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Microcurrent is a non-invasive and safe electrotherapy applied through a series of sub-sensory electrical currents (less than 1 mA), which are of a similar magnitude to the currents generated endogenously by the human body. This review focuses on examining the physiological mechanisms mediating the effects of microcurrent when combined with different exercise modalities (e.g. endurance and strength) in healthy physically active individuals. The reviewed literature suggests the following candidate mechanisms could be involved in enhancing the effects of exercise when combined with microcurrent: (i) increased adenosine triphosphate resynthesis, (ii) maintenance of intercellular calcium homeostasis that in turn optimises exercise-induced structural and morphological adaptations, (iii) eliciting a hormone-like effect, which increases catecholamine secretion that in turn enhances exercise-induced lipolysis and (iv) enhanced muscle protein synthesis. In healthy individuals, despite a lack of standardisation on how microcurrent is combined with exercise (e.g. whether the microcurrent is pulsed or continuous), there is evidence concerning its effects in promoting body fat reduction, skeletal muscle remodelling and growth as well as attenuating delayed-onset muscle soreness. The greatest hindrance to understanding the combined effects of microcurrent and exercise is the variability of the implemented protocols, which adds further challenges to identifying the mechanisms, optimal patterns of current(s) and methodology of application. Future studies should standardise microcurrent protocols by accurately describing the used current [e.g. intensity (µA), frequency (Hz), application time (minutes) and treatment duration (e.g. weeks)] for specific exercise outcomes, e.g. strength and power, endurance, and gaining muscle mass or reducing body fat.
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Terapia por Estimulación Eléctrica , Músculo Esquelético , Humanos , Músculo Esquelético/metabolismo , Ejercicio Físico/fisiología , Terapia por Estimulación Eléctrica/métodos , Adaptación Fisiológica , AclimataciónRESUMEN
PURPOSE: The impact of ingesting carbohydrates alone or combined with proteins to support exercise immune adaptation in endurance athletes is scarcely investigated. The present study compares the effect of ingesting a combined protein-carbohydrate supplement vs. a carbohydrate-only supplement post-workout on immune inflammation markers following a 10 week periodized endurance training program in well-trained athletes. METHODS: Twenty-five men completed the study after being randomly assigned to one of the following intervention groups: combined protein-carbohydrate (PRO-CHO n = 12, 31 ± 9 years, [Formula: see text]O2peak 61.0 ± 5.6 ml.kg-1.min-1) or non-protein isoenergetic carbohydrate (CHO, n = 13, 33 ± 8 years, [Formula: see text]O2peak 60.6 ± 6.9 ml.kg-1.min-1). Treatment consisted of ingesting 24 g of assigned supplement, mixed with 250 ml of orange juice, once a day for 10 weeks immediately post-workout (or before breakfast on non-training days). Measurements were conducted pre- and post-intervention on total leukocytes, leukocyte subsets (i.e., neutrophils, eosinophils, basophils, monocytes, and lymphocytes), and platelets. The inflammatory status was assessed by the neutrophil-to-lymphocyte ratio (NLR), the platelet-to-lymphocyte ratio (PLR), and the systemic-immune inflammation index (SII). RESULTS: Post-intervention, significant increases were observed for CHO group only for the three inflammatory markers: NLR (p = 0.050, d = 0.58), PLR (p = 0.041, d = 0.60), and SII (p = 0.004, d = 0.81) but not for PRO-CHO (p > 0.05). CONCLUSION: Ingesting a post-workout protein-carbohydrate combined beverage promoted a more favourable immune status than carbohydrate-only ingestion by attenuating cellular inflammation over a 10 week training period in endurance male athletes. TRIAL REGISTRATION: The study was registered in ClinicalTrials.gov with the following ID: NCT02954367. The study was registered by 3 November 2016.
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Carbohidratos de la Dieta , Suplementos Dietéticos , Humanos , Masculino , Carbohidratos de la Dieta/farmacología , Estado Nutricional , Atletas , Bebidas , Biomarcadores , Resistencia FísicaRESUMEN
To investigate the ability of the OMNI-RES (0-10) scale to estimate velocity and loading changes during sets to failure in the hang power clean (HPC) exercise. Eleven recreationally resistance-trained males (28.5 ± 3.5 years) with an average one-repetition maximum (1RM) value of 1.1 ± 0.07 kg body mass-1 in HPC, were assessed on five separate days with 48 hours of rest between sessions. After determining the 1RM value, participants performed four sets to self-determined failure with the following relative loading ranges: 60% < 70%, 70 < 80%, 80 < 90% and > 90%. The peak vertical velocity (PVV), and Rating of Perceived Exertion (RPE) were measured for every repetition of each set. The RPE expressed after the first repetition (RPE-1) and when the highest value of PVV was achieved during the set (RPE-max) were similar and significantly lower than the RPE associated with a 5% (RPE-5%) and 10% (RPE-10%) drop in PVV. In addition, the RPE produced at failure was similar to RPE-5% only for the heaviest range (≥ 90%). Furthermore, RPE-1 was useful to distinguish loading zones between the four assessed ranges (60 < 70%, vs. 70 < 80%, vs. 80 < 90%, vs. ≥ 90%). The RPE seems to be useful to identify PVV changes (maximal, 5% and 10% drop) during continuous sets to self-determined failure and to distinguish 10% loading zone increments, from 60 to 100% of 1RM in the HPC exercise.
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OBJECTIVE: Beef protein extracts are growing in popularity in recent years due to their purported anabolic effects as well as to their potential benefits on hematological variables. The present randomized, controlled, double-blind, cross-over study aimed to analyze the effects of beef protein supplementation on a group of male elite triathletes (Spanish National Team). METHODS: Six elite triathletes (age, 21 ± 3 years; VO2max, 71.5 ± 3.0 ml·kg·min-1) were randomly assigned to consume daily either 25 g of a beef supplement (BEEF) or an isoenergetic carbohydrates (CHO) supplement for 8 weeks, with both conditions being separated by a 5-week washout period. Outcomes, including blood analyses and anthropometrical measurements, were assessed before and after each 8-week intervention. RESULTS: No effects of supplement condition were observed on body mass nor on skinfold thicknesses, but BEEF induced significant and large benefits over CHO in the thigh cross-sectional area (3.02%, 95%CI = 1.33 to 4.71%; p = 0.028, d = 1.22). Contrary to CHO, BEEF presented a significant increase in vastus lateralis muscle thickness (p = 0.046), but differences between conditions were not significant (p = 0.173, d = 0.87). Although a significantly more favorable testosterone-to-cortisol ratio (TCR) was observed for BEEF over CHO (37%, 95% CI = 5 to 68%; p = 0.028, d = 1.29), no significant differences were found for the hematological variables (i.e., iron, ferritin, red blood cell count, hemoglobin or hematocrit). CONCLUSION: Beef protein supplementation seems to facilitate a more favorable anabolic environment (i.e., increased TCR and muscle mass) in male elite triathletes, with no impact on hematological variables.
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Anabolizantes , Composición Corporal , Suplementos Dietéticos , Animales , Bovinos , Humanos , Masculino , Anabolizantes/administración & dosificación , Atletas , Estudios Cruzados , Método Doble Ciego , Recuento de Eritrocitos , Ferritinas/sangre , Hematócrito , Hemoglobinas/análisis , Hierro/sangre , Carne Roja , Adolescente , Adulto JovenRESUMEN
ABSTRACT: Monajati, A, Larumbe-Zabala, E, Sampson, MG, and Naclerio, F. Injury prevention programs based on flywheel vs. body weight resistance in recreational athletes. J Strength Cond Res 35(2S): S188-S196, 2021-This study compares the effect of an isoinertial flywheel technology vs. a traditional gravity-dependent exercise protocol on modifiable factors associated with the incidence of hamstring strain (HAM) and anterior cruciate ligament (ACL) injuries. Furthermore, the effect on repeated sprint ability was also considered. Eighteen recreationally trained volleyball players completed one of the following 6-week protocols: (a) flywheel (FY) included 3 exercises using a YoYo isoinertial-squat machine and 3 exercises with a Versa-Pulley isoinertial device, and (b) gravity-dependent (GT) involved 6 similar exercises with no external resistance (participants' body weight). Both programs consisted in 2 sessions·wk-1 performing 2 sets of 8 repetitions with 2 minutes of rest. Outcomes included a 10-second tuck jump assessment (TJA), landing knee valgus score, hamstring and quadriceps concentric and eccentric isokinetic 60°·s-1 peak torque, optimal peak torque localization, conventional and functional hamstring-to-quadriceps ratio, and 30-m repeated shuttle sprint ability (RSSA) test. FY improved TJA (-2, interquartile range [IQR] = -3 to -1) and valgus (-1, IQR = -1 to 0) scores, hamstring eccentric (20.37, 95% confidence interval [CI] = 9.27-31.47 N·m) and concentric (17.87, 95% CI = 0.40-35.34 N·m) peak torque, as well as the RSSA (-0.28, 95% CI = -0.45 to -0.10 seconds), whereas GT only improved hamstring eccentric peak torque (21.41, 95% CI = 9.00-33.82 N·m). A 6-week protocol using flywheel technology seems to elicit better positive adaptations to protect athletes from HAM and ACL injuries and to enhance RSSA performance compared to exercising with no external resistance other than athletes' body weight.
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Lesiones del Ligamento Cruzado Anterior , Músculos Isquiosurales , Lesiones del Ligamento Cruzado Anterior/prevención & control , Atletas , Peso Corporal , Humanos , Músculo CuádricepsRESUMEN
ABSTRACT: Karsten, DB, Fu, Y, Larumbe-Zabala, DE, Seijo, DM, and Naclerio, DF. Impact of two high-volume set configuration workouts on resistance training outcomes in recreationally trained men. J Strength Cond Res 35(2S): S136-S143, 2021-This study compared the effects of 2 weekly equalized by volume, loading zone and frequency resistance training designs using repetition to failure (RTF) or not to failure (NTF), on body composition, strength, and mechanical power. Based on individual baseline maximal strength, 18 recreationally resistance-trained men were pair-matched and consequently randomly assigned to an RTF (n = 9) or an NTF (n = 9) protocol. Subjects trained for 6 weeks using 2 different routines performed once per week (2 workouts per week). The RTF protocol comprised 4 sets of 10 repetitions per exercise with 2-minute rest and the NTF involved 8 sets of 5 repetitions per exercise with 1-minute rest. Subjects were tested pre- and post-intervention for maximal strength, upper- and lower-body power, fat-free mass, limb circumferences, and muscle thickness. Compared to baseline, both groups improved (p < 0.01) the maximal loads lifted in the bench press (RTF +9.44 ± 3.00 kg; NTF +7.22 ± 4.41 kg) and the squat (RTF +9.44 ± 4.64 kg; NTF +11.1 ± 10.33 kg) exercises, but only the NTF group increased (p < 0.05) upper-body power (+15.73 ± 12.59 W). Conversely, only the RTF group showed significant (p < 0.05) increase of the elbow flexors (+3.44 ± 5.11 mm) and vastus medialis (+3.28 ± 2.32 mm) thickness, whereas both groups enhanced anterior deltoid thickness (RTF +1.84 ± 1.68 mm, p < 0.05; NTF +2.76 ± 2.63 mm, p < 0.01). Although both training strategies improved strength, the RTF group elicited superior hypertrophic outcomes, whereas the NTF protocol resulted in more favorable improvements for upper-body power.
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Entrenamiento de Fuerza , Composición Corporal , Humanos , Masculino , Fuerza Muscular , Músculo Esquelético , Músculo Cuádriceps , DescansoRESUMEN
ABSTRACT: Chapman, M, Larumbe-Zabala, E, Triplett, NT, and Naclerio, F. Velocity change estimation by subjective measures over a wide-load spectrum in squat and bench press. J Strength Cond Res 35(2S): S51-S56, 2021-This study compared whether the perception of effort measured on a repetition-by-repetition basis during continuous sets to failure is different between squat (SQ) and bench press (BP). After determining the one repetition maximum (1RM) value in both SQ and BP, 18 subjects (28.2 ± 5 years, 50% women) performed 7 sets to failure per exercise, separated by 24-48 hours, alternating SQ and BP, using the following relative load ranges: 30 < 40%, 40 < 50%, 50 < 60%, 60% < 70%, 70 < 80%, 80 < 90%, and >90%. The mean accelerative velocity (MAV) and rating of perceived exertion (RPE) using the OMNI-RES (0-10) scale were measured for every repetition of each set. The ability of the OMNI-RES (0-10) scale to identify velocity changes during continuous sets to volitional failure and to distinguish loading zones divided into 10% slots, from 30 to 100% of 1RM was confirmed for both SQ and BP. The RPE values measured at (a) the first repetition; (b) the repetition where MAV peaks; (c) the repetition where MAV drops by ≤10% compared the maximum and (d) the last repetition, showed no differences (p > 0.05, d < 0.2) between exercises. In conclusion, the same RPE scores can be applied to both exercises, for either estimating the relative load or monitoring changes in MAV during continuous sets to failure.
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Entrenamiento de Fuerza , Levantamiento de Peso , Aceleración , Ejercicio Físico , Femenino , Humanos , Masculino , PosturaRESUMEN
The original version of this article unfortunately contained a mistake.
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Naclerio, F, Larumbe-Zabala, E, Cooper, K, and Seijo, M. Effects of a multi-ingredient beverage on recovery of contractile properties, performance, and muscle soreness after hard resistance training sessions. J Strength Cond Res 34(7): 1884-1893, 2020-Carbohydrate-protein-based supplements have been proposed for maximizing postexercise recovery. This study compared the effects of postworkout supplementation ingesting a multi-ingredient (MTN) vs. carbohydrate alone (CHO) on the recovery of muscle function and perceived of delayed onset of muscle soreness (DOMS) after hard resistance workouts. In a double-blinded, crossover design, 10 resistance trained men (26.9 ± 7.4 years) performed 2 identical 5-day intervention periods while ingesting either MTN or CHO. The subjects performed one workout per day during the first 3 days. Thereafter, they were assessed 1, 24, and 48 hours after the completion of the third workout session. Primary outcome was tensiomyography (muscle displacement [Dm], contraction time [Tc], and contraction velocity [Vc]) of the vastus medialis (VM) and biceps femoris long head (BFLH). Secondary outcomes were performance and DOMS. At 24 hours, both conditions decreased (p < 0.05) Dm (MTN -1.71 ± 1.8, CHO -1.58 ± 1.46 mm) and Vc (MTN -0.03 ± 0.03, CHO 0.03 ± 0.04 m·s) in the VM. At 48 hours, all tensiomyography variables were recovered under the MTN while remained depressed (p < 0.01) in CHO (VM, Dm 1.61 ± 1.60, Vc -0.04 ± 0.04 m·s; BFLH, Dm 1.54 ± 1.52, Vc -0.02 ± 0.02 m·s). Vertical jump performance decreased in CHO, but not in MTN. Although both conditions decreased upper-body strength and power at 1 hour, values returned to baseline in 24 hours for MTM while needed 48 hours in CHO. DOMS similarly increased at both 24 and 48 hours in both conditions. Compared with the ingestion of only carbohydrates, postworkout multi-ingredient supplementation seems to hasten recovery of muscular contractile properties and performance without attenuating DOMS after hard resistance workouts.
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Bebidas , Contracción Muscular , Mialgia/prevención & control , Recuperación de la Función , Entrenamiento de Fuerza , Adulto , Aminoácidos/administración & dosificación , Estudios Cruzados , Carbohidratos de la Dieta/administración & dosificación , Grasas de la Dieta/administración & dosificación , Proteínas en la Dieta/administración & dosificación , Suplementos Dietéticos , Método Doble Ciego , Prueba de Esfuerzo , Músculos Isquiosurales/fisiología , Humanos , Masculino , Mialgia/etiología , Miografía , Músculo Cuádriceps/fisiología , Entrenamiento de Fuerza/efectos adversos , Adulto JovenRESUMEN
The purpose of the study was to examine the concurrent and construct validity of a new perceptual scale to control the exercise intensity using elastic bands (Resistance Intensity Scale for Exercise; RISE) in the elderly. Twenty-six participants underwent two sessions consisting of 4 exercises. The participants performed three sets of 15 repetitions per exercise of either low, medium, or high intensity. The criterion variables were heart rate and applied force (mean and peak). Following the final repetition of each set, active muscle (AM) and overall body (OB) ratings of perceived exertion (RPE) were collected from RISE and the OMNI-Resistance Exercise Scale of perceived exertion with elastic bands (OMNI-RES EB). Construct validity was established by correlating the perceptual score obtained from both scales, RISE and OMNI-RES EB. Significant (p ≤ 0.05) and positive linear relationships between both scales were found (RPE-AM R2 = 0.90; RPE-OB R2 = 0.77). Significant differences in heart rate, applied force, and RISE scores were observed between the sets of the three intensities. For all 4 analyzed exercises, high-intensity sets elicited higher heart rate, applied force, and perceptual scores compared with the medium- and low-intensity sets. Furthermore, the medium-intensity sets produced higher perceptual, physiologic, and performance responses than the low-intensity sets. Intersession reliability was 0.88 for heart rate, 0.94 and 0.95 for applied force, 0.88 for the RPE-AM, and 0.80 for the RPE-OB. Conclusion: The RISE scale can be considered a valid method for assessing the perceived exertion during resistance exercises performed with elastic bands in the elderly.
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Percepción/fisiología , Esfuerzo Físico/fisiología , Entrenamiento de Fuerza/métodos , Anciano , Prueba de Esfuerzo , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Persona de Mediana Edad , Músculo Esquelético/fisiología , Reproducibilidad de los ResultadosRESUMEN
Objective: This study examines the long-term effects of ingesting hydrolyzed beef protein versus carbohydrate on indirect markers of immunity during 10 weeks of endurance training in master-aged triathletes (n = 16, age 35-60 years). Methods: Participants were randomly assigned to either a hydrolyzed beef protein (PRO, n = 8) or nonprotein isoenergetic carbohydrate (CHO, n = 8) condition, which consisted of ingesting 20 g of each supplement, mixed with water, once a day immediately post workout, or before breakfast on nontraining days. Salivary human neutrophil peptides (HNP1-3) were measured before and after performing an incremental endurance test to volitional exhaustion at both pre and post intervention. Additionally, baseline levels of platelets, neutrophils, eosinophil basophils, monocytes, and lymphocytes were determined at pre and post intervention. Results: No significant changes in baseline concentration and secretion rate of salivary HNP1-3 were observed for either treatment. The CHO group showed a nonsignificant decrease in resting HNP1-3 concentrations following the intervention (p = 0.052, effect size d = 0.53). Protein supplementation demonstrated a significant reduction in lymphocyte counts pre to post intervention (mean [SD]: 2.30 [0.57] vs. 1.93 [0.45] 103/mm3, p = 0.046, d = 0.77), along with a moderate but not statistically significant increase (d = 0.75, p = 0.051) of the neutrophil-to-lymphocyte ratio. Conclusions: In master-aged triathletes, postworkout ingestion of only protein, with no carbohydrate, may not be as effective as carbohydrate alone to attenuate negative long-term changes of some salivary and cellular immunological markers. Future studies should consider the co-ingestion of both macronutrients.
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Carbohidratos de la Dieta/farmacología , Proteínas en la Dieta/farmacología , Suplementos Dietéticos , Fenómenos Fisiológicos en la Nutrición Deportiva/inmunología , alfa-Defensinas/efectos de los fármacos , Adulto , Atletas , Biomarcadores/análisis , Humanos , Masculino , Persona de Mediana Edad , Resistencia Física/inmunología , Carne Roja , Entrenamiento de Fuerza , Saliva/químicaRESUMEN
As life expectancy in people living with HIV (PWH) has increased, the focus of management has shifted to preventing and treating chronic illnesses. Regular physical activity (PA) has been shown to reduce the impact of HIV on both physical and mental health. Our objectives were to assess the PA levels of PWH compared to HIV negative controls; investigate factors associated with PA; and determine the effect of PA levels on quality of life and mental well-being. We recruited 110 PWH and 110 HIV negative controls in this cross-sectional, single-centre study. Physical activity, quality of life and mental well-being were assessed using the rapid assessment of physical activity tool, EQ-5D-5L Questionnaire, and the Warwick-Edinburgh Mental Well-being Score. Binary logistic regression and multiple linear regression were used to identify factors associated with PA levels and mental well-being scores respectively. PWH were less likely to meet the WHO-recommended PA requirements compared to controls (50.0% vs. 64.5%; p = 0.041) and had significantly lower mental wellbeing and quality of life scores. Additionally, in PWH higher PA levels were associated with improved self-rated quality of life scores (p = 0.027). Our results suggest that targeted exercise programmes could have a beneficial effect on health status in PWH.
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Ejercicio Físico , Infecciones por VIH/psicología , Salud Mental , Calidad de Vida , Adulto , Estudios de Casos y Controles , Enfermedad Crónica , Estudios Transversales , Femenino , Infecciones por VIH/tratamiento farmacológico , Estado de Salud , Humanos , Masculino , Persona de Mediana Edad , Encuestas y CuestionariosRESUMEN
INTRODUCTION: Microcurrent has been used to promote tissue healing after injury or to hasten muscle remodeling post exercise. PURPOSE: To compare the effects of resistance training in combination with either, microcurrent or sham treatment, on-body composition and muscular architecture. Additionally, changes in performance and perceived delayed onset muscle soreness (DOMS) were determined. METHODS: Eighteen males (25.7 ± 7.6 years) completed an 8-week resistance training program involving 3 workouts per week (24 total sessions) wearing a microcurrent (MIC, n = 9) or a sham (SH, n = 9) device for 3-h post-workout or in the morning during non-training days. Measurements were conducted at pre and post intervention. RESULTS: Compared to baseline, both groups increased (p < 0.05) muscle thickness of the elbow flexors (MIC + 2.9 ± 1.4 mm; SH + 3.0 ± 2.4 mm), triceps brachialis (MIC + 4.3 ± 2.8 mm; SH + 2.7 ± 2.6 mm), vastus medialis (MIC + 1.5 ± 1.5 mm; SH + 0.9 ± 0.8 mm) and vastus lateralis (MIC + 6.8 ± 8.0 mm; SH + 3.2 ± 1.8 mm). Although both groups increased (p < 0.01) the pennation angle of vastus lateralis (MIC + 2.90° ± 0.95°; SH + 1.90° ± 1.35°, p < 0.01), the change measured in MIC was higher (p = 0.045) than that observed in SH. Furthermore, only MIC enlarged (p < 0.01) the pennation angle of brachialis (MIC + 1.93 ± 1.51). Both groups improved (p < 0.05) bench press strength and power but only MIC enhanced (p < 0.01) vertical jump height. At post intervention, only MIC decreased (p < 0.05) DOMS at 12-h, 24-h, and 48-h after performing an exercise-induced muscle soreness protocol. CONCLUSION: A 3-h daily use of microcurrent maximized muscular architectural changes and attenuated DOMS with no added significant benefits on body composition and performance.
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This study analysed the validity and reliability of a new optoelectronic device (Velowin) for the measurement of vertical displacement and velocity as well as to estimate force and mechanical power. Eleven trained males with Mean (SD) age = 27.4 (4.8) years, completed an incremental squat exercise test with 5 different loads (<30-90% of their 1-repetition maximum) while displacement and vertical velocity of the barbell were simultaneously measured using an integrated 3D system (3D motion capture system + force platform) and Velowin. Substantial to almost perfect correlation (concordance correlation coefficient = 0.75-0.96), root mean square error as coefficient of variation ±90% confidence interval ≤10% and good to excellent intraclass correlation coefficient = 0.84-0.99 were determined for all the variables. Passing and Bablock regression methods revealed no differences for average velocity. However, significant but consistent bias were determined for average or peak force and power while systematic and not proportional bias was found for displacement. In conclusion, Velowin, in holds of some potential advantages over traditionally used accelerometer or linear transducers, represents a valid and reliable alternative to monitor vertical displacement and velocity as well as to estimate average force and mechanical power during the squat exercise.
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Acelerometría/instrumentación , Movimiento , Entrenamiento de Fuerza/métodos , Acelerometría/métodos , Adulto , Humanos , Masculino , Fuerza Muscular , Validación de Programas de Computación , Estudios de Tiempo y Movimiento , Adulto JovenRESUMEN
The impact of animal protein blend supplements in endurance athletes is scarcely researched. The authors investigated the effect of ingesting an admixture providing orange juice and protein (PRO) from beef and whey versus carbohydrate alone on body composition and performance over a 10-week training period in male endurance athletes. Participants were randomly assigned to a protein (CHO + PRO, n = 15) or a nonprotein isoenergetic carbohydrate (CHO, n = 15) group. Twenty grams of supplement mixed with orange juice was ingested postworkout or before breakfast on nontraining days. Measurements were performed pre- and postintervention on body composition (by dual-energy X-ray absorptiometry), peak oxygen consumption (VËO2peak), and maximal aerobic speed. Twenty-five participants (CHO + PRO, n = 12; CHO, n = 13) completed the study. Only the CHO + PRO group significantly (p < .05) reduced whole-body fat (mean ± SD) (-1.02 ± 0.6 kg), total trunk fat (-0.81 ± 0.9 kg), and increased total lower body lean mass (+0.52 ± 0.7 kg), showing close to statistically significant increases of whole-body lean mass (+0.57 ± 0.8 kg, p = .055). Both groups reduced (p < .05) visceral fat (CHO + PRO, -0.03 ± 0.1 kg; CHO, -0.03 ± 0.5 kg) and improved the speed at maximal aerobic speed (CHO + PRO, +0.56 ± 0.5 km/hr; CHO, +0.35 ± 0.5 km/hr). Although consuming animal protein blend mixed with orange juice over 10 weeks helped to reduce fat mass and to increase lean mass, no additional performance benefits in endurance runners were observed.
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Composición Corporal , Carbohidratos de la Dieta/administración & dosificación , Proteínas en la Dieta/administración & dosificación , Fenómenos Fisiológicos en la Nutrición Deportiva , Absorciometría de Fotón , Adulto , Atletas , Suplementos Dietéticos , Método Doble Ciego , Humanos , Masculino , Consumo de Oxígeno , Resistencia Física , Carne Roja , Proteína de Suero de Leche/administración & dosificación , Adulto JovenRESUMEN
Chapman, M, Larumbe-Zabala, E, Gosss-Sampson, M, Colpus, M, Triplett, NT, and Naclerio, F. Perceptual, mechanical, and electromyographic responses to different relative loads in the parallel squat. J Strength Cond Res 33(1): 8-16, 2019-The effectiveness of the OMNI-RES (0-10) Scale and the electromyographic signal for monitoring changes in the movement velocity were examined during a set to muscular failure using different percentages of 1 repetition maximum (1RM) in the parallel squat exercise (PSQ). Twelve men (26.3 ± 5.8 years) were evaluated on 8 separate days with 48 hours of rest between sessions. After determining the 1RM value, participants underwent 7 tests until achieving muscular failure with the following percentage ranges: 30 to <40%, 40 to <50%, 50 to <60%, 60 to <70%, 70 to <80%, 80 to <90%, and >90%. An optical rotary encoder measured mean accelerative velocity (MAV), and the OMNI-RES (0-10) Scale was used to express the rating of perceived exertion (RPE) after every repetition of each set. In addition, the normalized root mean square signal of the surface electromyography (N-EMG) was calculated for the vastus medialis muscle. The RPE expressed after the first repetition and when the maximum value of MAV was achieved along the sets was lower (p < 0.001, d > 0.8) than the RPE that corresponded to a 10% drop in MAV and at failure. In addition, the initial RPE was useful to distinguish different loading zones by anchoring the OMNI-RES value to the magnitude of the relative load (<60%, 60 to <70% or ≤70% 1RM). Similar patterns were observed using the N-EMG. In conclusion, apart from differentiating between relative loads during a set to failure in the PSQ, the RPE and the N-EMG can both reflect changes associated with the initial, maximal, 10% drop in movement velocity and the muscular failure.
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Electromiografía , Fuerza Muscular , Esfuerzo Físico , Músculo Cuádriceps/fisiología , Aceleración , Adulto , Humanos , Masculino , Movimiento , Postura , Levantamiento de Peso , Adulto JovenRESUMEN
Chapman, M, Larumbe-Zabala, E, Gosss-Sampson, M, Triplett, NT, and Naclerio, F. Using perceptual and neuromuscular responses to estimate mechanical changes during continuous sets in the bench press. J Strength Cond Res 33(10): 2722-2732, 2019-This study analyzed the effectiveness of the OMNI-RES (0-10) and the electromyographic signal for monitoring changes in the movement velocity during a set to muscular failure performed with different relative loads in the bench press (BP) exercise. Ten males (30.8 ± 5.7 years) were evaluated on 8 separate days with 48 hours of rest between sessions. After determining the 1 repetition maximum value, participants performed 7 sets to failure with the following relative loads ranges: 30 < 40%, 40 < 50%, 50 < 60%, 60 < 70%, 70 < 80%, 80 < 90%, and >90%. The mean accelerative velocity (MAV), the rating of perceived exertion (RPE), and the normalized root-mean-square (N-RMS) signal from the anterior deltoids were measured for every repetition of each set. The RPE expressed after the first repetition and when the maximum value of MAV was achieved over the sets was lower (p < 0.001, d > 0.80) than the RPE associated with a 10% drop in MAV and at failure. Furthermore, the initial RPE was useful to distinguish different loading zones between the light relative loads (30 < 40% vs. 40 < 50% vs. 50 < 60%) and from these 3 zones to the higher relative load ranges (60 to >90%). Similar, but less clear, differences were observed for the N-RMS. In conclusion, apart from differentiating between relative loads, the RPE and in some cases N-RMS can both reflect changes associated with the initial, maximal, 10% drop in movement velocity, and muscular failure during a continuous set in the BP.
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Músculo Esquelético/fisiología , Esfuerzo Físico , Entrenamiento de Fuerza , Levantamiento de Peso/fisiología , Aceleración , Adulto , Electromiografía , Humanos , Masculino , Movimiento , DescansoRESUMEN
OBJECTIVE: The present study compares the effect of ingesting hydrolyzed beef protein, whey protein, and carbohydrate on performance, body composition (via plethysmography), muscular thickness, and blood indices of health, including ferritin concentrations, following a 10-week intervention program. METHODS: After being randomly assigned to one of the following groups-beef, whey, or carbohydrate-24 master-age (35-60 years old) male triathletes (n = 8 per treatment) ingested 20 g of supplement mixed with plain water once a day (immediately after training or before breakfast). All measurements were performed pre- and postinterventions. RESULTS: Only beef significantly reduced body mass (p = 0.021) along with a trend to preserve or increase thigh muscle mass (34.1 ± 6.1 vs 35.5 ± 7.4 mm). Both whey (38.4 ± 3.8 vs 36.9 ± 2.8 mm) and carbohydrate (36.0 ± 4.8 vs 34.1 ± 4.4 mm) interventions demonstrated a significantly (p < 0.05) decreased vastus medialis thickness Additionally, the beef condition produced a significant (p < 0.05) increase in ferritin concentrations (117 ± 78.3 vs 150.5 ± 82.8 ng/mL). No such changes were observed for the whey (149.1 ± 92.1 vs 138.5 ± 77.7 ng/mL) and carbohydrate (149.0 ± 41.3 vs 150.0 ± 48.1 ng/mL) groups. Furthermore, ferritin changes in the beef group were higher than the modification observed in whey (p < 0.001) and carbohydrate (p = 0.025) groups. No differences were found between whey and carbohydrate conditions (p = 0.223). No further changes were observed. CONCLUSION: Ingesting a hydrolyzed beef protein beverage after workout or before breakfast (nontraining days) can be effective in preserving thigh muscle mass and in improving iron status in male master-age triathletes.
Asunto(s)
Carbohidratos de la Dieta/administración & dosificación , Suplementos Dietéticos , Carne Roja , Fenómenos Fisiológicos en la Nutrición Deportiva , Proteína de Suero de Leche , Adulto , Animales , Composición Corporal , Bovinos , Dieta , Proteínas en la Dieta/administración & dosificación , Método Doble Ciego , Ferritinas/sangre , Humanos , Hierro/sangre , Masculino , Persona de Mediana Edad , Músculo Esquelético/fisiología , Consumo de Oxígeno , Cooperación del Paciente , Entrenamiento de FuerzaRESUMEN
PURPOSE: To examine the impact of ingesting hydrolyzed beef protein, whey protein, and carbohydrate on resistance training outcomes, body composition, muscle thickness, blood indices of health and salivary human neutrophil peptides (HNP1-3), as reference of humoral immunity followed an 8-week resistance training program in college athletes. METHODS: Twenty-seven recreationally physically active males and females (n = 9 per treatment) were randomly assigned to one of the three groups: hydrolyzed beef protein, whey protein, or non-protein isoenergetic carbohydrate. Treatment consisted of ingesting 20 g of supplement, mixed with orange juice, once a day immediately post-workout or before breakfast on non-training days. Measurements were performed pre- and post-intervention on total load (kg) lifted at the first and last workout, body composition (via plethysmography) vastus medialis thickness (mm) (via ultrasonography), and blood indices of health. Salivary HNP1-3 were determined before and after performing the first and last workout. RESULTS: Salivary concentration and secretion rates of the HNP1-3 decreased in the beef condition only from pre-first-workout (1.90 ± 0.83 µg/mL; 2.95 ± 2.83 µg/min, respectively) to pre-last-workout (0.92 ± 0.63 µg/mL, p = 0.025, d = 1.03; 0.76 ± 0.74 µg/min, p = 0.049, d = 0.95), and post-last-workout (0.95 ± 0.60 µg/mL, p = 0.032, d = 1.00; 0.59 ± 0.52 µg/min, p = 0.027, d = 1.02). No other significant differences between groups were observed. CONCLUSIONS: Supplementation with a carbohydrate-protein beverage may support resistance training outcomes in a comparable way as the ingestion of only carbohydrate. Furthermore, the ingestion of 20 g of hydrolyzed beef protein resulted in a decreased level and secretion rates of the HNP1-3 from baseline with no negative effect on blood indices of health.
Asunto(s)
Composición Corporal/efectos de los fármacos , Carbohidratos/administración & dosificación , Suplementos Dietéticos , Sistema Inmunológico/efectos de los fármacos , Fuerza Muscular/efectos de los fármacos , Fuerza Muscular/fisiología , Músculo Esquelético/efectos de los fármacos , Proteínas/administración & dosificación , Adolescente , Adulto , Atletas , Método Doble Ciego , Femenino , Humanos , Masculino , Músculo Esquelético/fisiología , Músculo Cuádriceps/metabolismo , Entrenamiento de Fuerza/métodos , Adulto JovenRESUMEN
Beef powder is a new high-quality protein source scarcely researched relative to exercise performance. The present study examined the impact of ingesting hydrolyzed beef protein, whey protein, and carbohydrate on strength performance (1RM), body composition (via plethysmography), limb circumferences and muscular thickness (via ultrasonography), following an 8-week resistance-training program. After being randomly assigned to one of the following groups: Beef, Whey, or Carbohydrate, twenty four recreationally physically active males (n = 8 per treatment) ingested 20 g of supplement, mixed with orange juice, once a day (immediately after workout or before breakfast). Post intervention changes were examined as percent change and 95% CIs. Beef (2.0%, CI, 0.2-2.38%) and Whey (1.4%, CI, 0.2-2.6%) but not Carbohydrate (0.0%, CI, -1.2-1.2%) increased fat-free mass. All groups increased vastus medialis thickness: Beef (11.1%, CI, 6.3-15.9%), Whey (12.1%, CI, 4.0, -20.2%), Carbohydrate (6.3%, CI, 1.9-10.6%). Beef (11.2%, CI, 5.9-16.5%) and Carbohydrate (4.5%, CI, 1.6-7.4%), but not Whey (1.1%, CI, -1.7-4.0%), increased biceps brachialis thickness, while only Beef increased arm (4.8%, CI, 2.3-7.3%) and thigh (11.2%, 95%CI 0.4-5.9%) circumferences. Although the three groups significantly improved 1RM Squat (Beef 21.6%, CI 5.5-37.7%; Whey 14.6%, CI, 5.9-23.3%; Carbohydrate 19.6%, CI, 2.2-37.1%), for the 1RM bench press the improvements were significant for Beef (15.8% CI 7.0-24.7%) and Whey (5.8%, CI, 1.7-9.8%) but not for carbohydrate (11.4%, CI, -0.9-23.6%). Protein-carbohydrate supplementation supports fat-free mass accretion and lower body hypertrophy. Hydrolyzed beef promotes upper body hypertrophy along with similar performance outcomes as observed when supplementing with whey isolate or maltodextrin.