Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 84
Filtrar
1.
Nutrients ; 12(5)2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32365848

RESUMO

We investigated the impact of nutrient intake on hydration biomarkers in cyclists before and after a 161 km ride, including one hour after a 650 mL water bolus consumed post-ride. To control for multicollinearity, we chose a clustering-based, machine learning statistical approach. Five hydration biomarkers (urine color, urine specific gravity, plasma osmolality, plasma copeptin, and body mass change) were configured as raw- and percent change. Linear regressions were used to test for associations between hydration markers and eight predictor terms derived from 19 nutrients merged into a reduced-dimensionality dataset through serial k-means clustering. Most predictor groups showed significant association with at least one hydration biomarker: 1) Glycemic Load + Carbohydrates + Sodium, 2) Protein + Fat + Zinc, 3) Magnesium + Calcium, 4) Pinitol, 5) Caffeine, 6) Fiber + Betaine, and 7) Water; potassium + three polyols, and mannitol + sorbitol showed no significant associations with any hydration biomarker. All five hydration biomarkers were associated with at least one nutrient predictor in at least one configuration. We conclude that in a real-life scenario, some nutrients may serve as mediators of body water, and urine-specific hydration biomarkers may be more responsive to nutrient intake than measures derived from plasma or body mass.

2.
J Strength Cond Res ; 2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-32224716

RESUMO

da Silva Novaes, J, da Silva Telles, LG, Monteiro, ER, da Silva Araujo, G, Vingren, JL, Silva Panza, P, Reis, VM, Laterza, MC, and Vianna, JM. Ischemic preconditioning improves resistance training session performance. J Strength Cond Res XX(X): 000-000, 2020-The aim of this study was to investigate the acute effect of ischemic preconditioning (IPC) in a resistance exercise (RE) training session on the number of repetitions performed, total volume, and rating of perceived exertion in recreationally trained and normotensive men. Sixteen recreationally trained and normotensive men completed 3 RE sessions in a counterbalanced and randomized order: (a) IPC protocol using 220 mm Hg followed by RE (IPC), (b) IPC cuff control protocol with 20 mm Hg followed by RE (CUFF), and (c) no IPC (control) followed by RE (CON). RE was performed with 3 sets of each exercise (bench press, leg press, lateral pulldown, hack machine squat, shoulder press, and Smith back squat) until concentric muscular failure, at 80% of one repetition maximum, with 90 seconds of rest between sets and 2 minutes of rest between exercises. Ischemic preconditioning and CUFF consisted of 4 cycles of 5 minutes of occlusion/low pressure alternating with 5 minutes of no occlusion (0 mm Hg) using a pneumatic tourniquet applied around the subaxillary region of the upper arm. For each condition, the number of repetitions completed, total volume of work performed, and rating of perceived exertion were determined. No significant difference was found for rating of perceived exertion between any experimental protocol. Ischemic preconditioning significantly (p < 0.05) increased the number of repetitions across exercises. Consequently, total volume performed (sum of total number of repetitions x load for each exercise) was significantly higher in IPC (46,170 kg) compared with CON (34,069 kg) and CUFF (36,590 kg) across all exercises. This work may have important implications for athletic populations because it demonstrates increase in muscle performance outcomes during a single RE session. Therefore, performing IPC before RE could be an important exercise prescription recommendation to increase maximum repetition performance and total volume of work performed and thus potentially increase desired training adaptations (i.e., strength and hypertrophy).

3.
Int J Exerc Sci ; 12(4): 932-940, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31523350

RESUMO

The purpose of this study was to compare the effect of 24-, 36-, 48-, 72- and 96-hours between-test rest intervals on the reproducibility of the 10-RM smith machine back squat (BS), bench press (BP) and leg press at 45 degrees (LP45) exercises. Twelve resistance trained men (26.6 ± 4.5 yrs; 179.0 ± 5.5 cm; 92.2 ± 24.6 kg) performed five sets of identical 10-repetition maximum (10-RM) tests for the BS, BP, LP45 exercises, each set with a different interval between tests: 1) twenty-four hours (Post-24), 2) thirty-six hours (Post-36), 3) forty-eight hours (Post-48), 4) seventy-two (Post-72), and 5) ninety-six hours (Post-96). Significant differences in 10-RM from pretest to posttest were observed for BS in Post-24 (p < 0.001; Δ% = -12.62), Post-36 (p < 0.001; Δ% = -6.57), and Post-96 (p = 0.015; Δ% = 6.84). Similarly, significant differences in 10-RM from pretest to posttest were observed for BP in Post-24 (p < 0.001; Δ% = -9.22), Post-36 (p = 0.032; Δ% = -3.04), and Post-96 (p < 0.001; Δ% = 5.37). Finally, significant differences in 10-RM from pretest to posttest were observed for LP45 in Post-24 (p < 0.001; Δ% = -16.55), Post-36 (p = 0.032; Δ% = -5.09), and Post-96 (p < 0.001; Δ% = 5.54). The reproducibility of 10-RM was examined using intraclass correlation coefficients; BS: 0.944, 0.977, 0.988, 0.986, and 0.954 for Post-24, Post-36, Post-48, Post-72, and Post-96, respectively; BP: 0.894, 0.966, 0.966, 0.960, and 0.976; and LP45: 0.832, 0.957, 0.984, 0.974, and 0.977 5. Based on the findings, the optimal between test rest interval duration for 10-RM testing, to provide the best reproducibility, in resistance trained men appears to be 48 to 72 hours for the BS, BP, and LP45 exercises.

4.
J Bodyw Mov Ther ; 23(3): 575-580, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31563372

RESUMO

Increases in joint range-of-motion may be beneficial for improving performance and reducing injury risk. This study investigated the effects of different self-massage volumes and modalities on passive hip range-of-motion. Twenty-five recreationally resistance-trained men performed four experimental protocols using a counterbalanced, randomized, and within-subjects design; foam rolling (FR) or roller massage (RM) for 60 or 120-s. Passive hip flexion and extension range-of-motion were measured in a counterbalanced and randomized order via manual goniometry before self-massage (baseline) and immediately, 10-, 20-, and 30-min following each self-massage intervention. Following FR or RM of quadriceps, there was an increase in hip flexion range-of-motion at Post-0 (FR: Δ = 19.28°; RM: Δ = 14.96°), Post-10 (FR: Δ = 13.03°; RM: Δ = 10.40°), and Post-20 (FR: Δ = 6.00°; RM: Δ = 4.64°) for all protocols, but these did not exceed the minimum detectable change at Post-10 for RM60 and RM120, and Post-20 for FR60, FR120, RM60, and RM120. Similarly, hip extension range-of-motion increased at Post-0 (FR: Δ = 8.56°; RM: Δ = 6.56°), Post-10 (FR: Δ = 4.64°; RM: Δ = 3.92°), and Post-20 (FR: Δ = 2.80°; RM: Δ = 1.92°), but did not exceed the minimum detectable change at Post-10 for FR60, RM60, and RM120, and Post-20 for FR60, FR120, RM60, and RM120. In conclusion, both FR and RM increased hip range-of-motion but larger volumes (120- vs. 60-second) and FR produced the greatest increases. These findings have implications for self-massage prescription and implementation, in both rehabilitation and athletic populations.

5.
Am J Physiol Endocrinol Metab ; 317(2): E421-E432, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31237450

RESUMO

The purpose of this work was to determine the effect of resistance exercise (RE)-induced hormonal changes on the satellite cell (SC) myogenic state in response to muscle damage. Untrained men (n = 10, 22 ± 3 yr) and women (n = 9, 21 ± 4 yr) completed 2 sessions of 80 unilateral maximal eccentric knee extensions followed by either an upper body RE protocol (EX) or a 20-min rest (CON). Muscle samples were collected and analyzed for protein content of Pax7, MyoD, myogenin, cyclin D1, and p21 before (PRE), 12 h, and 24 h after the session was completed. Serum testosterone, growth hormone, cortisol, and myoglobin concentrations were analyzed at PRE, post-damage, immediately after (IP), and 15, 30, and 60 min after the session was completed. Testosterone was significantly (P < 0.05) higher immediately after the session in EX vs. CON for men. A significant time × sex × condition interaction was found for MyoD with an increase in EX (men) and CON (women) at 12 h. A significant time × condition interaction was found for Pax7, with a decrease in EX and increase in CON at 24 h. A significant time effect was found for myogenin, p21, and cyclin D1. Myogenin and p21 were increased at 12 and 24 h, and cyclin D1 was increased at 12 h. These results suggest that the acute RE-induced hormonal response can be important for men to promote SC proliferation after muscle damage but had no effect in women. Markers of SC differentiation appeared unaffected by the hormonal response but increased in response to muscle damage.


Assuntos
Proliferação de Células , Hormônio do Crescimento Humano/metabolismo , Hidrocortisona/metabolismo , Treinamento de Resistência , Descanso/fisiologia , Células Satélites de Músculo Esquelético/fisiologia , Adolescente , Adulto , Exercício Físico/fisiologia , Feminino , Hormônio do Crescimento Humano/fisiologia , Humanos , Hidrocortisona/fisiologia , Masculino , Desenvolvimento Muscular/fisiologia , Fatores Sexuais , Adulto Jovem
6.
J Sports Med Phys Fitness ; 59(2): 238-245, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29148630

RESUMO

BACKGROUND: The purpose of this study was to evaluate the influence of sex, exercise order, and rest interval on neuromuscular fatigue resistance for an alternated strength training sequence of bench press (BP) and leg press (LP) exercises. METHODS: Twelve women and 16 men, both recreationally trained, performed four sessions in a random order: 1) BP followed by LP with three-minutes rest (BP+LP with rest); 2) LP followed by BP with three-minutes rest (LP+BP with rest); 3) BP followed by LP without rest interval (BP+LP no rest), and 4) LP followed by BP without rest interval (LP+BP no rest). Participants performed four sets with 100% of 10RM load to concentric failure with the goal of completing the maximum number of repetitions in both exercises. The FI was analyzed from the first and last sets of each exercise bout. RESULTS: A main effect for sex showed that women exhibited 25.5% (P=0.001) and 24.5% (P=0.001) greater BP and LP fatigue than men respectively when performing 10RM. Men exhibited greater BP (P<0.0001; 34.1%) and LP (P<0.0001; 30.5%) fatigue resistance when a rest period was provided. Men did not show an exercise order effect for BP fatigue and exhibited greater (P=0.0003; 14.5%) LP fatigue resistance when BP was performed first. CONCLUSIONS: The present study demonstrated the greater fatigue resistance of men when performing 10RM BP and LP exercises. Since men tend to experience less fatigue with the second exercise in the exercise pairing, women's training programs should be adjusted to ensure they do not parallel men's resistance training programs.


Assuntos
Exercício Físico/fisiologia , Fadiga Muscular/fisiologia , Treinamento de Resistência/métodos , Fatores Sexuais , Adulto , Fenômenos Biomecânicos , Estudos Cross-Over , Feminino , Humanos , Masculino , Músculo Esquelético/fisiologia , Descanso/fisiologia
7.
J Sci Med Sport ; 21(12): 1180-1184, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29784554

RESUMO

Exercise, especially in the heat, can contribute to acute kidney injury, which can expedite chronic kidney disease onset. The additional stress of ibuprofen use is hypothesized to increase renal stress. OBJECTIVES: To observe the effects of endurance cycling in the heat on renal function. Secondarily, we investigated the effect of ibuprofen ingestion on kidney stress. DESIGN: Randomized, placebo controlled and observational methods were utilized. METHODS: Forty cyclists (52±9y, 21.7±6.5% body fat) volunteered and completed an endurance cycling event (5.7±1.2h) in the heat (33.2±5.0°C, 38.4±10.7% RH). Thirty-five participants were randomized to ingest a placebo (n=17) or 600mg ibuprofen (n=18) pre-event. A blood sample was drawn before and following the event. Serum creatinine was assessed by colorimetric assay. An ELISA was used to measure serum neutrophil gelatinase-associated lipocalin. Fractional excretion of sodium was calculated after urinary and serum electrolyte analyses. RESULTS: Placebo versus ibuprofen groups contributed no significant difference in any variable (p>0.05). Serum creatinine significantly increased from pre- (0.52±0.14mg/dL) to post-event (0.88±0.21mg/dL; p<0.001). Serum neutrophil gelatinase-associated lipocalin significantly increased (pre: 68.51±17.54ng/mL; post: 139.12±36.52ng/mL; p<0.001) and fractional excretion of sodium was significantly reduced from pre- (0.52±0.24%) to post-event (0.27±0.18%; p<0.001). CONCLUSIONS: Changes in renal biomarkers suggest mild acute kidney injury and reduced kidney function during a single bout of endurance cycling in the heat, without influence from moderate ibuprofen ingestion.


Assuntos
Lesão Renal Aguda/fisiopatologia , Ciclismo/fisiologia , Temperatura Alta/efeitos adversos , Ibuprofeno/uso terapêutico , Rim/fisiopatologia , Adulto , Biomarcadores/sangue , Creatinina/sangue , Método Duplo-Cego , Feminino , Humanos , Rim/efeitos dos fármacos , Lipocalina-2/sangue , Masculino , Pessoa de Meia-Idade , Resistência Física
8.
J Strength Cond Res ; 32(6): 1594-1600, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29470364

RESUMO

Duplanty, AA, Levitt, DE, Hill, DW, McFarlin, BK, DiMarco, NM, and Vingren, JL. Resistance training is associated with higher bone mineral density among young adult male distance runners independent of physiological factors. J Strength Cond Res 32(6): 1594-1600, 2018-Low bone mineral density (BMD) in male distance runners is common and could be modulated by a host of biomarkers involved in the dynamic balance of bone tissue. In contrast, resistance training can increase BMD; however, the efficacy of resistance training in protecting BMD in distance runners has not been elucidated. The aim of this study was to investigate the relationship between resistance training, testosterone and bone metabolism biomarker concentrations, and BMD in young adult male distance runners. Twenty-five apparently healthy men (23-32 years; mean ± SD: 25.9 ± 2.9 years; 1.77 ± 0.04 m; 75.4 ± 8.5 kg) were categorized into 1 of 3 groups: untrained control participants (CON; n = 8); nonresistance-trained runners (NRT; n = 8); or resistance-trained runners (RT; n = 9). Blood was collected and analyzed for concentrations of free and total testosterone and 14 bone metabolism biomarkers. Bone mineral density was assessed using dual-energy X-ray absorptiometry. At all measured sites, BMD was greater (p ≤ 0.05) for RT compared with NRT and CON. Vitamin D concentration was greater (p ≤ 0.05) in RT and NRT compared with CON. Concentrations of testosterone and remaining bone biomarkers did not differ between groups (p > 0.05). Resistance-trained runners had greater BMD than nonresistance-trained runners and untrained peers. This difference did not seem to be modulated by biomarkers that contribute to bone formation or resorption, indicating that differences in BMD are associated with habitual load-bearing exercise using external resistance. Runners should perform resistance exercise at least once per week because this is associated with greater BMD.


Assuntos
Densidade Óssea , Osso e Ossos/fisiologia , Treinamento de Resistência , Corrida/fisiologia , Testosterona/sangue , Vitamina D/sangue , Absorciometria de Fóton , Adulto , Biomarcadores/sangue , Osso e Ossos/metabolismo , Humanos , Masculino , Suporte de Carga , Adulto Jovem
9.
J Strength Cond Res ; 2018 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-29385007

RESUMO

The purpose of this study was to investigate the effect of alcohol consumed after heavy eccentric resistance exercise on measures of muscle power. After familiarization and an initial eccentric exercise bout to control for the "repeated-bout effect," ten recreationally resistance-trained men completed two identical heavy eccentric squat bouts (4 sets of 10 repetitions at 110% of concentric 1-repetition maximum) one week apart. Each exercise bout was followed by ingestion of a beverage containing either alcohol (1.09 g ethanol[BULLET OPERATOR]kg fat-free body mass) or no alcohol (placebo; volume of alcohol replaced with water). Vertical jump (VJ) peak power, VJ peak force, VJ jump height, change-of-direction ability (shuttle run), sprint acceleration (sprint test), and muscle soreness were measured before (PRE), 24 hrs after (24H), and 48 hrs after (48H) each eccentric exercise bout. Although the exercise bout resulted in significantly (p < 0.05) decreased VJ peak power at 24H, significantly decreased VJ jump height at 24H, and significantly increased muscle soreness at 24H and 48H, consuming alcohol after the exercise bout did not affect any of the performance outcome measures. When consumed after a non-novel heavy eccentric resistance exercise bout, alcohol did not affect soreness or recovery of muscular power. Practitioners can use this information to advise their athletes with regards to responsible alcohol use after non-novel exercise. Although short-term anaerobic performance does not appear compromised as a result of acute post-exercise alcohol ingestion, practitioners and athletes should be aware of potential long-term effects of such alcohol use.

10.
J Strength Cond Res ; 32(1): 76-82, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29257793

RESUMO

Vingren, JL, Curtis, JH, Levitt, DE, Duplanty, AA, Lee, EC, McFarlin, BK, and Hill, DW. Adding resistance training to the standard of care for inpatient substance abuse treatment in men with human immunodeficiency virus improves skeletal muscle health without altering cytokine concentrations. J Strength Cond Res 32(1): 76-82, 2018-Substance abuse and human immunodeficiency virus (HIV) infection can independently lead to myopathy and related inflammatory alterations; importantly, these effects seem to be additive. Resistance training (RT) can improve muscle health in people living with HIV (PLWH), but the efficacy of this intervention has not been examined for PLWH recovering from substance abuse. The purpose of this study was to determine the effect of RT on muscle health markers (mass, strength, and power) and basal circulating biomarkers for men living with HIV undergoing substance abuse treatment. Men living with HIV undergoing 60-day inpatient substance abuse treatment completed either RT (3×/wk) or no exercise training (control) for 6 weeks. Muscle mass, strength, and power, and fasting circulating cytokines (interferon γ, tumor necrosis factor-α, interleukin (IL)-1ß, IL-2, IL-4, IL-6, and IL-10), vascular cellular adhesion molecule-1, and cortisol were measured before (PRE) and after (POST) the 6-week period. Both groups received the standard of care for HIV and substance abuse treatment determined by the inpatient facility. Muscle mass, strength, and power increased (p ≤ 0.05) from PRE to POST for RT but were unchanged for control. No differences were found for circulating biomarkers. Adding RT to the standard of care for substance abuse treatment improved aspects of muscle health (mass, strength, and power) in men living with HIV. These improvements are associated with a lower risk of a number of health conditions. Therefore, practitioners should consider implementing RT interventions as part of substance abuse treatment programs in this population to help manage long-term health.


Assuntos
Infecções por HIV/terapia , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Treinamento de Resistência/métodos , Transtornos Relacionados ao Uso de Substâncias/terapia , Adulto , Biomarcadores , Composição Corporal , Citocinas/metabolismo , Feminino , Infecções por HIV/epidemiologia , Humanos , Pacientes Internados , Masculino , Pessoa de Meia-Idade , Transtornos Relacionados ao Uso de Substâncias/epidemiologia
11.
Wilderness Environ Med ; 28(3): 197-206, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28739377

RESUMO

OBJECTIVE: This study aims to examine blood hemostatic responses to completing a 164-km road cycling event in a hot environment. METHODS: Thirty-seven subjects (28 men and 9 women; 51.8±9.5 [mean±SD] y) completed the ride in 6.6±1.1 hours. Anthropometrics (height, body mass [taken also during morning of the ride], percent body fat [%]) were collected the day before the ride. Blood samples were collected on the morning of the ride (PRE) and immediately after (IP) the subject completed the ride. Concentrations of platelet, platelet activation, coagulation, and fibrinolytic markers (platelet factor 4, ß-thromboglobulin, von Willebrand factor antigen, thrombin-antithrombin complex, thrombomodulin, and D-Dimer) were measured. Associations between changes from PRE- to IP-ride were examined as a function of event completion time and subject characteristics (demographics and anthropometrics). RESULTS: All blood hemostatic markers increased significantly (P < .001) from PRE to IP. After controlling for PRE values, finishing time was negatively correlated with platelet factor 4 (r = 0.40; P = .017), while percent body fat (%BF) was negatively correlated with thrombin-antithrombin complex (r = -0.35; P = .038) and to thrombomodulin (r = -0.36; P = .036). In addition, male subjects had greater concentrations of thrombin-antithrombin complex (d = 0.63; P < .05) and natural logarithm thrombomodulin (d = 6.42; P < .05) than female subjects. CONCLUSION: Completing the 164-km road cycling event in hot conditions resulted in increased concentrations of platelet, platelet activation, coagulation, and fibrinolytic markers in both men and women. Although platelet activation and coagulation occurred, the fibrinolytic system markers also increased, which appears to balance blood hemostasis and may prevent clot formation during exercise in a hot environment.


Assuntos
Ciclismo , Hemostasia/fisiologia , Temperatura Alta , Resistência Física/fisiologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
12.
Eur J Appl Physiol ; 117(6): 1195-1206, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28386694

RESUMO

PURPOSE: To investigate the effect of acute alcohol consumption on muscular performance recovery, assessed by maximal torque production, and on inflammatory capacity, assessed by lipopolysaccharide (LPS)-stimulated cytokine production, following muscle-damaging resistance exercise in women. METHODS: Thirteen recreationally resistance-trained women completed two identical exercise bouts (300 maximal single-leg eccentric leg extensions) followed by alcohol (1.09 g ethanol kg-1 fat-free body mass) or placebo ingestion. Blood was collected before (PRE), and 5 (5 h-POST), 24 (24 h-POST), and 48 (48 h-POST) hours after exercise and analyzed for LPS-stimulated cytokine production (TNF-α, IL-1ß, IL-6, and IL-8 and IL-10). Maximal torque production (concentric, eccentric, isometric) was measured for each leg at PRE, 24 h-POST, and 48 h-POST. RESULTS: Although the exercise bout increased LPS-stimulated production of TNF-α (%change from PRE: 5 h-POST 109%; 24 h-POST 49%; 48 h-POST 40%) and decreased LPS-stimulated production of IL-8 (5 h-POST -40%; 24 h-POST -50%; 48 h-POST: -43%) and IL-10 (5 h-POST: -37%; 24 h-POST -32%; 48 h-POST -31%), consuming alcohol after exercise did not affect this response. Regardless of drink condition, concentric, eccentric, and isometric torque produced by the exercised leg were lower at 24 h-POST (concentric 106 ± 6 Nm, eccentric 144 ± 9 Nm, isometric 128 ± 8 Nm; M ± SE) compared to PRE (concentric 127 ± 7 Nm, eccentric 175 ± 11 Nm, isometric 148 ± 8 Nm). Eccentric torque production was partially recovered and isometric torque production was fully recovered by 48 h-POST. CONCLUSIONS: Alcohol consumed after muscle-damaging resistance exercise does not appear to affect inflammatory capacity or muscular performance recovery in resistance-trained women. Combined with previous findings in men, these results suggest a gender difference regarding effects of alcohol on exercise recovery.


Assuntos
Consumo de Bebidas Alcoólicas/efeitos adversos , Citocinas/sangue , Etanol/farmacologia , Contração Muscular/efeitos dos fármacos , Mialgia/etiologia , Treinamento de Resistência/efeitos adversos , Adulto , Etanol/administração & dosagem , Etanol/sangue , Feminino , Humanos , Masculino , Mialgia/complicações , Fatores Sexuais
13.
Curr Protoc Cytom ; 79: 7.47.1-7.47.10, 2017 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-28055115

RESUMO

Exposure to pathogen-associated molecular patterns (PAMPS), damage-associated molecular patterns (DAMPS), and physiologically challenging stimuli either positively or negatively affect leukocyte maturity. Cellular maturity has implications for the effectiveness of host response to bacterial or viral infection and/or tissue injury. Thus, the ability to accurately assess cellular maturity and health is important to fully understand immune status and function. The most common technique for measuring cellular maturity is to measure telomere length; however, existing techniques are not optimized for single-cell measurements using flow cytometry. Specifically, existing methods used to measure telomere length are PCR-based, making it difficult for a researcher to measure maturity within specific leukocyte subsets (e.g., T cells). In this report, we describe a new approach for the measurement of telomere length within individual T cells using an amplified fluorescence in situ hybridization (FISH) technique (PrimeFlow RNA Assay). The unique aspect of this technique is that it amplifies the fluorescent signal rather than the target up to 3000-fold, resulting in the detection of as few as 1 copy of the target nucleic acid. While the current technique focuses on human T cells, this method can be broadly applied to a variety of cell types and disease models. © 2017 by John Wiley & Sons, Inc.


Assuntos
Citometria de Fluxo/métodos , Hibridização in Situ Fluorescente/métodos , Coloração e Rotulagem , Linfócitos T/metabolismo , Telômero/metabolismo , Membrana Celular/metabolismo , Humanos
14.
Methods ; 112: 175-181, 2017 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-27524556

RESUMO

Muscle satellite cells can proliferate and differentiate into myocytes; this biological function has important implications for muscle development, aging, repair, and wasting diseases. Established analytical methods, including western blotting, PCR, and immunohistochemistry, has been used to characterize the stages of satellite cells growth and development but there is currently a lack of methods to simultaneously monitor cell proliferation and identify changes in cell properties (i.e., expression of myogenic regulatory factors) for each individual cell during the progression to become myocytes. Image-based flow cytometry has the capability to simultaneously obtain morphometric data, monitor cell division, and detect expression of multiple proteins of interest. In this article we demonstrate the use of image-based flow cytometry and cell-trace dye to monitor satellite cells proliferation and to identify different stages of satellite cell differentiation.


Assuntos
Citometria de Fluxo/métodos , Citometria por Imagem/métodos , Células Musculares/citologia , Células Satélites de Músculo Esquelético/citologia , Coloração e Rotulagem/métodos , Biomarcadores/metabolismo , Diferenciação Celular , Proliferação de Células , Fluoresceínas/química , Corantes Fluorescentes/química , Expressão Gênica , Humanos , Células Musculares/metabolismo , Proteína MyoD/genética , Proteína MyoD/metabolismo , Fator de Transcrição PAX7/genética , Fator de Transcrição PAX7/metabolismo , Cultura Primária de Células , Células Satélites de Músculo Esquelético/metabolismo , Succinimidas/química
15.
J Steroid Biochem Mol Biol ; 173: 286-291, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-27865973

RESUMO

There is debate concerning the association of 25-hydroxyvitamin D (25OHD) and parathyroid hormone (PTH) with cardiovascular disease (CVD) risk factors. As both hypertension and vitamin D deficiency are increasingly important public health concerns in China, we investigated these associations in 566 Macao residents. The aim was to investigate the association of serum 25OHD and PTH concentrations with CVD risk factors (hypertension, high pulse rate, abnormal blood lipids). The data were stratified by age, sex, and blood pressure (BP) medication use. Multiple linear regression analyses were performed to assess associations, adjusting for appropriate confounders. Lower 25OHD concentrations were significantly associated with higher systolic BP (SBP) mmHg (ß=-0.07), diastolic BP (DBP) mmHg (ß=-0.06) and pulse rate beats/min (ß=-0.12), lower high-density lipoprotein (HDL) concentrations nmol/L (ß=10.51) and higher triglycerides (TG) nmol/L (ß=-2.38). However, the inverse associations with lower 25OHD for higher SBP, DBP, pulse rate and TG were much stronger in those using BP medications, in those who were older, and in females. Higher PTH concentrations were significantly associated with higher low-density lipoprotein (LDL) nmol/L (ß=0.77) in the total population and with higher SBP mmHg (ß=0.08) in males and those who were older (ß=0.09). In conclusion, our major new finding is that lower 25OHD is associated with higher BP especially in those who use BP medications. These results might explain past discrepancies in findings regarding the association of BP and vitamin D and suggest that prospective studies and randomized control trials, in otherwise healthy Chinese populations taking blood pressure medications, are needed to confirm these cross-sectional results.


Assuntos
Doenças Cardiovasculares/etiologia , Hipertensão/etiologia , Deficiência de Vitamina D/complicações , Vitamina D/análogos & derivados , Adulto , Idoso , Idoso de 80 Anos ou mais , Pressão Sanguínea , Doenças Cardiovasculares/sangue , China/epidemiologia , Estudos Transversais , Feminino , Humanos , Hipertensão/sangue , Lipoproteínas HDL/sangue , Lipoproteínas LDL/sangue , Masculino , Pessoa de Meia-Idade , Hormônio Paratireóideo/sangue , Fatores de Risco , Vitamina D/sangue , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/epidemiologia , Adulto Jovem
16.
Int J Sport Nutr Exerc Metab ; 27(2): 139-147, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27710151

RESUMO

INTRODUCTION: Exertional hyponatremia (EH) during prolonged exercise involves all avenues of fluid-electrolyte gain and loss. Although previous research implicates retention of excess fluid, EH may involve either loss, gain, or no change of body mass. Thus, the etiology, predisposing factors, and recommendations for prevention are vague-except for advice to avoid excessive drinking. PURPOSE: This retrospective field study presents case reports of two unacquainted recreational cyclists (LC, 31y and AM, 39 years) who began exercise with normal serum electrolytes but finished a summer 164-km ride (ambient, 34±5°C) with a serum [Na+] of 130 mmol/L. METHODS: To clarify the etiology of EH, their pre- and post-exercise measurements were compared to a control group (CON) of 31 normonatremic cyclists (mean ± SD; 37±6 years; 141±3 mmol Na+/L). RESULTS: Anthropomorphic characteristics, exercise time, and post-exercise ratings of thermal sensation, perceived exertion and muscle cramp were similar for LC, AM and CON. These two hyponatremic cyclists consumed a large and similar volume of fluid (191 and 189 ml/kg), experienced an 11 mmol/L decrease of serum [Na+], reported low thirst sensations; however, LC gained 3.1 kg (+4.3% of body mass) during 8.9 hr of exercise and AM maintained body mass (+0.1kg, +0.1%, 10.6h). In the entire cohort (n = 33), post-event serum [Na+] was strongly correlated with total fluid intake (R2 = 0.45, p < .0001), and correlated moderately with dietary sodium intake (R2=0.28, p = .004) and body mass change (R2 = 0.22, p = .02). Linear regression analyses predicted the threshold of EH onset (<135 mmol Na+/L) as 168 ml fluid/kg. CONCLUSIONS: The wide range of serum [Na+] changes (+6 to -11 mmol/L) led us to recommend an individualized rehydration plan to athletes because the interactions of factors were complex and idiosyncratic.


Assuntos
Atletas , Comportamento Competitivo , Ingestão de Líquidos , Exercício Físico , Hiponatremia/etiologia , Resistência Física , Esforço Físico , Adulto , Desempenho Atlético , Ciclismo , Estudos de Coortes , Temperatura Alta/efeitos adversos , Humanos , Hiponatremia/sangue , Hiponatremia/prevenção & controle , Masculino , Cãibra Muscular/etiologia , Cãibra Muscular/prevenção & controle , Estudos Retrospectivos , Sódio/sangue , Sódio na Dieta/uso terapêutico , Fenômenos Fisiológicos da Nutrição Esportiva , Texas , Sede , Tempo (Meteorologia)
17.
J Strength Cond Res ; 31(3): 638-643, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27552210

RESUMO

Caldwell, AR, Tucker, MA, Butts, CL, McDermott, BP, Vingren, JL, Kunces, LJ, Lee, EC, Munoz, CX, Williamson, KH, Armstrong, LE, and Ganio, MS. Effect of caffeine on perceived soreness and functionality following an endurance cycling event. J Strength Cond Res 31(3): 638-643, 2017-Caffeine can reduce muscle pain during exercise; however, the efficacy of caffeine in improving muscle soreness and recovery from a demanding long-duration exercise bout has not been established. The purpose of this study was to investigate the effects of caffeine intake on ratings of perceived muscle soreness (RPMS) and perceived lower extremity functionality (LEF) following the completion of a 164-km endurance cycling event. Before and after cycling RPMS (1-to-6; 6 = severe soreness) and LEF (0-to-80; 80 = full functionality) were assessed by questionnaires. Subjects ingested 3 mg/kg body mass of caffeine or placebo pills in a randomized, double-blind fashion immediately after the ride and for the next 4 mornings (i.e., ∼800 hours) and 3 afternoons (i.e., ∼1200 hours). Before each ingestion, RPMS and LEF were assessed. Afternoon ratings of LEF were greater with caffeine ingestion the first day postride (65.0 ± 6.1 vs. 72.3 ± 6.7; for placebo and caffeine, respectively; p = 0.04), but at no other time points (p > 0.05). The caffeine group tended to have lower overall RPMS in the afternoon versus placebo (i.e., main effect of group; 1.1 ± 0.2 vs. 0.5 ± 0.2; p = 0.09). Afternoon RPMS for the legs was significantly lower in the caffeine group (main effect of caffeine; 1.3 ± 0.2 vs. 0.5 ± 0.3; p = 0.05). In conclusion, ingesting caffeine improved RPMS for the legs, but not LEF in the days following an endurance cycling event. Athletes may benefit from ingesting caffeine in the days following an arduous exercise bout to relieve feelings of soreness and reduced functionality.


Assuntos
Atletas , Ciclismo/fisiologia , Cafeína/uso terapêutico , Mialgia/tratamento farmacológico , Resistência Física/fisiologia , Adulto , Cafeína/administração & dosagem , Método Duplo-Cego , Teste de Esforço , Feminino , Humanos , Extremidade Inferior/fisiologia , Masculino , Pessoa de Meia-Idade , Percepção/efeitos dos fármacos
18.
J Strength Cond Res ; 31(1): 54-61, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27135475

RESUMO

Duplanty, AA, Budnar, RG, Luk, HY, Levitt, DE, Hill, DW, McFarlin, BK, Huggett, DB, and Vingren, JL. Effect of acute alcohol ingestion on resistance exercise-induced mTORC1 signaling in human muscle. J Strength Cond Res 31(1): 54-61, 2017-The purpose of this project was to further elucidate the effects postexercise alcohol ingestion. This project had many novel aspects including using a resistance exercise (RE) only exercise design and the inclusion of women. Ten resistance-trained males and 9 resistance-trained females completed 2 identical acute heavy RE trials (6 sets of Smith machine squats) followed by ingestion of either alcohol or placebo. All participants completed both conditions. Before exercise (PRE) and 3 (+3 hours) and 5 (+5 hours) hours postexercise, muscle tissue samples were obtained from the vastus lateralis by biopsies. Muscle samples were analyzed for phosphorylated mTOR, S6K1, and 4E-BP1. For men, there was a significant interaction effect for mTOR and S6K1 phosphorylation. At +3 hours, mTOR and S6K1 phosphorylation was higher for placebo than for alcohol. For women, there was a significant main effect for time. mTOR phosphorylation was higher at +3 hours than at PRE and at +5 hours. There were no significant effects found for 4E-BP1 phosphorylation in men or women. The major findings of this study was that although RE elicited similar mTORC1 signaling both in men and in women, alcohol ingestion seemed to only attenuate RE-induced phosphorylation of the mTORC1 signaling pathway in men. This study provides evidence that alcohol should not be ingested after RE as this ingestion could potentially hamper the desired muscular adaptations to RE by reducing anabolic signaling, at least in men.


Assuntos
Bebidas Alcoólicas/efeitos adversos , Atletas , Complexos Multiproteicos/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Treinamento de Resistência/métodos , Serina-Treonina Quinases TOR/efeitos dos fármacos , Proteínas Adaptadoras de Transdução de Sinal/efeitos dos fármacos , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adulto , Pesos e Medidas Corporais , Feminino , Humanos , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina , Complexos Multiproteicos/metabolismo , Músculo Esquelético/fisiologia , Fosfoproteínas/efeitos dos fármacos , Fosfoproteínas/metabolismo , Fosforilação , Proteínas Quinases S6 Ribossômicas 70-kDa/efeitos dos fármacos , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Adulto Jovem
19.
Eur J Appl Physiol ; 116(10): 2007-15, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27522585

RESUMO

PURPOSE: The purpose of this study was to examine the circulating cytokine response to a recreational 164-km road cycling event in a high ambient temperature and to determine if this response was affected by self-paced exercise time to completion. METHODS: Thirty-five men and five women were divided into tertiles based on time to complete the cycling event: slowest (SLOW), moderate (MOD), and fastest (FAST) finishers. Plasma samples were obtained 1-2 h before (PRE) and immediately after (IP) the event. A high-sensitivity multiplex assay kit was used to determine the concentration of plasma anti-inflammatory cytokines (IL-4, IL-5, IL-10, IL-13) and pro-inflammatory cytokines (IL-1ß, IL-2, IL-6, IL-7, IL-8, IL-12, GM-CSF, IFN-γ, and TNF-α). RESULTS: The concentration of plasma IL-10 increased significantly (p < 0.05) in FAST and MOD groups and had no change in the SLOW group in response to a 164-km cycling event in the hot environment. Other cytokine responses were not influenced by the Time to completion. Pro-inflammatory cytokines IL-1ß, IL-2, GM-CSF, and TNF-α decreased; whereas, IL-6 and IL-8 increased from PRE to IP. Additionally, anti-inflammatory cytokines IL-4 and IL-13 decreased. CONCLUSIONS: Completion of a 164-km cycling event induced substantial changes in circulating pro- and anti-inflammatory cytokine concentrations. Time to completion appears to have a greater influence on the systemic IL-10 response than the environmental condition; however, it is possible that a threshold for absolute intensity must be reached for environmental conditions to affect the IL-10 response to exercise. Thus, cyclists from the FAST/MOD groups appear more likely to experience an acute transient immune suppression than cyclists from the SLOW group.


Assuntos
Anti-Inflamatórios/imunologia , Ciclismo/fisiologia , Citocinas/imunologia , Resposta ao Choque Térmico/imunologia , Mediadores da Inflamação/imunologia , Resistência Física/fisiologia , Citocinas/sangue , Ecossistema , Feminino , Temperatura Alta , Humanos , Masculino , Pessoa de Meia-Idade , Esforço Físico
20.
J Strength Cond Res ; 30(8): 2286-91, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27328378

RESUMO

Donahue, RB, Vingren, JL, Duplanty, AA, Levitt, DE, Luk, H-Y, and Kraemer, WJ. Acute effect of whole-body vibration warm-up on footspeed quickness. J Strength Cond Res 30(8): 2286-2291, 2016-The warm-up routine preceding a training or athletic event can affect the performance during that event. Whole-body vibration (WBV) can increase muscle performance, and thus the inclusion of WBV to the warm-up routine might provide additional performance improvements. The purpose of this investigation was to examine the acute effect of a WBV warm-up, using a vertical oscillating platform and a more traditional warm-up protocol on feet quickness in physically active men. Twenty healthy and physically active men (18-25 years, 22 ± 3 years, 176.8 ± 6.4 cm, 84.4 ± 11.5 kg, 10.8 ± 1.4% body fat) volunteered for this study. A 2 × 2 factorial design was used to examine the effect of 4 warm-up scenarios (no warm-up, traditional warm-up only, WBV warm-up only, and combined traditional and WBV warm-up) on subsequent 3-second Quick feet count test (QFT) performance. The traditional warm-up consisted of static and dynamic exercises and stretches. The WBV warm-up consisted of 60 seconds of vertical sinusoidal vibration at a frequency of 35 Hz and amplitude of 4 mm on a vibration platform. The WBV protocol significantly (p ≤ 0.0005, η = 0.581) augmented QFT performance (WBV: 37.1 ± 3.4 touches; no-WBV: 35.7 ± 3.4 touches). The results demonstrate that WBV can enhance the performance score on the QFT. The findings of this study suggest that WBV warm-up should be included in warm-up routines preceding training and athletic events which include very fast foot movements.


Assuntos
Desempenho Atlético/fisiologia , Exercício Físico/fisiologia , Força Muscular/fisiologia , Vibração/uso terapêutico , Exercício de Aquecimento/fisiologia , Adolescente , Adulto , , Humanos , Masculino , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA