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1.
J Sports Med Phys Fitness ; 64(7): 694-706, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38916093

RESUMEN

BACKGROUND: There is mixed evidence on how the menstrual cycle (MC) affects sports performance, with many studies showing variations in performance during different phases of the MC, while other evidence shows that the MC's effects on performance may be trivial. Therefore, this exploratory longitudinal monitoring study was designed to investigate MC characteristics and symptoms in a resistance-trained (RT) population to look for associations between measures of well-being and perceived performance metrics across the MC. METHODS: RT females reported their workout habits, perceived performance metrics, and measures of well-being while tracking their MC with detailed methods via daily check-ins in an app. RESULTS: Most MC characteristics and symptoms in the present RT population aligned with previous research on the general population. However, the frequency of irregular cycles was higher than in previous research on the general population. The amount of individual variation and within-subject cycle-to-cycle variation in MC characteristics and MC symptoms was also high. All measures of well-being were significantly associated with specific days of the MC, demonstrating a change in well-being based on the timing of the MC. Several perceived performance metrics were significantly associated with changes across the MC, while others were not. CONCLUSIONS: Overall, with the current evidence as it stands, a highly individualized approach should be taken for any training or performance considerations surrounding the MC due to the high levels of individual variation.


Asunto(s)
Rendimiento Atlético , Ciclo Menstrual , Entrenamiento de Fuerza , Humanos , Femenino , Ciclo Menstrual/fisiología , Rendimiento Atlético/fisiología , Entrenamiento de Fuerza/métodos , Estudios Longitudinales , Adulto , Adulto Joven , Atletas/psicología
2.
J Sports Sci Med ; 22(4): 688-699, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38045746

RESUMEN

The objective of this study was to explore the effects of three weekly frequency doses of high-intensity functional training (HIFT) on an array of cardiometabolic markers in adults with metabolic syndrome (MetS). Twenty-one men and women, randomized into one (HIFT1), two (HIFT2), or three (HIFT3) days per week of HIFT, completed 3-weeks of familiarization plus a 12-week progressive training program. Pre- and post-intervention, several cardiometabolic, body composition, oxygen consumption, metabolic syndrome severity, and perceptions of fitness measurements were assessed. Additionally, an exercise enjoyment survey was administered post-intervention. A Cohen's d was used to demonstrate within-group change effect size. Although this study was not fully powered, a one-way and two-way ANOVA were used to compare the dose groups to provide provisional insights. No differences were found when frequency dose groups were compared. Many cardiometabolic, body composition, and fitness improvements were seen within each group, with clinically meaningful improvements in the metabolic syndrome severity score (MSSS) (HIFT1: -0.105, d = 0.28; HIFT2: -0.382, d = 1.20; HIFT3: -0.467, d = 1.07), waist circumference (HIFT1: -4.1cm, d = 3.33; HIFT2: -5.4cm, d = 0.89; HIFT3: -0.7cm, d = 0.20), and blood glucose (HIFT1: -9.5mg/dL, d = 0.98; HIFT2: -4.9mg/dL, d = 1.00; HIFT3: -1.7mg/dL, d = 0.23). All three groups similarly reported high exercise enjoyment and likeliness to continue after the intervention. In conclusion, HIFT performed once, twice, or thrice a week elicits improvements in MetS and is considered enjoyable. HIFT, even at a low weekly dose, therefore represents a potential strategy to reduce the global MetS burden.


Asunto(s)
Enfermedades Cardiovasculares , Entrenamiento de Intervalos de Alta Intensidad , Síndrome Metabólico , Adulto , Masculino , Humanos , Femenino , Síndrome Metabólico/prevención & control , Placer , Análisis de Varianza
3.
J Sports Sci Med ; 21(4): 545-554, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36523893

RESUMEN

High intensity functional training (HIFT) provides a potential option to meet public exercise recommendations for both cardiorespiratory and strength outcomes in a time efficient manner. To better understand the potential for HIFT as an exercise approach, energy expenditure (EE) and relative intensity need quantifying. In thirteen sedentary men and women with metabolic syndrome (MetS), we used both indirect calorimetry and blood lactate levels to calculate EE of a single session of HIFT. The HIFT session included four, 6-minute sets of consecutive functional exercises. Examples of the exercises involved were squats, deadlifts, suspension rows, suspension chest press, and planks. Intensity is described relative to individual ventilatory thresholds. The total group EE was 270.3 ± 77.3 kcal with approximately 5% attributed anaerobic energy production. VO2 ranged between 88.8 ± 12.3% and 99 ± 12% of the second ventilatory threshold (VT2), indicating a vigorous effort. After each work interval, peak blood lactate ranged between 7.9 ± 1.9 and 9.3 ± 2.9 mmol, and rate of perceived exertion between 6.9 ± 1.0 and 8.7 ± 0.8 arbitrary units from 1-10. These were achieved in approximately 46 minutes of exercise per participant. In conclusion, HIFT elicits the energy expenditure and effort requisite to result in the adaptive responses to produce the known suite of benefits of exercise for individuals with MetS.


Asunto(s)
Entrenamiento de Intervalos de Alta Intensidad , Masculino , Humanos , Femenino , Metabolismo Energético/fisiología , Calorimetría Indirecta , Ejercicio Físico/fisiología , Lactatos
4.
Exerc Sport Sci Rev ; 50(3): 128-136, 2022 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-35148533

RESUMEN

High-intensity interval training (HIIT) has become a polarizing form of exercise. In this article, we argue that adolescent HIIT programs can have population health impact if they are (i) integrated into existing opportunities, (ii) designed to develop physical literacy, (iii) delivered in an engaging manner, and (iv) guided and supported by an implementation framework that addresses relevant barriers and facilitators.


Asunto(s)
Entrenamiento de Intervalos de Alta Intensidad , Salud Poblacional , Adolescente , Ejercicio Físico , Humanos
5.
Med Sci Sports Exerc ; 51(4): 681-691, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30673687

RESUMEN

INTRODUCTION: Despite knowledge of cardiorespiratory fitness (CRF) training responders and nonresponders, it is not well understood how the exercise intensity prescription affects the incidence of response. The purpose of this study was to determine CRF training responsiveness based on cohort-specific technical error after 12 wk of standardized or individually prescribed exercise and the use of a verification protocol to confirm maximal oxygen uptake (V˙O2max). METHODS: Sedentary adult participants (9 men, 30 women; 48.2 ± 12.2 yr) completed exercise training on 3 d·wk for 12 wk, with exercise intensity prescribed based on standardized methods using heart rate reserve or an individualized approach using ventilatory thresholds. A verification protocol was used at baseline and 12 wk to confirm the identification of a true V˙O2max and subsequent relative percent changes to quantify CRF training responsiveness. A cohort-specific technical error (4.7%) was used as a threshold to identify incidence of response. RESULTS: Relative V˙O2max significantly increased (P < 0.05) from 24.3 ± 4.6 to 26.0 ± 4.2 and 29.2 ± 7.5 to 32.8 ± 8.6 mL·kg·min for the standardized and individualized groups, respectively. Absolute V˙O2max significantly increased (P < 0.05) from 2.0 ± 0.6 to 2.2 ± 0.6 and 2.4 ± 0.8 to 2.6 ± 0.9 L·min for the standardized and individualized groups, respectively. A significant difference in responsiveness was found between the individualized and standardized groups with 100% and 60% of participants categorized as responders, respectively. CONCLUSIONS: A threshold model for exercise intensity prescription had a greater effect on the incidence of CRF training response compared with a standardized approach using heart rate reserve. The use of thresholds for intensity markers accounts for individual metabolic characteristics and should be considered as a viable and practical method to prescribe exercise intensity.


Asunto(s)
Capacidad Cardiovascular/fisiología , Ejercicio Físico/fisiología , Consumo de Oxígeno/fisiología , Acondicionamiento Físico Humano/métodos , Adulto , Umbral Anaerobio/fisiología , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Persona de Mediana Edad , Ventilación Pulmonar
6.
Artículo en Inglés | MEDLINE | ID: mdl-30463388

RESUMEN

This study sought to investigate the efficacy of standardized versus individualized exercise intensity prescription on metabolic syndrome (MetS) severity following a 12-week exercise intervention. A total of 38 experimental participants (47.8 ± 12.2 yr, 170.7 ± 8.0 cm, 82.6 ± 18.7 kg, 26.9 ± 6.7 mL·k-1·min-1) were randomized to one of two exercise interventions (exercise intensity prescribed using heart rate reserve or ventilatory threshold). Following the 12-week intervention, MetS z-score was significantly improved for the standardized (-2.0 ± 3.1 to -2.8 ± 2.8 [p = 0.01]) and individualized (-3.3 ± 2.3 to -3.9 ± 2.2 [p = 0.04]) groups. When separating participants based on prevalence of MetS at baseline and MetS z-score responsiveness, there were six and three participants in the standardized and individualized groups, respectively, with three or more MetS risk factors. Of the six participants in the standardized group, 83% (5/6) of the participants were considered responders, whereas 100% (3/3) of the individualized participants were responders. Furthermore, only 17% (1/6) of the participants with MetS at baseline in the standardized group no longer had symptoms of MetS following the intervention. In the individualized group, 67% (2/3) of participants with baseline MetS were not considered to have MetS at week 12. These findings suggest that an individualized approach to the exercise intensity prescription may ameliorate the severity of MetS.


Asunto(s)
Terapia por Ejercicio/métodos , Síndrome Metabólico/epidemiología , Síndrome Metabólico/terapia , Adulto , Estudios de Factibilidad , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Factores de Riesgo , Índice de Severidad de la Enfermedad
7.
Artículo en Inglés | MEDLINE | ID: mdl-30210450

RESUMEN

We sought to determine the efficacy of 12 weeks high-intensity interval training (HIIT), compared to moderate-intensity continuous training (MICT) on glucose control, cardiometabolic risk and microvascular complication markers in men living with type 2 diabetes (T2D). Both modalities were combined with resistance training (RT). Additionally, the study aimed to determine the medium-term durability of effects. After a 12-week, thrice weekly, training intervention incorporating either MICT+RT (n = 11) or HIIT+RT (n = 12), the study concluded with a 6-month follow-up analysis. The middle-aged study participants were obese, had moderate duration T2D and were taking multiple medications including insulin, statins and beta-blockers. Participants, randomized via the method of minimization, performed MICT (progressing to 26-min at 55% maximum estimated workload [eWLmax]) or HIIT (progressing to two variations in which twelve 1-min bouts at 95% eWLmax interspersed with 1-min recovery bouts, alternated with eight 30-s bouts at 120% eWLmax interspersed with 2:15 min recovery bouts) under supervision at an exercise physiology facility. To account for fixed and random effects within the study sample, mixed-effect models were used to determine the significance of change following the intervention and follow-up phases and to evaluate group*time interactions. Beyond improvements in aerobic capacity (P < 0.001) for both groups, both training modalities elicited similar group*time interactions (P > 0.05) while experiencing benefits for glycated hemoglobin (HbA1c; P = 0.01), subcutaneous adiposity (P < 0.001), and heart rate variability (P = 0.02) during the 12-week intervention. Adiposity (P < 0.001) and aerobic capacity (P < 0.001) were significantly maintained in both groups at the 6-month follow-up. In addition, during the intervention, participants in both MICT+RT and HIIT+RT experienced favorable reductions in their medication usage. The study reported the inter-individual variability of change within both groups, the exaggerated acute physiological responses (using exercise termination indicators) that occurred during the interventions as well as the incidence of precautionary respite afforded in such a study sample. To reduce hyperglycaemia, and prevent further deterioration of cardiometabolic risk and microvascular complication markers (in both the short- and medium-term), future strategies that integrate the adoption and maintenance of physical activity as a cornerstone in the treatment of T2M for men should (cognisant of appropriate supervision) include either structured MICT+RT, or HIIT+RT. Clinical Trials Registration Number: ACTRN12617000582358 http://www.anzctr.org.au/default.aspx.

8.
Open Access J Sports Med ; 9: 47-53, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29563845

RESUMEN

BACKGROUND: Even though cardiorespiratory fitness (CRF) training elicits numerous health benefits, not all individuals have positive training responses following a structured CRF intervention. It has been suggested that the technical error (TE), a combination of biological variability and measurement error, should be used to establish specific training responsiveness criteria to gain further insight on the effectiveness of the training program. To date, most training interventions use an absolute change or a TE from previous findings, which do not take into consideration the training site and equipment used to establish training outcomes or the specific cohort being evaluated. The purpose of this investigation was to retrospectively analyze training responsiveness of two CRF training interventions using two common criteria and a site-specific TE. METHODS: Sixteen men and women completed two maximal graded exercise tests and verification bouts to identify maximal oxygen consumption (VO2max) and establish a site-specific TE. The TE was then used to retrospectively analyze training responsiveness in comparison to commonly used criteria: percent change of >0% and >+5.6% in VO2max. RESULTS: The TE was found to be 7.7% for relative VO2 max. χ2 testing showed significant differences in all training criteria for each intervention and pooled data from both interventions, except between %Δ >0 and %Δ >+7.7% in one of the investigations. Training nonresponsiveness ranged from 11.5% to 34.6%. CONCLUSION: Findings from the present study support the utility of site-specific TE criterion to quantify training responsiveness. A similar methodology of establishing a site-specific and even cohort specific TE should be considered to establish when true cardiorespiratory training adaptations occur.

9.
J Sports Med Phys Fitness ; 58(7-8): 1116-1126, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-28944646

RESUMEN

BACKGROUND: Optimizing exercise-induced physiological responses without increasing the risk of negative exaggerated responses is an important aspect of exercise prescription for people with type 2 diabetes mellitus (T2DM). However, knowledge of acute responses, including exaggerated responses, of different training modalities is limited. The aim of the study was to compare acute physiological responses of moderate-intensity continuous training (MICT) and high-intensity interval training (HIIT) in T2DM. METHODS: Baseline data were used to randomly assign male participants into supervised training groups for a 12-week intervention. During week 7, participants trialed either a fully progressed MICT (N.=11) or HIIT (N.=11) (combined with resistance training) session. The MICT included 26 minutes at 55% estimated maximum workload (eWLmax) while the HIIT included twelve 1-minute bouts at 95% eWLmax interspersed with 1-minute bouts at 40% eWLmax. RESULTS: While energy expenditure and peak systolic and diastolic blood pressure responses were similar between groups (P=0.47, P=0.71, P=0.56, respectively), peak heart rate, workload and perceived exertion were higher in the HIIT group (P=0.04, P<0.001, and P<0.001, respectively). Acute exaggerated responses were similar (P=0.39) for MICT (64%) and HIIT (36%) participants. CONCLUSIONS: While structured MICT and HIIT sessions resulted in comparable acute physiological responses, the individual variations and exaggerated responses, even after preparatory training, necessitated precautionary respite in T2DM men.


Asunto(s)
Glucemia , Diabetes Mellitus Tipo 2/sangre , Terapia por Ejercicio/métodos , Ejercicio Físico/fisiología , Entrenamiento de Intervalos de Alta Intensidad/métodos , Adulto , Presión Sanguínea/fisiología , Estudios de Cohortes , Metabolismo Energético/fisiología , Frecuencia Cardíaca/fisiología , Humanos , Masculino
10.
Can J Diabetes ; 41(5): 536-547, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28366674

RESUMEN

People with type 2 diabetes typically present with comorbidities, such as elevated blood pressure, high cholesterol, high blood glucose, obesity and decreased fitness, all contributive to increased risk for cardiovascular complications. Determination of effective exercise modalities for the management of such complications is important. One such modality is high-intensity interval training (HIIT). To conduct the review, PubMed and EBSCOHost databases were searched through June 1, 2016, for all HIIT intervention studies conducted in people living with type 2 diabetes. Thereafter, the central characteristics of HIIT were analyzed to obtain a broader understanding of the cardiometabolic benefits achievable by HIIT. Fourteen studies were included for review, but the heterogeneity of the participants with type 2 diabetes, the training equipment and HIIT parameters, accompanied by variations in supervision, dietary advice and medications, prevented direct comparisons. However HIIT, regardless of the specific parameters employed, was a suitable option in pursuing improved glycemic control, body composition, aerobic fitness, blood pressure and lipidemia measures in individuals with type 2 diabetes. HIIT is a therapy with at least equivalent benefit to moderate-intensity continuous training; hence, HIIT should be considered when prescribing exercise interventions for people living with type 2 diabetes.


Asunto(s)
Enfermedades Cardiovasculares/terapia , Diabetes Mellitus Tipo 2/complicaciones , Terapia por Ejercicio , Entrenamiento de Intervalos de Alta Intensidad/métodos , Enfermedades Cardiovasculares/etiología , Humanos
11.
J Strength Cond Res ; 31(5): 1177-1186, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-27537411

RESUMEN

Harris, NK, Dulson, DK, Logan, GRM, Warbrick, IB, Merien, FLR, and Lubans, DR. Acute responses to resistance and high-intensity interval training in early adolescents. J Strength Cond Res 31(5): 1177-1186, 2017-The purpose of this study was to compare the acute physiological responses within and between resistance training (RT) and high-intensity interval training (HIIT) matched for time and with comparable effort, in a school setting. Seventeen early adolescents (12.9 ± 0.3 years) performed both RT (2-5 repetitions perceived short of failure at the end of each set) and HIIT (90% of age-predicted maximum heart rate), equated for total work set and recovery period durations comprising of 12 "sets" of 30-second work followed by 30-second recovery (total session time 12 minutes). Variables of interest included oxygen consumption, set and session heart rate (HR), and rate of perceived exertion, and change in salivary cortisol (SC), salivary alpha amylase, and blood lactate (BL) from presession to postsession. Analyses were conducted to determine responses within and between the 2 different protocols. For both RT and HIIT, there were very large increases pretrial to posttrial for SC and BL, and only BL increased greater in HIIT (9.1 ± 2.6 mmol·L) than RT (6.8 ± 3.3 mmol·L). Mean set HR for both RT (170 ± 9.1 b·min) and HIIT (179 ± 5.6 b·min) was at least 85% of HRmax. V[Combining Dot Above]O2 over all 12 sets was greater for HIIT (33.8 ± 5.21 ml·kg·min) than RT (24.9 ± 3.23 ml·kg·min). Brief, repetitive, intermittent forays into high but not supramaximal intensity exercise using RT or HIIT seemed to be a potent physiological stimulus in adolescents.


Asunto(s)
Entrenamiento de Intervalos de Alta Intensidad , Esfuerzo Físico/fisiología , Entrenamiento de Fuerza , Adolescente , Niño , Estudios Cruzados , Femenino , Frecuencia Cardíaca , Humanos , Hidrocortisona/metabolismo , Ácido Láctico/sangre , Masculino , Consumo de Oxígeno , Distribución Aleatoria , Saliva/metabolismo , alfa-Amilasas/metabolismo
12.
Trials ; 17(1): 601, 2016 12 19.
Artículo en Inglés | MEDLINE | ID: mdl-27993169

RESUMEN

BACKGROUND: There is individual variability to cardiorespiratory fitness (CRF) training, but the underlying cause is not well understood. Traditionally, a standardized approach to exercise prescription has utilized relative percentages of maximal heart rate, heart rate reserve (HRR), maximal oxygen uptake (VO2max), or VO2 reserve to establish exercise intensity. However, this model fails to take into consideration individual metabolic responses to exercise and may attribute to the variability in training responses. It has been proposed that an individualized approach would take into consideration metabolic responses to exercises to increase responsiveness to training. METHODS: In this randomized control trial, participants will undergo a 12-week exercise intervention using individualized (ventilatory thresholds) and standardized (HRR) methods to prescribe CRF training intensity. Following the intervention, participants will be categorized as responders or non-responders based on changes in maximal aerobic abilities. Participants who are non-responders will complete a second 12-week intervention in a crossover design to determine whether they can become responders with a differing exercise prescription. There are four main research outcomes: (1) determine the cohort-specific technical error to use in the categorization of response rate; (2) determine if an individualized intensity prescription is superior to a standard approach in regards to VO2max and cardiometabolic risk factors; (3) investigate the time course changes throughout 12 weeks of CRF training between the two intervention groups; and (4) determine if non-responders can become responders if the exercise prescription is modified. DISCUSSION: The findings from this research will provide evidence on the effectiveness of individualized exercise prescription related to training responsiveness of VO2max and cardiometabolic risk factors compared to a standardized approach and further our understanding of individual exercise responses. If the individualized approach proposed is deemed effective, it may change the way exercise specialists prescribe exercise intensity to enhance training responsiveness. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02868710 . Registered on 15 August 2016.


Asunto(s)
Capacidad Cardiovascular , Enfermedades Cardiovasculares/prevención & control , Terapia por Ejercicio/métodos , Frecuencia Cardíaca , Ventilación Pulmonar , Adulto , Anciano , Enfermedades Cardiovasculares/etiología , Enfermedades Cardiovasculares/fisiopatología , Protocolos Clínicos , Estudios Cruzados , Prueba de Esfuerzo , Tolerancia al Ejercicio , Femenino , Estado de Salud , Voluntarios Sanos , Humanos , Masculino , Persona de Mediana Edad , Consumo de Oxígeno , Proyectos de Investigación , Factores de Tiempo , Resultado del Tratamiento
13.
J Sports Sci ; 34(21): 2047-53, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26890884

RESUMEN

This study investigated the effects of epoch length and cut point selection on adolescent physical activity intensity quantification using vertical axis and vector magnitude (VM) measurement with the ActiGraph GT3X+ accelerometer. Four hundred and nine adolescents (211 males; 198 females) aged 12-16 years of age wore accelerometers during waking hours. The GT3X+ acceleration counts were reintegrated into 1, 5, 15, 30 and 60 s epoch lengths for both vertical axis and VM counts. One cut point was applied to vertical axis counts and three different cut points were applied to VM counts for each epoch length. Significant differences (P < 0.01) in mean total counts per day were observed between vertical axis and VM counts, and between epoch lengths for VM only. Differences in physical activity levels were observed between vertical and VM cut points, and between epoch lengths across all activity intensities. Our findings illustrate the magnitude of differences in physical activity outcomes that occur between axis measurement, cut points and epoch length. The magnitude of difference across epoch length must be considered in the interpretation of accelerometer data and seen as a confounding variable when comparing physical activity levels between studies.


Asunto(s)
Acelerometría/métodos , Ejercicio Físico , Actigrafía , Adolescente , Niño , Factores de Confusión Epidemiológicos , Femenino , Humanos , Masculino , Monitoreo Ambulatorio , Conducta Sedentaria , Estadística como Asunto
14.
J Strength Cond Res ; 30(5): 1397-408, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26439778

RESUMEN

Strongman training (ST) has become an increasingly popular modality, but data on physiological responses are limited. This study sought to determine physiological responses to an ST session compared to a traditional strength exercise training (RST) session. Ten healthy men (23.6 ± 27.5 years, 85.8 ± 10.3 kg) volunteered in a crossover design, where all participants performed an ST session, an RST session, and a resting session within 7 days apart. The ST consisted of sled drag, farmer's walk, 1 arm dumbbell clean and press, and tire flip at loads eliciting approximately 30 seconds of near maximal effort per set. The RST consisted of squat, deadlift, bench press, and power clean, progressing to 75% of 1 repetition maximum. Sessions were equated for approximate total set duration. Blood lactate and salivary testosterone were recorded immediately before and after training sessions. Heart rate, caloric expenditure, and substrate utilization were measured throughout the resting session, both training protocols and for 80 minutes after training sessions. Analyses were conducted to determine differences in physiological responses within and between protocols. No significant changes in testosterone occurred at any time point for either session. Lactate increased significantly immediately after both sessions. Heart rate, caloric expenditure, and substrate utilization were all elevated significantly during ST and RST. Heart rate and fat expenditure were significantly elevated compared to resting in both sessions' recovery periods; calorie and carbohydrate expenditures were not. Compared to RST, ST represents an equivalent physiological stimulus on key parameters indicative of potential training-induced adaptive responses. Such adaptations could conceivably include cardiovascular conditioning.


Asunto(s)
Ejercicio Físico/fisiología , Entrenamiento de Fuerza/métodos , Adaptación Fisiológica , Adulto , Estudios Cruzados , Metabolismo Energético/fisiología , Frecuencia Cardíaca/fisiología , Humanos , Ácido Láctico/sangre , Masculino , Consumo de Oxígeno/fisiología , Testosterona/metabolismo
15.
Phys Ther Sport ; 16(4): 355-60, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26239217

RESUMEN

OBJECTIVES: To investigate differences in strength, shoulder range of motion and scapula position in a cohort of boxers in comparison with a control group of non-boxers. DESIGN: Cross-sectional study. PARTICIPANTS: 18 boxers with 3 or more years of experience (years = 5.5 ± 3.1, sessions per week = 4.3 ± 0.7, age = 27.0 ± 6.8) and 20 control participants (age = 28.3 ± 4.6). EXPERIMENTAL PROTOCOL: The participants were tested for isometric internal and external rotation strength measured with a hand held dynamometer, passive internal and external rotation measured via 2D video using a digital camera, and scapular function measured with a scoliometer and visual inspection by a trained researcher. Both arms (dominant and non-dominant) were tested to allow for comparison. Magnitude based inferences were used to find meaningful differences intra and inter group. RESULTS: Boxers had greater scapular dyskinesis (hazard ratio (HR) = 2.73 ×/÷ 3.37) and increased external rotation in the dominant arm (effect size (ES) = 0.70 ± 0.68) when compared to the non-boxer group. CONCLUSION: Boxers with 3 or more years of experience displayed symptoms that increase their risk of upper limb injury when compared to a control group.


Asunto(s)
Boxeo/fisiología , Escápula/fisiología , Articulación del Hombro/fisiología , Adulto , Estudios de Casos y Controles , Estudios Transversales , Humanos , Masculino , Fuerza Muscular/fisiología , Dinamómetro de Fuerza Muscular , Rango del Movimiento Articular/fisiología , Rotación
16.
Hum Mov Sci ; 40: 89-97, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25544341

RESUMEN

The segmental and muscular complexity of the human body can result in challenges when examining the kinetics of impacts. To better understand this complexity, combat sports literature has selected effective mass as a measure of an athlete's inertial contribution to the momentum transfer during the impact of strikes. This measure helps to clarify the analysis of striking kinetics in combat sports. This paper will review: (1) effective mass as a concept and its usage as a measure of impact intensity in combat sports, (2) the neuromuscular pattern known as "double peak muscle activation" which has been theorized to help enhance initial hand velocity upon impact and joint stiffening during impact, (3) the methods and equations used to calculate effective mass, and (4) practitioner recommendations based on the literature. We will argue in this manuscript that the act of punching presents unique challenges to the current understanding of effective mass due to additional force application during impact. This review will improve the understanding of effective mass and its roles in effective striking serving to underpin future research into performance enhancement in striking based combat sports.


Asunto(s)
Atletas , Peso Corporal , Boxeo/fisiología , Artes Marciales/fisiología , Movimiento , Electromiografía , Femenino , Mano , Humanos , Masculino
17.
J Strength Cond Res ; 28(2): 308-18, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24476742

RESUMEN

The purpose of this study was to investigate the physiological characteristics of Fédération Internationale de Football Association (FIFA) eligible international female soccer players aged 14-36 years and to determine if measures were significantly different for players selected (i.e., starters) to the starting line up for an FIFA tournament as compared with those not selected (i.e., nonstarters). Fifty-one (N = 18 Under 17; N = 18 Under 20; N = 15 Senior) international female soccer players participated in this study. The subjects underwent measurements of anthropometry (height and body mass), lower body strength (isokinetic testing), sprint kinetics and kinematics (nonmotorized treadmill), leg power (unilateral jumping), and maximal aerobic velocity (30:15 intermittent fitness test) during the final preparatory stage for an FIFA event. Outcomes of the age group data indicate that differences in physiological capacities are evident for the Under 17 players as compared with those for the Under 20 and Senior capped international players, suggesting a plateau in the acquisition of physical qualities as players mature. Starters tended to be faster (effect size [ES] = 0.55-1.0, p < 0.05) and have a higher maximal aerobic velocity (ES = 0.78-2.45, p < 0.05), along with greater eccentric leg strength (ES = 0.33-1.67, p < 0.05). Significant differences were detected between starters and nonstarters for isokinetic leg strength (ES = 0.54-1.24, p < 0.05) and maximal aerobic velocity (ES = 0.87, p < 0.05) for Under 17 players, where maximal aerobic velocity was the primary difference between starters and nonstarters (ES = 0.83-2.45, p < 0.05) for the Under 20 and Senior players. Coaches should emphasize the development of speed, maximal aerobic velocity, and leg strength in developing female soccer players.


Asunto(s)
Rendimiento Atlético/fisiología , Articulación de la Cadera/fisiología , Articulación de la Rodilla/fisiología , Carrera/fisiología , Fútbol/fisiología , Adolescente , Adulto , Factores de Edad , Fenómenos Biomecánicos , Estatura , Peso Corporal , Femenino , Humanos , Fuerza Muscular , Músculo Esquelético/fisiología , Consumo de Oxígeno , Aptitud Física/fisiología , Adulto Joven
18.
J Strength Cond Res ; 27(9): 2449-55, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23238097

RESUMEN

This study investigated the relative efficacy of postgame recovery modalities on jump height performance and subjective ratings of muscle soreness and muscle damage at 1, 18, and 42 hours after professional rugby league competition games. Twenty-one professional rugby league players performed 3 different postmatch recovery modalities: cold water immersion (CWI), contrast water therapy (CWT), and active recovery (ACT). The effects of the recovery treatments were analyzed with mixed modeling including a covariate (fatigue score) to adjust for changes in the intensity of each match on the postmatch values of the dependent variables of interest. Standardization of effects was used to make magnitude-based inferences, presented as mean with ±90% confidence limits. Cold water immersion and CWT clearly recovered jump height performance (CWI 2.3 ± 3.7%; CWT 3.5 ± 4.1%), reduced muscle soreness (CWI -0.95 ± 0.37; CWT -0.55 ± 0.37), and decreased creatine kinase (CWI -11.0 ± 15.1%; CWT 18.2 ± 20.1%) by 42 hours postgame compared with ACT. Contrast water therapy was however clearly more effective compared with CWI on the recovery of muscle soreness and creatine kinase by 42 hours postgame. Based on these findings, CWT recovery is recommended postmatch for team rugby sports.


Asunto(s)
Fútbol Americano/fisiología , Mialgia/terapia , Rendimiento Atlético/fisiología , Creatina Quinasa/sangre , Crioterapia , Humanos , Hidroterapia , Fatiga Muscular/fisiología , Adulto Joven
19.
J Strength Cond Res ; 26(2): 513-22, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22233785

RESUMEN

The sport of strongman is relatively new; hence, specific research investigating this sport is currently very limited. The purpose of this study was to determine the relationships between anthropometric dimensions and maximal isoinertial strength to strongman performance in novice strongman athletes. Twenty-three semiprofessional rugby union players with considerable resistance training and some strongman training experience (age 22.0 ± 2.4 years, weight 102.6 ± 10.8 kg, height 184.6 ± 6.5 cm) were assessed for anthropometry (height, body composition, and girth measurements), maximal isoinertial performance (bench press, squat, deadlift, and power clean), and strongman performance (tire flip, log clean, and press, truck pull, and farmer's walk). The magnitudes of the relationships were determined using Pearson correlation coefficients, and interpreted qualitatively according to Hopkins (90% confidence limits ∼±0.37). The highest relationship observed was between system force (body mass + squat 1-repetition maximum) and overall strongman performance (r = 0.87). Clear moderate to very large relationships existed between performance in all strongman events and the squat (r = 0.61-0.85), indicating the importance of maximal squat strength for strongman competitors. Flexed arm girth and calf girth were the strongest anthropometric correlates of overall strongman performance (r = 0.79 and 0.70, respectively). The results of this study suggest that body structure and common gymnasium-based exercise strength are meaningfully related to strongman performance in novice strongman athletes. Future research should investigate these relationships using more experienced strongman athletes and determine the relationships between changes in anthropometry, isoinertial strength, and strongman performance to determine the role of anthropometry and isoinertial strength in the sport of strongman.


Asunto(s)
Rendimiento Atlético/fisiología , Composición Corporal , Tamaño Corporal , Fuerza Muscular , Adulto , Estatura , Peso Corporal , Impedancia Eléctrica , Humanos , Masculino , Entrenamiento de Fuerza , Adulto Joven
20.
J Strength Cond Res ; 26(8): 2243-8, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21997448

RESUMEN

Despite widespread popularity of competitive surfing internationally, very little research has investigated the physiological profile of surf athletes and attempted to identify the relationships between physiological measures and surfing performance. This study determined the peak oxygen uptake (V(O2)peak) from an incremental ramp test and anaerobic power (watts) during a 10-second maximal-paddling burst using a surf paddle-specific modified kayak ergometer, customized with a surfboard and hand paddles. Twenty nationally ranked surf athletes volunteered to participate in the VV(O2)peak test, and 8 also participated in the anaerobic power test. The interrelationships between these components of athletic performance and surfing performance, as assessed by season rank, were determined using Pearsons correlations. We found a significant relationship between anaerobic power and season rank (r = 0.55, p = 0.05). No significant relationship between VV(O2)peak and season rank was found (r = -0.02, p = 0.97). Although correlations do not imply cause and effect, such a finding provides theoretical support for the importance of including anaerobic paddling power in assessment batteries and conditioning practice for surf athletes.


Asunto(s)
Aptitud Física/fisiología , Deportes/fisiología , Adolescente , Adulto , Atletas , Rendimiento Atlético/fisiología , Prueba de Esfuerzo/instrumentación , Prueba de Esfuerzo/métodos , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Consumo de Oxígeno , Adulto Joven
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