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1.
Eur J Appl Physiol ; 123(12): 2699-2710, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37335354

RESUMEN

PURPOSE: To investigate (1) the boosting effects immediately and 4 weeks following 2-week, 6-session repeated-sprint training in hypoxia (RSH2-wk, n = 10) on the ability of team-sport players in performing repeated sprints (RSA) during a team-sport-specific intermittent exercise protocol (RSAIEP) by comparing with normoxic counterpart (CON2-wk, n = 12), and (2) the dose effects of the RSH by comparing the RSA alterations in RSH2-wk with those resulting from a 5-week, 15-session regimen (RSH5-wk, n = 10). METHODS: Repeated-sprint training protocol consisted of 3 sets, 5 × 5-s all-out sprints on non-motorized treadmill interspersed with 25-s passive recovery under the hypoxia of 13.5% and normoxia, respectively. The within- (pre-, post-, 4-week post-intervention) and between- (RSH2-wk, RSH5-wk, CON2-wk) group differences in the performance of four sets of RSA tests held during the RSAIEP on the same treadmill were assessed. RESULTS: In comparison with pre-intervention, RSA variables, particularly the mean velocity, horizontal force, and power output during the RSAIEP enhanced significantly immediate post RSH in RSH2-wk (5.1-13.7%), while trivially in CON2-wk (2.1-6.2%). Nevertheless, the enhanced RSA in RSH2-wk diminished 4 weeks after the RSH (- 3.17-0.37%). For the RSH5-wk, the enhancement of RSA immediately following the 5-week RSH (4.2-16.3%) did not differ from that of RSH2-wk, yet the enhanced RSA was well-maintained 4-week post-RSH (0.12-1.14%). CONCLUSIONS: Two-week and five-week RSH regimens could comparably boost up the effects of repeated-sprint training in normoxia, while dose effect detected on the RSA enhancement was minimal. Nevertheless, superior residual effects of the RSH on RSA appear to be associated with prolonged regimen.


Asunto(s)
Rendimiento Atlético , Acondicionamiento Físico Humano , Carrera , Humanos , Hipoxia , Acondicionamiento Físico Humano/métodos , Ejercicio Físico
2.
J Appl Res Intellect Disabil ; 35(5): 1073-1087, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35445495

RESUMEN

BACKGROUND: Poor health-related physical fitness (HRPF) and overweight and obesity are common health problems for children with intellectual disability. This study aimed to review existing lifestyle intervention studies, and identify effective strategies for this population. METHODS: A systematic search was undertaken in three databases. The random-effects model was used to pool the weighted results by inverse variance methods, and the I2 statistic was applied to assess heterogeneity among the included studies. RESULTS: Most of the identified interventions (27/29) adopted physical activity (PA). For obesity-related outcomes, the results showed no significant effect of PA studies on reducing obesity. For HRPF outcomes, significant effects were found on 6-min walk distance (51.86 m, 95% CI [16.49, 87.22], p < .05). CONCLUSIONS: PA is the predominant intervention component adopted and may contribute to improving cardiopulmonary fitness; but the lack of research limits our ability to draw any confirmed conclusion on obesity-related outcomes and other HRPF outcomes.


Asunto(s)
Discapacidad Intelectual , Obesidad Infantil , Niño , Humanos , Discapacidad Intelectual/epidemiología , Estilo de Vida , Sobrepeso/epidemiología , Sobrepeso/prevención & control , Obesidad Infantil/epidemiología , Obesidad Infantil/prevención & control , Aptitud Física
3.
J Exerc Sci Fit ; 20(1): 32-39, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34987588

RESUMEN

OBJECTIVES: This study examined the influences of the volume of all-out sprint-interval exercise (SIE) on acute post-exercise heart rate variability (HRV) recovery. METHODS: HRV recovery following a session of (i) 2 × 30-s SIE (SIE2), (ii) 4 × 30-s SIE (SIE4), and (iii) non-exercising control (CON) were compared in 15 untrained young males. Time domain [standard deviation of normal-to-normal intervals, root mean square of successive R-R differences] and frequency domain [low frequency (0.04-0.14 Hz), high frequency (0.15-0.40 Hz)] measures of HRV were assessed every 20 min for 140 min after the exercise, and every hour during the first 4 h of actual sleep time at immediate night. All trials were scheduled at 19:00. RESULTS: In comparison to CON, both SIE2 and SIE4 attenuated the HRV markedly (p < 0.05), while the declined HRV restored progressively during recovery. Although the sprint repetitions of SIE4 was twice as that of SIE2, the declined HRV indices at corresponding time points during recovery were not different between the two trials (p > 0.05). Nevertheless, the post-exercise HRV restoration in SIE2 appeared to be faster than that in SIE4. Regardless, nocturnal HRV measured within 10 h following the exercise was not different among the SIE and CON trials (p > 0.05). CONCLUSION: Such findings suggest that the exercise volume of the SIE protocol may be a factor affecting the rate of removal of the cardiac autonomic disturbance following the exercise. In addition, rest for ∼10 h following either session of the SIE protocol appears to be appropriate for the cardiovascular system to recover.

4.
Scand J Med Sci Sports ; 31(1): 30-43, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32789898

RESUMEN

Visceral fat loss in response to four-cycle ergometer training regimens with explicit differences in exercise intensity and modality was compared. Fifty-nine obese young women (body fat percentage ≥ 30%) were randomized to a 12-week intervention consisting of either all-out sprint interval training (SITall-out , n = 11); supramaximal SIT (SIT120 , 120% V ˙ O2peak , n = 12); high-intensity interval training (HIIT90 , 90% V ˙ O2peak , n = 12), moderate-intensity continuous training (MICT, 60% V ˙ O2peak , n = 11), or no training (CON, n = 13). The total work done per training session in SIT120 , HIIT90 , and MICT was confined to 200 kJ, while it was deliberately lower in SITall-out . The abdominal visceral fat area (AVFA) was measured through computed tomography scans. The whole-body and regional fat mass were assessed through dual-energy X-ray absorptiometry. Pre-, post-, and 3-hour post-exercise serum growth hormone (GH), and epinephrine (EPI) were measured during selected training sessions. Following the intervention, similar reductions in whole-body and regional fat mass were found in all intervention groups, while the reductions in AVFA resulting from SITall-out , SIT120 , and HIIT90 (>15 cm2 ) were greater in comparison with MICT (<3.5 cm2 , P < .05). The AVFA reductions among the SITs and HIIT groups were similar, and it was concomitant with the similar exercise-induced releases of serum GH and EPI. CON variables were unchanged. These findings suggest that visceral fat loss induced by interval training at or above 90% V ˙ O2peak appeared unresponsive to the change in training intensity. Nonetheless, SITall-out is still the most time-efficient strategy among the four exercise-training regimes for controlling visceral obesity.


Asunto(s)
Terapia por Ejercicio/métodos , Grasa Intraabdominal/anatomía & histología , Obesidad/patología , Obesidad/terapia , Absorciometría de Fotón , Adolescente , Distribución de la Grasa Corporal , Registros de Dieta , Metabolismo Energético , Epinefrina/sangre , Femenino , Entrenamiento de Intervalos de Alta Intensidad/métodos , Hormona de Crecimiento Humana/sangre , Humanos , Grasa Intraabdominal/diagnóstico por imagen , Ácido Láctico/sangre , Obesidad/sangre , Obesidad/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adulto Joven
5.
Eur J Appl Physiol ; 121(7): 1933-1942, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33730209

RESUMEN

PURPOSE: For optimizing the quality of repeated-sprint training in hypoxia, the differences in the acute performance responses to a single session of repeated-sprint exercise with various (i) inspired oxygen fractions; (ii) exercise-to-recovery (E:R) ratios and (iii) recovery modalities were examined. METHODS: Ten male participants performed three sets, 5 × 5-s all-out treadmill sprints, E:R ratio of 1:5, passive recovery, in seven trials randomly. In four of the seven trials, hypoxic levels were set corresponding to sea level (SL1:5P), 1500 (1.5K1:5P), 2500 (2.5K1:5P), and 3500 m (3.5K1:5P), respectively. In a further two trials, the hypoxic level of 3.5K1:5P was maintained, while the E:R ratio was reduced to 1:4 (3.5K1:4P) and 1:3 (3.5K1:3P), respectively. In the last trial, the passive recovery mode of 3.5K1:5P was changed to active (3.5K1:5A). RESULTS: In comparison to SL1:5P, the averaged peak velocity (P-Vel), mean velocity (M-Vel), and velocity decrement score (Sdec) of the sprints, and the cumulative HR-based training impulse (cTRIMP) in 1.5K1:5P and 2.5K1:5P were well maintained. Minor decrement in the M-Vel was found in 3.5K1:5P. Conversely, lowered E:R ratio in 3.5K1:4P and 3.5K1:3P significantly reduced the P-Vel (≥ -2.3%, Cohen's d ≥ 0.43) and M-Vel (≥ -2.4%, ≥ 0.49), and in 3.5K1:3P altered the Sdec (107%, ≥ 0.96), and cTRIMP (-16%, 1.39), when compared to 3.5K1:5P. Furthermore, mild reductions in M-Vel (-2.6%, 0.5) was observed in 3.5K1:5A using the active recovery mode. Other variables did not change. CONCLUSION: The findings suggest that a 3.5K1:5P marginally maintained sea-level training loads, and as a result, could maximally optimize the training stress of hypoxia.


Asunto(s)
Rendimiento Atlético/fisiología , Fatiga/fisiopatología , Hipoxia/fisiopatología , Consumo de Oxígeno/fisiología , Carrera/fisiología , Prueba de Esfuerzo , Humanos , Masculino , Adulto Joven
6.
J Sports Sci ; 37(11): 1257-1264, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30563431

RESUMEN

This study compared the effects of 12-week sprint interval training (SIT), high-intensity interval training (HIIT), and moderate-intensity continuous training (MICT) on cardiorespiratory fitness (V̇O2peak), body mass and insulin sensitivity in overweight females. Forty-two overweight women (age 21.2 ± 1.4 years, BMI 26.3 ± 2.5 kg·m-2) were randomized to the groups of SIT (80 × 6-s sprints + 9-s rest), and isoenergetic (300KJ) HIIT (~9 × 4-min cycling at 90% V̇O2peak + 3-min rest) and MICT (cycling at 60% V̇O2peak for ~ 61-min). Training intervention was performed 3 d·week-1 for 12 weeks. After intervention, all three groups induced the same improvement in V̇O2peak (~ +25%, p < 0.001) and a similar reduction in body mass (~ - 5%, p < 0.001). Insulin sensitivity and fasting insulin levels were improved significantly on post-training measures in SIT and HIIT by ~26% and ~39% (p < 0.01), respectively, but remain unchanged in MICT. In contrast, fasting glucose levels were only reduced with MICT (p < 0.01). The three training strategies are equally effective in improving V̇O2peak and reducing body mass, however, the SIT is time-efficient. High-intensity training (i.e. SIT and HIIT) seems to be more beneficial than MICT in improving insulin sensitivity. Abbreviations: BMI: body mass index; CVD: cardiovascular disease; HIEG: hyperinsulinaemic euglycaemic glucose; HIIT: high-intensity interval training; HOMA-IR: homeostasis model assessment of insulin resistance; HR: heart rate; MICT: moderate-intensity continuous training; RPE: ratings of perceived exertion; SIT: sprint interval training; T2D: type 2 diabetes; V̇O2peak: peak oxygen consumption.


Asunto(s)
Capacidad Cardiovascular , Terapia por Ejercicio/métodos , Sobrepeso/fisiopatología , Sobrepeso/terapia , Acondicionamiento Físico Humano/métodos , Adulto , Glucemia/metabolismo , Índice de Masa Corporal , Ingestión de Energía , Femenino , Entrenamiento de Intervalos de Alta Intensidad , Humanos , Insulina/sangre , Resistencia a la Insulina , Sobrepeso/sangre , Pérdida de Peso , Adulto Joven
7.
J Sports Sci Med ; 18(3): 479-489, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31427870

RESUMEN

This study examined the effects of a specific core exercise program, as a re-warm-up regime during the half-time period, on inspiratory (IM) and core (CM) muscle functions, leg perfusion and the team sport-specific sprint performance in the initial stage of the second half of a simulated exercise task. Nine team-sports players performed a simulated team-sport intermittent exercise protocol (IEP) in two phases, on a non-motorized treadmill, interspersed by a 15-min half-time break. During the half-time period subsequent to the 25-min Phase-1 IEP, the players either rested passively or performed 4-min CM exercise concomitant with inspiratory loaded breathing following 11-min passive recovery. The changes in IM and CM functions, leg perfusion and repeated-sprint ability mediated by the two recovery modes were compared. Following Phase-1 IEP, there was a significant decline in IM and CM functions respectively, revealed by the decreases in maximal inspiratory pressure (PImax: -8.1%) and performance of a sport-specific endurance plank test (SEPT: -29.7%, p < 0.05). With the 15-min passive recovery, the decline in IM and CM functions from pre-exercise levels were not restored satisfactorily (PImax: -6.4%, SEPT: -19.0%, p < 0.05). Moreover, repeated-sprint ability during the Phase-2 IEP tended to decrease (peak velocity: -2.3%, mean velocity: -2.1%) from the levels recorded in Phase-1. In contrast, following the re-warm-up exercises during half-time, the restoration of IM and CM function was accelerated (PImax: -0.9%, SEPT: -3.3%, p <0 .05). This was associated with enhanced repeated-sprint ability (peak velocity: +3.0%, mean velocity: +2.0%, p < 0.05) in Phase-2 IEP. Nevertheless, the changes in the anterior thigh muscle perfusion assessed by near-infrared spectroscopy following the re-warm-up exercises was not different from that of passive recovery (p > 0.05). The findings suggest that a brief inspiratory-loaded CM exercise regime appears to be an effective re-warm-up strategy that optimizes second-half repeated-sprint performance and core function of players in team sports.


Asunto(s)
Rendimiento Atlético/fisiología , Pierna/fisiología , Músculo Esquelético/fisiología , Músculos Respiratorios/fisiología , Carrera/fisiología , Ejercicio de Calentamiento/fisiología , Estudios Cruzados , Prueba de Esfuerzo/métodos , Humanos , Inhalación , Pierna/irrigación sanguínea , Masculino , Adulto Joven
8.
Exp Physiol ; 103(3): 370-380, 2018 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-29247498

RESUMEN

NEW FINDINGS: What is the central question of this study? Does exercise training impact resting and postexercise cardiac troponin T (cTnT) concentration? What is the main finding and its importance? This randomized controlled intervention study demonstrated that 12 weeks of either high-intensity interval training or moderate-intensity continuous training largely abolished the exercise-induced elevation in cTnT when exercise was performed at the same absolute intensity. There was no impact of training on resting cTnT or postexercise appearance of cTnT when exercise was performed at the same relative intensity. These findings provide new information that might help clinicians with decision-making in relationship to basal and postexercise values of cTnT in individuals with different training status. ABSTRACT: We evaluated the influence of 12 weeks of high-intensity interval training [HIIT; repeated 4 min cycling at 90% of maximal oxygen uptake (V̇O2max) interspersed with 3 min rest, 200-300 kJ per session, 3 or 4 days each week] and work-equivalent moderate-intensity continuous training (MICT; continuous cycling at 60% V̇O2max) on resting cardiac troponin T (cTnT) and the appearance of exercise-induced cTnT. Forty-eight sedentary obese young women were randomly assigned to HIIT, MICT or a control group. The V̇O2max and body composition were measured before and after training. At baseline, cTnT was assessed using a high-sensitivity assay at rest and immediately, 2 and 4 h after 45 min cycling at 60% V̇O2max. After a 12 week training period, cTnT was assessed before and after 45 min cycling at the same relative and absolute intensities as before training. Training led to higher V̇O2max and lower fat mass in both HIIT and MICT groups (all P < 0.05). Before training, cTnT was significantly elevated in all three groups (by 35-118%, all P < 0.05) with acute exercise. After training, both resting and postexercise cTnT concentrations (same relative intensity) were similar to pretraining values. In contrast, postexercise cTnT (same absolute intensity, which represented a smaller exercise stimulus) was not elevated from rest in both HIIT and MICT groups. In conclusion, 12 weeks of either HIIT or MICT largely abolished the postexercise elevation of cTnT concentration when exercise was performed at the same absolute intensity. There was, however, no impact of training on resting cTnT or postexercise appearance of cTnT for exercise performed at the same relative intensity.


Asunto(s)
Ejercicio Físico/fisiología , Entrenamiento de Intervalos de Alta Intensidad , Obesidad/sangre , Acondicionamiento Físico Humano/fisiología , Troponina T/sangre , Adolescente , Adulto , Composición Corporal/fisiología , Femenino , Humanos , Masculino , Consumo de Oxígeno/fisiología , Acondicionamiento Físico Humano/métodos , Descanso , Conducta Sedentaria , Adulto Joven
9.
J Exerc Sci Fit ; 16(1): 16-20, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30662487

RESUMEN

BACKGROUND/OBJECTIVE: This study examined whether time spent at high rates of oxygen consumption (VO2) during 6-s sprint interval exercises (SIE) is a function of recovery interval duration. METHODS: In a randomised crossover study, thirteen male endurance runners performed 40 × 6-s all-out sprints interspersed with 15-s, 30-s and 60-s passive recovery intervals (SIE15, SIE30, and SIE60 trials respectively), and a work duration-matched Wingate-SIE (8 × 30-s all-out sprints with 4-min passive recovery, SIEWin trial). The accumulated exercise time at ≥ 80%, 85%, 90%, 95% and 100% of VO2max, and maximum heart rate (HRmax) in the four trials were compared. RESULTS: During the 6-s SIEs, accumulated time spent at all selected high rates of VO2max increased as recovery time decreased, whilst the SIE work rate decreased (p < .05). In SIEWin, although the exercise lasted longer, the time spent at ≥90% VO2max (74 ±â€¯16 s) was significant less than that in SIE15 (368 ±â€¯63 s, p < .05), yet comparable to that in SIE30 (118 ±â€¯30 s, p > .05), and longer than that in SIE60 (20 ±â€¯14 s, p < .05). The differences between the four trials in accumulated time at high percentages of HRmax were similar to those for VO2, although the temporal characteristics of the increases in HR and VO2 during the SIEs were different. CONCLUSION: In conclusion, the duration of the recovery interval in 6-s SIE protocols appears to be a crucial parameter when sprint interval training is prescribed to enhance aerobic capacity. Further, the SIE15 protocol may represent a potential alternative to 30-s SIEWin in the development of time-efficient aerobic training intervention.

10.
Biomarkers ; 22(3-4): 345-350, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27879166

RESUMEN

CONTEXT: Post-exercise cardiac troponin release has been extensively described in athletic groups but little attention has been given to any role of sex in mediating this phenomenon. OBJECTIVE: We compared the release of cardiac troponin T (cTnT) after endurance running in training-experience, biological-age and maturity-matched young male and female runners. MATERIALS AND METHODS: Nineteen male (training history: 2.3 ± 1.0 years; mean age: 16.1 ± 1.2 years; Tanner stage: 3.7 ± 0.6) and 19 female (training history: 2.2 ± 1.0 years; mean age: 15.9 ± 1.4 years; Tanner stage: 4.0 ± 0.4) runners performed a 21 km run with "all-out" effort. Serum cTnT levels were assessed at pre-exercise (Pre-ex) and at 4 h post-exercise (Post-ex). RESULTS: At Pre-ex, cTnT concentrations were below the 99th percentile value (10 ng.l-1) in 32/38 runners. Post-ex cTnT increased in all subjects but the response was substantially higher (p < 0.05) in males [median (range): 210 (20-1360) ng.l-1] than females [median (range): 80 (10-550) ng.l-1]. At Post-ex, 95% (95% confidence interval: 75-99%) of males and 63% (95% confidence interval: 41-81%) of females (p < 0.05) had cTnT concentrations above the cut-off for acute myocardial infarction. CONCLUSIONS: The present data suggest that post-exercise cTnT elevation occurs in all runners but is augmented in young male compared to female athletes.


Asunto(s)
Ejercicio Físico , Troponina T/sangre , Adolescente , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Infarto del Miocardio/sangre , Resistencia Física , Factores Sexuales
11.
J Aging Phys Act ; 24(4): 516-524, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-26796916

RESUMEN

This study evaluated the effectiveness of the community-based Exercise for Balance Improvement Program (ExBP) in improving dynamic balance (DB) and static balance with compromised sensations and reducing fear of falling (FF) among older nonfallers. Sixty-one participants (70 ± 3 years) at risk for falling were randomly allocated to receive ExBP practice for 16 weeks, Tai Chi (TC), or no treatment (CON) with an 8-week follow-up. The ExBP group exhibited significant improvements in DB (2.18, 95% CI = 1.16-3.19), static balance with compromised vision and somatosensation (ECSS; 0.46, 95% CI = 0.06-0.85), and FF (8.65, 95% CI = 0.52-16.8). After the intervention, the ExBP group showed significantly more improvement than did the CON group in DB, static balance with compromised somatosensation, and ECSS. No significant difference was observed between the ExBP and TC groups. Therefore, the ExBP can be applied as an effective alternative exercise regimen for improving balance and fall efficacy for older nonfallers.


Asunto(s)
Accidentes por Caídas/prevención & control , Ejercicio Físico/fisiología , Miedo , Equilibrio Postural/fisiología , Anciano , Femenino , Humanos , Masculino , Autoeficacia , Método Simple Ciego
12.
J Strength Cond Res ; 30(10): 2942-51, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25162653

RESUMEN

Tong, TK, McConnell, AK, Lin, H, Nie, J, Zhang, H, and Wang, J. "Functional" inspiratory and core muscle training enhances running performance and economy. J Strength Cond Res 30(10): 2942-2951, 2016-We compared the effects of two 6-week high-intensity interval training interventions. Under the control condition (CON), only interval training was undertaken, whereas under the intervention condition (ICT), interval training sessions were followed immediately by core training, which was combined with simultaneous inspiratory muscle training (IMT)-"functional" IMT. Sixteen recreational runners were allocated to either ICT or CON groups. Before the intervention phase, both groups undertook a 4-week program of "foundation" IMT to control for the known ergogenic effect of IMT (30 inspiratory efforts at 50% maximal static inspiratory pressure [P0] per set, 2 sets per day, 6 days per week). The subsequent 6-week interval running training phase consisted of 3-4 sessions per week. In addition, the ICT group undertook 4 inspiratory-loaded core exercises (10 repetitions per set, 2 sets per day, inspiratory load set at 50% post-IMT P0) immediately after each interval training session. The CON group received neither core training nor functional IMT. After the intervention phase, global inspiratory and core muscle functions increased in both groups (p ≤ 0.05), as evidenced by P0 and a sport-specific endurance plank test (SEPT) performance, respectively. Compared with CON, the ICT group showed larger improvements in SEPT, running economy at the speed of the onset of blood lactate accumulation, and 1-hour running performance (3.04% vs. 1.57%, p ≤ 0.05). The changes in these variables were interindividually correlated (r ≥ 0.57, n = 16, p ≤ 0.05). Such findings suggest that the addition of inspiratory-loaded core conditioning into a high-intensity interval training program augments the influence of the interval program on endurance running performance and that this may be underpinned by an improvement in running economy.


Asunto(s)
Ejercicio Físico/fisiología , Músculos Respiratorios/fisiología , Carrera/fisiología , Humanos , Masculino , Consumo de Oxígeno/fisiología , Adulto Joven
13.
J Sports Sci Med ; 13(2): 244-51, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24790475

RESUMEN

This study investigated the occurrence of core muscle fatigue during high-intensity running exercise and its limitation to exercise performance. A secondary aim was to investigate whether respiratory muscle work performed during intense running periods, would contribute to core muscle fatigue. Nine male recreational runners were recruited for two reasons; (1) to perform a continuous treadmill run at 85% VO2max with and without core muscle fatigue in the CR_F and CR trials, respectively; and (2) to mimic the treadmill run-induced respiratory response recorded in the CR trial while subjects were free of whole-body exercise (Mimic trial). The changes in global core muscle function with fatigue in this study were evaluated by performing a sport-specific endurance plank test (SEPT), and the associated influence on running performance was examined by comparing the time to exhaustion during the treadmill run between the CR and CR_F trials. Subsequent to the treadmill run in the CR trial, SEPT (255.7 ± 85.3 vs 177.3 ± 80.6 s) was reduced from baseline in all runners. The reduction correlated (r = 0.67) with the concomitant decline in inspiratory muscle function revealed by maximal inspiratory mouth pressure (PImax: 151.3 ± 18.2 vs 133.3 ± 17.2 cmH2O, p < 0.05). In the Mimic trial, similar results in SEPT (212.3 ± 90.2 s), PImax (129.0 ± 26.7 cmH2O), and correlation (r = 0.77, p < 0.05) were observed following voluntary hyperpneic activity. With the preceded fatigued core muscle workout in the CR_F trial, the running capacity was impaired significantly (10.7 ± 4.5 vs 6.5 ± 2.0 min, p < 0.05). The impairment was correlated (r=0.72) to the SEPT reduction resulting from the workout. The results suggest that a high-intensity maximum run may induce core muscle fatigue in runners. The core muscle fatigue, which may be partly attributed to the corresponding respiratory work, may limit their running endurance. Inspiratory muscle function appears to be essential for core stabilization during the intense running. Key pointsA high-intensity maximum run may induce core muscle fatigue in runners. The core muscle fatigue, which may be partly attributed to the corresponding respiratory work, may limit their running endurance.In support of previous notion, inspiratory muscles may share the work of core stabilization during intense exercise, while simultaneously increasing the demand for breathing.Inspiratory muscle training incorporated into a running specific-core training regime potentially enhances the training effect on the core muscles in a functional manner to deal with the challenges faced during intense exercise.

14.
Appl Physiol Nutr Metab ; 47(9): 949-962, 2022 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-35728265

RESUMEN

This study examined the alterations of heart rate variability (HRV) following iso-duration resistance (RES) and sprint-interval exercises (SIE) by comparing with that of non-exercise control (CON) in 14 non-obese (NOB) and 15 obese (OB) young men. Time and frequency domain measures as well as nonlinear metrics of HRV were assessed before and immediately after exercise, and during every 20 min until 120 min post-exercise. The variables during the first 4 h of actual sleep time at night, and the period of 12-14 h post-exercise were also measured. All trials were scheduled at 20:00. It was found that RES and SIE attenuated the HRV in both NOB and OB (P < 0.05), and the attenuated HRV restored progressively during subsequent recovery. Although the changes in HRV indices among various time points during the recovery period and its interaction across RES, SIE, and CON were not different between NOB and OB, the restoration of the declined HRV indices to corresponding CON level in the 2 exercise trials in OB appeared to be sluggish in relative to NOB. Notwithstanding, post-exercise HRV that recorded during actual sleep at night and during 12-14 h apart from exercise were unvaried among the 3 trials in both groups (P > 0.05). These findings suggest that obesity is likely to be a factor hindering the removal of exercise-induced cardiac autonomic disturbance in young men. Nonetheless, the declined HRV following both the RES and SIE protocols was well restored after a resting period of ∼10 h regardless of obesity. The study was registered at ISRCTN as https://doi.org/10.1186/ISRCTN88544091.


Asunto(s)
Sistema Nervioso Autónomo , Ejercicio Físico , Sistema Nervioso Autónomo/fisiología , Ejercicio Físico/fisiología , Corazón/fisiología , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Obesidad/terapia
15.
Front Physiol ; 13: 925958, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35770195

RESUMEN

Background: The aim of this review was to examine the physiological and psychological benefits of dance and its effects on children and adolescents. We consider the therapeutic benefits of dance and outline the potential of dance as an alternative therapy for certain pathologies and medical disorders. Secondly, we summarize the types of dances used in physical interventions, and comment on the methodologies used. Finally, we consider the use of dance as a different exercise modality that may have benefits for increased physical activity generally, and for increased physical education provision in schools. Methods: A structured search strategy was conducted using the databases of PubMed, MEDLINE, Web of science, PsycARTICLES, and Social Science database. This review used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for systematic reviews. Studies that were published in the past 20 years were considered for inclusion. All written publications were searched for in English, and all articles included in this review were peer reviewed full papers. Conclusion: The key findings from this review indicate that dance is a feasible alternative to traditional physical activity. The findings also indicate that dance provides physiological and psychological benefits to healthy and medically compromised populations. Implementation of dance programs in schools and society generally needs serious consideration by policy makers. We hope that the results of this review stimulate debate and provide the necessary evidence to profile dance as a viable alternative medium of physical activity. Comprehensive and integrated changes will be needed including economical and legislative support from politicians and associated governmental agencies. The findings reported here are important and have implications for health policy change, reconfiguration, and implementation.

16.
Healthcare (Basel) ; 9(2)2021 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-33546247

RESUMEN

BACKGROUND: It has been shown that prolonged exhaustive exercise, such as half-marathon running, could lead to transient post-exercise elevation of cardiac troponins, increase in oxidative stress, and mild decline in renal function in adolescent athletes. With increases in sports participation involving young people, there has been much interest in pre and post health evaluations following exercise. Evaluations can be used to identify pre-existing health confounders and to examine any detrimental responses that may occur post exercise. Study purpose & Methods: The purpose of this study was to evaluate pre and post exercise measures of cardiac function, serum albumin, systemic immunoglobulin (Serum IgA and IgG), cortisol and testosterone in adolescent (age: 16.2 ± 0.6) male endurance runners performing in 21-km maximal run. RESULTS: Results revealed that cortisol, IgA and IgG levels significantly decreased 2, 4, and 24 h post exercise compared to pre-exercise levels (p < 0.05). Testosterone levels reduced 4 h post exercise (p < 0.05) but were restored to baseline values following 24 h. There were no changes recorded for albumin levels post exercise (p > 0.05). ECG assessments did not show any abnormalities at the T wave axis, ST segments and Q wave pre or post exercise. CONCLUSIONS: The findings from this study suggest that a single bout of prolonged maximum running is not likely to induce abnormal electrical activity in the heart, but does decrease serum immunoglobulin, and homeostasis of anabolic and catabolic hormones in trained adolescent endurance runners.

17.
JMIR Res Protoc ; 10(3): e25838, 2021 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-33749611

RESUMEN

BACKGROUND: Childhood obesity accompanied by lower levels of health-related physical fitness (HRPF) is a major threat to public health both internationally and locally. Children with intellectual disability, especially adolescents, have a higher risk of being overweight/obese and having poor HRPF levels. Therefore, more interventions are needed to help this population attain their optimal health levels. However, there has been relatively limited research on this population compared with on their typically developing peers. OBJECTIVE: The proposed study aims to fill this knowledge gap by developing and examining the success of a physical activity (PA) intervention for the target population. METHODS: The proposed study will be a 12-week, school-based randomized controlled trial. The participants (N=48) will be recruited from special schools for students with mild intellectual disability and then randomly allocated to either the intervention group (IG) or the wait-list control group (CG). During the intervention period, the participants in the IG will receive a fun game-based moderate-to-vigorous PA (MVPA) training program (2 sessions/week, 60 minutes/session, for a total of 24 sessions). The intensity of the activities will increase in a progressive manner. Participants in the CG will receive no program during the study period, but the same PA program will be provided to them after the completion of the study. To observe and evaluate the sustaining effects of the intervention, follow-up testing will be scheduled for the participants 12 weeks after the intervention concludes. The study outcomes will include primary outcomes (obesity- and fitness-related outcomes) and a secondary outcome (blood pressure). All of the measurements will be taken at 3 time points. After the follow-up tests, the same PA training program will be provided to the participants in the CG. RESULTS: This study is ongoing. The participants were recruited from October 2020 to November 2020. The total duration of the study is 13 months. Study results are expected at the end of 2021. CONCLUSIONS: The proposed study is expected to reduce obesity and improve HRPF levels in children with intellectual disability. If proven effective, the intervention will be made accessible to more special schools and mainstream schools with students with intellectual disability. Furthermore, the study can serve as an example for international researchers, policy makers, and members of the public who are seeking to tackle the problem of obesity and poor HRPF among children with intellectual disability. TRIAL REGISTRATION: ClinicalTrials.gov NCT04554355; https://www.clinicaltrials.gov/ct2/show/NCT04554355. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/25838.

18.
Front Physiol ; 11: 856, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32848830

RESUMEN

The purpose of this study was to examine the effects of a short-term ketogenic diet (KD) on body composition and cardiorespiratory fitness (CRF) in overweight/obese Chinese females. Twenty young females [age: 21.0 ± 3.7 years, weight: 65.5 ± 7.7 kg, body mass index (BMI): 24.9 ± 2.7 kg⋅m-2] consumed 4 weeks of a normal diet (ND) as a baseline and then switched to a low-carbohydrate, high-fat, and adequate protein KD for another 4 weeks. With the same daily caloric intake, the proportions of energy intake derived from carbohydrates, proteins, and fats were changed from 44.0 ± 7.6%, 15.4 ± 3.3%, 39.6 ± 5.8% in ND to 9.2 ± 4.8%, 21.9 ± 3.4%, and 69.0 ± 5.4% in KD. The results showed that, without impairing the CRF level, the 4-week KD intervention significantly reduced body weight (-2.9 kg), BMI (-1.1 kg⋅m-2), waist circumference (-4.0 cm), hip circumference (-2.5 cm), and body fat percentage (-2.0%). Moreover, fasting leptin level was lowered significantly, and serum levels of inflammatory markers (i.e., TNF-α and MCP-1) were unchanged following KD. These findings suggest that KD can be used as a rapid and effective approach to lose weight and reduce abdominal adiposity in overweight/obese Chinese females without exacerbating their CRF.

19.
Prim Care Diabetes ; 13(6): 568-573, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31109784

RESUMEN

AIMS: To compare postprandial glucose responses to high-intensity interval exercise (HIE) between obese and lean individuals. METHODS: Thirty healthy young adult males (15 obese, 15 lean) ate a standardised meal, then performed HIE (4 × 30-s Wingate cycling/4-min rest) or a no-exercise control trial (CON). Blood glucose was measured preprandially and up to 150 min postprandially. RESULTS: Compared to CON, HIE reduced postprandial glucose concentrations at 120-150 min in obese (p < 0.001) and lean men (p < 0.05), with greater reductions in obese than lean subjects at 120 (-27.0% vs. -8.3%), 135 (-31.9% vs. -15.7%), and 150 min (-21.8% vs. -10.6%). The total glucose area under the curve (AUC) for the testing period was lower with HIE than CON among obese men (p < 0.05), but not lean men (p > 0.05). We found moderate correlations between body mass and postprandial glucose changes (r = 0.39-0.44, p < 0.05), and between glucose AUC and body mass and fat free mass (r = 0.39-0.48, p < 0.05). CONCLUSIONS: Our findings suggest that HIE may act as a time-efficient lifestyle intervention strategy for improving obesity-related diabetes risk factors, and might play a role in primary diabetes prevention for the healthy but sedentary population.


Asunto(s)
Glucemia/metabolismo , Índice de Masa Corporal , Estilo de Vida , Obesidad/fisiopatología , Esfuerzo Físico/fisiología , Periodo Posprandial/fisiología , Delgadez/fisiopatología , Biomarcadores/sangre , Humanos , Masculino , Obesidad/sangre , Delgadez/sangre , Adulto Joven
20.
Front Physiol ; 9: 1048, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30123136

RESUMEN

Introduction: High-intensity interval training (HIIT) is an emerging lifestyle intervention strategy for controlling obesity. HIIT consisted of brief all-out supramaximal sprint intervals was termed as sprint interval training (SIT). This study was designed to examine the time-efficient characteristics of SIT in reducing abdominal visceral fat. Methods: A randomized controlled trial was conducted to compare the specific adaptations of SIT (80 × 6 s all-out cycle sprints interspersed with 9 s passive recovery) with those resulting from a HIIT regimen with training volume relatively higher (repeated 4 min bouts of cycling at 90% V˙ O2max alternated with 3 min rest, until the work of 400KJ was achieved), and with those of nonexercising control counterparts (CON). Forty-six obese young women (body fat percentage ≥30) received either SIT (n = 16), HIIT (n = 16), or no training (n = 14), 3-4 sessions per week, for 12 weeks. The abdominal visceral fat area (AVFA) and abdominal subcutaneous fat area (ASFA) of the participants were measured through computed tomography scans pre-intervention and post-intervention. Total fat mass and the fat mass of the android, gynoid, and trunk regions were assessed through dual-energy X-ray absorptiometry. Results: Following the intervention, abdominal visceral and subcutaneous fat were reduced markedly (p < 0.05). The reduction in AVFA (-6.31, -9.7 cm2) was not different between SIT and HIIT (p > 0.05), while the reduction in ASFA (-17.4, -40.7 cm2) in SIT was less than that in HIIT (p < 0.05). Less reduction in the fat mass of the trunk (-1.2, -2.0 kg) region was also found in SIT, while the reductions in fat percentage (-1.9%, -2.0%), total fat mass (-2.0, -2.8 kg), and fat mass of the android (-0.2, -0.2 kg), and gynoid (-0.4, -0.3 kg) regions did not differ between the two regimes (p > 0.05). In contrast, the increase in V˙ O2max was significant greater following the SIT than HIIT (p < 0.01). No variable changed in CON. Conclusion: Such findings suggest that the lower training load and exercise time commitments of the SIT regime could optimize the time-efficiency advantage of the traditional HIIT, facilitating the abdominal visceral fat reduction in obese young women.

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