Search results for "RC1200"
showing 10 items of 174 documents
A standard calculation methodology for human doubly labeled water studies.
2021
Summary The doubly labeled water (DLW) method measures total energy expenditure (TEE) in free-living subjects. Several equations are used to convert isotopic data into TEE. Using the International Atomic Energy Agency (IAEA) DLW database (5,756 measurements of adults and children), we show considerable variability is introduced by different equations. The estimated rCO2 is sensitive to the dilution space ratio (DSR) of the two isotopes. Based on performance in validation studies, we propose a new equation based on a new estimate of the mean DSR. The DSR is lower at low body masses (<10 kg). Using data for 1,021 babies and infants, we show that the DSR varies non-linearly with body mass betw…
Representation of physical activity domains and sedentary behaviors across categories of gender and disability in children’s TV cartoons
2018
Television (TV) cartoons could reflect and shape social values about children’s health-related behaviors. The main aim of this study is to analyze the portrayal of physical activity (PA) domains in the most popular Spanish children’s television (TV) cartoons. It is performed a content analysis of each scene following a coding scheme. The sample selected included the five most popular children’s TV cartoons for the 2013-2014 period in Spain. Our results show a large gap between the modest representation of different PA domains compared to the overwhelming depiction of sedentary behaviors. We do not find evidence of males and females participating equally in a variety of PA domains, and we fa…
In vivo localized gastrocnemius subtendon representation within the healthy and ruptured human Achilles tendon
2022
The Achilles tendon (AT) is composed of three distinct in-series elastic subtendons, arising from different muscles in the triceps surae. Independent activation of any of these muscles is thought to induce sliding between the adjacent AT subtendons. We aimed to investigate displacement patterns during voluntary contraction (VOL) and selective transcutaneous stimulation of medial (MGstim) and lateral (LGstim) gastrocnemius between ruptured and healthy tendons, and to examine the representative areas of AT subtendons. Twenty-eight patients with unilateral AT rupture performed bilateral VOL at 30% of the maximal isometric un-injured plantarflexion torque. AT displacement was analysed from sagi…
The relationship between the incidence of winners/errors and the time spent in different areas of the court in elite tennis
2013
Martinez-Gallego R, Guzman JF, James N, Ramon-Llin J, Crespo M, Vuckovic G. The relationship between the incidence of winners/errors and the time spent in different areas of the court in elite tennis. J. Hum. Sport Exerc. Vol. 8, No. Proc3, pp. S601-S607, 2013. Winners and errors have been two of the most studied performance indicators in tennis, contributing to the prediction of match outcome and definition of the playing style of the players. Furthermore, the position occupied by the player on the court has also been shown to be a good indicator of both the final result and style of play. The aim of this study was to examine whether there were differences between game winners and losers i…
Sport burnout inventory–Dual career form for student-athletes: Assessing validity and reliability in a Finnish sample of adolescent athletes
2020
Background: The pressure of pursuing an athletic career simultaneously with education may set adolescent student-athletes at risk for sport and school burnout. Although the 2 life domains of student-athletes are strongly intertwined, so far, there has not been an instrument for investigating sport burnout parallel to school burnout. The aim of the present study was to introduce a sport burnout measure for adolescents in a dual career context and investigate its validity and reliability by using confirmatory factor analysis. Methods: The participants were 391 student-athletes (51% females) who filled in a questionnaire of sport burnout and background variables in the beginning of upper secon…
Daily energy expenditure through the human life course
2021
Total daily energy expenditure (“total expenditure”, MJ/d) reflects daily energy needs and is a critical variable in human health and physiology, yet it is unclear how daily expenditure changes over the life course. Here, we analyze a large, globally diverse database of total expenditure measured by the doubly labeled water method for males and females aged 8 days to 95 yr. We show that total expenditure is strongly related to fat free mass in a power-law manner and identify four distinct metabolic life stages. Fat free mass-adjusted daily expenditure accelerates rapidly in neonates (0-1yr) to ~46% above adult values at ~1 yr, declines slowly throughout childhood and adolescence (1-20 yr) t…
Effects of caffeine on neuromuscular function in a non‐fatigued state and during fatiguing exercise
2020
New findings What is the central question of the study? What are the effects of caffeine on neuromuscular function in a non-fatigued state and during fatiguing exercise? What is the main finding and its importance? In a non-fatigued state, caffeine decreased the duration of the silent period evoked by transcranial magnetic stimulation. Caffeine-induced reduction of inhibitory mechanisms in the central nervous system before exercise was associated with an increased performance. Individuals who benefit from caffeine ingestion may experience lower perception of effort during exercise and an accelerated recovery of M-wave amplitude postfatigue. This study elucidates the mechanisms of action of …
Time-restricted eating effects on performance, immune function, and body composition in elite cyclists: a randomized controlled trial.
2020
Abstract Background Although there is substantial interest in intermittent fasting as a dietary approach in active individuals, information regarding its effects in elite endurance athletes is currently unavailable. The present parallel randomized trial investigated the effects of a particular intermittent fasting approach, called time-restricted eating (TRE), during 4 weeks of high-level endurance training. Methods Sixteen elite under-23 cyclists were randomly assigned either to a TRE group or a control group (ND). The TRE group consumed 100% of its estimated daily energy needs in an 8-h time window (from 10:00 a.m. to 6:00 p.m.) whilst energy intake in the ND group was distributed in 3 me…
Striated muscle-specific serine/threonine-protein kinase beta (SPEGβ) segregates with high- versus low-responsiveness to endurance exercise training
2019
Bidirectional selection for either high or low responsiveness to endurance running has created divergent rat phenotypes of high-response trainers (HRT) and low-response trainers (LRT). We conducted proteome profiling of HRT and LRT gastrocnemius of 10 female rats (body weight 279 ± 35 g; n = 5 LRT and n = 5 HRT) from generation 8 of selection. Differential analysis of soluble proteins from gastrocnemius was conducted by label-free quantitation. Genetic association studies were conducted in 384 Russian international-level athletes (age 23.8 ± 3.4 yr; 202 men and 182 women) stratified to endurance or power disciplines. Proteomic analysis encompassed 1,024 proteins, 76 of which exhibited stat…
Is device-measured vigorous physical activity associated with health-related outcomes in children and adolescents? A systematic review and meta-analy…
2021
Highlights • Higher vigorous-intensity physical activity seems to be negatively related to adiposity and cardiometabolic risk score among children and adolescents later in life. • Higher vigorous-intensity physical activity is positively related to cardiorespiratory fitness and total body bone mineral density among children and adolescents later in life. • The present results support the need to further strengthen vigorous-intensity physical activity recommendations for children and adolescents.