Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Hum Kinet ; 70: 103-114, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31915480

RESUMO

The aim of this study was to determine changes in climbers' hormonal, cardiovascular, neuromuscular, sleep and fatigue status, and their relationship with performance and workloads during a sport rock climbing camp. Mean difficulty of individual leading climbing routes (mean Difficulty) was calculated for six male, intermediate level sport rock climbers participating in a 2-week camp in Orpierre. Additionally, each morning climbers were tested for: cortisol (d-Cortisol) and testosterone (d-Testosterone) concentrations, testosterone/cortisol ratio (T/C), heart rate and heart rate variability in supine (d-L-HR, d-L-SD1, d-L-SD2) and standing positions (d-S-HR, d-S-SD1, d-S-SD2), difference in S-HR and L-HR (HR-S-L), maximal voluntary hand grip strength (MVC), sleep duration (Sleep) and the self-perception of fatigue (M-Fatigue). Only M-Fatigue and d-Testosterone did not change significantly during the camp. Changes in other variables were large and significant, especially in the second week of the camp when the mean Difficulty was > 70%. The greatest changes were noted on the last day, when T/C, HR-S-L, and Sleep decreased and d-Cortisol, d-L-HR, and d-SD1 increased. The monitoring of the uncoupling of neuromuscular, hormonal, and cardiovascular markers can be instrumental in determining the level of athletes' morning fatigue and readiness during a climbing camp. An increase in d-Cortisol and a decrease in T/C and HR-S-L are relevant indicators of overreaching in sport climbers.

2.
J Hum Kinet ; 65: 111-123, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30687424

RESUMO

Rock climbing is a physical activity that not only causes an increase in muscle tension, heart rate and blood pressure, but also results in the elevation of stress hormones including cortisol. It has not been established which of the above mentioned variables serve as the most accurate indicator of rock climbing-induced physical and mental stress. The aim of this study was to evaluate the effect of physical activity, short-term fatigue and mental demand on heart rate (HR), salivary cortisol (C) and blood plasma lactate (LA) concentrations in rock climbers under laboratory conditions. Twelve male and female rock climbers of comparable climbing performance (5a - 6b OS) were recruited. The participants completed two routes of different climbing difficulty (effect of physical demand), repeated a difficult route with a short 5-min recovery period three times (effect of fatigue), and repeated a difficult lead climb (effect of mental demand). Heart rate as well as C and LA concentrations were determined. The results indicated that more difficult climbing routes elicited increases in HR (especially relative values) and LA concentrations, whereas fatigue accumulation had an effect on climbing HR and relative C concentration values. Lead climbing only caused an increase in climbing HR. Based on the results it was concluded that HR was a good indicator of physical and mental stress intensity. Performing the same difficult route three times with a short recovery period in-between turned out to be the most demanding task and resulted in the highest increase of the cortisol concentration. Dynamics of changes in lactate concentrations depend on muscle loading (local muscular effort), lactate clearance and technical/tactical skills of the climber.

3.
Nutrients ; 9(8)2017 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-28933745

RESUMO

Extracts of Ginkgo biloba leaves, a natural source of flavonoids and polyphenolic compounds, are commonly used as therapeutic agents for the improvement of both cognitive and physiological performance. The present study was aimed to test the effects of a six-week supplementation with 160 mg/day of a standardized extract of Ginkgo biloba or a matching placebo on aerobic performance, blood antioxidant capacity, and brain-derived neurotrophic factor (BDNF) level in healthy, physically active young men, randomly allocated to two groups (n = 9 each). At baseline, as well as on the day following the treatment, the participants performed an incremental cycling test for the assessment of maximal oxygen uptake. Venous blood samples taken at rest, then immediately post-test and following 1 h of recovery, were analyzed for activities of antioxidant enzymes and plasma concentrations of non-enzymatic antioxidants, total phenolics, uric acid, lipid peroxidation products, ferric reducing ability of plasma (FRAP), and serum brain-derived neurotrophic factor (BDNF). Our results show that six weeks' supplementation with Ginkgo biloba extract in physically active young men may provide some marginal improvements in their endurance performance expressed as VO2max and blood antioxidant capacity, as evidenced by specific biomarkers, and elicit somewhat better neuroprotection through increased exercise-induced production of BDNF.


Assuntos
Antioxidantes/metabolismo , Fator Neurotrófico Derivado do Encéfalo/sangue , Suplementos Nutricionais , Ginkgo biloba , Estresse Oxidativo/efeitos dos fármacos , Resistência Física/efeitos dos fármacos , Aptidão Física , Extratos Vegetais/administração & dosagem , Ciclismo , Biomarcadores/sangue , Esquema de Medicação , Teste de Esforço , Ginkgo biloba/química , Humanos , Masculino , Consumo de Oxigênio/efeitos dos fármacos , Fitoterapia , Extratos Vegetais/isolamento & purificação , Folhas de Planta , Plantas Medicinais , Polônia , Fatores de Tempo , Adulto Jovem
4.
J Hum Kinet ; 49: 109-18, 2015 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-26839611

RESUMO

Evidence of the role of ANGPTL3, a liver-secreted glycoprotein, in serum lipid turnover, led us to hypothesize that this protein may be involved in modification of the lipid profile induced by exercise-training. Given the lack of data regarding this issue, the main goal of the present study was to investigate the effects of regular participation in a recreational physical activity program on serum ANGPTL3 and selected lipid profile measures in young, apparently healthy female and male adults. We compared serum ANGPTL3, lipid profile measures, common lipid ratios, the Atherogenic Index of Plasma (AIP) and glucose in fasting blood samples derived from 22 active physical education students including active females (AF, N=6) and males (AM, N=16) with samples from 28 relatively sedentary age-matched peers, including female (SF, N=9) and male (SM, N=19) individuals not involved in any regular physical conditioning program. Despite high inter-individual variability of serum ANGPTL3, there was a general tendency toward higher serum ANGPTL3 and HDL-C in women compared to men, but without significant differences related to their physical activity status. Based on both routine lipid profile measures and lipid ratios, all participants had normal lipid profiles, normal glycemia, as well as favorable anthropometric indices not suggesting increased cardiometabolic risk. However, lower levels of the TG/HDL-C ratio and AIP in physically active compared to relatively sedentary participants, reflecting the predominance of large, buoyant LDL particles, strongly support the view of beneficial health-promoting effects of regular participation in recreational sport activities.

5.
Eur J Appl Physiol ; 112(5): 1679-88, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-21879351

RESUMO

The study was conducted to evaluate the metabolic responses to a 24 h ultra-endurance race in male runners. Paired venous and capillary blood samples from 14 athletes (mean age 43.0 ± 10.8 years, body weight 64.3 ± 7.2 kg, VO(2max) 57.8 ± 6.1 ml kg(-1) min(-1)), taken 3 h before the run, after completing the marathon distance (42.195 km), after 12 h, and at the finish of the race, were analyzed for blood morphology, acid-base balance and electrolytes, lipid profile, interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsCRP), and serum enzyme activities. Mean distance covered during the race was 168.5 ± 23.1 km (range 125.2-218.5 km). Prolonged ultra-endurance exercise triggered immune and inflammatory responses, as evidenced by a twofold increase in total leukocyte count with neutrophils and monocytes as main contributors, nearly 30-fold increase in serum IL-6 and over 20-fold rise in hsCRP. A progressive exponential increase in mean creatine kinase activity up to the level 70-fold higher than the respective pre-race value, a several fold rise in serum activities of aspartate aminotransferase and alanine aminotransferase, and a fairly stable serum γ-glutamyl transferase level, were indicative of muscle, but not of liver damage. With duration of exercise, there was a progressive development of hyperventilation-induced hypocapnic alkalosis, and a marked alteration in substrate utilization towards fat oxidation to maintain blood glucose homeostasis. The results of this study may imply that progressive decline in partial CO(2) pressure (hypocapnia) that develops during prolonged exercise may contribute to increased interleukin-6 production.


Assuntos
Músculo Esquelético/fisiologia , Resistência Física/fisiologia , Corrida/fisiologia , Equilíbrio Ácido-Base , Adulto , Biomarcadores/sangue , Proteína C-Reativa/análise , Eletrólitos/sangue , Ensaios Enzimáticos , Humanos , Interleucina-6/sangue , Lipídeos/sangue , Masculino , Músculo Esquelético/metabolismo , Inquéritos e Questionários
6.
Biol Trace Elem Res ; 108(1-3): 1-15, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16327055

RESUMO

The selenium status and the relationship of whole-blood selenium and plasma homocysteine are reported for healthy human subjects living in Upper Silesia. A total of 1063 individuals (627 male and 436 female) examined for whole-blood selenium were subdivided into six groups according to age; the youngest included adolescents (n=143) aged 10-15 yr, and the oldest were centenarians (n=132). The mean Se content was relatively low (62.5+/-18.4 microg/L), and it tended to be higher in men (65.9+/-17.2 microg/L) than in women (57.5+/-18.9 microg/L). Selenium levels appeared to be age dependent, as the highest values were observed in young and middle-age adults (21-40 yr), whereas they were significantly lower in adolescents and in the elderly. In more than 40% of apparently healthy adults (aged 21-69 yr), the Se concentration was within the range 60-80 microg/L (i.e., below the lower limit of the nutritional adequacy range [80 microg/L]). A significant inverse correlation between whole-blood selenium and plasma total homocysteine was detected in a smaller population sample of middle-aged and elderly persons (n=204).


Assuntos
Selênio/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Homocisteína/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Polônia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...