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1.
J Strength Cond Res ; 26(11): 2924-8, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23090215

RESUMO

Reasons for participation in National Collegiate Athletic Association (NCAA) Division III athletics vary greatly. The purpose of this study was to investigate if differences in motivational climate existed between championship and non-championship-level NCAA Division III football teams, and differences in player status (starter vs. nonstarter). Players (N = 224) from 3 NCAA Division III football programs (1 championship level and 2 non-championship level) were recruited as participants. All players completed the Sport Motivation Scale, and the results were analyzed using a 2 × 2 multivariate analysis of variance (MANOVA) to examine differences among the motivation variables for starter vs. nonstarter and championship vs. non-championship teams. A 1-way MANOVA was used to examine differences across year in school. Dependent variables included internal motivation to experience stimulation, internal motivation for accomplishment, internal motivation for knowledge, external motivation for identification regulation, external motivation for introjection regulation, external motivation for external regulation, and amotivation. The interaction between starter status and team was not significant (Λ = 0.996, p > 0.40). Additionally, there were no significant differences in the mean vector scores for starter vs. nonstarter (Λ = 0.965, p = 0.378). For team type, however, differences did exist across dependent variables (Λ = 0.898, p = 0.002). For all variables except amotivation, the championship-level team had significantly higher scores than the non-championship-level teams. Members of NCAA Division III championship-level football teams have higher motivation to participate in their sport compared with members of non-championship teams. These results could have an impact on player morale, coaching strategies, and future success in athletic-related activities.


Assuntos
Comportamento Competitivo , Futebol Americano/psicologia , Motivação , Logro , Análise de Variância , Desempenho Atlético/psicologia , Impulso (Psicologia) , Humanos , Análise Multivariada , Prática Psicológica , Identificação Social , Inquéritos e Questionários
2.
J Sports Sci Med ; 11(4): 660-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-24150076

RESUMO

Interval and circuit weight training are popular training methods for maximizing time-efficiency, and are purported to deliver greater physiological benefits faster than traditional training methods. Adding interval training into a circuit weight-training workout may further enhance the benefits of circuit weight training by placing increased demands upon the cardiovascular system. Our purpose was to compare acute effects of three circuit weight training protocols 1) traditional circuit weight training, 2) aerobic circuit weight training, and 3) combined circuit weight-interval training on blood lactate (BLA), heart rate (HR), and ratings of perceived exertion (RPE). Eleven recreationally active women completed 7 exercise sessions. Session 1 included measurements of height, weight, estimated VO2max, and 13 repetition maximum (RM) testing of the weight exercises. Sessions 2-4 were held on non-consecutive days for familiarization with traditional circuit weight training (TRAD), aerobic circuit weight training (ACWT), and combined circuit weight-interval training (CWIT) protocols. In sessions 5-7, TRAD, ACWT, and CWIT were performed in a randomized order ≥ 72 hr apart for measures of BLA, HR, and RPE at pre-exercise and following each of three mini-circuit weight training stations. Repeated-measures ANOVAs yielded significant interactions (p < 0.05) in BLA, HR, and RPE. Combined circuit weight-interval training (CWIT) produced higher BLA (7.31 ± 0.37 vs. TRAD: 3.99 ± 0.26, ACWT: 4.54 ± 0.31 mmol.L(-1)), HR (83.51 ± 1.18 vs. TRAD: 70.42 ± 1.67, ACWT: 74.13 ± 1.43 beats.min(-1)) and RPE (8.14 ± 0.41 vs. TRAD: 5.06 ± 0.43, ACWT: 6.15 ± 0.42) at all measures. Aerobic circuit weight training (ACWT) elicited greater RPE than traditional circuit weight training (TRAD) at all measures. Including combined circuit weight-interval training (CWIT) workouts into exercise programming may enhance fitness benefits and maximize time-efficiency more so than traditional circuit training methods.

3.
Eur J Appl Physiol ; 111(8): 1649-58, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21203888

RESUMO

Estradiol (E(2)) has been documented to have anti-inflammatory effects on the immune system. Interleukin-6 (IL-6), is classified as a "myokine", and has known metabolic consequences. Thus, the purpose of this study was to determine the effects of menstrual phase and exercise on the interaction of E(2) and IL-6, and the role of IL-6 in substrate metabolism. Ten female subjects completed three separate testing sessions: baseline evaluation, and 1 h of treadmill exercise at 65% of peak [Formula: see text] during both the midfollicular (MF) and midluteal (ML) menstrual phases. Saliva was collected prior to, during, and post-exercise for determination of E(2) and IL-6. Expired gases and an additional saliva sample were collected 30 min post-exercise. No significant differences were observed in any of the measured variables across menstrual phase. Exercise resulted in an acute rise in estradiol and IL-6; however, E(2) was not related to IL-6 at baseline or in response to exercise. IL-6 remained elevated at the end of exercise and was found to be related to energy expenditure from fat, and to total energy expenditure at 60 min, and 30 min post-exercise. No relationships were found between the anti-inflammatory estrogen E(2) and the cytokine IL-6. However, relationships were found between IL-6 and indices of substrate metabolism. Based on the data from the current research, IL-6 likely plays a metabolic role in healthy individuals during exercise when released from the muscle as a result of reduced energy availability, acting as a "myokine", in comparison to inflammation-induced IL-6 release.


Assuntos
Metabolismo Energético/fisiologia , Estradiol/metabolismo , Exercício Físico/fisiologia , Interleucina-6/metabolismo , Saliva/metabolismo , Adulto , Citocinas/sangue , Estradiol/análise , Estradiol/sangue , Teste de Esforço , Feminino , Hormônios/sangue , Humanos , Interleucina-6/análise , Interleucina-6/sangue , Ciclo Menstrual/metabolismo , Ciclo Menstrual/fisiologia , Saliva/química , Fatores Sexuais , Fatores de Tempo , Adulto Jovem
4.
J Strength Cond Res ; 22(5): 1638-44, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18714220

RESUMO

The purpose of this study was to determine the effects of varying intensities of exercise in normoxic and hypoxic environments on selected immune regulation and metabolic responses. Using a within-subjects design, subjects performed maximal tests on a cycle ergometer in both normoxic (PiO2 = 20.94%) and hypoxic (PiO2 = 14.65%) environments to determine [latin capital V with dot above]O2max. On separate occasions, subjects then performed four randomly assigned, 1-hour exercise bouts on a cycle ergometer (two each in normoxic and hypoxic environments). The hypoxic environment was created by reducing the O2 concentration of inspired air using a commercially available hypoxic chamber. The intensities for the exercise bouts were predetermined as 40 and 60% of their normoxic [latin capital V with dot above]O2max for the normoxic exercise bouts and as 40 and 60% of their hypoxic [latin capital V with dot above]O2max for the hypoxic exercise bouts. Blood samples were collected preexercise, postexercise, 15 minutes postexercise, 2 hours postexercise, and 24 hours postexercise for the determination of interleukin-1 (IL-1), tumor necrosis factor-[alpha] (TNF-[alpha]), glucose, glycerol, free fatty acids, epinephrine, norepinephrine, and cortisol. There were no significant differences (p < 0.05) between condition or intensity for IL-1 or TNF-[alpha]. Significant differences (p < 0.05) between intensities were demonstrated for epinephrine, norepinephrine, and cortisol (p < 0.05). A significant difference was identified between normoxic and hypoxic environments with respect to nonesterifed fatty acids (0.45 +/- 0.37 vs. 0.58 +/- 0.31 mEq x L-1, respectively; p = 0.012). During prolonged exercise at 40 and 60% of their respective [latin capital V with dot above]O2max values, hypoxia did not seem to dramatically alter the response of the selected immune system or metabolic markers. Exercise training that uses acute hypoxic environments does not adversely affect immune regulation system status and may be beneficial for those individuals looking to increase endurance performance.


Assuntos
Meio Ambiente , Exercício Físico/fisiologia , Hipóxia/imunologia , Hipóxia/metabolismo , Consumo de Oxigênio/fisiologia , Adulto , Análise de Variância , Glicemia/análise , Ensaio de Imunoadsorção Enzimática , Epinefrina/sangue , Teste de Esforço , Ácidos Graxos não Esterificados/sangue , Glicerol/sangue , Humanos , Hidrocortisona/sangue , Interleucina-1/sangue , Masculino , Norepinefrina/sangue , Fator de Necrose Tumoral alfa/sangue
5.
Nutrition ; 21(3): 301-7, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15797670

RESUMO

OBJECTIVE: We hypothesized that creatine supplementation would interfere with normal body fluid shifts that occur during exercise in a hot environment due to its osmotic effect intracellularly. This study examined the effects of acute creatine loading (20 g/d for 5 d) on the thermoregulatory response of the body during a bout of exercise at 39 degrees C. METHODS: Subjects (15 men and 1 woman) performed a cycle test of maximum oxygen consumption to determine the proper work rate for the heat-stress test (40 min at 55% maximum oxygen consumption at 39 degrees C) and were assigned to a creatine group (n = 8) or a placebo group (n = 8) in a double-blind fashion. Each group performed the heat-stress test on two separate occasions: before supplementation and after supplementation (20 g/d of creatine with Gatorade or Solka-floc plus Gatorade). Dependent variables included rectal temperature, mean skin temperature, mean body temperature, and perceived thermal sensation. RESULTS: Repeated measure analysis of variance showed a significant (P < or = 0.05) increase in body weight in the group supplemented with Gatorade. Core temperature was significantly lower after supplementation for both groups combined (before supplementation at 37.85 degrees C and after supplementation at 37.7 degrees C), with no difference between groups. A significant three-way interaction (group x trial x time) was also found for rectal temperature, with both groups having significantly lower rectal temperature after supplementation. Mean body and mean skin temperatures showed no differences. CONCLUSIONS: Short-term creatine supplementation (20 g/d for 5 d) did not have a negative effect on thermoregulatory responses during exercise at 39 degrees C.


Assuntos
Regulação da Temperatura Corporal/efeitos dos fármacos , Creatina/farmacologia , Exercício Físico/fisiologia , Temperatura Alta/efeitos adversos , Adulto , Análise de Variância , Temperatura Corporal/efeitos dos fármacos , Regulação da Temperatura Corporal/fisiologia , Peso Corporal/efeitos dos fármacos , Suplementos Nutricionais , Método Duplo-Cego , Teste de Esforço/métodos , Feminino , Humanos , Masculino , Concentração Osmolar , Temperatura Cutânea/efeitos dos fármacos , Fatores de Tempo
6.
Aviat Space Environ Med ; 75(7): 589-95, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15267080

RESUMO

INTRODUCTION: Due to the impact of nicotine (NIC) on the physiological processes involved in temperature regulation during cold exposure, it is conceivable that NIC may affect the body's thermoregulatory abilities during a cold stress. Thus, the purpose of this study was to examine the effects of NIC on thermoregulatory responses during acute cold exposure. METHODS: There were six men and six women between the ages of 18 and 25 yr who participated in this study. All subjects were active, apparently healthy smokers. Each subject performed two cold air trials consisting of a 30-min baseline period (BASE) and a 120-min exposure to 10 degrees C air. One cold air trial was performed following a NIC dosing using a 21-mg transdermal patch while the other trial was performed after a placebo (PL) treatment. RESULTS: During the cold air trials, there were no differences in rectal temperature (Tre) or mean skin temperature (Tsk) between the PL and NIC treatments in either sex (p > 0.05). However, in men, heat production (M) was 12% lower (p < or = 0.05) and tissue insulation was 17% higher (p < or = 0.05) during the NIC treatment compared with the PL treatment, while these responses in women were unaffected. In both men and women, finger skin vascular conductance (SVCfin), expressed as a percentage of the BASE value, was higher during the NIC treatment compared with the PL treatment during the cold air trials (p < or = 0.05). Lastly, throughout the cold air trials, there was no difference in thermal sensation between the PL and NIC treatments (p > 0.05). DISCUSSION: In conclusion, although NIC administration resulted in sex-specific alterations in M and tissue insulation during cold exposure, the response in Tre was unaffected.


Assuntos
Regulação da Temperatura Corporal/efeitos dos fármacos , Temperatura Baixa , Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Adulto , Feminino , Humanos , Masculino , Nicotina/sangue , Norepinefrina/sangue , Fatores Sexuais , Fumar/fisiopatologia
7.
Wilderness Environ Med ; 17(3): 147-57, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17078309

RESUMO

OBJECTIVE: To examine the effects of nicotine on the metabolic and hormonal responses during acute cold exposure. METHODS: Participants in this study included 6 men and 5 women between the ages of 19 and 25 years. Each subject performed 2 cold-air trials (CATs) consisting of a 30-minute baseline (BASE) period and a 120-minute exposure to 10 degree C air. One CAT was performed after a nicotine (NIC) dosing using a 21-mg transdermal patch, whereas the other CAT was performed after a placebo (PL) treatment. Blood samples for metabolic and hormonal measurements were obtained at the end of BASE and immediately after the cold exposure. RESULTS: When examining the sexes separately, there was no difference in norepinephrine between PL and NIC (P = .066). There was also no difference in epinephrine between PL and NIC in either sex (P = .634). From BASE to 120 minutes of the CAT, there was a significant decrease in cortisol (P = .036), but this response was similar between the 2 treatments (P = .077). Glucose and glycerol concentrations were not different between the PL and NIC treatments. At BASE, nonesterified fatty acid (NEFA) concentration was lower during PL compared with NIC (P = .021); however, at 120 minutes of the CAT, NEFA was greater during PL compared with NIC (P = .035). CONCLUSIONS: During 120 minutes of cold exposure, NIC resulted in alterations in the responses in NEFA, whereas the other blood measurements were not significantly different between the 2 groups.


Assuntos
Temperatura Baixa , Ácidos Graxos não Esterificados/sangue , Hormônios/sangue , Nicotina/farmacologia , Adulto , Área Sob a Curva , Glicemia/análise , Regulação da Temperatura Corporal/fisiologia , Estudos Cross-Over , Feminino , Glicerol/sangue , Humanos , Hidrocortisona/sangue , Masculino , Norepinefrina/sangue , Fatores Sexuais
8.
J Strength Cond Res ; 19(4): 816-20, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16287369

RESUMO

The purpose of this study was to identify the differences that exist between collegiate (CS) and scholastic (SS) longsnappers. Six CS (21.4 +/- 1.37 years) and 7 SS (16.7 +/- 1.11 years) longsnappers were filmed performing 10 longsnaps each. The CS and SS longsnappers had 7.0 +/- 0.89 and 2.7 +/- 0.95 years experience longsnapping, respectively. Each of the 10 longsnaps for all subjects were analyzed for takeoff velocity and accuracy. The snap that most closely approximated the individual snapper's median values for takeoff velocity and accuracy was digitized using a 20-point model. CS were both faster (0.85 +/- 0.10 seconds vs. 1.25 +/- 0.19 seconds) and more accurate in terms of mean radial error (29.36 +/- 8.4 cm vs. 47.2 +/- 8.26 cm) than their SS counterparts. These differences were related to body positioning both before and during the longsnap. CS exhibited more shoulder flexion (135 +/- 6.33 degrees ; vs. 98 +/- 9.01 degrees ) and greater elbow extension (133 +/- 8.1 degrees vs. 95 +/- 6.77 degrees ) in the set position phase, along with greater center of mass movement (0.27 +/- 0.02 m vs. 0.14 +/- 0.04 m) in the anterior-posterior direction and less hip flexion (72 +/- 1.85 degrees vs. 49 +/- 9.42 degrees ) during the preflight phase. Longsnapping experience and accuracy were significantly related (r = -0.82, p < 0.05). These results suggest that body positioning both before and during the longsnap motion significantly influence the velocity and accuracy of the longsnap.


Assuntos
Futebol Americano/fisiologia , Movimento/fisiologia , Adolescente , Adulto , Fenômenos Biomecânicos , Articulação do Cotovelo/fisiologia , Articulação do Quadril/fisiologia , Humanos , Masculino , Articulação do Ombro/fisiologia , Universidades , Gravação em Vídeo
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