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1.
J Sports Sci ; 38(6): 644-651, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32009514

RESUMEN

The purpose of this study was to investigate the neuromuscular and perceptual fatigue responses of elite rugby players during the inaugural Under-18 (U18) Six Nations Festival. One hundred and thirty-three male players from five national squads (73 forwards, 60 backs) were examined during the competition. Each national squad was involved in three matches separated by 96 h each. Over the competition, players completed a daily questionnaire to monitor perceived well-being (WB) and performed daily countermovement jumps (CMJ) to assess neuromuscular function (NMF). Reductions in WB were substantial 24 h after the first and second match in forwards (d=0.77±0.21, p<0.0001; d=0.84±0.22, p< 0.001) and backs (d=0.89±0.22, p <0.0001; d=0.58±0.23, p<0.0001) but reached complete recovery in time for the subsequent match. Reductions in CMJ height were substantial 24 h after the first and second match for forwards (d=0.31±0.15, p=0.001; d=0.25±0.17, p=0.0205) and backs (d=0.40±0.17, p=0.0001; d=0.28±0.17, p=0.0062) and recovered at 48 h after match-play. Average WB and CMJ height attained complete recovery within matchday cycles in the investigated international competition. The findings of this study can be useful for practitioners and governing bodies involved with fixture scheduling and training prescription during competitive periods.


Asunto(s)
Conducta Competitiva/fisiología , Fatiga/fisiopatología , Fútbol Americano/fisiología , Fatiga Muscular/fisiología , Adolescente , Humanos , Estudios Longitudinales , Extremidad Inferior/fisiología , Masculino , Percepción/fisiología , Esfuerzo Físico/fisiología , Estudios Prospectivos , Factores de Tiempo
2.
Int J Sports Med ; 41(3): 161-167, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31902130

RESUMEN

Aerobic performance is negatively impacted by tropical climate due to impairment of thermoregulatory mechanisms. We tested the hypothesis that a torso application of a 4% menthol solution would have the same effect on a best performance 10-km run as an external use of cold water. Thirteen trained male athletes completed four outdoor 10-km runs (T=29.0±1.3°C, relative humidity 59.0±13.6%) wearing a tee-shirt soaked every 2-km either in a cold (~6°C) or warm/ambient (~28°C) solution, consisting in water or in a 4% menthol solution, (CTL, MENT-Amb, CLD and MENT-CLD). Run performances were improved from 4.8 to 6.1% in CLD (51.4±5.5 min), MENT-Amb (52.2±5.9 min) and MENT-CLD (51.4±5.1 min) conditions (vs. CTL, 55.4±8.4 min, P<0.05), without differences between these three conditions, whereas heart rate (177±13bpm), body temperature (38.7±0.6°C) and drink ingestion (356±170 g) were not modified. Thermal sensation after running was lower in MENT-CLD (vs. CTL, P<0.01) and thermal acceptability was higher in CLD and MENT-Amb (vs. CTL, P<0.05), but thermal comfort, feeling scale and rate of perceived exertion remained unchanged. The use of menthol on skin enhances aerobic performance in a tropical climate, and no differences in performance were observed between menthol and traditional percooling strategies. However, combining both menthol and traditional percooling brought no further improvements.


Asunto(s)
Rendimiento Atlético/fisiología , Regulación de la Temperatura Corporal/efectos de los fármacos , Humedad , Mentol/administración & dosificación , Carrera/fisiología , Clima Tropical , Administración Cutánea , Adulto , Ingestión de Líquidos , Marcha/fisiología , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Percepción/fisiología , Esfuerzo Físico/fisiología , Pérdida de Peso/fisiología , Adulto Joven
3.
J Sports Sci ; 38(2): 140-149, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31680636

RESUMEN

The aim of this study was to assess the influence of a half-time (HT) re-warm up (RWU) strategy on measures of performance and the physical and perceptual response to soccer-specific activity. Ten male soccer players completed a control (CON) and RWU trial, in which participants completed 60 min (4 x 15-min periods with a 15-min HT interspersing the third and fourth periods) of a soccer-specific exercise protocol. The CON trial comprised a passive 15-min HT, whilst the RWU trial comprised a passive 12-min period, followed by a 3-min RWU. The RWU elicited an improvement in 20 m sprint times (d= 0.6; CON: 3.42 ± 0.20 s; RWU: 3.32 ± 0.12 s), and both squat (d= 0.6; CON: 26.96 ± 5.00 cm; RWU: 30.17 ± 5.13 cm) and countermovement jump height (d= 0.7; CON: 28.15 ± 4.72 cm; RWU: 31.53 ± 5.43 cm) following the RWU and during the initial stages of the second half. No significant changes were identified for 5 m or 10 m sprint performance, perceived muscle soreness, or PlayerLoadTM. Ratings of perceived exertion were however higher (~2 a.u) following the RWU. These data support the use of a HT RWU intervention to elicit acute changes in performance.


Asunto(s)
Rendimiento Atlético/fisiología , Rendimiento Atlético/psicología , Fútbol/fisiología , Ejercicio de Calentamiento/fisiología , Adulto , Estudios Cruzados , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Mialgia/psicología , Percepción/fisiología , Esfuerzo Físico/fisiología , Proyectos Piloto , Ejercicio Pliométrico/psicología , Adulto Joven
4.
J Sports Sci ; 38(2): 121-129, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31661663

RESUMEN

A common barrier to exercise is "lack of time". Accordingly, interest in low-volume, high-intensity training has grown exponentially since this activity is considered time-efficient. However, the high-intensity nature of this exercise may frequently result in feelings of displeasure creating another barrier for many people. The purpose of this study was to compare affective (pleasure-displeasure) responses to three low-volume, high-intensity exercise conditions, including a novel shortened-sprint protocol. Using a within-subjects, randomised crossover experiment, healthy participants (N = 36) undertook a single bout of: 1) traditional reduced-exertion, high-intensity interval training (TREHIT), 2) a novel, shortened-sprint REHIT (SSREHIT) protocol, and 3) sprint continuous training (SCT). Affect and perceived efforts were recorded throughout exercise using the Feeling Scale (FS) and the 15-point Borg Rating of Perceived Exertion (RPE) scale, respectively. Enjoyment was recorded 5 min post-exercise using the Exercise Enjoyment Scale (EES). Differences were found for FS (condition by time interaction: P = 0.01GG, η2 = 0.26), RPE (P = 0.01GG, η2 = 0.23), and enjoyment (P < 0.01) with all outcomes favouring SSREHIT. Shortened-sprint protocols may diminish feelings of displeasure and might be a time-efficient yet tolerable exercise choice to help motivate some people to increase their physical activity and fitness.


Asunto(s)
Entrenamiento de Intervalos de Alta Intensidad/métodos , Entrenamiento de Intervalos de Alta Intensidad/psicología , Placer , Adulto , Estudios Cruzados , Femenino , Humanos , Masculino , Motivación , Percepción/fisiología , Esfuerzo Físico/fisiología , Adulto Joven
5.
J Sports Sci ; 38(1): 1-5, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31575324

RESUMEN

Previous research has shown enhanced performance and altered pacing behaviour in the presence of a virtual opponent during middle-distance cycling time trials with a duration of 2 min and longer. The purpose of this study was to determine whether these effects are also present in cycling time trials of shorter duration. Twelve physically active men completed three 1-km time trials. After a familiarisation trial (FAM), participants performed two experimental conditions: one without opponent (NO) and one with a virtual opponent (OP). Repeated-measures ANOVAs were used to assess differences in pacing and performance using power output and duration (p<0.05). No differences in mean finishing times (FAM: 91.5 ± 7.7 s; NO: 91.6 ± 6.4 s; OP: 90.9 ± 4.9 s; p=0.907) or power output (FAM: 382 ± 111 W; NO: 363 ± 80 W; OP: 367 ± 67; p=0.564) were found between experimental conditions. Furthermore, no differences in pacing profiles between experimental conditions were found (p=0.199). Similarly, rate of perceived exertion did not differ between experimental conditions at any moment (p=0.831). In conclusion, unlike events of a more prolonged duration (>2 min), the presence of an opponent did not affect participants' pacing behaviour in short duration 1-km time trials.


Asunto(s)
Rendimiento Atlético/fisiología , Ciclismo/fisiología , Conducta Competitiva/fisiología , Adulto , Rendimiento Atlético/psicología , Ciclismo/psicología , Toma de Decisiones , Humanos , Masculino , Percepción/fisiología , Esfuerzo Físico/fisiología , Factores de Tiempo , Adulto Joven
6.
Br J Sports Med ; 54(2): 110-115, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31420319

RESUMEN

INTRODUCTION: The brain plays a key role in the perceptual regulation of exercise, yet neuroimaging techniques have only demonstrated superficial brain areas responses during exercise, and little is known about the modulation of the deeper brain areas at different intensities. OBJECTIVES/METHODS: Using a specially designed functional MRI (fMRI) cycling ergometer, we have determined the sequence in which the cortical and subcortical brain regions are modulated at low and high ratings perceived exertion (RPE) during an incremental exercise protocol. RESULTS: Additional to the activation of the classical motor control regions (motor, somatosensory, premotor and supplementary motor cortices and cerebellum), we found the activation of the regions associated with autonomic regulation (ie, insular cortex) (ie, positive blood-oxygen-level-dependent (BOLD) signal) during exercise. Also, we showed reduced activation (negative BOLD signal) of cognitive-related areas (prefrontal cortex), an effect that increased during exercise at a higher perceived intensity (RPE 13-17 on Borg Scale). The motor cortex remained active throughout the exercise protocol whereas the cerebellum was activated only at low intensity (RPE 6-12), not at high intensity (RPE 13-17). CONCLUSIONS: These findings describe the sequence in which different brain areas become activated or deactivated during exercise of increasing intensity, including subcortical areas measured with fMRI analysis.


Asunto(s)
Ejercicio/fisiología , Corteza Motora/fisiología , Adolescente , Adulto , Cerebelo/fisiología , Corteza Cerebral/fisiología , Ergometría/métodos , Humanos , Imagen por Resonancia Magnética , Masculino , Percepción/fisiología , Esfuerzo Físico/fisiología , Corteza Prefrontal/fisiología , Adulto Joven
7.
Int J Sports Med ; 41(1): 36-43, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31747699

RESUMEN

Subconcussive head impacts (SHI), defined as impacts to the cranium that do not result in concussion symptoms, are gaining traction as a major public health concern. The contribution of physiological factors such as physical exertion and muscle damage to SHI-dependent changes in neurological measures remains unknown. A prospective longitudinal study examined the association between physiological factors and SHI kinematics in 15 high school American football players over one season. Players wore a sensor-installed mouthguard for all practices and games, recording frequency and magnitude of all head impacts. Serum samples were collected at 12 time points (pre-season, pre- and post-game for five in-season games, and post-season) and were assessed for an isoenzyme of creatine kinase (CK-MM) primarily found in skeletal muscle. Physical exertion was estimated in the form of excess post-exercise oxygen consumption (EPOC) from heart rate data captured during the five games. Mixed-effect regression models indicated that head impact kinematics were significantly and positively associated with change in CK-MM but not EPOC. There was a significant and positive association between CK-MM and EPOC. These data suggest that when examining SHI, effects of skeletal muscle damage should be considered when using outcome measures that may have an interaction with muscle damage.


Asunto(s)
Fútbol Americano/lesiones , Cabeza/fisiopatología , Músculo Esquelético/lesiones , Esfuerzo Físico/fisiología , Adolescente , Fenómenos Biomecánicos , Conmoción Encefálica/fisiopatología , Forma MM de la Creatina-Quinasa/sangre , Fútbol Americano/fisiología , Humanos , Estudios Longitudinales , Masculino , Músculo Esquelético/enzimología , Consumo de Oxígeno/fisiología , Estudios Prospectivos , Estados Unidos
8.
Int J Sports Med ; 41(1): 12-20, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31747702

RESUMEN

In view of the growing amount of (intense) training in competitive sports, quick recovery plays a superior role in performance restoration. The aim of the present study was to compare the effects of active versus passive recovery during high-intensity interval training (HIIT) and sprint interval training (SIT) protocols on acute alterations of circulating blood cells. Twelve male triathletes/cyclists performed 1) a HIIT consisting of 4×4 min intervals, 2) a SIT consisting of 4×30s intervals, separated by either active or passive recovery. Blood samples were collected immediately before and at 0', 30', 60' and 180' (minutes) post-exercise. Outcomes comprised leukocytes, lymphocytes, neutrophils, mixed cell count, platelets, cellular inflammation markers (neutrophil/lymphocyte-ratio (NLR), platelet/lymphocyte-ratio (PLR)), and the systemic immune-inflammation index (SII). In view of HIIT, passive recovery attenuated the changes in lymphocytes and neutrophils compared to active recovery. In view of SIT, active recovery attenuated the increase in leukocytes, lymphocytes and absolute mixed cell count compared to passive recovery. Both protocols, independent of recovery, significantly increased NLR, PLR and SII up to 3h of recovery compared to pre-exercise values. The mode of recovery influences short-term alterations in the circulating fraction of leukocytes, lymphocytes, neutrophils and the mixed cell count, which might be associated with different hormonal and metabolic stress responses due to the mode of recovery.


Asunto(s)
Recuento de Células Sanguíneas , Entrenamiento de Intervalos de Alta Intensidad/métodos , Homeostasis/fisiología , Inflamación/sangre , Esfuerzo Físico/fisiología , Adulto , Biomarcadores/sangre , Recuento de Eritrocitos , Humanos , Recuento de Leucocitos , Recuento de Linfocitos , Masculino , Neutrófilos/metabolismo , Recuento de Plaquetas , Adulto Joven
9.
Life Sci ; 240: 117107, 2020 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-31785241

RESUMEN

BACKGROUND: Toll-like receptor 4 (Tlr4) is recognized due to its role in the immune response. Also, this protein can participate in the signaling pathway of events triggered by physical exercise such as apoptosis, inflammation, and endoplasmic reticulum (ER) stress. The main objective of this study was to evaluate the role of Tlr4 in the markers of these events in the myocardium of mice submitted to acute physical exercise (APE) protocols at different intensities. METHODS: Echocardiogram, RT-qPCR, and immunoblotting technique were used to evaluate the left ventricle of wild-type (WT) and Tlr4 knockout (Tlr4 KO) submitted to APE protocols at 45, 60, and 75% of their maximal velocity. Also, we performed the bioinformatics analysis to establish the connection of heart mRNA levels of Tlr4 with heart genes of inflammation and ER stress of several isogenic strains of BXD mice. RESULTS: Under basal conditions, the Tlr4 deletion diminished the performance, and expression of inflammation and ER stress genes in the left ventricle, but increased the serum levels of CK, Il-17, and Tnf-alpha. Under the same exercise conditions, the Tlr4 deletion reduced the glycemia, serum levels of CK, Il-17, and Tnf-alpha, as well as genes and/or proteins related to apoptosis, inflammation and ER stress in the left ventricle, but increased the levels of CK-mb and LDH, as well as other genes related to apoptosis, inflammation, and ER stress in the left ventricle. CONCLUSION: Altogether, the current findings highlighted the effects of different acute exercise intensities were attenuated in the heart of Tlr4 KO mice.


Asunto(s)
Apoptosis/fisiología , Estrés del Retículo Endoplásmico/fisiología , Corazón/fisiología , Inflamación , Esfuerzo Físico/fisiología , Receptor Toll-Like 4/fisiología , Animales , Apoptosis/genética , Biología Computacional , Creatina Quinasa/sangre , Ecocardiografía , Estrés del Retículo Endoplásmico/genética , Corazón/diagnóstico por imagen , Interleucina-17/sangre , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Esfuerzo Físico/genética , Transducción de Señal/fisiología , Receptor Toll-Like 4/genética , Factor de Necrosis Tumoral alfa/sangre
10.
Aquat Toxicol ; 218: 105373, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31786386

RESUMEN

Production of industrial effluents have led to increased copper (Cu) pollution of aquatic ecosystems, impacting the physiology of aquatic vertebrates. Past work has shown that Cu exerts its toxicity by disruption ion regulation and/ or increasing oxidative stress. However, it remains unclear how Cu may influence aerobic metabolism and hypoxia tolerance, two possible targets of its toxicity. To address this issue, we exposed freshwater acclimated killifish (F. heteroclitus) to a 96 h Cu exposure at a target concentration of 100 µg L-1. We determined resting oxygen consumption (MO2), MO2max after exhaustive exercise, and followed MO2 for 3 h in post-exercise recovery in water with either no Cu or 100 µg L-1 Cu. We assessed hypoxia tolerance by determining the critical oxygen tension (Pcrit). It was found that killifish exposed to combined 96 h Cu exposure and Cu present during metabolic measurements, showed a significant decrease in MO2max and in aerobic scope (MO2max - MO2rest), compared to control fish. However, changes in blood and muscle lactate and muscle glycogen were not consistent with an upregulation of anaerobic metabolism as compensation for reduced aerobic performance in Cu exposed fish. Hypoxia tolerance was not influenced by the 96 h Cu exposure or by presence or absence of Cu during the Pcrit test. This study suggests that Cu differentially influences responses to changes in oxygen demand and oxygen availability.


Asunto(s)
Aclimatación/efectos de los fármacos , Cobre/toxicidad , Fundulidae/metabolismo , Hipoxia/metabolismo , Consumo de Oxígeno/efectos de los fármacos , Esfuerzo Físico/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Anaerobiosis , Animales , Ecosistema , Agua Dulce/química , Fundulidae/sangre , Fundulidae/fisiología , Glucógeno/metabolismo , Ácido Láctico/sangre , Músculos/efectos de los fármacos , Músculos/metabolismo , Estrés Oxidativo/efectos de los fármacos , Esfuerzo Físico/fisiología
11.
J Sports Sci ; 38(3): 248-255, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31726955

RESUMEN

Accelerometers are often placed on the tibia to measure segmental accelerations, and external mechanical load during running. However, in applied sport settings it is sometimes preferable to place accelerometers on the dorsal foot to avoid tibial impact injuries. This study aimed to quantify the differences in accelerations measured at the dorsal foot compared with the distal tibia during running. Sixteen recreationally active participants performed a sprint protocol on a non-motorised treadmill. Accelerometers were positioned bilaterally on the medial tibia (TIBLeft and TIBRight), and bilateral dorsal foot surfaces (DORLeft and DORRight). Continuous acceleration signal waveform analysis was performed using one-dimensional statistical parametric mapping (1DSPM). Resultant accelerations were greater for DORLeft than TIBLeft for 60% of the gait cycle (p < 0.001) and greater for DORRight than TIBRight for 50% of the gait cycle (p < 0.003). The larger accelerations at the dorsal foot than the tibia can be explained by movement at the ankle joint, and the placement location relative to the hip. The dorsal foot location can be used to effectively measure accelerations and external mechanical load when it is not feasible to place the accelerometer on the tibia, however results between the two locations should not be compared.


Asunto(s)
Acelerometría/instrumentación , Monitores de Ejercicio , Pie/fisiología , Carrera/fisiología , Tibia/fisiología , Aceleración , Adulto , Articulación del Tobillo/fisiología , Fenómenos Biomecánicos , Estudios de Factibilidad , Femenino , Cadera/fisiología , Humanos , Masculino , Movimiento/fisiología , Percepción/fisiología , Esfuerzo Físico/fisiología , Adulto Joven
12.
Sports Biomech ; 19(2): 201-211, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29792560

RESUMEN

The purpose of this study was to describe the mechanical characteristics of a trampoline circus act and its individual tracks performed in training and shows using a tri-axial accelerometer. A track is an artist's specific role within a choreographed act. Seven male acrobats performed their trampoline act during training and shows while wearing a triaxial accelerometer and reported ratings of perceived exertion (RPE) after each trial. Average acceleration (AVG), root mean square (RMS), root mean to the fourth (RM4), time spent in specific acceleration ranges and RPE were measured/recorded from training and show acts. Paired t-tests compared dependent variables between training and show. Acceleration AVG, RMS and RM4 were significantly higher (p < 0.05) in training than show. RPE was significantly higher (p < 0.05) in show than training. No significant differences existed in time spent in any of the acceleration ranges between training and show. GPS devices have been used to manage workloads in field sports but are inoperable in theatres. But, inertial measurements may be an effective alternative to describe mechanical demands in theatre or arena environments. Wearable technology may be useful to coaches to improve understanding of track demands to manage artist workloads.


Asunto(s)
Acelerometría/instrumentación , Rendimiento Atlético/fisiología , Gimnasia/fisiología , Acondicionamiento Físico Humano/fisiología , Dispositivos Electrónicos Vestibles , Aceleración , Adulto , Fenómenos Biomecánicos , Humanos , Masculino , Percepción/fisiología , Esfuerzo Físico/fisiología
13.
Int J Sports Med ; 41(2): 106-112, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31842245

RESUMEN

This study aimed to investigate training-induced fitness changes and their relationship with training-competition load during half a soccer season (18 wks). Training load [heart rate (HR) and ratings of perceived exertion (RPE)] and match time were monitored, including 108 training (3 223 individuals) and 23 match sessions, in 38 youth elite male soccer players. Fitness variables were assessed before and after the study. Yo-Yo intermittent recovery test 1 (Yo-Yo IRT1) improved (P<0.001; 90%CI: 418-632 m; ES: 2.14). Anthropometrical, jump, sprint, and change-of-direction measures remained unchanged. Jump test correlated with sprint (r=0.74; P<0.001; SEE=3.38 m·s-1) and Yo-Yo IRT1 (r=-0.58; P=0.005; SEE=4.11 m) tests. Initial sum of 6 skinfolds was associated with changes in this same measure (r=-0.51; P<0.001; SEE=21%). Initial Yo-Yo IRT1 results were related to changes in Yo-Yo IRT1 (r=-0.84; P<0.001; SEE=10%) and match time played (r=0.44; P=0.033; SEE=445 m). Mean RPE records were related to training spent within 75-90% maximal HR (r=0.54; P<0.001; SEE=4%). The half-season was beneficial for endurance running performance but not for lower-limb strength-velocity production capacity. The more aerobically deconditioned players played fewer minutes of match, although they showed the greatest improvements in endurance performance. Non-soccer-specific, scientifically based, and individualized fitness programs in addition to soccer-specific training are recommended.


Asunto(s)
Adaptación Fisiológica , Conducta Competitiva/fisiología , Acondicionamiento Físico Humano/fisiología , Resistencia Física/fisiología , Fútbol/fisiología , Adolescente , Prueba de Esfuerzo , Humanos , Estudios Longitudinales , Masculino , Percepción/fisiología , Esfuerzo Físico/fisiología , Aptitud Física , Carrera/fisiología , Estaciones del Año , Adulto Joven
14.
J Sports Sci Med ; 18(4): 636-644, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31827347

RESUMEN

Prediabetes is associated with impaired oxidative capacity and altered substrate utilization during exercise. The effects of continuous (CONT) versus interval (INT) exercise training on fat oxidation during an acute exercise bout at the same absolute and relative intensities are unknown in this population. Obese females/males (n = 17, n = 5) with prediabetes (BMI 32.2 ± 1.2 kg·m-2; age 62.8 ± 1.6 y; fasting glucose 103.4 ± 1.6 mg·dL-1; 2-hour glucose 153.7 ± 7.1 mg·dL-1; VO2peak 19.9 ± 1.0 mL·kg-1·min-1) were screened with a 75g OGTT. Subjects completed a peak oxygen consumption test and a submaximal exercise substrate utilization test consisting of 5min stages at absolute (30W) and relative (70%HRpeak) intensities before and after randomization to 12 sessions (60min each) of CONT (70% HRpeak) or INT (alternating 3min 90% HRpeak, 3min 50% HRpeak) over a two-week period. Body mass decreased and VO2peak increased more after INT than CONT (INT: -0.6 ± 0.2 kg, CONT: -0.1 ± 0.2 kg; p = 0.04; INT: 1.9 ± 0.6 mL/kg/min, CONT: 0.1 ± 0.6 mL·kg-1·min-1; p = 0.04). Training increased fat oxidation by 0.7 ± 0.2 mL·kg-1·min-1 during the absolute intensity test (p < 0.001), independent of intensity. During the relative intensity test, fat oxidation increased more after INT than CONT (INT: 1.3 ± 0.4 mL·kg-1·min-1, CONT: 0.3 ± 0.3 mL·kg-1·min-1; p = 0.03), with no difference in exercise energy expenditure between groups. Enhanced fat oxidation during the relative test was correlated with increased VO2peak (r = 0.53 p = 0.01). High intensity INT training enhances fat oxidation during the same relative intensity exercise in people with prediabetes.


Asunto(s)
Tejido Adiposo/metabolismo , Entrenamiento de Intervalos de Alta Intensidad , Obesidad/metabolismo , Estado Prediabético/metabolismo , Anciano , Glucemia/metabolismo , Índice de Masa Corporal , Capacidad Cardiovascular/fisiología , Metabolismo Energético/fisiología , Femenino , Prueba de Tolerancia a la Glucosa , Humanos , Masculino , Persona de Mediana Edad , Obesidad/sangre , Obesidad/complicaciones , Oxidación-Reducción , Consumo de Oxígeno/fisiología , Percepción/fisiología , Esfuerzo Físico/fisiología , Estado Prediabético/sangre , Estado Prediabético/complicaciones
15.
J Sports Sci Med ; 18(4): 695-707, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31827354

RESUMEN

Aquatic cycling is a program of physical exercises performed with immersed stationary bikes. Few studies have provided evidence about the intensity control during its practice. Therefore, the primary aim of this study was to examine the concurrent and construct validity of a new scale for rating perceived exertion (RPE) during aquatic cycling in young men. Thirty physically active, healthy young men performed a load-incremented aquatic cycle ergometer protocol. Concurrent validity was established by correlating the Aquatic Cycling Scale (ACS) with oxygen uptake, pulmonary ventilation (VE), heart rate (HR), and blood lactate concentration (BL) responses to the maximal load-incremental test. Construct validity was established by correlating RPE derived from the Aquatic Cycling Scale (0-10) from the Borg Scale (6-20). RPE-overall, maximal oxygen uptake (VO2max), oxygen uptake indexed to body weight (VO2), VE, HR, and BL were measured during each exercise stage. The range of exercise responses across the incremental test were VO2max = 1.07-3.55 L/min, VO2 = 14.26-46.89 ml/Kg/min, VE = 23.17-138.57 L/min, HR = 99.54-173.31 beats/min, BL= 1.18-11.63 mM, ACS RPE-overall = 1.11-9.33. Correlation/regression analyses showed ACS RPE as a positive linear function of VO2max (r = 0.78; p < 0.05), VO2 (r = 0.87; p < 0.05), VE (r = 0.86; p < 0.05), HR (r = 0.77; p < 0.05), and BL (r = 0.85; p < 0.05). RPE-ACS distributed as a positive linear function of the RPE-Borg Scale (r = 0.97; p < 0.05). ANOVA indicated that an incremental pedalling cadence of 15 revolutions per minute (rpm) provoked significant differences (p < 0.05) regarding previous stages in the majority of the variables analysed. The Aquatic Cycling Scale is an appropriate tool for monitoring exertion intensity during aquatic cycling in fit men. A brief increment in aquatic pedalling cadence of 15 rpm increases the intensity of the aquatic pedalling exercise.


Asunto(s)
Ciclismo/fisiología , Prueba de Esfuerzo , Percepción/fisiología , Esfuerzo Físico/fisiología , Frecuencia Cardíaca/fisiología , Humanos , Ácido Láctico/sangre , Masculino , Consumo de Oxígeno/fisiología , Intercambio Gaseoso Pulmonar/fisiología , Análisis de Regresión , Reproducibilidad de los Resultados , Adulto Joven
16.
Medicine (Baltimore) ; 98(41): e17400, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31593091

RESUMEN

INTRODUCTION: Cardiac autonomic modulation is an important marker of cardiovascular health and the practice of physical activity is a fundamental tool for good maintenance or increments in this marker. However, it is not clear in the literature whether different intensities and different domains of physical activity are related in the same way to cardiac autonomic modulation. OBJECTIVES: This randomized epidemiologic study will examine the relationship between cardiac autonomic modulation and different intensities and domains of physical activity in a representative sample of adults. METHODS: The sample of study will consist of 252 subjects aged from 18 years and above. The sample will be randomized through census sectors in which the neighborhoods, streets, and houses will also be randomized. Cardiac autonomic modulation will be assessed by heart rate variability and the intensity (mild, moderate, intense) of physical activity will be evaluated by means of accelerometers, while the different domains of physical activity (physical activity at work, occupational activities) will be evaluated through a questionnaire. The relationship between cardiac autonomic modulation and different physical activity intensities, as well as the different domains will be analyzed by linear regression, considering a statistical significance of 5% and a 95% confidence interval. This research protocol is registered in ClinicalTrials.gov at number NCT03986879.


Asunto(s)
Acelerometría/estadística & datos numéricos , Sistema Nervioso Autónomo/fisiología , Ejercicio/fisiología , Corazón/fisiología , Esfuerzo Físico/fisiología , Adolescente , Adulto , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Estudios Observacionales como Asunto , Encuestas y Cuestionarios , Adulto Joven
17.
Int J Sports Med ; 40(14): 886-896, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31648353

RESUMEN

Exercise physiological responses can be markedly affected by acute hypoxia. We investigated cardiac autonomic and physiological responses to different hypoxic training protocols. Thirteen men performed three exercise sessions (5×5-min; 1-min passive recovery): normoxic exercise at 80% of the power output (PO) at the first ventilatory threshold (N), hypoxic exercise (FiO2=14.2%) with the same PO as N (HPO) and hypoxic exercise at the same heart rate (HR) as N (HHR). PO was lower in HHR (21.1±9.3%) compared to N and HPO. Mean HR was higher in HPO (154±11 bpm, p<0.01) than N and HHR (139±10 vs. 138±9 bpm; p=0.80). SpO2 was reduced (p<0.01) to a similar extent (p>0.05) in HPO and HHR compared to N. HR recovery (HRR) and HR variability indices were similar in N and HHR (p>0.05) but reduced in HPO (p<0.05), mirroring a delayed parasympathetic reactivation. Blood lactate and ventilation were similar in N and HHR (p>0.05) and increased in HPO (p<0.001). During recovery oxygen consumption and ventilation were similar in N and HHR (p>0.05) and increased in HPO (p<0.01). Moderate HR-matched hypoxic exercise triggers similar cardiac autonomic and physiological responses to normoxic exercise with a reduced mechanical load. On the contrary, the same absolute intensity exercise in hypoxia is associated with increased exercise-induced metabolic stress and delayed cardiac autonomic recovery.


Asunto(s)
Sistema Nervioso Autónomo/fisiología , Ejercicio/fisiología , Corazón/inervación , Hipoxia/fisiopatología , Adulto , Frecuencia Cardíaca/fisiología , Humanos , Ácido Láctico/sangre , Masculino , Consumo de Oxígeno/fisiología , Percepción/fisiología , Esfuerzo Físico/fisiología , Frecuencia Respiratoria , Adulto Joven
18.
Int J Sports Med ; 40(14): 879-885, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31574544

RESUMEN

The potential anti-fatigue and performance benefits of hydrogen rich water (HRW) have resulted in increased research interest over the past 5 years. The aim of this study was to assess physiological and perceptual responses to an incremental exercise protocol after administration of 600 ml HRW within 30 min before exercise. This randomized, double blinded placebo-controlled cross over study included twelve healthy males aged 27.1±4.9 years. The exercise protocol consisted of a 10 min warm-up at 1.0 W.kg-1, followed by 8 min at 2.0, 3.0, and 4.0 W.kg-1, respectively. Cardio-respiratory variables, lactate and ratings of perceived exertion (RPE) were assessed in the last minute of each step. A significantly lower blood lactate was found with HRW (4.0±1.6 and 8.9±2.2 mmol.l-1) compared to Placebo (5.1±1.9 and 10.6±3.0 mmol.l-1) at 3.0, and 4.0 W.kg-1, respectively. Ventilatory equivalent for oxygen and RPE exhibited significantly lower values with HRW (32.3±7.2, and 17.8±1.2 points, respectively) compared to Placebo (35.0±8.4, and 18.5±0.8 points, respectively) at 4 W.kg-1. To conclude, acute pre-exercise supplementation with HRW reduced blood lactate at higher exercise intensities, improved exercise-induced perception of effort, and ventilatory efficiency.


Asunto(s)
Ingestión de Líquidos , Ejercicio/fisiología , Hidrógeno , Ácido Láctico/sangre , Percepción/fisiología , Esfuerzo Físico/fisiología , Respiración , Agua/química , Adulto , Método Doble Ciego , Ejercicio/psicología , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Fatiga Muscular/fisiología , Consumo de Oxígeno/fisiología , Adulto Joven
19.
Int J Occup Med Environ Health ; 32(5): 645-652, 2019 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-31511702

RESUMEN

OBJECTIVES: Individual protection against contamination is the kind of protection provided to persons in an environment contaminated with radioactive substances, and war toxic or biological agents, including the use of gas masks, and insulating or filtration skin protection agents. The aim of this work was to perform a comparative assessment of energy expenditure of chemical troop soldiers wearing L-2 insulating personal protective clothes (PPC) and FOO-1 filter-sorptive PPC during training in the training ground conditions. Surveys on the subjective assessment of comfort related to using the L-2 and FOO-1 PPC were carried out as well. MATERIAL AND METHODS: A total of 29 men doing the same training tasks, wearing the L-2 PPC and FOO-1 filter-sorptive protective clothing with an MP-5 filter gas mask, underwent the examination. Measurements of energy expenditure values were done based on the frequency of heart contractions, recorded by the Polar Sport Tester 810 heart rate monitor. RESULTS: It was found that an average energy expenditure of soldiers, resulting from performing training tasks, was lower among the subjects wearing the FOO- 1 filter-sorptive PPC, compared to the energy load of the ones using the L-2 PPC. CONCLUSIONS: According to Christensen's classification of work severity, the average energy expenditure makes it possible to qualify works performed by soldiers using both types of PPC to moderate work. In the opinion of the examined soldiers serving in the chemical troops, the FOO-1 filter-sorptive PPC increases the sense of security while on a threatened ground. The FOO-1 filter-sorptive PPC is assessed by chemical troop soldiers as better because it hinders tasks fulfillment to a lesser extent. Int J Occup Med Environ Health. 2019;32(5):645-52.


Asunto(s)
Metabolismo Energético , Personal Militar , Ropa de Protección/efectos adversos , Adulto , Frecuencia Cardíaca , Humanos , Masculino , Consumo de Oxígeno , Esfuerzo Físico/fisiología , Polonia , Dispositivos de Protección Respiratoria
20.
J Sports Sci ; 37(23): 2691-2701, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31526108

RESUMEN

This study investigated effects of total sleep deprivation on self-paced endurance performance, and heart rate (HR) indices of athletes' "readiness to perform". Endurance athletes (n = 13) completed a crossover experiment comprising a normal sleep (NS) and sleep deprivation (SD) condition. Each required completion of an endurance time-trial (TT) on consecutive days (D1, D2) separated by normal sleep or total sleep deprivation. Finishing time, perceived exertion (RPE), mood, psychomotor vigilance (PVT), and HR responses were assessed. Time on D2 of SD was 10% slower than D2 of NS (64 ± 7 vs 59 ± 4 min, P < 0.01), and 11% slower than D1 of SD (58 ± 5 min, P < 0.01). Subjective to objective (RPE:mean HR) intensity ratio was higher on D2 of SD compared with D2 of NS and D1 of SD (P < 0.01). Mood disturbance and PVT mean response time increased on D2 of SD compared with D2 of NS and D1 of SD. Anaerobic threshold and change in TT time were correlated (R = -0.73, P < 0.01). Sleep helps to optimise endurance performance. Subjective to objective intensity ratios appear sensitive to effects of sleep on athletes' readiness. Research examining more subtle sleep manipulation is required.


Asunto(s)
Ciclismo/fisiología , Frecuencia Cardíaca/fisiología , Resistencia Física/fisiología , Privación de Sueño/fisiopatología , Actigrafía/instrumentación , Adulto , Afecto/fisiología , Ciclismo/psicología , Estudios Cruzados , Prueba de Esfuerzo , Humanos , Masculino , Percepción/fisiología , Esfuerzo Físico/fisiología , Tiempo de Reacción/fisiología , Dispositivos Electrónicos Vestibles
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