scholarly journals High-Intensity Multimodal Training for Young People: It's Time to Think Inside the Box!

2021 ◽  
Vol 12 ◽  
Author(s):  
Paulo Gentil ◽  
Claudio Andre Barbosa de Lira ◽  
Rodrigo Luiz Vancini ◽  
Rodrigo Ramirez-Campillo ◽  
Daniel Souza
Keyword(s):  
Young People ◽  
High Intensity ◽  
Multimodal Training

Polarized Versus High-Intensity Multimodal Training in Recreational Runners

2019 ◽  
Vol 14 (1) ◽  
pp. 105-112 ◽  
Author(s):  
Andrew J. Carnes ◽  
Sara E. Mahoney
Keyword(s):  
Body Composition ◽  
Oxygen Uptake ◽  
Endurance Training ◽  
Maximal Oxygen Uptake ◽  
High Intensity ◽  
Time Trial ◽  
Lower Volume ◽  
High Zone ◽  
Multimodal Training ◽  
Recreational Runners

Purpose: This study longitudinally compared changes in running performance (5-km time trial) and fitness (maximal oxygen uptake [VO2max] and body composition [BC]) between polarized training and CrossFit Endurance (CFE) in recreational runners. Methods: Participants (N = 21) completed 12 wk of CFE or polarized endurance training (POL). Both groups trained 5 d·wk−1. POL ran 5 d·wk−1, whereas CFE ran 3 d·wk−1 and performed CrossFit 3 d·wk−1 (run + CrossFit 1 d·wk−1). Intensity was classified as low, moderate, or high (zone 1, 2, or 3) according to ventilatory thresholds. POL was prescribed greater volume (295 [67] min·wk−1), distributed as 85%/5%/10% in Z1/Z2/Z3. CFE emphasized a lower volume (110 [18] min·wk−1) distribution of 48%/8%/44%. Results: POL ran 283 (75.9) min·wk−1 and 47.3 (11.6) km·wk−1, both exceeding the 117 (32.2) min·wk−1 and 19.3 (7.17) km·wk−1 in CFE (P < .001). The POL distribution (74%/11%/15%) had greater total and percentage Z1 (P < .001) than CFE (46%/15%/39%), which featured higher percentage Z3 (P < .001). Time trial improved −93.8 (40.4) s (−6.21% [2.16%]) in POL (P < .001) and −84.2 (65.7) s (−5.49% [3.56%]) in CFE (P = .001). BC improved by −2.45% (2.59%) fat in POL (P = .02) and −2.62% (2.53%) in CFE (P = .04). The magnitude of improvement was not different between groups for time trial (P = .79) or BC (P = .88). Both groups increased VO2max (P ≤ .01), but with larger magnitude (P = .04, d = 0.85) in POL (4.3 [3.6] mL·kg·min−1) than CFE (1.78 [1.9] mL·kg·min−1). Conclusions: Recreational runners achieved similar improvement in 5-km performance and BC through polarized training or CFE, but POL yielded a greater increase in VO2max. Extrapolation to longer distances requires additional research.

scholarly journals Student Employment and Education: A Meta-Analysis

2021 ◽  
Author(s):  
Katerina Kroupova ◽  
Tomas Havranek ◽  
Zuzana Irsova
Keyword(s):  
Young People ◽  
Publication Bias ◽  
Educational Outcomes ◽  
High Intensity ◽  
Meta Analysis ◽  
Model Averaging ◽  
Student Employment ◽  
Frequentist Model Averaging

Educational outcomes have many determinants, but one that most young people can readily control is choosing whether to work while in school. Sixty-nine studies have estimated the effect, but results vary from large negative to positive estimates. We show that the results are systematically driven by context, publication bias, and treatment of endogeneity. Studies ignoring endogeneity suffer from an upward bias, which is almost fully compensated by publication selection in favor of negative estimates. Net of the biases, the literature suggests a negative but economically inconsequential mean effect. The effect is more negative for high-intensity employment and educational outcomes measured as decisions to dropout, but it is positive in Germany. To derive these results we collect 861 previously reported estimates together with 32 variables reflecting estimation context, use recently developed nonlinear techniques to correct for publication bias, and employ Bayesian and frequentist model averaging to assign a pattern to the heterogeneity in the literature.

scholarly journals Explaining the Maximal Intensity Exercise Performance of Young People

2005 ◽  
Vol 11 (1) ◽  
pp. 14-34
Author(s):  
Michael CHIA
Keyword(s):  
Young People ◽  
Oxygen Uptake ◽  
High Intensity ◽  
Oxygen Uptake Kinetics ◽  
High Intensity Exercise ◽  
Future Research ◽  
Older Children ◽  
Maximal Intensity ◽  
Anaerobic Energy ◽  
Persuasive Argument

LANGUAGE NOTE | Document text in English; abstract also in Chinese.Explanations for children maximal intensity exercise fitness in the literature fluctuate between the incapacity of young children to generate energy anaerobically and a reduced need for the metabolic pathway. A number of propositions are advanced to explain young children's relative inaptitude in anaerobic performance in comparison with older children and adults. These range from a smaller quantity of active muscle mass to perform the anaerobic task, to the quality of the muscle which may not yet be energetically, chemically or neurogenically mature, in comparison to their older and more mature counterparts. No one single factor, whether quantitative or qualitative in nature, however, can account exclusively for the anaerobic fitness of young people. The other persuasive argument advanced is that children are less reliant than adults on the anaerobic energy pathway, for their energy supply. Arguments supporting such a contention include a swifter oxygen uptake response in children during high intensity exercise, a greater blood flow to muscle and greater oxygen extraction capability, and a blunted response to catecholamines during high intensity exercise. Either way, the evidence in the current literature is equivocal. Future research employing the use of non-invasive methods such as MRI to determine muscle fibre type, MRS to determine baseline energy substrates and utilisation rates during exercise, as well as mass spectroscopy to analyse oxygen uptake kinetics and other ventilatory responses during high intensity exercise, may help bring to the fore new knowledge to a most interesting area of research in children's exercise.有關兒童最大強度運動能力的文獻報導結果不一。有些學者認為兒童的無氧代謝的能力非常低下，而有些學者則認為是因為兒童對無氧代謝的需求較低。一些文獻闡述了年幼兒童無氧代謝能力較少年或成人低下的原因是由於肌肉的數量，尤其是無氧代謝能力較強的肌肉數量較少以及肌肉在能量代謝、生物化學和神經支配方面的成熟度較成年人低。而僅以某一單一因素，無論是肌肉數 量還是成熟度，都不足以解釋兒童無氧代謝能力的特點。另一些研究則表明兒童對無氧供能的需求量較成年人低，主要表現在兒童進行大強度運動時其攝氧量急劇上升，肌肉的血流量和氧攝取量明顯增加，以及運動中對兒茶酚胺的反應不敏感等。然而，迄今為 止對於兒童最大強度運動能力的特點仍不十分清楚，需作進一步的研究。應用無創傷性方法，如應用核磁共振成像法檢測肌纖維類 型、核磁共振光譜分析法測定運動中的能量物質及其利用率，以及質譜法分析大強度運動過程中攝氧量的動態變化和通氣量的變化 等，則將有助於提高和促進兒童體育科學研究。

A New High Intensity Grid Cap for RCA-EMU-3 Electron Microscopes

1968 ◽  
Vol 26 ◽  
pp. 316-317
Author(s):  
George Christov ◽  
Bolivar J. Lloyd
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
High Voltage ◽  
High Intensity ◽  
Electron Gun ◽  
Tungsten Filament ◽  
Fluorescent Screen ◽  
Electron Microscopes ◽  
Pass Through ◽  
Ground Potential

A new high intensity grid cap has been designed for the RCA-EMU-3 electron microscope. Various parameters of the new grid cap were investigated to determine its characteristics. The increase in illumination produced provides ease of focusing on the fluorescent screen at magnifications from 1500 to 50,000 times using an accelerating voltage of 50 KV.The EMU-3 type electron gun assembly consists of a V-shaped tungsten filament for a cathode with a thin metal threaded cathode shield and an anode with a central aperture to permit the beam to course the length of the column. The cathode shield is negatively biased at a potential of several hundred volts with respect to the filament. The electron beam is formed by electrons emitted from the tip of the filament which pass through an aperture of 0.1 inch diameter in the cap and then it is accelerated by the negative high voltage through a 0.625 inch diameter aperture in the anode which is at ground potential.

Developing theory-based risk-reduction interventions for HIV-positive young people with haemophilia

Haemophilia ◽  
2001 ◽  
Vol 7 (1) ◽  
pp. 64-71 ◽  
Author(s):  
J. R. Schultz ◽  
R. B. Butler ◽  
L. Mckernan ◽  
R. Boelsen ◽  
Keyword(s):  
Young People ◽  
Risk Reduction ◽  
Hiv Positive
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