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1.
Muscle Nerve ; 64(6): 683-690, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34550609

RESUMEN

INTRODUCTION/AIMS: Aerobic deconditioning, due to lower levels of physical activity, could impact independence for people with neuromuscular conditions. We report the maximal cardiopulmonary response in a cohort of people with Charcot Marie Tooth disease type 1A (CMT 1A) and inclusion body myositis (IBM). We also explored potential predictors of aerobic capacity with measures of physical impairment and functional performance. METHODS: Participants underwent maximal cardiopulmonary exercise testing (CPET) using a semi-recumbent cycle ergometer. Data were analyzed to determine the peak O2 consumption (VO2 peak), anaerobic threshold (AT), maximum heart rate (MHR), ventilatory equivalent for CO2 slope (VE /VCO2 ), and respiratory exchange ratio (RER). Impairment, functional and patient reported measures were also recorded. Predicted CPET variables were calculated based on published normative data for age, gender, and weight. RESULTS: Twenty-two people with CMT and 17 people with IBM were recruited. Both groups showed significantly lower VO2 peak, MHR, AT, and VE /VCO2 . The CMT group overall performed better than the IBM group, with significantly higher VO2 peak, MHR, and AT, but lower VE /VCO2. Linear regression analysis demonstrated that VO2 peak was related to body fat percentage and 6-min walk distance for both groups, and steps per day for the IBM group. DISCUSSION: Lower than predicted CPET variables were observed that were not explained by cardiopulmonary limitations or reduced effort, implicating peripheral factors in limiting the cycling task. Regression analysis implied prediction of VO2 peak by body fat percentage and 6-min walk distance. Six-minute walk distance could be a potential proxy measure of cardiopulmonary fitness.


Asunto(s)
Insuficiencia Cardíaca , Enfermedades Neuromusculares , Umbral Anaerobio , Ejercicio Físico , Prueba de Esfuerzo , Tolerancia al Ejercicio , Humanos , Consumo de Oxígeno
2.
Eur J Appl Physiol ; 119(8): 1711-1723, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31098832

RESUMEN

PURPOSE: To examine the effect of carbohydrate (CHO) mouth rinsing on endurance running responses and performance in dehydrated individuals. METHODS: In a double blind, randomised crossover design, 12 well-trained male runners completed 4 running time to exhaustion (TTE) trials at a speed equivalent to 70% of VO2peak in a thermoneutral condition. Throughout each run, participants mouth rinsed and expectorated every 15 min either 25 mL of 6% CHO or a placebo (PLA) solution for 10 s. The four TTEs consisted of two trials in the euhydrated (EU-CHO and EU-PLA) and two trials in the dehydrated (DY-CHO and DY-PLA) state. Prior to each TTE run, participants were dehydrated via exercise and allowed a passive rest period during which they were fed and either rehydrated equivalent to their body mass deficit (i.e., EU trials) or ingested only 50 mL of water (DY trials). RESULTS: CHO mouth rinsing significantly improved TTE performance in the DY compared to the EU trials (78.2 ± 4.3 vs. 76.9 ± 3.8 min, P = 0.02). The arousal level of the runners was significantly higher in the DY compared to the EU trials (P = 0.02). There was no significant difference among trials in heart rate, plasma glucose and lactate, and psychological measures. CONCLUSIONS: CHO mouth rinsing enhanced running performance significantly more when participants were dehydrated vs. euhydrated due to the greater sensitivity of oral receptors related to thirst and central mediated activation. These results show that level of dehydration alters the effect of brain perception with presence of CHO.


Asunto(s)
Carbohidratos/uso terapéutico , Deshidratación/tratamiento farmacológico , Tolerancia al Ejercicio , Antisépticos Bucales/uso terapéutico , Carrera , Adulto , Umbral Anaerobio , Carbohidratos/administración & dosificación , Deshidratación/prevención & control , Humanos , Masculino , Antisépticos Bucales/administración & dosificación , Estado de Hidratación del Organismo
3.
J Strength Cond Res ; 31(5): 1236-1240, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-27537409

RESUMEN

Carlson, LA, Lawrence, MA, LeCavalier, K, and Koch, AJ. Salivary lymphocyte responses following acute anaerobic exercise in a cool environment. J Strength Cond Res 31(5): 1236-1240, 2017-The purpose of this study was to examine the impact of anaerobic training on salivary lymphocytes (s-LYMPH), and further determine whether these responses differ between cool vs. thermoneutral environments. Nine lightly clothed (∼0.3 clo) volunteers (7/2 women/men: age, 21 ± 1 years; height, 168.7 ± 7.3 cm; weight, 66.4 ± 8.4 kg; body fat, 20.6 ± 7.6%) completed speed, agility, and quickness (SAQ) sessions in both warm (18.9° C; Biddeford) and cool (10.4° C; Thorsmörk) temperatures. The SAQ sessions consisted of 3 trials of 20-m sprints, 40-m sprints, t-tests, and box drills, and two 300-yd shuttle runs in both conditions. Saliva samples via passive drool were collected at baseline, immediately postexercise, and after 2 hours of recovery. The s-LYMPH increased (p < 0.001) immediately postexercise, followed by a decrease (p < 0.001) below baseline values after 2 hours of recovery in both environments. The s-LYMPH counts were lower (p < 0.001) for the cool environment than for the thermoneutral environment. The s-LYMPH counts increased postexercise, followed by a decrease after 2 hours of recovery regardless of environment. Acute anaerobic exercise induced transient changes in s-LYMPH counts similar to that observed in peripheral blood. Compared with baseline measures, changes in s-LYMPH were of a smaller magnitude after exercise in the cool environment compared with thermoneutral environment. In summary, there is no indication that exercise in the cool environment presented a greater challenge to the subjects' immunity. Rather, these data indicate exercise in a cool environment produces smaller fluctuations in salivary immune cells compared with resting levels.


Asunto(s)
Umbral Anaerobio/fisiología , Linfocitos , Carrera/fisiología , Saliva/citología , Temperatura , Prueba de Esfuerzo , Femenino , Humanos , Recuento de Linfocitos , Masculino , Adulto Joven
4.
Harefuah ; 155(6): 335-9, 388, 2016 Jun.
Artículo en Hebreo | MEDLINE | ID: mdl-27544983

RESUMEN

PURPOSE: To examine the reliability and validity of a newly developed anaerobic and repeated sprint (RST0 performance capability. METHODS: A total of 35 untrained adolescent schoolchildren (age range 16-18 years) performed four tests: The newly developed 4 x 30 m RST, the Wingate Anaerobic Test (WAnT) and 200 m and 50 m sprint runs. The reliability of the test was assessed by comparing the test and retest performances of the test. The validity of the 4x30m RST was evaluated by computing the relationships among the various indices of the four studied anaerobic tests, and by comparing the effect of a well-defined anaerobic training program on the performance of the four anaerobic tests. RESULTS: Strong and highly significant relationships were found between the mean (MP) and peak (PP) values of the 4x30 m RST (r = 0.88; p < 0.001), and between the MP of the RST and the two short sprints (50m and 200m) (r = 0.81 and 0.94, respectively; p < 0.011. Somewhat weaker, but still significant relationships were observed between the 4x30 RST and the WAnT indices (r's range = 0.56-0.64; p < 0.05). Such relationships suggest that the energetics of all four tests are closely related. Compared with baseline, the training group demonstrated similar and significant improvement in all four anaerobic tests. No such changes were detected for the control group. CONCLUSIONS: The anaerobic system plays a dominant role in the performance of the new 4x30m RST. Furthermore, the new field test is highly reliable and was found to be valid for quantifying gross anaerobic and repeated sprints performance. Therefore, it can be used in pursuing athletes in a wide range of sports, as well as in some relevant occupations.


Asunto(s)
Umbral Anaerobio/fisiología , Rendimiento Atlético/fisiología , Prueba de Esfuerzo , Atletismo/fisiología , Adolescente , Prueba de Esfuerzo/métodos , Prueba de Esfuerzo/normas , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , Medicina Deportiva/métodos
5.
J Strength Cond Res ; 28(3): 825-33, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23897021

RESUMEN

The purpose of this study was to examine the effects of 28 days of polyethylene glycosylated creatine (PEG-creatine) supplementation (1.25 and 2.50 g·d) on anaerobic performance measures (vertical and broad jumps, 40-yard dash, 20-yard shuttle run, and 3-cone drill), upper- and lower-body muscular strength and endurance (bench press and leg extension), and body composition. This study used a randomized, double-blind, placebo-controlled parallel design. Seventy-seven adult men (mean age ± SD, 22.1 ± 2.5 years; body mass, 81.7 ± 10.8 kg) volunteered to participate and were randomly assigned to a placebo (n = 23), 1.25 g·d of PEG-creatine (n = 27), or 2.50 g·d of PEG-creatine (n = 27) group. The subjects performed anaerobic performance measures, muscular strength (one-repetition maximum [1RM]), and endurance (80% 1RM) tests for bench press and leg extension, and underwater weighing for the determination of body composition at day 0 (baseline), day 14, and day 28. The results indicated that there were improvements (p < 0.0167) in vertical jump, 20-yard shuttle run, 3-cone drill, muscular endurance for bench press, and body mass for at least one of the PEG-creatine groups without changes for the placebo group. Thus, the present results demonstrated that PEG-creatine supplementation at 1.25 or 2.50 g·d had an ergogenic effect on lower-body vertical power, agility, change-of-direction ability, upper-body muscular endurance, and body mass.


Asunto(s)
Umbral Anaerobio/efectos de los fármacos , Rendimiento Atlético/fisiología , Creatina/farmacología , Suplementos Dietéticos , Fuerza Muscular/efectos de los fármacos , Resistencia Física/efectos de los fármacos , Composición Corporal/efectos de los fármacos , Creatina/administración & dosificación , Método Doble Ciego , Prueba de Esfuerzo , Humanos , Masculino , Músculo Esquelético/fisiología , Polietilenglicoles , Carrera/fisiología , Levantamiento de Peso/fisiología , Adulto Joven
6.
Eur J Sport Sci ; 23(9): 1913-1921, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35997234

RESUMEN

ABSTRACTThis study aimed to clarify the contribution of L-menthol administration to endurande exercise capacity. Thirteen male runners (age, 35.8 ± 7.8 years; peak oxygen uptake, 62.7 ± 6.8 mL kg-1 min-1) ran on treadmills at fixed intensities of their anaerobic thresholds to exhaustion. All participants underwent three trials-water ingestion (W-IG), L-menthol mouth rinsing (M-MR), and L-menthol ingestion (M-IG)- in a random order every 5 min while running. Breathing comfort (BC) was measured immediately after fluid intake. Dyspnea threshold against external inspiratory resistance was examined before and after the running test. The running time with M-IG (1683.9 ± 520.3 s) was longer than that with W-IG (1410.2 ± 465.9 s, effect size [ES] = 0.55). BC with M-IG (2.00 ± 0.74) was higher than that with W-IG (0.42 ± 0.79) at exhaustion (ES > 2.00). The dyspnea threshold after running decreased to 19.2 ± 7.6 cm H2O L-1 s-1 with W-IG, whereas that with M-MR (26.2 ± 6.5 cm H2O L-1 s-1) and M-IG (29.2 ± 2.8 cm H2O L-1 s-1) remained high (p for interaction < 0.001). M-IG facilitated BC during running, improved endurance capacity, and prevented decreases in the dyspnea threshold against external inspiratory resistance after exhaustive running.HighlightsL-menthol ingestion facilitated breathing comfort during high intensity endurance running and improved exhaustive endurance running capacity.Even after exhaustion, L-menthol solution relieved dyspnea sensitivity against external inspiratory resistance.L-menthol ingestion might help athletes improve their endurance running capacity.


Asunto(s)
Mentol , Resistencia Física , Humanos , Masculino , Adulto , Estudios Cruzados , Umbral Anaerobio , Extractos Vegetales , Disnea
7.
J Stroke Cerebrovasc Dis ; 21(8): 647-51, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21482143

RESUMEN

The aim of this study was to clarify changes in the lactate threshold (LT) in the acute period after cerebral infarction. Cerebral infarction was induced by the injection of microspheres (MS) into the right internal carotid artery. To estimate the degree of neurologic deficit caused by surgery, the behaviors of all rats were evaluated in terms of typical symptoms of stroke in rats. The rotarod test was used to evaluate equilibrium function. Rats were forced to perform stepwise treadmill exercises, and serial changes in blood lactate concentration were measured for determination of the LT. The average treadmill speed at the LT and the rotarod test performance in MS rats was significantly lower than those in sham-operated rats on postsurgery day 2. However, although neurologic deficits disappeared on postsurgery day 7 in MS rats, LT level and rotarod test performance were significantly lower than in sham-operated rats. These results suggest that the decrease in LT in the acute period after cerebral infarction might be induced by impaired equilibrium function. Other possibilities are discussed as well.


Asunto(s)
Umbral Anaerobio , Infarto Cerebral/sangre , Ácido Láctico/sangre , Esfuerzo Físico , Animales , Conducta Animal , Arteria Carótida Interna , Infarto Cerebral/etiología , Infarto Cerebral/fisiopatología , Infarto Cerebral/psicología , Modelos Animales de Enfermedad , Inyecciones Intraarteriales , Masculino , Microesferas , Actividad Motora , Poliestirenos , Ratas , Ratas Sprague-Dawley , Factores de Tiempo
8.
Scand J Med Sci Sports ; 20 Suppl 2: 1-10, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20840557

RESUMEN

Performance in intense exercise events, such as Olympic rowing, swimming, kayak, track running and track cycling events, involves energy contribution from aerobic and anaerobic sources. As aerobic energy supply dominates the total energy requirements after ∼75s of near maximal effort, and has the greatest potential for improvement with training, the majority of training for these events is generally aimed at increasing aerobic metabolic capacity. A short-term period (six to eight sessions over 2-4 weeks) of high-intensity interval training (consisting of repeated exercise bouts performed close to or well above the maximal oxygen uptake intensity, interspersed with low-intensity exercise or complete rest) can elicit increases in intense exercise performance of 2-4% in well-trained athletes. The influence of high-volume training is less discussed, but its importance should not be downplayed, as high-volume training also induces important metabolic adaptations. While the metabolic adaptations that occur with high-volume training and high-intensity training show considerable overlap, the molecular events that signal for these adaptations may be different. A polarized approach to training, whereby ∼75% of total training volume is performed at low intensities, and 10-15% is performed at very high intensities, has been suggested as an optimal training intensity distribution for elite athletes who perform intense exercise events.


Asunto(s)
Adaptación Fisiológica/fisiología , Umbral Anaerobio/fisiología , Tolerancia al Ejercicio/fisiología , Ejercicio Físico/fisiología , Contracción Isométrica/fisiología , Medicina Deportiva , Metabolismo Energético , Humanos , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiología , Consumo de Oxígeno , Transducción de Señal , Análisis y Desempeño de Tareas
9.
J Sports Med Phys Fitness ; 50(1): 19-24, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20308967

RESUMEN

AIM: The purpose of this study was to determine if there are different physiological characteristics in water polo players of three different competitive levels (national team, NT, junior national team, NJ, and amateur club, AC). METHODS: To better define the training levels of water polo players competing at different levels, we administered a shuttle swim test (SST, a specific test used by Italian coaches) and a classic speed-lactate test. The shuttle swim test is based on actions at maximum intensity followed by incomplete recoveries. To compare the athletes, we used their morphological characteristics, the speed during an incremental test associated with fixed blood lactate concentrations of 2 mmol*1-1 (Aerobic Threshold, AT) and 4 mmol*1-1 (Anaerobic Threshold, AnT), and the SST data (speed, heart rate and lactate concentration). RESULTS: The heart rate at the end of the SST was 164+/-12 beats*min-1 for NT, 166+/-10 beats*min-1 for NJ (no significant difference, P>0.05) and 179+/-9 beats*min-1 for AC (significantly different from NT and NJ, P<0.05). The AT and AnT speeds were significantly higher in NT than in AC and NJ (P<0.05). No significant differences were found in AT and AnT speeds between AC and NJ (P>0.05). The mean speed during the shuttle swim test was significantly higher in NT and NJ than in AC (P<0.05). Lactate values were similar in the NT, AC and NJ groups (P>0.05). The SST mean speed was significantly correlated with the AT (P<0.01) and AnT speeds (P<0.05) in three groups . In all groups no significant correlation was found between SST blood lactate and AT or AnT speeds (P>0.05). CONCLUSION: Some differences were found among the senior and junior professional and amateur water polo players in both SST performance and Aerobic and Anaerobic Thre-shold speeds. The shuttle swim test for water polo provides conditioning coaches and sport scientists with data on the sport-specific movement speed and the competition-specific fatigue resistance in each athlete.


Asunto(s)
Conducta Competitiva , Medicina Deportiva , Natación/fisiología , Adaptación Fisiológica , Adulto , Factores de Edad , Umbral Anaerobio/fisiología , Análisis de Varianza , Intervalos de Confianza , Ejercicio Físico/fisiología , Prueba de Esfuerzo , Frecuencia Cardíaca , Humanos , Lactatos/sangre , Masculino , Estadística como Asunto , Adulto Joven
10.
J Sports Med Phys Fitness ; 50(1): 85-92, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20308978

RESUMEN

AIM: To validate the testosterone (T) and cortisol (C) concentration measures in saliva in response to short high-intensity exercise. METHODS: Nine healthy males provided matching saliva and plasma samples before and after a 30-second Wingate cycle test. Saliva was assayed for T (Sal-T) and C (Sal-C) concentrations, and plasma for total T and total C, sex hormone-binding globulin, corticosteroid-binding globulin (CBG) and albumin concentrations. The plasma free and bioavailable hormones were calculated. RESULTS: The Sal-T and plasma T correlations were weak to moderate (r=0.57-0.61) when examined between individuals (pooled data for all participants), but these relationships improved (r = 0.71-0.73) within individuals (data for each participant on average). The Sal-C and plasma C correlations were strong both between individuals (r=0.81-0.84) and within individuals (r=0.83-0.84). The peak relative increases in Sal-T (35+/-9%) and Sal-C (63+/-29%) concentrations exceeded the plasma total and/or free hormones, but not the bioavailable hormones. Albumin (10+/-3%) and CBG (16+/-4%) also increased with exercise, along with blood lactate (943+/-119%). CONCLUSION: The Sal-T and Sal-C concentration measures were validated in response to short high-intensity exercise, especially for individuals. The hormonal changes in saliva were also more sensitive to exercise (i.e. greater relative responses) than the plasma total and/or free hormones, potentially arising from changes in the binding proteins and blood lactate. These findings support the use of saliva as a medium for steroid determination in sport.


Asunto(s)
Adaptación Fisiológica , Umbral Anaerobio/fisiología , Ejercicio Físico/fisiología , Hidrocortisona/análisis , Saliva/química , Testosterona/análisis , Glándulas Suprarrenales , Adulto , Albúminas/análisis , Análisis de Varianza , Composición Corporal , Humanos , Hidrocortisona/sangre , Hidrocortisona/química , Masculino , Globulina de Unión a Hormona Sexual/análisis , Estadística como Asunto , Testosterona/sangre , Transcortina/análisis
11.
J Sports Med Phys Fitness ; 60(1): 69-74, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31640317

RESUMEN

BACKGROUND: The purpose was to investigate the effect of caffeine (CAF) mouth rinse on peak power (PP), mean power (MP), peak power relative to body mass (rel PP), mean power relative to body mass (rel MP), fatigue index (FI) and anaerobic contribution in the Wingate Test. METHODS: Ten healthy men (age: 24.8±3.7 years; body mass: 71.0±7.8 kg; height: 170±3 cm; body fat: 17.02±4.9%; VO2max: 44.15±5.5 ml·kg-1·min=) were recruited. A randomized, double-blind, cross-over design was employed. Participants were instructed to complete Wingate Test in the fastest time possible under 2 conditions: CAF (25 ml of mint syrup with 1.2% of CAF, equivalent to 300 mg of CAF) and placebo (PLA) (25 ml of mint syrup without CAF). RESULTS: There was no difference at PP (P=0.66), MP (P=0.16), rel PP (P=0.82), rel MP (P=0.18), FI (P=0.19), anaerobic alactic (P=0.71), anaerobic lactic (P=0.25), total energy expenditure (P=0.41) and peak plasma lactate concentration (P=0.57). CONCLUSIONS: CAF mouth rinse did not increase peak power (PP), mean power (MP), peak power relative to body mass (rel PP), mean power relative to body mass (rel MP), Fatigue Index (FI) nor anaerobic contribution in the Wingate Test.


Asunto(s)
Umbral Anaerobio/efectos de los fármacos , Cafeína/farmacología , Metabolismo Energético/efectos de los fármacos , Prueba de Esfuerzo/métodos , Antisépticos Bucales/administración & dosificación , Adulto , Cafeína/administración & dosificación , Estudios Cruzados , Método Doble Ciego , Humanos , Ácido Láctico/sangre , Masculino
12.
J Physiol ; 587(Pt 8): 1779-94, 2009 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-19237430

RESUMEN

Exercise studies have suggested that the presence of carbohydrate in the human mouth activates regions of the brain that can enhance exercise performance but direct evidence of such a mechanism is limited. The first aim of the present study was to observe how rinsing the mouth with solutions containing glucose and maltodextrin, disguised with artificial sweetener, would affect exercise performance. The second aim was to use functional magnetic resonance imaging (fMRI) to identify the brain regions activated by these substances. In Study 1A, eight endurance-trained cyclists (VO2max 60.8 +/- 4.1 ml kg(-1) min(-1)) completed a cycle time trial (total work = 914 +/- 29 kJ) significantly faster when rinsing their mouths with a 6.4% glucose solution compared with a placebo containing saccharin (60.4 +/- 3.7 and 61.6 +/- 3.8 min, respectively, P = 0.007). The corresponding fMRI study (Study 1B) revealed that oral exposure to glucose activated reward-related brain regions, including the anterior cingulate cortex and striatum, which were unresponsive to saccharin. In Study 2A, eight endurance-trained cyclists (VO2max 57.8 +/- 3.2 ml kg(-1) min(-1)) tested the effect of rinsing with a 6.4% maltodextrin solution on exercise performance, showing it to significantly reduce the time to complete the cycle time trial (total work = 837 +/- 68 kJ) compared to an artificially sweetened placebo (62.6 +/- 4.7 and 64.6 +/- 4.9 min, respectively, P = 0.012). The second neuroimaging study (Study 2B) compared the cortical response to oral maltodextrin and glucose, revealing a similar pattern of brain activation in response to the two carbohydrate solutions, including areas of the insula/frontal operculum, orbitofrontal cortex and striatum. The results suggest that the improvement in exercise performance that is observed when carbohydrate is present in the mouth may be due to the activation of brain regions believed to be involved in reward and motor control. The findings also suggest that there may be a class of so far unidentified oral receptors that respond to carbohydrate independently of those for sweetness.


Asunto(s)
Encéfalo/fisiología , Carbohidratos de la Dieta/farmacología , Ejercicio Físico/fisiología , Boca/fisiología , Gusto/fisiología , Adulto , Umbral Anaerobio/efectos de los fármacos , Encéfalo/anatomía & histología , Prueba de Esfuerzo , Femenino , Glucosa/farmacología , Frecuencia Cardíaca/fisiología , Humanos , Imagen por Resonancia Magnética , Masculino , Consumo de Oxígeno/fisiología , Polisacáridos/farmacología , Sacarina/farmacología , Edulcorantes/farmacología , Adulto Joven
13.
J Strength Cond Res ; 23(3): 818-26, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19387397

RESUMEN

The purpose of this study was to examine the effects of a moderate dose of creatine monohydrate (CM) and two smaller doses of polyethylene glycosylated (PEG) creatine on muscular strength, endurance, and power output. Fifty-eight healthy men (mean +/- SD: age, 21 +/- 2 years; height, 176 +/- 6 cm; body mass [BM], 75 +/- 14 kg) volunteered and were randomly assigned to 1 of 4 groups: (a) placebo (PL; 3.6 g of microcrystalline cellulose; n = 15), (b) CM (5 g of creatine; n = 13), (c) small-dose PEG creatine (1.25 g of creatine: PEG1.25; n = 14), or (d) moderate-dose PEG creatine (2.50 g of creatine: PEG2.50; n = 16). Testing was conducted before (pre-) and after (post-) a 30-day supplementation period. Measurements included body mass, countermovement vertical jump (CVJ) height, power output during the Wingate test (peak power [PP] and mean power [MP]), 1 repetition maximum bench press (1RMBP), 1RM leg press (1RMLP) strength, and repetitions to failure at 80% of the 1RM for bench press (REPBP) and leg press (REPLP). BM and MP (W) increased (p

Asunto(s)
Creatina/administración & dosificación , Suplementos Dietéticos , Fuerza Muscular/efectos de los fármacos , Resistencia Física/efectos de los fármacos , Umbral Anaerobio , Análisis de Varianza , Índice de Masa Corporal , Estudios Transversales , Método Doble Ciego , Prueba de Esfuerzo , Humanos , Masculino , Placebos , Polietilenglicoles/administración & dosificación , Levantamiento de Peso/fisiología , Adulto Joven
14.
Dent Traumatol ; 25(3): 272-6, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19583574

RESUMEN

The purpose of this study was to test the influence of custom-made mouth guards on strength and anaerobic performance of taekwondo athletes. The study included 21 (11 male and 10 female) trained subjects participating in taekwondo. Anaerobic power and anaerobic capacity, isokinetic quadriceps and hamstring strength, handgrip strength, isometric lower extremity and back strength, 20 m sprint time, squat and counter movement jumping height were measured in two randomized conditions: with or without custom-made (CM) mouth guards. No significant differences were observed between the two conditions (with or without CM mouth guards) in 20 m sprint time, jumping tests, handgrip strength, isometric leg or back strength. On the other hand, peak power and average power in Wingate Anaerobic Test and Hamstring Isokinetic Peak Torque significantly increased as a result of wearing mouth guard (P < 0.05). In conclusion, we can suggest that taekwondo athletes can use CM mouth guards without any negative effects on their strength and anaerobic performance.


Asunto(s)
Umbral Anaerobio/fisiología , Rendimiento Atlético/fisiología , Diseño de Prótesis Dental , Artes Marciales/fisiología , Protectores Bucales , Adolescente , Fenómenos Biomecánicos , Femenino , Humanos , Masculino , Dinamómetro de Fuerza Muscular , Estadísticas no Paramétricas
15.
Neurology ; 92(15): e1773-e1785, 2019 04 09.
Artículo en Inglés | MEDLINE | ID: mdl-30850441

RESUMEN

OBJECTIVE: The aim of this phase 2 trial was to ascertain the feasibility and effect of community-based aerobic exercise training for people with 2 of the more common neuromuscular diseases: Charcot-Marie-Tooth disease type 1A (CMT) and inclusion body myositis (IBM). METHODS: A randomized single-blinded crossover trial design was used to compare a 12-week aerobic training program using recombinant exercise bicycles compared to a control period. The training occurred 3 times per week in community gyms local to the participants. Support was available from trained gym staff and a research physiotherapist. The 2 disease groups were analyzed separately. The primary outcome measure was peak oxygen uptake (VO2 peak) during a maximal exercise test, with secondary measures of muscle strength, function, and patient-reported measures. RESULTS: Data from 23 people with CMT and 17 people with IBM were included in the analysis. Both disease groups had high levels of participation and demonstrated improvements in VO2 peak, with a moderate effect size in the CMT participants (Cohen d = 0.53) and a strong effect size in the IBM group (Cohen d = 1.72). No major changes were observed in the secondary outcome measures. Qualitative interviews revealed that participants valued the support of gym instructors and the research physiotherapists in overcoming challenges to participation. CONCLUSION: Twelve weeks of aerobic training in community gyms was feasible, safe, and improved aerobic capacity in people with CMT and IBM. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that for patients with CMT type 1A and IBM, an aerobic training program increases aerobic capacity.


Asunto(s)
Servicios de Salud Comunitaria , Terapia por Ejercicio/organización & administración , Ejercicio Físico , Enfermedades Neuromusculares/terapia , Adulto , Umbral Anaerobio , Enfermedad de Charcot-Marie-Tooth/terapia , Estudios Cruzados , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fuerza Muscular , Miositis por Cuerpos de Inclusión/terapia , Enfermedades Neuromusculares/metabolismo , Método Simple Ciego , Resultado del Tratamiento
16.
Int J Sports Physiol Perform ; 14(3): 331-338, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30160561

RESUMEN

PURPOSE: To determine the effect of different high-intensity interval-training (IT) sessions on the postexercise recovery response and time course across varying recovery measures. METHODS: A total of 13 highly trained rowers (10 male and 3 female, peak oxygen uptake during a 6-min maximal test 4.9 [0.7] L·min-1) completed 3 IT sessions on a rowing ergometer separated by 7 d. Sessions consisted of 5 × 3.5 min, 4-min rest periods (maximal oxygen uptake [VO2max]); 10 × 30 s, 5-min rest periods (glycolytic); and 5 × 10 min, 4-min rest periods (threshold). Participants were instructed to perform intervals at the highest maintainable pace. Blood lactate and salivary cortisol were measured preexercise and postexercise. Resting heart-rate (HR) variability, post-submaximal-exercise HR variability, submaximal-exercise HR, HR recovery, and modified Wingate peak and mean power were measured preexercise and 1, 10, 24, 34, 48, 58, and 72 h postexercise. Participants resumed training throughout the measurement period. RESULTS: Between-groups short-term response differences (1 h post-IT) across IT sessions were trivial or unclear for all recovery variables. However, post-submaximal-exercise HR variability demonstrated the longest recovery time course (threshold = 37.8 [14.2], glycolytic = 20.2 [11.0], and VO2max = 20.6 [15.2]; mean [h] ± confidence limits). CONCLUSION: Short-term responses to threshold, glycolytic, and VO2max IT in highly trained male and female rowers were similar. Recovery time course was greatest following threshold compared with glycolytic and VO2max-focused training, suggesting a durational influence on recovery time course at HR intensities ≥80% HRmax. As such, this provides valuable information around the programming and sequencing of high-intensity IT for endurance athletes.


Asunto(s)
Umbral Anaerobio/fisiología , Corazón/inervación , Entrenamiento de Intervalos de Alta Intensidad , Sistema Nervioso Parasimpático/fisiología , Resistencia Física/fisiología , Deportes Acuáticos/fisiología , Estudios Cruzados , Prueba de Esfuerzo , Femenino , Glucólisis , Frecuencia Cardíaca , Humanos , Ácido Láctico/sangre , Masculino , Consumo de Oxígeno , Saliva/metabolismo , Factores de Tiempo , Adulto Joven
17.
Br J Sports Med ; 42(10): 823-7, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18308881

RESUMEN

OBJECTIVE: To examine whether inspiratory muscle training (IMT) is a useful additional technique with which to augment cardiovascular exercise training adaptations. METHODS: 16 healthy untrained males agreed to participate in the study and were randomly assigned to training (TRA; n = 8) and placebo (PLA; n = 8) groups. Pre- and post-training measurements of spirometry and maximal inspiratory mouth pressure (MIP) were taken in addition to i) maximal aerobic power (VO(2max)) and ii) 5000 m run time-trial. All subjects completed the same 4 week cardiovascular training programme which consisted of three running sessions (CV1: 5 x 1000 m, CV2: 3 x 1600 m, SP1: 20 min run) in each of the 4 weeks. IMT was performed daily by both groups using an inspiratory muscle trainer (POWERbreathe). TRA completed 30 maximal inspirations while PLA inspired 30 times against a negligible resistance. RESULTS: Mean MIP increased significantly in both groups (TRA: 14.5 (SD 6.8)% change, PLA: 7.8 (7.4)% change) from pre- to post-training (p<0.01) but was not significantly related to changes in running performance. Mean CV1 training-repetition runs improved similarly in both groups, but RPE evaluations were significantly reduced in TRA (15.7 (0.7)) compared with PLA (16.6 (0.8)) at week 4 (p<0.05). Pre- to post-training changes in VO(2max) were well-matched between both TRA (+2.1 (2.3)%) and PLA (+1.3 (2.4)%) while post-intervention 5000 m performance was significantly augmented in TRA compared with PLA (TRA: 4.3 (1.6)%, PLA: 2.2 (1.9)%, p<0.05). CONCLUSIONS: The addition of IMT to a cardiovascular training programme augments 5000 m running performance but exerts no additional influence over VO(2max) compared with a cardiovascular-training group. This is probably due to IMT-induced reduction in perceived effort at high ventilatory rates, which is of greater consequence to longer duration time-trial performances than incremental tests of VO(2max).


Asunto(s)
Rendimiento Atlético/fisiología , Sistema Cardiovascular , Educación y Entrenamiento Físico/métodos , Resistencia Física/fisiología , Músculos Respiratorios/fisiología , Carrera/fisiología , Umbral Anaerobio/fisiología , Tolerancia al Ejercicio/fisiología , Humanos , Masculino , Consumo de Oxígeno/fisiología
18.
J Strength Cond Res ; 22(5): 1402-12, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18714251

RESUMEN

This study aimed to investigate the effects of immediate postgame recovery interventions (seated rest, supine electrostimulation, low-intensity land exercises, and water exercises) on anaerobic performance (countermovement jump [CMJ], bounce jumping, 10-m sprint), hormones (salivary cortisol, urinary catecholamines), and subjective ratings (rate of perceived exertion [RPE], leg muscle pain, Questionnaire of Recovery Stress for Athletes [RestQ Sport], 10-point Likert scale), and hours of sleep of futsal players. Heart rate (HR), blood lactate, and RPE were used to evaluate the intensity of 4 futsal games in 10 players using a crossover design (P < 0.05), randomly allocating athletes to 1 of the 4 recovery interventions at the end of each game. No significant difference emerged between HR, blood lactate, RPE, and level of hydration of the games. A significant difference (P < 0.001) between games emerged for total urinary catecholamines, with an increase from the first to the second game and a gradual reduction up to the fourth game. After the game, significant reductions in CMJ (P < 0.001) and 10-m sprints (P < 0.05) emerged. No significant difference was found between recovery interventions for anaerobic performances, hormones, muscle pain, and RestQ Sport. Even though a well-balanced diet, rehydration, and controlled lifestyle might represent a sufficient recovery intervention in young elite athletes, the players perceived significantly increased benefit (P < 0.01) from the electrostimulation (7.8 +/- 1.4 points) and water exercises (7.6 +/- 2.1 points) compared to dry exercises (6.6 +/- 1.8 points) and seated rest (5.2 +/- 0.8 points.), which might improve their attitude toward playing. To induce progressive hormonal adaptation to the high exercise load of multiple games, in the last 2 weeks of the preseason, coaches should organize friendly games at a level similar to that of the competitive season.


Asunto(s)
Umbral Anaerobio/fisiología , Recuperación de la Función/fisiología , Fútbol/fisiología , Adulto , Análisis de Varianza , Antropometría , Catecolaminas/orina , Distribución de Chi-Cuadrado , Estudios Cruzados , Deshidratación/fisiopatología , Estimulación Eléctrica , Frecuencia Cardíaca/fisiología , Humanos , Hidrocortisona/análisis , Lactatos/sangre , Masculino , Educación y Entrenamiento Físico , Esfuerzo Físico/fisiología , Aptitud Física/fisiología , Descanso , Saliva/química , Sueño , Fútbol/psicología , Posición Supina , Encuestas y Cuestionarios
19.
Sports Med ; 37(12): 1019-28, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-18027991

RESUMEN

Although the concept of maximal oxygen uptake (V-dotO(2max)) was conceived as early as 1923, the criteria used to establish whether a true V-dotO(2max) has been attained have been heavily criticised. Consequently, an improvement in the methodology of the existing criteria, or development of new criteria, is required. In order to be valid across experimental studies, new or improved criteria need to be independent of exercise modality, test protocol and subject characteristics. One procedure that has shown potential for yielding valid V-dotO(2max) criteria is the verification phase, which consists of a supramaximal constant speed run to exhaustion performed after the incremental phase of a V-dotO(2max) test. A peak oxygen uptake (V-dotO(2peak)) in the verification phase that is similar (within the tolerance of measurement error, e.g. within 2%) to the V-dotO(2max) value attained in the incremental phase would indicate that a true V-dotO(2max) has been elicited. Verification of the maximal heart rate would also indicate that a subject has given a maximum effort. Although the validity of the present methodology for identifying an oxygen uptake (V-dotO(2)) plateau is questionable, a V-dotO(2) plateau criterion based on the individual slope of the V-dotO(2)-work-rate relationship should improve its validity. This approach also allows determination of the 'total V-dotO(2) plateau', which is in contrast to currently used V-dotO(2) plateau criteria that are based on the difference in V-dotO(2) between only two test stages or V-dotO(2) data points. The ratings of perceived exertion scale has been criticised for being a one-dimensional measure of physical effort and V-dotO(2max) criteria based on a multidimensional psychophysiological approach should increase validity. Visual analogue scales can be used to assess aspects such as muscular pain, determination and overall perceived effort. Furthermore, they are easy to complete and have demonstrated good reliability and validity in clinical and health settings. Future research should explore these and other potential approaches to developing new or improved V-dotO(2max) criteria, so that, ultimately, a standardised set of V-dotO(2max) criteria can be established. At present, however, the greatest challenge is identifying V-dotO(2max) criteria that remain valid across studies.


Asunto(s)
Umbral Anaerobio/fisiología , Consumo de Oxígeno/fisiología , Humanos , Resistencia Física/fisiología , Ventilación Pulmonar/fisiología , Reproducibilidad de los Resultados , Investigación , Medicina Deportiva , Reino Unido
20.
Rev Chilena Infectol ; 34(1): 27-32, 2017 Feb.
Artículo en Español | MEDLINE | ID: mdl-28394978

RESUMEN

BACKGROUND: Aim: To compare the concentration of secretory immunoglobulin-A (sIgA) in young adults with average or excellent aerobic capacity before and after a cardiopulmonary graded exercise test. METHODS: Participants were nine apparently healthy physically active males (Mean age = 21.3 ± 2.1 yr.), randomly allocated in two groups based on their VO2max: a) average aerobic capacity (AEC, n = 5) or b) excellent aerobic capacity (EAC, n = 4). Participants performed the Bruce protocol to determine their aerobic capacity. The sIgA was measured before the test, immediately after the test and 60-, 120-, 240-, and 1440-min after the test. RESULTS: Mixed factorial 2 x 6 ANOVA indicated no significant interactions between groups and measurements (p = 0.956), and main effect groups on sIgA (AEC = 85.4 ± 19.3 µg/mL vs. EAC = 79.2 ± 21.5 µg/mL, p = 0.836). Tukey's post hoc analysis revealed significant differences measurement obtained immediately after the test and between the initial measurement (p = 0.020), 60-min (p = 0.030), 240-min (p = 0.016), and 1440-min (p = 0.028) following the test. CONCLUSION: There is no change in sIgA kinetics depending on the aerobic capacity of the participants following an aerobic capacity cardiopulmonary graded exercise test.


Asunto(s)
Umbral Anaerobio/fisiología , Inmunoglobulina A Secretora/análisis , Resistencia Física/fisiología , Saliva/química , Adulto , Estudios Transversales , Prueba de Esfuerzo , Humanos , Inmunoglobulina A Secretora/metabolismo , Cinética , Masculino , Distribución Aleatoria , Adulto Joven
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