ΔVO 2 52±76mL/min, p =0.01) and from 568±116 to 619±124mL/min (ΔVO 2 69±96mL/min, p =0.02) at peak exercise and at Anaerobic Threshold, respectively. Δ(Ca−Cv)O 2 did not change significantly, while ventilatory efficiency improved (VE/VCO 2 slope from 39.9±5.4 to 34.9±8.3, ΔVE/VCO 2 −5.0±6.4, p Conclusions In HF, an increase in CO with a higher LVAD pump speed is associated with increased peak VO 2 , postponed Anaerobic Threshold, and improved ventilatory efficiency.

Ricardo J Fernandes - One of the best experts on this subject based on the ideXlab platform.

  • Anaerobic Threshold biophysical characterisation of the four swimming techniques
    International Journal of Sports Medicine, 2020
    Co-Authors: Diogo D Carvalho, Joao Paulo Vilasboas, Susana Soares, Rodrigo Zacca, Joao Borges De Sousa, Daniel A Marinho, Antonio J Silva, Ricardo J Fernandes
    Abstract:

    The Anaerobic Threshold (AnT) seems to be not only a physiologic boundary but also a transition after which swimmers technique changes, modifying their biomechanical behaviour. We expanded the AnT concept to a biophysical construct in the four conventional swimming techniques. Seventy-two elite swimmers performed a 5×200 m incremental protocol in their preferred swimming technique (with a 0.05 m·s−1 increase and a 30 s interval between steps). A capillary blood samples were collected from the fingertip and stroke rate (SR) and length (SL) determined for the assessment of [La], SR and SL vs. velocity inflexion points (using the interception of a pair of linear and exponential regression curves). The [La] values at the AnT were 3.3±1.0, 3.9±1.1, 2.9±1 .34 and 4.5±1.4 mmol·l−1 (mean±SD) for front crawl, backstroke, breaststroke and butterfly, and its corresponding velocity correlated highly with those at SR and SL inflection points (r=0.91–0.99, p<0.001). The agreement analyses confirmed that AnT represents a biophysical boundary in the four competitive swimming techniques and can be determined individually using [La] and/or SR/SL. Blood lactate increase speed can help characterise swimmers’ Anaerobic behaviour after AnT and between competitive swimming techniques.

  • Differences in kinematics and energy cost between front crawl and backstroke below the Anaerobic Threshold
    European Journal of Applied Physiology, 2018
    Co-Authors: Tomohiro Gonjo, Ricardo J Fernandes, Carla Mccabe, Ana Sousa, João Ribeiro, João Paulo Vilas-boas, Ross Sanders
    Abstract:

    Purpose The purpose of this study was to determine kinematic and energetic differences between front crawl and backstroke performed at the same aerobic speeds. Methods Ten male competitive swimmers performed front crawl and backstroke at a pre-determined sub-Anaerobic Threshold speed to assess energy cost (through oxygen uptake measurement) and kinematics (using three-dimensional videography to determine stroke frequency and length, intra-cycle velocity fluctuation, three-dimensional wrist and ankle speeds, and vertical and lateral ankle range of motion). For detailed kinematic analysis, resultant displacement, the duration, and three-dimensional speed of the wrist during the entry, pull, push, and release phases were also investigated. Results There were no differences in stroke frequency/length and intra-cycle velocity fluctuation between the swimming techniques, however, swimmers had lower energy cost in front crawl than in backstroke (0.77 ± 0.08 vs 0.91 ± 0.12 kJ m^−1, p  

  • step length and individual Anaerobic Threshold assessment in swimming
    International Journal of Sports Medicine, 2011
    Co-Authors: Ricardo J Fernandes, Marisa Sousa, Leandro Machado, Joao Paulo Vilasboas
    Abstract:

    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.