scholarly journals Relación entre el tipo de ejercicio físico y la fatiga cuantificada mediante VFC, CK y el lactato en sangre (Relationship between physical exercise type and fatigue quantified through HRV, CK, and blood lactate)

Retos ◽  
2021 ◽  
Vol 44 ◽  
pp. 176-182
Author(s):  
German Hernández-Cruz ◽  
Edson Francisco Estrada-Meneses ◽  
Arnulfo Ramos-Jiménez ◽  
Blanca Rocío Rangel-Colmenero ◽  
Luis Felipe Reynoso-Sánchez ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Blood Lactate ◽  
Athletic Performance ◽  
Stress Index ◽  
Exercise Type ◽  
Para Determinar ◽  
Intensity Of Exercise ◽  
Sports Coaches ◽  
Aerobic And Anaerobic

  Los atletas son expuestos a cargas de alta intensidad en la búsqueda del rendimiento deportivo, sin embargo, sus efectos no se evalúan apropiadamente. El presente estudio analiza los efectos de cuatro diferentes tipos de ejercicios sobre la variabilidad de la frecuencia cardíaca (VFC), diagrama de Poincaré (SD1: desviación estándar 1 y SD2: desviación estándar 2), así como la Creatina Cinasa (CK) y las concentraciones de lactato en sangre como marcadores de fatiga. Para lograr el objetivo, participaron 10 voluntarios sanos quienes se expusieron a fatiga mediante protocolos de ejercicio isotónicos, isométricos, aeróbicos y anaeróbicos. Se tomaron muestras de la SD1 y de la SD2 para posteriormente probar el comportamiento de la fatiga mediante el índice de estrés (SS) como parámetro simpático, y el índice simpático/parasimpático (S/PS), además se midió la raíz cuadrada media de las diferencias sucesivas (rMSSD) como indicadores parasimpáticos. Se recolectaron muestras sanguíneas al comienzo y al final de cada uno de los tipos de ejercicio para determinar los niveles de CK y lactato. La SD1 disminuye en cada protocolo de ejercicio, mientras que el SS y el S/PS incrementan. Lactato y CK incrementan al final de cada protocolo y correlacionan positivamente con el SD1 y S/PS. La VFC, CK y lactato son marcadores sensibles para la detección de fatiga, son sensibles tanto al tipo, duración e intensidad del ejercicio, siendo la VFC un marcador no invasivo y novedoso, simple y útil para los entrenadores y atletas.  Abstract: Athletes are exposed to high-intensity loads to promote athletic performance, however, the effects are not evaluated appropriately. This study investigates the effects of four types of exhaustion exercises on Heart Rate Variability (HRV) and Poincaré features (SD1: Standard deviation 1and SD2: Standard deviation 2), Creatine Kinase (CK) and blood lactate concentrations as biomarkers of fatigue. To achieve this purpose, 10 healthy volunteers were exposed to exhaustive exercise using isotonic, isometric, aerobic and anaerobic fatigue protocols. HRV Poincaré features, standard deviation of instantaneous beat-to-beat R-R interval variability (SD1) and standard deviation of continuous long-term R-R interval variability (SD2) variables were collected. Fatigue was tested through the sympathetic stress index (SS), the index sympathetic/parasympathetic index (S/PS) and the root Mean Square of the Successive Differences (rMSSD) as parasympathetic index. Blood samples were collected at the beginning and at the end of the exercises to determine CK and lactate. The SD1 decreased in each exercise protocol, while the SS and S/PS increased. Lactate and CK increased at the end of each protocol and correlated with SD1 and S/PS. HRV, CK, and lactate are acute markers to detect fatigue, are sensitive to the type, duration, and intensity of exercise, being HRV a novel noninvasive marker, simple and useful for sports coaches and athletes.

scholarly journals Central and Peripheral Fatigue Related to the Type of Exercise

2018 ◽  
Author(s):  
José Trinidad Quezada Chacón ◽  
Edson Francisco Estrada Meneses ◽  
Gustavo Sierra Muñiz ◽  
Arnulfo Ramos-Jimenez ◽  
Felipe Reynoso Sánchez ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Athletic Performance ◽  
Central Fatigue ◽  
Stress Index ◽  
Peripheral Fatigue ◽  
Type Of Exercise ◽  
Intensity Of Exercise ◽  
Sports Coaches ◽  
Aerobic And Anaerobic

Athletes are exposed to high-intensity loads to promote athletic performance, however without appropriate evaluation for its effects. This study investigates the effects of four types of exhaustion exercises on Heart Rate Variability (HRV) and Poincaré features as markers of central fatigue; Creatine Kinase (CK) and blood lactate concentrations ([LA-]b) as biomarkers of peripheral fatigue. To achieve this purpose, ten healthy volunteers were exposed to exhaustive exercise using isotonic-, isometric-, aerobic-, and anaerobic-fatigue protocols. HRV Poincaré features, standard deviation of instantaneous beat-to-beat R-R interval variability (SD1) and standard deviation of continuous long-term R-R interval variability (SD2) variables were collected. Central fatigue was tested through the sympathetic stress index (SS) and the sympathetic and parasympathetic index (SS/SD1). Blood samples were collected at the beginning and at the end of the exercises to determine CK and [LA-]b. The SD1 decreased in each exercise protocol, while the SS and SS/SD1 increased. [LA-]b and CK increased at the end of each protocol and correlated with SD1 and SS/SD1. HRV, CK, and [LA-]b are acute markers to detect, both central and peripheral fatigue; sensitive to the type, duration, and intensity of exercise, being HRV a novel noninvasive marker, simple and useful for sports coaches and athletes.

Long term habitual vigorous physical activity is associated with lower visit-to-visit systolic blood pressure variability

2020 ◽  
Author(s):  
Xiaoyong Xu ◽  
Xianghong Meng ◽  
Shin-ichi Oka
Keyword(s):  
Physical Activity ◽  
Blood Pressure ◽  
Standard Deviation ◽  
Systolic Blood Pressure ◽  
Blood Pressure Variability ◽  
Vigorous Physical Activity ◽  
Systolic Blood Pressure Variability ◽  
Average Real Variability ◽  
Post Hoc

Abstract Objective Our work aimed to investigate the association between vigorous physical activity and visit-to-visit systolic blood pressure variability (BPV). Methods We conducted a post hoc analysis of SPRINT (Systolic Blood Pressure Intervention Trial), a well-characterized cohort of participants randomized to intensive (<120 mmHg) or standard (<140 mmHg) SBP targets. We assessed whether patients with hypertension who habitually engage in vigorous physical activity would have lower visit-to-visit systolic BPV compared with those who do not engage in vigorous physical activity. Visit-to-visit systolic BPV was calculated by standard deviation (SD), average real variability (ARV), and standard deviation independent of the mean (SDIM) using measurements taken during the 1-, 2-, 3-, 6-, 9- and 12-month study visits. A medical history questionnaire assessed vigorous physical activity, which was divided into three categories according to the frequency of vigorous physical activity. Results A total of 7571 participants were eligible for analysis (34.8% female, mean age 67.9±9.3 years). During a follow-up of 1-year, vigorous physical activity could significantly reduce SD, ARV, and SDIM across increasing frequency of vigorous physical activity. There were negative linear trends between frequency of vigorous physical activity and visit-to-visit systolic BPV. Conclusions Long-term engagement in vigorous physical activity was associated with lower visit-to-visit systolic BPV.

scholarly journals Peripheral Modulators of the Central Fatigue Development and Their Relationship with Athletic Performance in Jumper Horses

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 743
Author(s):  
Francesca Arfuso ◽  
Claudia Giannetto ◽  
Elisabetta Giudice ◽  
Francesco Fazio ◽  
Michele Panzera ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Athletic Performance ◽  
Lactate Concentration ◽  
Indirect Evidence ◽  
Blood Lactate Concentration ◽  
Central Fatigue ◽  
Serotoninergic System ◽  
Stressful Situation ◽  
Passive Behavior ◽  
Fatigue Development

The current study aimed to investigate whether peripheral modulators of serotoninergic function and neurohumoral factors’ changes in athletic horses during an official jumping competition, and to evaluate their relationship with the physical performance of competing horses. From 7 Italian Saddle mares (6–9 years; mean body weight 440 ± 15 kg), performing the same standardized warm-up and jumping course during an official class, heart rate (HR) was monitored throughout the competition. Rectal temperature (RT) measurement, blood lactate and glucose concentration, serum tryptophan, leucine, valine, the tryptophan/branched-chain amino-acids ratio (Try/BCAAs), dopamine, prolactin, and non-esterified fatty acids (NEFAs) were assessed before the exercise event (T0), at the end of the competition stage (5 min ± 10 s following the cessation of the exercise, TPOST5), and 30 min after the end of competition (TPOST30). Highest HR values were recorded during the course and at the outbound (p < 0.0001); blood lactate concentration and RT increased after exercise with respect to the rest condition (p < 0.0001). Lower leucine and valine levels (p < 0.01), and higher tryptophan, Try/BCAAs ratio, and NEFAs values were found at TPOST5 and TPOST30 with respect to T0 (p < 0.0001). A higher prolactin concentration was found at TPOST5 and TPOST30 compared to T0 (p < 0.0001), whereas dopamine showed decreased values after exercise compared to rest (p < 0.0001). Statistically significant correlations among the peripheral indices of serotoninergic function, neurohumoral factors, and athletic performance parameters were found throughout the monitoring period. The findings provide indirect evidence that the serotoninergic system may be involved in fatigue during jumper exercise under a stressful situation, such as competition, in which, in addition to physical effort, athletic horses exhibit more passive behavior.

scholarly journals Association between physical exercise and stroke recurrence among first-ever ischemic stroke survivors

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lisha Hou ◽  
Mier Li ◽  
Ju Wang ◽  
Yawen Li ◽  
Qianwen Zheng ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Exercise Duration ◽  
Stroke Recurrence ◽  
Stroke Survivors ◽  
Face To Face ◽  
Baseline Information ◽  
Exercise Type ◽  
The Relationship

AbstractThe relationship between exercise and stroke recurrence is controversial. This study was designed to test whether an association exists between exercise and ischemic stroke recurrence in first-ever ischemic stroke survivors. Data were collected from January 2010 to June 2016. Baseline information was obtained during face-to-face interviews, and follow-up phone interviews were conducted every 3 months. Exercise type, frequency, intensity, and duration were recorded. Discrete-time survival analysis was used to determine the relationship between exercise and stroke recurrence. 760 first-ever ischemic stroke survivors who were able to exercise were enrolled. After adjusting for covariates, patients who exercised 3.5–7 h per week and more than 7 h per week had a lower relapse risk than patients who did not exercise (3.5–7: OR 0.415; > 7: OR 0.356). Moreover, if the fluctuation of exercise duration was over 4 h, the patients had a higher risk of stroke recurrence than those with variability of less than 2 h (OR 2.153, P = 0.013). Stroke survivors who engage in long-term regular mild exercise (more than 5 sessions per week and lasting on average 40 min per session) have a lower recurrence rate. Irregular exercise increases the risk of stroke recurrence.

scholarly journals Exercise intensity during official soccer matches

2016 ◽  
Vol 18 (6) ◽  
pp. 621 ◽  
Author(s):  
Daniel Barbosa Coelho ◽  
Rodney Coelho da Paixão ◽  
Emerson Cruz de Oliveira ◽  
Lenice Kappes Becker ◽  
João Batista Ferreira-Júnior ◽  
...  
Keyword(s):  
Heart Rate ◽  
Blood Lactate ◽  
Field Test ◽  
Exercise Intensity ◽  
Intermediate Phase ◽  
Age Groups ◽  
Soccer Players ◽  
Blood Lactate Accumulation ◽  
Intensity Of Exercise ◽  
In The Beginning

DOI: http://dx.doi.org/10.5007/1980-0037.2016v18n6p621 The aims of the study were: 1) to analyze the exercise intensity in several phases (six phases of 15 min) of soccer matches; 2) to compare the match time spent above anaerobic threshold (AT) between different age groups (U-17 and U-20); and 3) to compare the match time spent above AT between players’ positions (backs, midfielders, forwards and wingabcks). Forty-four male soccer players were analyzed. To express players’ effort, the heart rate (HR) was continuously monitored in 29 official matches. Further, HR corresponding to the intensity at the onset of blood lactate accumulation (OBLA) was obtained in a field test. The highest exercise intensity during match was observed in the 15-30 min period of the first half (p< 0.05). Match time spent above AT was not different between players from U-17 and U-20. In the comparison among players’ positions, wingbacks showed lower time above AT (p< 0.05) than players of other positions. The intensity of effort is higher in the 15 to 30 minutes of play (intermediate phase), probably because the players are more rested in the beginning and wearing out is progressive throughout the game. It is also noteworthy that the intensity of exercise (HR and time above AT) of wingbacks was lower, probably because they usually are required to run a larger number of sprints and need more time below the AT to recover. 

scholarly journals Maturity, Indebtedness, and Default Risk

2012 ◽  
Vol 102 (6) ◽  
pp. 2674-2699 ◽  
Author(s):  
Satyajit Chatterjee ◽  
Burcu Eyigungor
Keyword(s):  
Standard Deviation ◽  
Default Risk ◽  
Sovereign Debt ◽  
External Debt ◽  
Equilibrium Price ◽  
Short Term ◽  
Price Function ◽  
Output Ratio ◽  
Novel Method

We advance quantitative-theoretic models of sovereign debt by proving the existence of a downward sloping equilibrium price function for long-term debt and implementing a novel method to accurately compute it. We show that incorporating long-term debt allows the model to match Argentina's average external debt-to-output ratio, average spread on external debt, the standard deviation of spreads, and simultaneously improve upon the model's ability to account for Argentina's other cyclical facts. We also investigated the welfare properties of maturity length and showed that if the possibility of self-fulfilling rollover crises is taken into account, long-term debt is superior to short-term debt. (JEL E23, E32, F34, O11, O19)

The Preservation of Specialization by Dispersed Steer Thyroidal Cells in Long-Term Culture

1971 ◽  
Vol 9 (1) ◽  
pp. 49-69
Author(s):  
E. SIEGEL
Keyword(s):  
Standard Deviation ◽  
Trichloroacetic Acid ◽  
Doubling Time ◽  
Ultrastructural Level ◽  
Thyroid Stimulating Hormone ◽  
Linear Variation ◽  
Thyroid Cells ◽  
Long Acting ◽  
Number Of Cells

Serially propagated cells derived from the steer thyroid gland preserve several specialized characteristics, some demonstrable for as long as 8 months (over 15 passes). For about 5 passes (3 months), follicular-like arrays of cells develop. Thyroid-stimulating hormone (TSH) or thyrotropin (1 and 10 mu./ml) induces the formation of supernumerary nucleoli, and promotes at the ultrastructural level the prompt (within 10 min) appearance of microvilli, pseudopodia, and intracytoplasmic droplets. These cells have a mean plating efficiency (PE) of 16.5 ± 4.5% (standard deviation) and with 3x104 cells as the standard inoculum, a mean doubling time (Td) of 43.7 ± 1.2 h. The linear variation of Td with the number of cells seeded probably signifies strong cell-cell interactions. TSH (1-5o mu./ml) influences both PE and Td, with 1 mu./ml producing the maximum stimulation. TSH (0.001-100 mu./ml) also induces the discharge of incorporated radio-iodide from the cultured thyroid cells, achieving a peak by 2-4 h, titres of 0.1-1 mu./ml being most potent. Long-acting thyroid stimulator (LATS) (0.2 u./ml) likewise effects release of 131I into growth medium (1 experiment), but over a more protracted period. After labelling with [3H]leucine, radioautographs demonstrate that the synthesis of proteins is stimulated by exposure to TSH (1 mu./ml). Precipitation with trichloroacetic acid indicates that these cells persist in synthesizing 131I-tagged iodoproteins, an activity optimally stimulated by 1 mu./ml TSH and marked by 3 h. Hence, such thyroidal cell lines afford a useful model for studying differentiation and hormonal effects.

scholarly journals Inter-annual variability of wind climates and wind turbine annual energy production

2018 ◽  
Author(s):  
Sara C. Pryor ◽  
Tristan J. Shepherd ◽  
Rebecca J. Barthelmie
Keyword(s):  
Standard Deviation ◽  
Wind Energy ◽  
Wind Turbine ◽  
Energy Production ◽  
Wind Farm ◽  
Wind Farms ◽  
Wind Speeds ◽  
Annual Variability ◽  
Eastern Usa

Abstract. Inter-annual variability (IAV) of expected annual energy production (AEP) from proposed wind farms plays a key role in dictating project financing. IAV in pre-construction projected AEP and the difference in 50th and 90th percentile (P50 and P90) AEP derives in part from variability in wind climates. However, the magnitude of IAV in wind speeds at/close to wind turbine hub-heights is poorly constrained and maybe overestimated by the 6 % standard deviation of annual mean wind speeds that is widely applied within the wind energy industry. Thus there is a need for improved understanding of the long-term wind resource and the inter-annual variability therein in order to generate more robust predictions of the financial value of a wind energy project. Long-term simulations of wind speeds near typical wind turbine hub-heights over the eastern USA indicate median gross capacity factors (computed using 10-minute wind speeds close to wind turbine hub-heights and the power curve of the most common wind turbine deployed in the region) that are in good agreement with values derived from operational wind farms. The IAV of annual mean wind speeds at/near to typical wind turbine hub-heights in these simulations is lower than is implied by assuming a standard deviation of 6 %. Indeed, rather than in 9 in 10 years exhibiting AEP within 0.9 and 1.1 times the long-term mean AEP, results presented herein indicate that over 90 % of the area in the eastern USA that currently has operating wind turbines simulated AEP lies within 0.94 and 1.06 of the long-term average. Further, IAV of estimated AEP is not substantially larger than IAV in mean wind speeds. These results indicate it may be appropriate to reduce the IAV applied to pre-construction AEP estimates to account for variability in wind climates, which would decrease the cost of capital for wind farm developments.

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