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1.
J Sleep Res ; 33(1): e14052, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37803885

RESUMEN

This study aims to investigate the impact of a 40-min nap opportunity on perceived recovery, exertion, and maximal voluntary isometric contraction (MVIC) following the 5-m shuttle run test (5SRT), after 1 night of normal sleep. In a randomised, counterbalanced, cross-over design, 17 trained men (mean [SD] age 20 [3] years, height 173 [6] cm, body mass 68 [6] kg) performed a 5SRT under two conditions: a 40-min nap opportunity and no-nap condition. After both conditions, electromyography signals during a 5-s isometric knee extension were recorded before and immediately after the 5SRT. Two electrical nerve stimulations at the femoral nerve were measured during and after the MVIC. Force, voluntary activation level, M-wave amplitudes, potentiated twitch, and electromyography signals (root mean square) were measured during each MVIC. Perceived exertion was recorded after each repetition of the test and perceived recovery was determined after the end of the MVIC. Compared to the no-nap condition, the 40-min nap resulted in significant enhancements in both the highest distance (p < 0.01, Δ = +7.6%) and total distance (p < 0.01, Δ = +7.5%). Before and after exercise, values for MVIC, root mean square, M-wave amplitudes, and voluntary activation level were improved after the 40-min nap opportunity compared to no-nap condition (all p ≤ 0.01). Values for perceived exertion and recovery were improved after the 40-min nap opportunity in comparison with no-nap condition (p ≤ 0.01). A 40-min nap opportunity improved repeated high-intensity short-term maximal performance, perceived recovery, associated neuromuscular responses, and reduced perceived fatigue. Therefore, our findings suggest that central and peripheral processes are involved in the improvements of 5SRT performance after napping.


Asunto(s)
Fatiga Muscular , Sueño , Humanos , Masculino , Adulto Joven , Electromiografía , Músculo Esquelético/fisiología , Sueño/fisiología
2.
Br J Sports Med ; 58(3): 136-143, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-37923379

RESUMEN

OBJECTIVE: To systematically review, summarise and appraise findings of published systematic reviews, with/without meta-analyses, examining associations between Ramadan fasting observance (RO), health-related indices and exercise test performances in athletes and physically active individuals. DESIGN: Overview of systematic reviews with assessment of reviews' methodological quality. DATA SOURCES: PubMed, Web of Science, Scopus, Cochrane Database of Systematic Reviews, SPORTDiscus, ProQuest, PsycINFO and SciELO. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Systematic reviews with/without meta-analyses examining associations of RO with health-related indices and exercise performances in athletes and physically active individuals. RESULTS: Fourteen systematic reviews (seven with meta-analyses) of observational studies, with low-to-critically-low methodological quality, were included. Two reviews found associations between RO and decreased sleep duration in athletes and physically active individuals. One review suggested athletes may experience more pronounced reductions in sleep duration than physically active individuals. One review found associations between RO and impaired sleep quality in athletes and physically active individuals. RO was associated with decreased energy, carbohydrate and water intake in adult-aged athletes, but not adolescents. One review suggests RO was associated with athletes' increased feelings of fatigue and decreased vigour. No association was found between RO and athletes' lean mass or haematological indices. RO was unfavourably associated with changes in athletes' performance during high-intensity exercise testing. CONCLUSION: Continuance of training during RO could be associated with athletes' mood state disturbances, decreased sleep duration and performance decline during high-intensity exercise testing, while preserving lean mass. However, careful interpretation is necessary due to the low-to-critically-low methodological quality of the included reviews.


Asunto(s)
Rendimiento Atlético , Prueba de Esfuerzo , Humanos , Anciano , Ayuno Intermitente , Revisiones Sistemáticas como Asunto , Ejercicio Físico , Atletas
3.
Biol Sport ; 41(2): 221-241, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38524814

RESUMEN

The rise of artificial intelligence (AI) applications in healthcare provides new possibilities for personalized health management. AI-based fitness applications are becoming more common, facilitating the opportunity for individualised exercise prescription. However, the use of AI carries the risk of inadequate expert supervision, and the efficacy and validity of such applications have not been thoroughly investigated, particularly in the context of diverse health conditions. The aim of the study was to critically assess the efficacy of exercise prescriptions generated by OpenAI's Generative Pre-Trained Transformer 4 (GPT-4) model for five example patient profiles with diverse health conditions and fitness goals. Our focus was to assess the model's ability to generate exercise prescriptions based on a singular, initial interaction, akin to a typical user experience. The evaluation was conducted by leading experts in the field of exercise prescription. Five distinct scenarios were formulated, each representing a hypothetical individual with a specific health condition and fitness objective. Upon receiving details of each individual, the GPT-4 model was tasked with generating a 30-day exercise program. These AI-derived exercise programs were subsequently subjected to a thorough evaluation by experts in exercise prescription. The evaluation encompassed adherence to established principles of frequency, intensity, time, and exercise type; integration of perceived exertion levels; consideration for medication intake and the respective medical condition; and the extent of program individualization tailored to each hypothetical profile. The AI model could create general safety-conscious exercise programs for various scenarios. However, the AI-generated exercise prescriptions lacked precision in addressing individual health conditions and goals, often prioritizing excessive safety over the effectiveness of training. The AI-based approach aimed to ensure patient improvement through gradual increases in training load and intensity, but the model's potential to fine-tune its recommendations through ongoing interaction was not fully satisfying. AI technologies, in their current state, can serve as supplemental tools in exercise prescription, particularly in enhancing accessibility for individuals unable to access, often costly, professional advice. However, AI technologies are not yet recommended as a substitute for personalized, progressive, and health condition-specific prescriptions provided by healthcare and fitness professionals. Further research is needed to explore more interactive use of AI models and integration of real-time physiological feedback.

4.
J Aging Phys Act ; 31(6): 923-929, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37263599

RESUMEN

Prior work, primarily focusing on habitual gait velocity, has demonstrated a cost while walking when coupled with a cognitive task. The cost of dual-task walking is exacerbated with age and complexity of the cognitive or motor task. However, few studies have examined the dual-task cost associated with maximal gait velocity. Thus, this cross-sectional study examined age-related changes in dual-task (serial subtraction) walking at two velocities. Participants were classified by age: young-old (45-64 years), middle-old (65-79 years), and oldest-old (≥80 years). They completed single- and dual-task walking trials for each velocity: habitual (N = 217) and maximal (N = 194). While no significant Group × Condition interactions existed for habitual or maximal gait velocities, the main effects for both condition and age groups were significant (p < .01). Maximal dual-task cost (p = .01) was significantly greater in the oldest-old group. With age, both dual-task velocities decreased. Maximal dual-task cost was greatest for the oldest-old group.


Asunto(s)
Cognición , Marcha , Humanos , Anciano de 80 o más Años , Estudios Transversales , Caminata/psicología
5.
J Strength Cond Res ; 37(6): 1225-1230, 2023 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-34319940

RESUMEN

ABSTRACT: Gills, JL, Spliker, B, Glenn, JM, Szymanski, D, Romer, B, Lu, H-C, and Gray, M. Acute citrulline-malate supplementation increases total work in short lower-body isokinetic tasks for recreationally active females during menstruation. J Strength Cond Res 37(6): 1225-1230, 2023-Citrulline-malate (CM) exhibits acute ergogenic benefits through nitric oxide production (NO) and augmentation of vasodilatory properties. Nitric oxide is upregulated by estrogen and may influence CM's ergogenic efficacy in women. Therefore, the objective of this study was to evaluate the acute effects of CM supplementation on lower-body isokinetic performance in recreationally active women. Nineteen women (23.5 ± 3.1 years; 164.8 ± 7.0 cm; 61.9 ± 27.4 kg; 28.8 ± 8.1% body fat) completed 2 randomized, double-blind, crossover trials consuming CM (8 g CM + 12 g dextrose) or placebo (12 g dextrose). For testing trials, subjects were in the menstruating portion of the follicular phase of their menstrual cycle. Subjects performed a 5-repetition isokinetic leg extension protocol (5RP) followed by a 50-repetition isokinetic leg extension protocol (50RP), 60 minutes after supplement consumption. Repeated measures analysis of variance analysis showed that CM significantly increased total work completed, relative total work, and total work during maximum repetition compared with placebo ( p < 0.05); but no significant performance differences existed between trials for peak torque production ( p = 0.14) for the 5RP. No significant differences were identified between trials for peak torque production ( p = 0.69 ) or total work ( p = 0.33) completed during the 50RP. CM increased total work completed during the 5RP, but provided no ergogenic benefit during the 50RP in recreationally active menstruating women. CM amplifies power-based resistance exercise performance in women during the follicular phase of the menstrual cycle, potentially because of depressed estrogen levels. Additional research is needed to identify timing efficacy of CM to increase sport performance during each phase of the menstrual cycle.


Asunto(s)
Rendimiento Atlético , Menstruación , Humanos , Femenino , Citrulina/farmacología , Malatos/farmacología , Óxido Nítrico , Suplementos Dietéticos , Método Doble Ciego , Glucosa/farmacología , Músculo Esquelético
6.
Biol Sport ; 40(1): 303-309, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36636191

RESUMEN

The aim of the present study was to evaluate the effects of two different formats of small-sided games (SSGs; 2 vs. 2 and 3 vs. 3) on physiological parameters in youth volleyball players. Twelve youth volleyball players (17.2 ± 7.44 years, 1.89 ± 0.6 m, 72.83 ± 8.57 kg) completed three different games formats (regular game (RG): 6 vs. 6, SSG3: 3 vs. 3 and SSG2: 2 vs. 2). associated with two pitch dimensions (i.e., 2 vs. 2 and 3 vs. 3 on 18 × 4.5 m; 6 vs. 6 on 18 × 9 m). Each player performed 4 × 5 min SSG with a recovery period of 1 min between bouts. All players were members of the same youth team and played in a professional league. They had at least 6 years of volleyball training and no current injuries. This study was carried out during the competitive period. Heart rate (HR), blood lactate ([La-]), and rating of perceived exertion (RPE) were measured. Compared to RG, physiological (i.e., HR and [La-]) and RPE responses were significantly higher during SSG3 and SSG2 (all p < 0.05; ƞp 2 = 0.77, ƞp 2 = 0.65, ƞp 2 = 0.30, respectively). Moreover, HR and RPE were significantly higher in SSG2 compared to SSG3. In contrast, no significant differences were observed in [La-] between SSG2 and SSG3. These results suggest that the number of players influences the exercise intensity in small-sided volleyball games in youth players. Therefore, coaches could benefit from incorporating SSGs to manipulate the exercise intensity in youth volleyball players.

7.
Biol Sport ; 40(1): 63-75, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36636199

RESUMEN

This study examined the effects of a six-week preparatory training program on physical performance and physiological adaptations in junior soccer players. Additionally, we investigated whether a relationship existed between external and internal loads. Youth soccer players (aged 16 years old) from a youth football academy participated in six weeks of pre-conditioning training. Wireless Polar Team Pro and Polar heart rate sensors (H10) were used to monitor physical performance indicators (sprint and acceleration scores, covered distance, maximum and average speed and duration), physiological responses (maximum and average heart rate [HR] and R-R interval, time in HR zones 4+5, and heart rate variability [HRV]), and training load score. Additionally, muscle status and rating of perceived exertion (RPE) scores were measured using digital questionnaires. Significant increases were observed in the majority of physical performance indicators [i.e., sprints (p = 0.015, ES = 1.02), acceleration (p = 0.014, ES = 1), total distance (p = 0.02, ES = 0.87), as well as maximum speed (p = 0.02, ES = 0.87)]. A trend towards improvement was observed in the remaining performance indicators (i.e., distance/min and avg speed; ES = 0.6), training load (ES = 0.2), muscle status (ES = 0.3)), and all physiological responses parameters (ES = 0.1 to 0.6). Significant correlations were found between the majority of external load parameters (i.e., performance indicators) and objective (i.e., physiological responses) and subjective (i.e., RPE, muscle status) internal load parameters (p < 0.001). The highest number of moderate-large correlations were registered between performance indicators and time in HR zone 4+5 (0.58 < r < 0.82), training load (0.53 < r < 0.83), average HR (0.50 < r < 0.87), maximal HR (0.51 < r < 0.54) and average R-R interval (0.58 < r < 0.76). HR zone 4+5, average and maximal HR, average R-R interval, and training load score may help control training parameters and reduce the risk of under- or over-training in youth soccer players. However, these conclusions should be confirmed and replicated in future studies with more diverse subject populations.

8.
Biol Sport ; 40(3): 835-855, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37398951

RESUMEN

The purpose of this investigation is to estimate the global disease burden attributable to low physical activity (PA) in 204 countries and territories from 1990 to 2019 by age, sex, and Socio-Demographic Index (SDI). Detailed information on global deaths and disability-adjusted life years (DALYs) attributable to low PA were collected from the Global Burden of Disease Study 2019. The ideal exposure scenario of PA was defined as 3000-4500 metabolic equivalent minutes per week and low PA was considered to be less than this threshold. Age-standardization was used to improve the comparison of rates across locations or between time periods. In 2019, low PA seems to contribute to 0.83 million [95% uncertainty interval (UI) 0.43 to 1.47] deaths and 15.75 million (95% UI 8.52 to 28.62) DALYs globally, an increase of 83.9% (95% UI 69.3 to 105.7) and 82.9% (95% UI 65.5 to 112.1) since 1990, respectively. The age-standardized rates of low-PA-related deaths and DALYs per 100,000 people in 2019 were 11.1 (95% UI 5.7 to 19.5) and 198.4 (95% UI 108.2 to 360.3), respectively. Of all age-standardized DALYs globally in 2019, 0.6% (95% UI 0.3 to 1.1) may be attributable to low PA. The association between SDI and the proportion of age-standardized DALYs attributable to low PA suggests that regions with the highest SDI largely decreased their proportions of age-standardized DALYs attributable to low PA during 1990-2019, while other regions tended to have increased proportions in the same timeframe. In 2019, the rates of low-PA-related deaths and DALYs tended to rise with increasing age in both sexes, with no differences between males and females in the age-standardized rates. An insufficient accumulation of PA across the globe occurs together with a considerable public health burden. Health initiatives to promote PA within different age groups and countries are urgently needed.

9.
J Sleep Res ; 31(3): e13503, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-34693577

RESUMEN

The purpose of this systematic review and meta-analysis is to provide an accurate description of the effect of Ramadan observance on sleep duration, sleep quality, daily nap duration, and daytime sleepiness in athletes and physically active individuals. Five electronic databases (PubMed, Web of Science, Scopus, Wiley, and Taylor and Francis) were used to search for relevant studies conducted with athletes or physically active individuals during Ramadan, published in any language, and available before May 23, 2021. Studies that included assessments of sleep quantity and/or quality, and/or daytime sleepiness, and/or daily naps in athletes and physically active individuals were included. The methodological quality of the studies was assessed using "QualSyst". Of the 18 papers included in this study (298 participants in total), 14 were of strong quality, two were moderate, and the remaining two were rated as weak. Individuals who continued to train during Ramadan experienced a decrease in sleep duration (number of studies, K = 17, number of participants, N = 289, g = -0.766, 95% confidence interval [CI] -1.199 to -0.333, p = 0.001). Additionally, the global score of the Pittsburgh Sleep Quality Index increased from 4.053 (K = 5, N = 65, 95% CI 3.071-5.034) pre-Ramadan, to 5.346 (95% CI 4.362-6.333) during Ramadan, indicating a decrease in sleep quality. The duration of daytime naps increased during compared to pre-Ramadan (K = 2, N = 31, g = 1.020, 95% CI 0.595-1.445, p = 0.000), whereas Epworth Sleepiness Scale scores remained unchanged during versus pre-Ramadan (K = 3, N = 31, g = 0.190, 95% CI -0.139-0.519, p = 0.257). In conclusion, individuals who continued to train during Ramadan experienced a decrease in sleep duration, impairment of sleep quality, and increase in daytime nap duration, with no change in daytime sleepiness levels.


Asunto(s)
Trastornos de Somnolencia Excesiva , Islamismo , Atletas , Ayuno , Humanos , Sueño
10.
J Aging Phys Act ; 30(4): 678-688, 2022 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-34706338

RESUMEN

Lower-body power measured by a linear position transducer during the sit-to-stand (STS) movement declines with age and may be a predictor of physical disability in older adults. The purpose of this study was to establish normative data for STS power across the lifespan and to determine if differences exist between age cohorts, sexes, and age cohort-sex subgroups. Adults (N = 557) aged 18-89 were divided into five age cohorts and performed the STS connected to a linear position transducer, which calculated power and velocity during the movement. Significantly lower (p < .01) velocity was observed in a younger age cohort in females than males, whereas males saw a significant average power decrement (p < .01) in a younger age cohort than females. STS power norms give clinicians a metric predicting physical disability and may be of particular interest to males as their power production begins to decline at an earlier age.


Asunto(s)
Longevidad , Movimiento , Anciano , Estudios Transversales , Femenino , Humanos , Masculino
11.
Biol Sport ; 38(3): 391-396, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34475622

RESUMEN

Although recognized as effective measures to curb the spread of the COVID19 outbreak, social distancing and home confinement have generated a mental health burden with older adults who are considered to be more vulnerable to psychosocial strains. To date, the application of digital technologies in response to COVID-19 pandemic has been narrowed to public-health needs related to containment and mitigation. However, information and communications technology (ICT)-based initiatives directed toward prediction and prevention of psychosocial support are still limited. Given the power of digital health solutions to allow easy and accurate characterization and intervention for health and disease, as well as to flatten the COVID19 incidence curves in many countries, our ECLB-COVID19 consortium is highlighting the importance of providing innovative ICT-based solutions (ICT-COVID-Companion) to improve elderly physical and mental health, thereby preventing/dampening psychosocial strain during pandemics. Based on innovative approaches (e.g., emotional/social computing, open social platform, interactive coaching, gamification, fitness-tracker, internet of things) and smart digital solutions (smartwatch/smartphone), smart companions must provide safe personalised physical, mental and psychosocial health surveillance. Additionally, by delivering personalised multi-dimension crisis-oriented health recommendations, such innovative crisis-oriented solutions would help (i) facilitate a user's adherence to active and healthy confinement lifestyle (AHCL), (ii) achieve a rapid psychosocial recovery in case of depression issues and (iii) enhance preparedness for eventual future pandemics.

12.
Biol Sport ; 38(1): 9-21, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33795912

RESUMEN

Although recognised as effective measures to curb the spread of the COVID-19 outbreak, social distancing and self-isolation have been suggested to generate a burden throughout the population. To provide scientific data to help identify risk factors for the psychosocial strain during the COVID-19 outbreak, an international cross-disciplinary online survey was circulated in April 2020. This report outlines the mental, emotional and behavioural consequences of COVID-19 home confinement. The ECLB-COVID19 electronic survey was designed by a steering group of multidisciplinary scientists, following a structured review of the literature. The survey was uploaded and shared on the Google online survey platform and was promoted by thirty-five research organizations from Europe, North Africa, Western Asia and the Americas. Questions were presented in a differential format with questions related to responses "before" and "during" the confinement period. 1047 replies (54% women) from Western Asia (36%), North Africa (40%), Europe (21%) and other continents (3%) were analysed. The COVID-19 home confinement evoked a negative effect on mental wellbeing and emotional status (P < 0.001; 0.43 ≤ d ≤ 0.65) with a greater proportion of individuals experiencing psychosocial and emotional disorders (+10% to +16.5%). These psychosocial tolls were associated with unhealthy lifestyle behaviours with a greater proportion of individuals experiencing (i) physical (+15.2%) and social (+71.2%) inactivity, (ii) poor sleep quality (+12.8%), (iii) unhealthy diet behaviours (+10%), and (iv) unemployment (6%). Conversely, participants demonstrated a greater use (+15%) of technology during the confinement period. These findings elucidate the risk of psychosocial strain during the COVID-19 home confinement period and provide a clear remit for the urgent implementation of technology-based intervention to foster an Active and Healthy Confinement Lifestyle AHCL).

13.
Telemed J E Health ; 26(4): 477-481, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31161968

RESUMEN

Introduction:Widespread screening for cognitive decline is an important challenge to address as the aging population grows, but there is currently a shortage of clinical infrastructure to meet the demand for in-person evaluation. Remotely delivered assessments that utilize eye-tracking data from webcams, such as visual paired comparison (VPC) tasks, could increase access to remote, asynchronous neuropsychological screening for cognitive decline but further validation against clinical-grade eye trackers is required.Methods:To demonstrate equivalence between a novel automated scoring system for eye-tracking metrics acquired through a laptop-embedded camera and a gold-standard eye tracker, we analyzed VPC data from 18 subjects aged 50+ with normal cognitive function across three visits. The eye tracker data were scored by the manufacturer's software, and the webcam data were scored by a novel algorithm.Results:Automated scoring of webcam-based VPC data revealed strong correlations with the clinical-grade eye-tracking camera. Correlation of mean VPC performance across all time points was robust: r = 0.95 (T1 r = 0.97; T2 r = 0.88; T3 r = 0.97; p's < 0.001). Correlation of per-trial performance across time points was also robust: r = 0.88 (T1 r = 0.85; T2 r = 0.89; T3 r = 0.92; p's < 0.001). Mean differences between performance data acquired by each device were 0.00.Conclusion:These results suggest that device-embedded cameras are a valid and scalable alternative to traditional laboratory-based equipment for gaze-based tasks measuring cognitive function. The validation of this technique represents an important technical advance for the field of teleneuropsychology.


Asunto(s)
Disfunción Cognitiva , Tecnología de Seguimiento Ocular , Anciano , Envejecimiento , Cognición , Humanos , Persona de Mediana Edad , Programas Informáticos
14.
J Strength Cond Res ; 32(2): 565-571, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29369956

RESUMEN

Stone, MS, Glenn, JM, Vincenzo, JL, and Gray, M. Comparison of exercise performance in recreationally active and masters athlete women. J Strength Cond Res 32(2): 565-571, 2018-Master athletes (MA) are an understudied, ever-growing cohort. As such, it is important to examine how age affects muscular power and fatigability. Of particular interest is muscular power maintenance and fatigue mitigation of MA compared with young, healthy adults. The purpose of this investigation was to examine the differences in peak power, average power, total work (WRK), and fatigue index (FI) between recreationally active (RA) younger adults and female MA during anaerobic cycling exercise. Two groups, RA (n = 15; 20.6 ± 0.8 years) and MA (n = 17; 50.5 ± 8.6 years), participated in this study. Peak power, APWR, WRK, and FI were measured during a 30-second Wingate maximum anaerobic cycling protocol at a predetermined resistance of 7.5% body mass. Peak power (p = 0.92; RA: 654.1 ± 114.5 W; MA: 658.6 ± 147.6 W), APWR (p = 0.09; RA: 429.8 ± 73.3 W; MA: 384 ± 73.8 W), WRK (p = 0.09; RA: 12,894.3 ± 2,198.3 J; MA: 18,044.3 ± 27,184.9 J), and FI (p = 0.30; RA: 11.8 ± 4.1 W·s; MA: 14 ± 5.2 W·s) were not significantly different between groups. Master athletes produce power and WRK comparable to rates of fatigue among RA. This suggests that MA can maintain physical ability similar to RA in multiple parameters of high-intensity exercise while mitigating fatigue comparably. These data allow for advancements in exercise training and performance outcomes in MA populations. Further research within the MA population is warranted regarding other aspects of exercise and sport performance.


Asunto(s)
Atletas , Ciclismo/fisiología , Ejercicio Físico/fisiología , Fatiga Muscular/fisiología , Adulto , Anciano , Índice de Masa Corporal , Estudios Transversales , Prueba de Esfuerzo , Femenino , Humanos , Persona de Mediana Edad , Adulto Joven
15.
Eur J Nutr ; 56(2): 775-784, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26658899

RESUMEN

PURPOSE: Citrulline malate (CM) is a nonessential amino acid that increases exercise performance in males. However, based on physiological differences between genders, these results cannot be extrapolated to females. Therefore, the purpose of this investigation was to evaluate effects of acute CM supplementation on upper- and lower-body weightlifting performance in resistance-trained females. METHODS: Fifteen females (23 ± 3 years) completed two randomized, double-blind trials consuming either CM (8 g dextrose + 8 g CM) or a placebo (8 g dextrose). One hour after supplement consumption, participants performed six sets each of upper- (i.e., bench press) and lower-body (i.e., leg press) exercises to failure at 80 % of previously established one-repetition maximum. Immediately after each set, repetitions completed, heart rate and rating of perceived exertion (RPE) were recorded. RESULTS: Repeated-measures analysis of variance indicated that subjects completed significantly (p = .045) more repetitions throughout upper-body exercise when consuming CM versus placebo (34.1 ± 5.7 vs. 32.9 ± 6.0, respectively). When consuming CM, similar significant (p = .03) improvements in total repetitions completed were observed for lower-body exercise (66.7 ± 30.5 vs. 55.13 ± 20.64, respectively). Overall RPE score was significantly lower (p = .02) in upper-body exercise when subjects consumed CM versus placebo (7.9 ± 0.3 and 8.6 ± 0.2, respectively). The supplement consumed exhibited no significant effects on heart rate at any time point. CONCLUSIONS: Acute CM supplementation in females increased upper- and lower-body resistance exercise performance and decreased RPE during upper-body exercise. These data indicate that athletes competing in sports with muscular endurance-based requirements may potentially improve performance by acutely supplementing CM.


Asunto(s)
Rendimiento Atlético , Citrulina/análogos & derivados , Suplementos Dietéticos , Malatos/administración & dosificación , Músculo Esquelético/fisiología , Sustancias para Mejorar el Rendimiento/administración & dosificación , Fenómenos Fisiológicos en la Nutrición Deportiva , Levantamiento de Peso , Adulto , Atletas , Citrulina/administración & dosificación , Citrulina/efectos adversos , Citrulina/uso terapéutico , Estudios Cruzados , Suplementos Dietéticos/efectos adversos , Método Doble Ciego , Fatiga/epidemiología , Fatiga/etiología , Fatiga/prevención & control , Femenino , Frecuencia Cardíaca , Humanos , Malatos/efectos adversos , Malatos/uso terapéutico , Sustancias para Mejorar el Rendimiento/efectos adversos , Sustancias para Mejorar el Rendimiento/uso terapéutico , Esfuerzo Físico , Prevalencia , Entrenamiento de Fuerza , Estados Unidos/epidemiología , Adulto Joven
16.
J Aging Phys Act ; 25(2): 305-310, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27768504

RESUMEN

This investigation examined differences in functional sit-to-stand power/velocity between cohorts of adults aged 18-97 years. This study included 264 healthy adults classified into four cohorts (18-40, C1; 60-69, C2; 70-79, C2; ≥ 80, C4). Participants completed the sit-to-stand task five times. Power and velocity were measured via the TENDO power analyzer. Absolute average power was maintained from C1-C3, but decreased (p < .01) in C4. Absolute peak power decreased between C1-C2 (p < .01), was similar between C2-C3, and decreased in C4 (p < .01). Relative (to body weight) average and peak power decreased between C1-C2 (p < .01), was similar between C2-C3, and decreased in C4 (p < .01). Average velocity was similar between C1 and C2, but decreased in C3 (p < .01) and C4 (p < .01), respectively. Peak velocity was significantly different between all cohorts (p < .01). Declines in functional power may plateau during the seventh and eighth decades, accelerating after 80 years.


Asunto(s)
Envejecimiento/fisiología , Extremidad Inferior/fisiología , Fuerza Muscular/fisiología , Músculo Esquelético/fisiología , Aptitud Física/fisiología , Actividades Cotidianas , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad
17.
Aging Clin Exp Res ; 28(4): 679-86, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26458942

RESUMEN

BACKGROUND: Clinical functional assessments of balance often lack specificity and sensitivity in discriminating and predicting falls among community-dwelling older adults. AIMS: We determined the feasibility of using a smart-device application measuring balance to discriminate fall status among older adults. We also evaluated differences between smart-device balance measurements when secured with or without a harness. METHODS: A cross-sectional study design to determine the ability of the Sway Balance smart-device application (SWAY) to discriminate older adults based on fall history. The Berg Balance Scale (BBS) and Activities-Specific Balance Confidence Scale (ABC) were used as comparative, clinically based assessments. Community-dwelling older adults with (n = 25) and without (n = 32) a history of fall(s) participated. Multivariate analysis of variance was used to determine differences among assessments based on fall history. Logistic regression models determined the ability of each assessment to discriminate fall history. RESULTS: Older adults with and without a history of falls were not significantly different on SWAY (P = 0.92) but were different on BBS (P = 0.01), and ABC (P < 0.001). Similarly, SWAY did not discriminate fall history (P = 0.92), while BBS and ABC both discriminated fall history (P < 0.01). Paired t tests between SWAY scores with and without a harness indicated no differences (P ≥ 0.05). CONCLUSION: Among the older adults studied, the BBS and ABC measures discriminated groups defined by fall history, while the SWAY smart-device balance application did not. Modifications to the application may improve the discriminating ability of the measure in the recognition of fall status in older adults.


Asunto(s)
Accidentes por Caídas , Equilibrio Postural , Adulto , Anciano , Estudios Transversales , Femenino , Humanos , Modelos Logísticos , Masculino
18.
J Aging Phys Act ; 24(4): 501-507, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-26796422

RESUMEN

Muscular power decreases with age, and lower-body power relates to overall functional fitness; however, functional lower-body power has not been evaluated in late-middle-aged (LMA) populations. PURPOSE: To evaluate average and peak lower-body functional power and velocity among sedentary (SED), recreationally active (RA), and masters athlete (MA) LMA adults. METHODS: Participants were SED (n = 13, age = 59.3 ± 4.5 years), RA (n = 35, age = 59.6 ± 5.0 years), and MA (n = 26, age = 56.7 ± 5.4 years). Five sit-to-stand trials were completed to assess lower-body functional power. Average/peak power and velocity were calculated for each trial. Power was expressed relatively to account for participant body weight. RESULTS: MA (13.44 ± 2.76 W/kg) had significantly (p < .01) greater peak power compared with SED (9.99 ± 2.70 W/ kg) and RA (9.93 ± 2.30 W/kg). Similar significant (p < .01) differences existed for peak velocity (SED = 1.02 ± 0.22 m/s, RA = 1.04 ± 0.22 m/s, MA = 1.25 ± 0.19 m/s). No differences existed for average power or velocity between groups. CONCLUSIONS: Maintaining a competitively active lifestyle results in greater lower-body functional power in LMA adults and may support longitudinal functionality.


Asunto(s)
Envejecimiento/fisiología , Atletas , Extremidad Inferior/fisiología , Fuerza Muscular/fisiología , Conducta Sedentaria , Actividades Cotidianas , Arkansas , Composición Corporal , Femenino , Humanos , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios
19.
J Strength Cond Res ; 30(1): 200-7, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26110349

RESUMEN

Beta-alanine (BA) supplementation increases exercise performance due to increases in the intramuscular lactate buffer, carnosine. Females are more sensitive to these increases and results are further pronounced in trained individuals. Baseline intramuscular carnosine levels also naturally decrease with age; therefore, trained older females may experience augmented benefits from BA supplementation. However, the ability of BA to increase lower-body isokinetic strength (ISO) in female masters athletes (MA) is unknown. The purpose of this study was to examine the longitudinal effects of BA supplementation on ISO, handgrip strength (HG), and body composition in female MA cyclists. Twenty-two subjects participated in this double-blind randomized study. Subjects were randomized into 2 groups (placebo [PLA] = 8 g dextrose; BA = 800 mg + 8 g dextrose) and supplemented 4 times per day for 28 days. ISO, HG, and body composition were evaluated at baseline and at the same day/time each week over the 28-day intervention. No differences existed between groups at baseline or at the 7, 14, and 21 days time points for any variables (p > 0.05). When evaluating ISO (isokinetic) after 28 days, total work performed during the final third of the assessment (24.0 vs. -16.8% change) in flexion and average peak torque (5.4 vs. 2.9% change) in extension were significantly increased from baseline in BA compared with PLA (p ≤ 0.05). No differences existed for HG or body composition after supplementation. Twenty-eight days of BA supplementation increased peak torque and work completed, indicating BA improves lower-body exercise performance in female MA.


Asunto(s)
Rendimiento Atlético , Composición Corporal/efectos de los fármacos , Fuerza Muscular/efectos de los fármacos , Sustancias para Mejorar el Rendimiento/farmacología , beta-Alanina/farmacología , Suplementos Dietéticos , Método Doble Ciego , Esquema de Medicación , Prueba de Esfuerzo , Femenino , Fuerza de la Mano , Humanos , Persona de Mediana Edad , Fuerza Muscular/fisiología , Sustancias para Mejorar el Rendimiento/administración & dosificación , beta-Alanina/administración & dosificación
20.
Age Ageing ; 44(6): 926-31, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26163681

RESUMEN

BACKGROUND: Physical function declines up to 4% per year after the age of 65. High-velocity training is important for maintaining muscular power and ultimately, physical function; however, whether performing high-velocity training without external resistance increases functional fitness among older adults remains unclear. OBJECTIVE: The purpose of this investigation was to evaluate loaded and unloaded high-velocity training on lower body muscular power and functional fitness in older adults. SUBJECTS: Fifty-seven community-dwelling older adults (n = 16 males, n = 41 females) participated in this study. Inclusion criteria comprised ≥65 years of age, ≥24 on the Mini-mental state examination and no falls within past year. METHODS: Two groups completed a 20-week high-velocity training intervention. The non-weighted group (UNLOAD, n = 27) performed the protocol without external load while the intervention group (LOAD, n = 30) used external loads via exercise machines. Functional fitness was assessed using the Short Physical Performance Battery (SPPB), Senior Fitness Test (SFT), hand-grip and lower body power measures. RESULTS: Multivariate ANOVA revealed that both groups had significant improvements for average (17.21%) and peak (9.26%) lower body power, along with the SFT arm curl (16.94%), chair stand (20.10%) and 8 ft. up-and-go (15.67%). Improvements were also noticed for SPPB 8 ft. walk (25.21%). However, improvements for all functional fitness measures were independent of training group. CONCLUSIONS: Unloaded high-velocity training increased functional fitness and power the same as loaded training. The ability of high-velocity movements to elicit gains in functional fitness without external loads may help health professionals develop fitness programs when time/space is limiting factor.


Asunto(s)
Aptitud Física , Entrenamiento de Fuerza/métodos , Anciano , Femenino , Humanos , Vida Independiente , Masculino , Fuerza Muscular , Soporte de Peso
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