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BACKGROUND: Patellar tendinopathy is a common inflammatory condition in athletes who undergo large volumes of running and jumping. Kinesio-tape® (KT) is proposed to provide pain relief; however, its effect has not been examined on patellar tendinopathy. OBJECTIVE: To examine the effects of KT on pain modulation for active individuals with patellar tendinopathy during functional activities. METHODS: Thirteen symptomatic knees from seven college-aged females (6 bilateral; 1 unilateral) were included. Participants underwent three data collection sessions with KT, sham, and no tape (NT) in a randomized order. During the session, participants performed a maximum vertical jump, single-leg squats and isometric knee extension. The KT intervention was applied according to the KT manual and the sham utilized the same pattern without tension. Pain level was evaluated using the numeric pain scale before, during and after each activity. Function was assessed as maximum vertical jump height and maximum isometric strength. A separate repeated measures ANOVA was used to compare each dependent variable (pain level, vertical jump height, and isometric strength) among the conditions. RESULTS: Reported pain scores were significantly lower (p = 0.05) during the maximal vertical jump test for KT (3.38 ± 1.26) compared to NT (4.54 ± 2.22). Significantly lower jump heights were found under KT (17.73 ± 3.06in) during the maximum vertical jump test compared to sham (18.65 ± 2.17in, p = 0.000) and NT (18.18 ± 2.93in, p = 0.008). CONCLUSIONS: The use of the KT tape with a tendon corrective strip and muscle facilitative strip was effective for decreasing pain associated with patellar tendinopathy during jump landing but led to decreased maximum jump height. CLINICAL TRIAL IDENTIFIER: NCT04153877.
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Fita Atlética , Tendinopatia , Feminino , Humanos , Articulação do Joelho , Dor , Patela , Tendinopatia/terapia , Adulto JovemRESUMO
Kocher, MH, Oba, Y, Kimura, IF, Stickley, CD, Morgan, CF, and Hetzler, RK. Allometric grip strength norms for American children. J Strength Cond Res 33(8): 2251-2261, 2019-To develop normative data from a large cohort of American school children (ages 6-18) for unscaled and allometrically scaled handgrip strength data that are uninfluenced by body size (body mass [BM] and stature [Ht]). Data (age, handgrip strength, BM, and Ht) were collected from the 2011-2012 and 2013-2014 National Health and Nutrition Examination Survey databases, resulting in 4,665 cases (2,384 boys and 2,281 girls). Multiple log-linear regressions were used to determine allometric exponents for BM and Ht separately for each age and sex to satisfy the common exponent and group difference principles described by Vanderburgh. Appropriateness of the allometric model was assessed through regression diagnostics, including normality and homoscedasticity of residuals. Allometrically scaled, ratio-scaled, and unscaled grip strength were then correlated with BM and Ht to examine the effectiveness of the procedure in controlling for body size. The data did not allow for development of a common exponent across age and sex that did not violate the common exponent and group difference principles. Correlations between allometrically scaled handgrip strength with BM and Ht were not significant (p ≤ 0.479) and approached zero, unlike correlations of unscaled handgrip strength with BM and Ht (p < 0.001 for all), indicating that allometric scaling was successful in removing the influence of body size. Allometric scaling handgrip strength by age and sex effectively controls for body size (Ht and BM) and perhaps maturation (Ht). The allometric exponents and normative values developed can be used to compare handgrip strength within age and sex while controlling for body size.
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Força da Mão/fisiologia , Adolescente , Fatores Etários , Androstanóis , Estatura , Índice de Massa Corporal , Criança , Feminino , Humanos , Modelos Lineares , Masculino , Inquéritos Nutricionais , Padrões de Referência , Fatores Sexuais , Estados UnidosRESUMO
Various scaling methods are used when attempting to remove the influence of anthropometric differences on ground reaction forces (GRF) when comparing groups. Though commonly used, ratio scaling often results in an over-correction. Allometric scaling has previously been suggested for kinetic variables but its effectiveness in partialing out the effect of anthropometrics is unknown due to a lack of consistent application. This study examined the effectiveness of allometric scaling vertical, braking and propulsive GRF and loading rate for 84 males and 47 females while running at 4.0â¯m/s. Raw, unfiltered data were ratio scaled by body mass (BM), height (HT), and BM multiplied by HT (BM∗HT). Gender specific exponents for allometric scaling were determined by performing a log-linear (for BM and HT individually) or log-multilinear regression (BMHT). Pearson productmoment correlations were used to assess the effectiveness of each scaling method. Ratio scaling by BM, HT, or BM∗HT resulted in an over-correction of the data for most variables and left a considerable portion of the variance still attributable to anthropometrics. Allometric scaling by BM successfully removed the effect of BM and HT for all variables except for braking GRF in males and vertical GRF in females. However, allometric scaling for BMHT successfully removed the effect of BM and HT for all reactionary forces in both genders. Based on these results, allometric scaling for BMHT was the most appropriate scaling method for partialing out the effect of BM and HT on kinetic variables to allow for effective comparisons between groups or individuals.
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Antropometria , Fenômenos Mecânicos , Estatística como Assunto/métodos , Adulto , Feminino , Humanos , Cinética , Modelos Lineares , Masculino , Dinâmica não Linear , Adulto JovemRESUMO
CONTEXT: Although the risk of osteoarthritis development after acute knee injury has been widely studied, the long-term consequences of knee overuse injury are not well understood. OBJECTIVE: To identify the relationship between gait-related risk factors associated with osteoarthritis and the development of iliotibial band syndrome (ITBS) in members of a single University Army Reserve Officers' Training Corps unit. DESIGN: Prospective cohort study. SETTING: Biomechanics laboratory. PATIENTS OR OTHER PARTICIPANTS: Sixty-eight cadets undergoing standardized physical fitness training. INTERVENTION(S): Three-dimensional lower extremity kinematics (240 Hz) and kinetics (960 Hz) were collected for 3 bilateral trials during shod running at 4.0 m/s ± 10%. Injury tracking was conducted for 7 months of training. MAIN OUTCOME MEASURE(S): Biomechanical variables, including varus thrust and knee-adduction moment, were compared between the injured and control groups. RESULTS: Twenty-six cadets with no history of overuse injury served as the control group, whereas 6 cadets (7 limbs) who developed ITBS that required them to modify their training program or seek medical care (or both) served as the injured group. Maximum varus velocity was higher ( P = .006) and occurred sooner during stance ( P = .04) in the injured group than in the control group, indicating greater varus thrust. Maximum knee-varus angle and maximum knee-adduction moment were higher ( P = .02 and P = .002, respectively) and vertical stiffness was lower ( P = .03) in the injured group. CONCLUSIONS: Measures of dynamic varus stability appeared to be altered in individuals who developed ITBS. Biomechanical knee variables previously identified as increasing the risk for knee osteoarthritis were also associated with the development of ITBS in healthy adults.
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Transtornos Traumáticos Cumulativos , Marcha/fisiologia , Síndrome da Banda Iliotibial , Traumatismos do Joelho , Osteoartrite do Joelho , Corrida , Adulto , Fenômenos Biomecânicos , Transtornos Traumáticos Cumulativos/complicações , Transtornos Traumáticos Cumulativos/diagnóstico , Transtornos Traumáticos Cumulativos/fisiopatologia , Feminino , Humanos , Síndrome da Banda Iliotibial/diagnóstico , Síndrome da Banda Iliotibial/etiologia , Síndrome da Banda Iliotibial/prevenção & controle , Traumatismos do Joelho/complicações , Traumatismos do Joelho/diagnóstico , Traumatismos do Joelho/fisiopatologia , Articulação do Joelho/fisiopatologia , Masculino , Osteoartrite do Joelho/diagnóstico , Osteoartrite do Joelho/etiologia , Osteoartrite do Joelho/prevenção & controle , Estudos Prospectivos , Corrida/lesões , Corrida/fisiologia , Inquéritos e QuestionáriosRESUMO
Ankle braces and taping are commonly used to prevent ankle sprains and allow return to play following injury, however, it is unclear how passive restriction of joint motion may effect running gait kinematics and energy expenditure during exercise. The purpose of this study was to determine the effect of different types of ankle supports on lower extremity kinematics and energy expenditure during continuous running. Thirteen healthy physically active adults ran at self-selected speed on the treadmill for 30min in four different ankle support conditions: semi-rigid hinged brace, lace-up brace, tape and control. Three-dimensional lower extremity kinematics and energy expenditure were recorded every five minutes. The semi-rigid hinged brace was most effective in restricting frontal plane ankle motion. The lace-up brace and tape restricted sagittal plane ankle motion, while semi-rigid hinged bracing allowed for normal sagittal plane ankle kinematics. Kinematic changes from all three ankle supports were generally persistent through 25-30min of exercise. Only tape influenced knee kinematics, limiting flexion velocity and flexion-extension excursion. Small but significant increased in energy expenditure was found in tape and semi-rigid hinged brace conditions; however, the increases were not to any practically significant level (<0.5kcal/min).
Assuntos
Metabolismo Energético/fisiologia , Marcha/fisiologia , Extremidade Inferior/fisiologia , Aparelhos Ortopédicos , Corrida/fisiologia , Adulto , Tornozelo , Traumatismos do Tornozelo/prevenção & controle , Fenômenos Biomecânicos , Teste de Esforço , Feminino , Humanos , Masculino , Amplitude de Movimento ArticularRESUMO
In HIV-infected individuals, impaired mitochondrial function may contribute to cardiometabolic disease as well as to fatigue and frailty. Aerobic exercise improves total body energy reserves; however, its impact at the cellular level is unknown. We assessed alterations in cellular bioenergetics in peripheral blood mononuclear cells (PBMC) before and after a 12-week aerobic exercise study in sedentary HIV-infected subjects on stable antiretroviral therapy who successfully completed a 12-week aerobic exercise program. In this prospective study, participants underwent supervised 20-40 min of light aerobic exercise (walking or jogging) performed three times per week for 12 weeks, gradually increasing to maintain an intensity of 50%-80% of heart rate reserve. Maximal aerobic capacity (VO2MAX) was assessed by a graded exercise test on a cycle ergometer before and after completion of the study. PBMC from compliant subjects (attended at least 70% of exercise sessions) were assessed for mitochondrial respiration using the Seahorse XF24 Bio-Analyzer. Seven of 24 enrolled subjects were compliant with the exercise regimen. In these individuals, a significant increase (p = .04) in VO2MAX over 12 weeks was found with a median increase of 14%. During the same interval, a 2.45-fold increase in PBMC mitochondrial respiratory capacity (p = .04), a 5.65-fold increase in spare respiratory capacity (p = .01), and a 3.15-fold (p = .04) increase in nonmitochondrial respiration was observed. Aerobic exercise improves respiration at the cellular level. The diagnostic and prognostic value of such improved cellular respiration in the setting of chronic HIV warrants further investigation.
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Respiração Celular/fisiologia , Metabolismo Energético/fisiologia , Exercício Físico/fisiologia , Infecções por HIV/patologia , Consumo de Oxigênio/fisiologia , Aptidão Física/fisiologia , Infecções por HIV/virologia , Frequência Cardíaca/fisiologia , Humanos , Mitocôndrias/metabolismo , Cooperação do Paciente , Projetos Piloto , Estudos Prospectivos , Fatores de TempoRESUMO
The purpose of the study was to determine allometric exponents for scaling grip strength in children that effectively control for body mass (BM) and stature (Ht) and to develop normative grip strength data for Hawaiian children. One thousand, four hundred thirty-seven students (754 boys) from a rural community in Hawaii participated in this 5-year study, resulting in 2,567 data points. Handgrip strength, BM, and Ht were collected every year. Multiple log-linear regression was used to determine allometric exponents for BM and Ht. Appropriateness of the allometric model was assessed through regression diagnostics, including normality of residuals and homoscedasticity. Allometrically scaled, ratio-scaled, and unscaled grip strength were then correlated with BM and Ht to examine the effectiveness of the procedure in controlling for body size. Allometric exponents for BM and Ht were calculated separately for each age group of boys and girls to satisfy the common exponent and group difference principles described by Vanderburgh. Unscaled grip strength had moderate to strong positive correlations with BM and Ht (p ≤ 0.05 for all) for all age groups. Ratio-scaled handgrip strength had significant moderate to strong negative correlations with BM (p ≤ 0.05 for all) and, to a lesser extent, Ht (p ≤ 0.05 for 8- to 12-year-old boys; p ≤ 0.05 for 8- to 12- and 14-year-old girls). Correlations between allometrically scaled handgrip strength and BM and Ht were not significant and approached zero. This study was the first to allometrically scale handgrip strength for BM and Ht in Hawaiian children. Allometric scaling applied to grip strength provides a useful expression of grip strength free of the confounding influence of body size.
Assuntos
Força da Mão/fisiologia , Havaiano Nativo ou Outro Ilhéu do Pacífico , Adolescente , Fatores Etários , Estatura , Índice de Massa Corporal , Criança , Estudos Transversais , Feminino , Havaí , Humanos , Modelos Lineares , Masculino , Análise de Regressão , Fatores SexuaisRESUMO
BACKGROUND: The use of standard radiographs, and measured tibiofemoral angle (TFA), to assess lower extremity alignment is commonly practiced despite limited knowledge of its relationship to the mechanical axis (MA), as measured on hip-to-ankle (HTA) radiographs. This study assessed the predictive accuracy of previously developed equations, developed gender-specific regression equations using predictors from standard radiographs, and the clinical effectiveness of these equations in a large sample of cases using HTA radiographs as a gold standard. METHODS: The MA was measured on HTA radiographs, whereas TFA and femoral angle were measured on standard radiographs in 788 cases diagnosed with knee osteoarthritis. RESULTS: Multiple regression analyses indicated that TFA, femoral angle, and height were the strongest factors associated with the predicting MA, accounting for 83% of the variance for men and 86% for women, but were able to predict only the actual MA within ±3° in 66% of men and 69% of women. When applied to previously reported regression equations with similar results, the best predicative accuracy obtained within ±3° was 61% and 63% of men and women, respectively. CONCLUSION: Standard radiographs are not sufficient for determining MA, and HTA radiographs should be used while making surgical decisions aimed at correcting alignment to within ±3° or for assessing alignment post-total knee arthroplasty. In addition, surgical alignment outcomes reported in previous research using standard radiographs should be viewed with caution.
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Artroplastia do Joelho , Articulação do Joelho/diagnóstico por imagem , Osteoartrite do Joelho/diagnóstico por imagem , Radiografia/normas , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Articulação do Tornozelo/diagnóstico por imagem , Mau Alinhamento Ósseo/cirurgia , Feminino , Fêmur/cirurgia , Humanos , Joelho/cirurgia , Articulação do Joelho/cirurgia , Extremidade Inferior/cirurgia , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/cirurgia , Radiografia/métodos , Estudos Retrospectivos , Fatores SexuaisRESUMO
Although normal gait is often considered symmetrical in healthy populations, differences between limbs during walking suggest that limbs may be used preferentially for braking or propulsion. The purpose of this study was to evaluate kinematic and kinetic variables, at both rested state and following a two-stage treadmill fatiguing run, for asymmetry between limbs. Kinematic (240Hz) and kinetic (960Hz) running data were collected bilaterally for 20 physically active individuals at both rested and fatigued states. Symmetry angles were calculated to quantify asymmetry magnitude at rested and fatigued states. Paired t-tests were used to evaluate differences between right and left limbs at rested and fatigued states, as well as rested and fatigued states symmetry angles. Variables that have been previously associated with the development of overuse injuries, such as knee internal rotation, knee stiffness, loading rate, and adduction free moment, were found to be significantly different between limbs at both rested and fatigued states. Significant differences in vertical stiffness were found, potentially indicating functional asymmetry during running. Symmetry angle was used to investigate changes in percentage of asymmetry at rested and fatigued states. Small (1-6%), but significant decreases in vertical stiffness, loading rate, and free moment symmetry angles indicate that these variables may become more symmetrical with fatigue. Knee internal rotation and knee stiffness became more asymmetrical with fatigue, increasing by 14% and 5.3%, respectively. The findings of the current study indicate that fatigue induced changes in gait may progress knee movement pattern asymmetry.
Assuntos
Marcha , Articulação do Joelho/fisiopatologia , Extremidade Inferior/fisiopatologia , Fadiga Muscular , Corrida , Fenômenos Biomecânicos , Teste de Esforço , Feminino , Humanos , Masculino , Valores de Referência , Adulto JovemRESUMO
BACKGROUND: Cardiovascular fitness can improve autonomic function (AF) in human immunodeficiency virus (HIV)-infected individuals. METHODS: Cross-sectional study investigating relationship between AF and cardiovascular fitness in HIV+ individuals on antiretroviral therapy. Participants' (n=29) maximal oxygen consumption (VO2MAX) were assessed by graded exercise test and scaled allometrically, then divided into tertiles by fitness level (Unfit, Low-fit, and Moderately-fit). Heart rate variability (HRV) and the Autonomic Reflex Screen were used to assess AF. RESULTS: Median VO2MAX were 104.9, 130.5, and 150.2 mLâ¢kg-.67â¢min-1 for Unfit (n=10), Low-fit (n=10), and Moderately-fit (n= 9) groups respectively (p<0.05). Positive correlations were found between VO2MAX and HRV (Spearman's rho range 0.383 to 0.553) were found. Quantitative Sudomotor Axon Reflex Test (QSART) Distal Leg volumes was lower in Unfit compared to Low-fit (p=0.007) and Moderately-fit groups (p=0.018). Unfit QSART total volumes was lower than Moderately-fit (p=0.014). CONCLUSION: A positive relationship existed between AF and fitness levels. HIV+ individuals could benefit from improved fitness.
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BACKGROUND: Physical activity guidelines for youth and adults include recommendations for moderate intensity activity to attain health benefits. Indirect calorimetry studies have consistently reported a 100 step·min(-1) threshold for moderate intensity walking in adults. No indirect calorimetry studies have investigated step-rate thresholds in children and therefore the primary purpose of the study was to determine preliminary step-rate thresholds for moderate physical activity walking in children. METHODS: Oxygen consumption was measured at rest and used to determine 3 and 4 age-adjusted metabolic equivalents (A-AMETs) for 4 treadmill trials (self-selected, 2.5, 3.0, and 3.5 MPH). Two trained observers simultaneously counted children's steps during each walking trial. Step-rate thresholds associated with moderate-intensity activity, defined as 3 and 4 A-AMETs, were determined using hierarchical linear modeling. RESULTS: Regression analysis determined an overall step rate of 112 and 134 steps·min(-1) for 3 and 4 A-AMETs respectively. Body mass index (BMI) weight status and age were positively related to A-AMETs. CONCLUSIONS: We suggest age and BMI weight status specific recommendations that range from a low of 100 step·min(-1) threshold (3 A-AMETs) for overweight/obese 11- to 12-year-olds to a high of 140 step·min(-1) threshold (4 A-AMETs) for healthy weight 9- to 10-year-old children.
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Obesidade/terapia , Caminhada/fisiologia , Índice de Massa Corporal , Peso Corporal , Calorimetria Indireta , Criança , Teste de Esforço , Feminino , Humanos , Masculino , Equivalente Metabólico , Consumo de Oxigênio/fisiologia , Análise de RegressãoRESUMO
This study examined population-specific allometric exponents to control for the effect of body mass (BM) on bench press, clean, and squat strength measures among Division I-A collegiate football athletes. One repetition maximum data were obtained from a university pre-season football strength assessment (bench press, n = 207; clean, n = 88; and squat n = 86) and categorized into 3 groups by positions (line, linebacker, and skill). Regression diagnostics and correlations of scaled strength data to BM were used to assess the efficacy of the allometric scaling model and contrasted with that of ratio scaling and theoretically based allometric exponents of 0.67 and 0.33. The log-linear regression models yielded the following exponents (b): b = 0.559, 0.287, and 0.496 for bench press, clean, and squat, respectively. Correlations between bench press, clean, and squat to BM were r = -0.024, -0.047, and -0.018, respectively, suggesting that the derived allometric exponents were effective in partialling out the effect of BM on these lifts and removing between-group differences. Conversely, unscaled, ratio-scaled, and allometrically scaled (b = 0.67 or 0.33) data resulted in significant differences between groups. It is suggested that the exponents derived in the present study be used for allometrically scaling strength measures in National Collegiate Athletic Association Division I-A football athletes. Use of the normative percentile rank scores provide coaches and trainers with a valid means of judging the effectiveness of their training programs by allowing comparisons between individuals without the confounding influence of BM.
Assuntos
Futebol Americano/fisiologia , Força Muscular , Treinamento Resistido , Adolescente , Adulto , Peso Corporal , Teste de Esforço , Feminino , Humanos , Modelos Lineares , Masculino , Levantamento de Peso/fisiologia , Adulto JovemRESUMO
BACKGROUND: Non-exercise (N-EX) questionnaires have been developed to determine maximal oxygen consumption (VO2max) in healthy populations. There are limited reliable and validated N-EX questionnaires for the HIV+ population that provide estimates of habitual physical activity and not VO2max. OBJECTIVES: To determine how well regression equations developed previously on healthy populations, including N-EX prediction equations for VO2max and age-predicted maximal heart rates (APMHR), worked on an HIV+ population; and to develop a specific N-EX prediction equation for VO2max and APMHR for HIV+ individuals. METHODS: Sixty-six HIV+ participants on stable HAART completed 4 N-EX questionnaires and performed a maximal graded exercise test. RESULTS: Sixty males and 6 females were included; mean (SD) age was 49.2 (8.2) years; CD4 count was 516.0 ± 253.0 cells·mm-3; and 92% had undetectable HIV PCR. Mean VO2max was 29.2 ± 7.6 (range, 14.4-49.4) mL·kg-1·min-1 Despite positive correlations with VO2max, previously published N-EX VO2max equations produced results significantly different than actual VO2 scores (P < .0001). An HIV+ specific N-EX equation was developed and produced similar mean VO2max values, R = 0.71, when compared to achieved VO2max (P = .53). CONCLUSION: HIV+ individuals tend to be sedentary and unfit, putting them at increased risk for the development of chronic diseases associated with a sedentary lifestyle. Based on the level of error associated with utilizing APMHR and N-EX VO2max equations with HIV+ individuals, neither should be used in this population for exercise prescription.
Assuntos
Infecções por HIV/diagnóstico , HIV-1/isolamento & purificação , HIV-2/isolamento & purificação , Consumo de Oxigênio/fisiologia , Aptidão Física/psicologia , Adulto , Terapia Antirretroviral de Alta Atividade , Teste de Esforço , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Valor Preditivo dos Testes , Análise de Regressão , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Inquéritos e Questionários , Carga Viral , Adulto JovemRESUMO
This study examined the reliability and validity of the Hawaii anaerobic run test (HART) by comparing anaerobic capacity measures obtained to those during the Wingate Anaerobic Test (WAnT). Ninety-six healthy physically active volunteers (age, 22.0 ± 2.8 years; height, 163.9 ± 9.5 cm; body mass, 70.6 ± 14.7 kg; body fat %, 19.29 ± 5.39%) participated in this study. Each participant performed 2 anaerobic capacity tests: the WAnT and the HART by random assignment on separate days. The reliability of the HART was calculated from 2 separate trials of the test and then determined through intraclass correlation coefficients (ICCs). Blood samples were collected, and lactate was analyzed both pretest and posttest for each of the 2 exercise modes. Heart rate and rate of perceived exertion were also measured pre- and post-exercise. Hawaii anaerobic run test peak and mean momentum were calculated as body mass times highest or average split velocity, respectively. Intraclass correlation coefficients between trials of the HART for peak and mean momentum were 0.98 and 0.99, respectively (SEM = 18.8 and 25.7, respectively). Validity of the HART was established through comparison of momentum on the HART with power on the WAnT. High correlations were found between peak power and peak momentum (r = 0.88), as well as mean power and mean momentum (r = 0.94). The HART was considered to be a reliable test of anaerobic power. The HART was also determined to be a valid test of anaerobic power when compared with the WAnT. When testing healthy college-aged individuals, the HART offers an easy and inexpensive alternative maximal effort anaerobic power test to other established tests.
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Limiar Anaeróbio/fisiologia , Teste de Esforço , Corrida/fisiologia , Adolescente , Adulto , Estudos Cross-Over , Feminino , Havaí , Frequência Cardíaca/fisiologia , Humanos , Ácido Láctico/sangue , Masculino , Esforço Físico/fisiologia , Reprodutibilidade dos Testes , Adulto JovemRESUMO
This study examined the appropriate magnitude of allometric scaling of the Wingate anaerobic test (WAnT) power data for body mass (BM) and established normative data for the WAnT for adult men. Eighty-three men completed a standard WAnT using 0.1 kg·kg(-1) BM resistance. Allometric exponents and percentile ranks for 1-second peak power (PP), 5-second PP, and mean power (MP) were established. The Predicted Residual Sum of Squares (PRESS) procedure was used to assess external validity while avoiding data splitting. The mean 1-second PP, 5-second PP, and MP were 1,049.1 ± 168.8 W, 1,013.4 ± 158.6 W, and 777.9 ± 105.0 W, respectively. Allometric exponents for 1-second PP, 5-second PP, and MP scaled for BM were b = 0.89, 0.88, and 0.86, respectively. Correlations between allometrically scaled 1-second PP, 5-second PP, and MP, and BM were r = -0.03, -0.03, and -0.02, respectively, suggesting that the allometric exponents derived were effective in partialling out the effect of BM on WAnT values. The PRESS procedure values resulted in small decreases in R² (0.03, 0.04, and 0.02 for 1-second PP, 5-second PP, and MP, respectively) suggesting acceptable levels of external validity when applied to independent samples. The allometric exponents and normative values provide a useful tool for comparing WAnT scores in college-aged females without the confounding effect of BM. It is suggested that exponents of b = 0.89 (1-second PP), b = 0.88 (5-second PP), and b = 0.86 (MP) be used for allometrically scaling WAnT power values in healthy adult men and that the confidence limits for these allometric exponents be considered as 0.66-1.0 for PP and 0.69-1.0 for MP. The use of these exponents in allometric scaling of male WAnT power values provide coaches and practitioners with valid means for comparing power production between individuals without the confounding influence of BM.
Assuntos
Limiar Anaeróbio/fisiologia , Teste de Esforço/normas , Força Muscular/fisiologia , Índice de Massa Corporal , Feminino , Humanos , Masculino , Resistência Física/fisiologia , Valores de Referência , Reprodutibilidade dos Testes , Adulto JovemRESUMO
CONTEXT: The effectiveness of education in modifying hydration behaviors in adolescent athletes is unclear. OBJECTIVE: To assess the hydration status and behaviors of female athletes before and after a 1-time educational intervention and prescribed hydration intervention in a warm, humid, tropical environment. DESIGN: Cohort study. SETTING: Non-air-conditioned gymnasium in a tropical environment (indoor wet bulb globe temperature = 24.0 ± 0.2°C). Patient or Other Participants: Thirty-six female adolescent elite volleyball players (age = 14.8 ± 0.8 years, height = 168.2 ± 8.2 cm, mass = 60.8 ± 9.0 kg, body mass index = 21.7 ± 2.7, body surface area = 1.65 ± 0.14 m(2), body surface area to mass ratio = 2.71 ± 0.18 m(2)·kg(-1)·10(-2)) participated. INTERVENTION(S): Four observational periods consisting of 3 practices per observational period separated by 48 hours. The 4 periods included a control period, educational intervention, prescribed hydration intervention (PHI), and observational follow-up (OF-U). After the control period, an educational intervention consisting of a slide presentation was provided to the participants, followed by a week of observation. In the PHI, a precalculated volume of water based on individual sweat rate was consumed every 20 minutes during each 2-hour practice. During all other periods, participants consumed their fluid of choice ad libitum. The order of the treatment periods was not randomized and was the same for all participants. MAIN OUTCOME MEASURE(S): Prepractice to postpractice changes in body mass (ΔBM), percentage of body mass lost (%BML), urine specific gravity, urine color, urine osmolality, sweat rate, and volume of fluid consumed (F(vol)). RESULTS: The PHI was the only period during which participants maintained body mass (ΔBM = 0.05 ± 1.3%); F(vol) consumed was greatest during this time (F(vol) = 1.3 ± 0.4 L; F(1,3) = 34.869, P ≤ .001). TheΔBM was less for the PHI (ΔBM = 0.05 ± 0.9 kg, %BML = 0.04 ± 1.3%) than the OF-U period (ΔBM = -0.7 ± 1.1 kg, %BML = -1.2 ± 1.9%; F(1,3) = 6.220, P = .01). The F(vol) (1.3 ± 0.4 L) and percentage of fluid consumed (143.7 ± 110.8%) to restore sweat loss for the PHI period were higher than for any other period (F(1,3) = 34.869, P ≤ .001). None of the participants experienced serious dehydration in any of the conditions. CONCLUSIONS: A 1-time education session alone was not successful in changing hydration behaviors. However, prescribing individualized hydration protocols improved hydration for adolescents exercising in a warm, humid environment.
Assuntos
Atletas , Comportamento de Ingestão de Líquido , Água Potável , Educação em Saúde , Adolescente , Índice de Massa Corporal , Estudos de Coortes , Desidratação , Exercício Físico , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Esportes , SudoreseRESUMO
This study examined the validity of estimating anaerobic power in college-aged students using anthropometric data and a paper and pencil test. Peak power (PP) and mean power (MP) were determined for 157 subjects (92 men and 65 women) using a standard Wingate anaerobic test (WAnT) at a resistance of 0.075 and 0.10 kg·body mass for women and men, respectively. Subjects completed previously established paper and pencil tests for assessing aerobic capacity and rated their ability to perform tasks related to anaerobic power, such as their vertical jump height relative to peers. Descriptive statistics were generated, and multiple regression was performed using SAS v9.1 to assess the ability of paper and pencil tests to predict PP and MP from the WAnT. Mean (±SD) age, height, body mass, body mass index, PP, and MP for subjects were 22.1 ± 2.5 years, 175.6 ± 7.5 cm, 78.5 ± 11.4 kg, 25.4 ± 3.0 kg·m, 1015.2 ± 169.7 W, and 784.5 ± 122.1 W and 22.0 ± 3.0 years, 163.6 ± 7.4 cm, 61.1 ± 10.4 kg, 22.8 ± 3.4 kg·m, 593.0 ± 102.4 W, and 478.8 ± 72.8 W, respectively. Mean estimated jump height (EJHt) rating values were 5.8 ± 1.5 and 4.7 ± 1.5 (on a 1-9 Likert-type scale) for men and women, respectively. The following multiple regression models were developed:PP = -34.5 + 249.6 (gender; female = 0, male = 1) + 8.1 (BMkg) + 27.8 (EJHt) (R = 0.82, SEE = 106.6 W);MP = -37.7 + 163.7 (gender) + 6.7 (BMkg) + 22.8 (EJHt) (R = 0.87, SEE = 65.5 W).It was concluded that valid estimates for PP and MP could be obtained from anthropometric data and a single question paper and pencil test asking subjects to estimate relative jumping ability, without the need for performing the Wingate anaerobic cycle test.
Assuntos
Desempenho Atlético/fisiologia , Conceitos Matemáticos , Aptidão Física/fisiologia , Autorrelato , Adolescente , Adulto , Estatura , Índice de Massa Corporal , Peso Corporal , Teste de Esforço , Feminino , Frequência Cardíaca , Humanos , Masculino , Valor Preditivo dos Testes , Análise de Regressão , Adulto JovemRESUMO
This study investigated the accuracy of age-predicted equations to predict heart rate maximum (HRmax) in a college-age sample and establish efficacy of short-duration anaerobic capacity tests to determine the actual HRmax. A criterion HRmax (CHRmax) was obtained from 96 (52 men and 44 women, age = 22.0 ± 2.8 years, height = 163.9 ± 9.5 cm, 70.6 ± 14.7 kg, resting HR = 68.9 ± 11.2 b·min) healthy volunteers during 2 200-m sprint trials on a standard track. Maximal effort was confirmed via plasma lactate ≥7 mmol·L(-1) and rating of perceived exertion ≥17 points. The CHRmax was compared to 7 age-predicted HRmax equations: Fox et al., 3 equations from Gellish et al., Tanaka et al., and gender-specific equations from Fairbarn et al., and Hossack et al. Descriptive statistics and standard errors of estimate (SEEs) were calculated. One-way analysis of variance was used to assess differences between the criterion HRmax and the age-predicted HRmax from the 7 equations. The predicted HRmax from the Fox equation and those of Gellish(3), Tanaka, and Hossack were all significantly higher (p ≤ 0.05) than the CHRmax. The Fox equation resulted in overpredicting HRmax in 88.5% of the cases compared to the CHRmax. Compared to the CHRmax, the age-predicted HRmax equations resulted in the following percentages of the CHRmax: Fox = 104.8%, SEE = 12.7; Gellish(1) = 95.2%, SEE = 12.2; Gellish(2) = 99.6%, SEE = 8.3; Gellish(3) = 101.8%, SEE = 9.1; Tanaka = 102.0%, SEE = 9.3; Fairbarn = 100.1%, SEE = 8.5; and Hossack = 105.2%, SEE = 13.9 of CHRmax. It was concluded that the Gellish(2) and Fairbarn equations were the most accurate of the age-predicted HRmax equations in a college-age population. In practical application, 2 200-m sprint trials provide a reasonable estimate of HRmax compared to a graded exercise test.
Assuntos
Teste de Esforço/métodos , Frequência Cardíaca/fisiologia , Modelos Biológicos , Adulto , Feminino , Humanos , Ácido Láctico/sangue , Masculino , Consumo de Oxigênio/fisiologia , Esforço Físico , Corrida/fisiologia , Adulto JovemRESUMO
In this study, we developed allometric exponents for scaling Wingate anaerobic test (WAnT) power data that are effective in controlling for body mass (BM) and lean body mass (LBM) and established a normative WAnT data set for college-age women. One hundred women completed a standard WAnT Allometric exponents and percentile ranks for peak (PP) and mean power (MP) were established. Allometric exponents were applied to WAnT scores for an independent sample (n=31) to assess external validity. PP and MP were 477.0 W (SD = 80.0) and 372.6 W (SD = 61.5), respectively. Allometrice exponents for PP and MP scaled for BM were b = 0.92 and b = 0.76, respectively, and for LBM they were b = 0.93 and b = 0.91, respectively. In the independent sample, these exponents produced correlations between allometrically scaled PP and MP and BM of r = -.02 and r = .02, respectively. Correlations between allometrically scaled PP and MP and LBM were r = .004 and r = -.02, respectively. The allometric exponents were effective in partialing out the effect of BM for PP and MP and demonstrated acceptable levels of external validity when applied to an independent sample. The allometric exponents and normative values provide a useful tool for comparing WAnT scores in college-age women without the confounding effects of BM or LBM.