scholarly journals SPRINTING. . . Dietary Approaches to Optimize Training Adaptation and Performance

2019 ◽  
Vol 29 (2) ◽  
pp. 85-94 ◽  
Author(s):  
Gary J. Slater ◽  
Jennifer Sygo ◽  
Majke Jorgensen
Keyword(s):  
Dietary Habits ◽  
Muscle Power ◽  
Weight Ratio ◽  
Essential Amino Acids ◽  
Macronutrient Intake ◽  
Sprint Training ◽  
Anaerobic Energy ◽  
Moderate Energy ◽  
And Performance ◽  
Professional Guidance

Although sprint athletes are assumed to primarily be interested in promoting muscle hypertrophy, it is the ability to generate explosive muscle power, optimization of power-to-weight ratio, and enhancement of anaerobic energy generation that are key outcomes of sprint training. This reflects the physique of track sprinters, being characterized as ecto-mesomorphs. Although there is little contemporary data on sprinters dietary habits, given their moderate energy requirements relative to body mass, a carbohydrate intake within the range of 3–6 g·kg−1·day−1 appears reasonable, while ensuring carbohydrate availability is optimized around training. Similarly, although protein needs may be twice general population recommendations, sprint athletes should consume meals containing ∼0.4 g/kg high biological value protein (i.e., easily digested, rich in essential amino acids) every 3–5 hr. Despite the short duration of competitions and relative long-recovery periods between races, nutrition still plays an important role in sprint performance. As energy expenditure moderates during competition, so too should intake of energy and macronutrients to prevent unwanted weight gain. Further adjustments in macronutrient intake may be warranted among athletes contemplating optimization of power-to-weight ratio through reductions in body fat prior to the competitive season. Other novel acute methods of weight loss have also been proposed to enhance power-to-weight ratio, but their implementation should only be considered under professional guidance. Given the metabolic demands of sprinting, a few supplements may be of benefit to athletes in training and/or competition. Their use in competition should be preceded with trialing in training to confirm tolerance and perceived ergogenic potential.

Some consequences of body size

1984 ◽  
Vol 247 (4) ◽  
pp. H495-H507 ◽  
Author(s):  
L. E. Ford
Keyword(s):  
Heart Rate ◽  
Body Weight ◽  
Metabolic Rate ◽  
Muscle Power ◽  
Weight Ratio ◽  
Single Species ◽  
Hill Climbing ◽  
Proper Size ◽  
Higher Power ◽  
Metabolic Indices

The question of the proper size denominator for metabolic indices is addressed. Metabolic rate among different species is proportional to the 3/4 power of body weight, not surface area. Muscle power also varies with the 3/4 power of weight, suggesting that metabolic rate is determined mainly by muscle power. Power-to-weight ratio, specific metabolic rate, and a number of metabolic periods, including heart rate, all vary inversely with the 1/4 power of body weight. Thus the relative times required for physiological and pathological processes in different species may be estimated from the average resting heart rate for the species. There are not many small humans among athletic record holders in events involving acceleration and hill climbing, as would be expected if they had higher power-to-weight ratios. Thus the relationship between size and metabolic rate in different species should not be applied within the single species of humans. Evidence is reviewed showing that basal metabolic rate in humans is determined mainly by lean body mass.

scholarly journals Acute Effects of Different Postactivation Potentiation Protocols on Traditional Rowing Performance

2020 ◽  
Vol 18 (1) ◽  
pp. 80
Author(s):  
Alfonso Penichet-Tomas ◽  
Jose M. Jimenez-Olmedo ◽  
Luis Serra Torregrosa ◽  
Basilio Pueo
Keyword(s):  
Effect Size ◽  
Muscle Power ◽  
Average Power ◽  
Postactivation Potentiation ◽  
Warm Up ◽  
Maximal Load ◽  
Rowing Performance ◽  
Load Intensity ◽  
And Performance ◽  
Student’S T

Postactivation potentiation (PAP) describes an initial muscular activation with a submaximal or maximal load intensity that produces acute improvements in muscle power and performance in subsequent explosive activities. The objective of this study was to compare the effect of different PAP protocols in rowing performance. A crossover design involving seven rowers was used, in which two different PAP protocols were applied: PAP of maximal conditioning contractions (PAP MCC) on a rowing ergometer to provide greater transferability and, thus, enhance the magnitude of PAP stimuli on subsequent rowing performance; and PAP of maximal strength contractions (PAP MSC) in half squat and bench pull exercises, similar to the main exercises in rowing strength training, to perform a 20 s “all-out” test simulating a competition start. Student’s t-test was used to compare means of the variables (p < 0.05). Effect size statistics were calculated using Cohen’s d. The PAP MCC protocol resulted in significant differences, with an extremely large effect size in average power output (p = 0.034, d = 0.98) in the first 3 (p = 0.019, d = 1.15) and first 5 (p = 0.036, d = 0.91) strokes. This group also reached a greater number of strokes (p = 0.049, d = 2.29) and strokes per minute (p = 0.046, d = 1.15). PAP with maximal conditioning contractions in rowing warm-up enhanced subsequent rowing sprint and is an advisable strategy to potentiate performance at the start of rowing competitions and sprint regattas.

A Sensitivity-Based Approach to Improve Efficiency of Automotive Chassis Architecture

2013 ◽  
Author(s):  
Alessandro Valgimigli ◽  
Enrico Bertocchi ◽  
Alberto Lazzarini ◽  
Luca D’agostino ◽  
Luca Splendi
Keyword(s):  
Weight Reduction ◽  
Material Properties ◽  
Weight Ratio ◽  
Performance Standards ◽  
Torsional Stiffness ◽  
Response Analysis ◽  
Frequency Response Analysis ◽  
Automotive Market ◽  
Strong Competition ◽  
And Performance

The strong competition of the automotive market brings the industries to look continuously for more challenging comfort and performance standards. These requirements often contrast with the need for weight reduction related to the restrictive emissions limits. In this scenario, the investments aimed at increasing the structure efficiency (stiffness-to-weight ratio) become fundamental. The objective of this work is to propose a methodology that allows to identify the most important chassis areas in terms of efficiency: the design and research efforts could then be focused on the real determinant parts. This is done through a sensitivity process that works on frame subsystems and then on each component, first varying the material properties and then the thickness (and so the mass). The designing loadcases considered are the torsional stiffness, bending stiffness, modal analysis and frequency response analysis. The results show which are the most important subsystems and components that affects the chassis efficiency and that will have to be re-designed in order to improve the current architecture.

Effects of an Amino Acid/Creatine Energy Supplement on the Acute Hormonal Response to Resistance Exercise

2007 ◽  
Vol 17 (6) ◽  
pp. 608-623 ◽  
Author(s):  
Nicholas A. Ratamess ◽  
Jay R. Hoffman ◽  
Ryan Ross ◽  
Miles Shanklin ◽  
Avery D. Faigenbaum ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Resistance Exercise ◽  
Venous Blood ◽  
Area Under The Curve ◽  
Essential Amino Acids ◽  
Total Testosterone ◽  
Hormonal Response ◽  
Energy Supplement ◽  
And Performance

The authors aimed to examine the acute hormonal and performance responses to resistance exercise with and without prior consumption of an amino acid/creatine/energy supplement. Eight men performed a resistance-exercise protocol at baseline (BL), 20 min after consuming a supplement (S) consisting of essential amino acids, creatine, taurine, caffeine, and glucuronolactone or a maltodextrin placebo (P). Venous blood samples were obtained before and immediately after (IP), 15 min (15P), and 30 min (30P) after each protocol. Area under the curve of resistance-exercise volume revealed that BL was significantly less than S (10%) and P (8.6%). For fatigue rate, only S (18.4% ± 12.0%) was significantly lower than BL (32.9% ± 8.4%). Total testosterone (TT) and growth hormone (GH) were significantly elevated at IP and 15P in all conditions. The GH response was significantly lower, however, in S and P than in BL. The TT and GH responses did not differ between S and P. These results indicated that a supplement consisting of amino acids, creatine, taurine, caffeine, and glucuronolactone can modestly improve high-intensity endurance; however, the anabolic-hormonal response was not augmented.

The Coagulation Performance and Floc Properties of Polymeric Ferric Aluminum Chloride - Polydimethyl Diallylammonium Chloride Coagulant during Surface Water Treatment

2011 ◽  
Vol 90-93 ◽  
pp. 2921-2924
Author(s):  
Cui Zhen Sun ◽  
Jian Guang Liu ◽  
Li Zhu ◽  
Feng Qi
Keyword(s):  
Surface Water ◽  
Aluminum Chloride ◽  
Weight Ratio ◽  
Optimal Dosage ◽  
Surface Water Treatment ◽  
Coagulation Performance ◽  
Floc Properties ◽  
And Performance ◽  
Neutral Conditions ◽  
Different Molecular Weight

In this paper, new composite coagulants, polymeric ferric aluminum-polydimethyl diallylammonium chloride, were synthesized by combing Polymeric ferric aluminum chloride (PFAC) with polydimethyl diallylammonium chloride (PDMDAAC) under different molecular weight ratio (Aluminum to PDMDAAC, Wr=10, 4, 2 and 1). Furthermore, flocculating mechanisms and performance of these new composite coagulants were investigated in treating surface water. The growth of flocs during coagulation using composite coagulants were measured under optimal dosage and neutral conditions. The results indicated that the new composite coagulants exhibited better coagulation performance than PFAC for removing turbidity and dissolved organic matter. For the composite coagulants, the predominant coagulation mechanisms were bridge formation and charge neutralization.

scholarly journals Fifteen-year time trends in energy and macronutrient intake in German children and adolescents: results of the DONALD study

2002 ◽  
Vol 87 (6) ◽  
pp. 595-604 ◽  
Author(s):  
Ute Alexy ◽  
Wolfgang Sichert-Hellert ◽  
Mathilde Kersting
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Children And Adolescents ◽  
Dietary Habits ◽  
Saturated Fatty Acids ◽  
Age Groups ◽  
Monounsaturated Fatty Acids ◽  
Macronutrient Intake ◽  
Fat Intake ◽  
Added Sugars

The DONALD study (Dortmund Nutritional and Anthropometric Longitudinally Designed study) gives the opportunity to evaluate long-term food and nutrient intake data on the basis of 3 d weighed dietary records of infants, children and adolescents since 1985. In this paper, we examine changes in energy and macronutrient intakes (protein, fat, saturated, mono- and polyunsaturated fatty acids, carbohydrates and added sugars) of 795 2–18-year-old subjects between 1985 and 2000 (4483 records). No significant changes in intakes of energy and of protein, polyunsaturated fatty acids and added sugars (as % energy intake, E %) were found. Fat intake decreased significantly in all age groups (between -0·20 and -0·26 E %/year), as well as intake of saturated fatty acids (between -0·11 and -0·14 E %/year) and monounsaturated fatty acids (between -0·07 and -0·014 E %/year). This decline was compensated for by a significant increase in carbohydrate intake (between +0·18 and +0·27 E %/year). The changes in macronutrient intake were mainly due to a decreased consumption of fats–oils (between -0·29 and -1·26 g/year) and meat–fish–eggs (between -0·21 and -2·92 g/year), whereas consumption of bread–cereals (between +0·12 and +2·42 g/year) and potatoes–pasta–rice (between +0·15 and +2·26 g/year) increased slightly. However, since recommended fat intake and fatty acid composition was not reached at the end of the study period by far, further efforts will be necessary to improve macronutrient composition and to stabilize favourable dietary habits.

scholarly journals Nutritional Considerations for Bouldering

2017 ◽  
Vol 27 (4) ◽  
pp. 314-324 ◽  
Author(s):  
Edward J. Smith ◽  
Ryan Storey ◽  
Mayur K. Ranchordas
Keyword(s):  
Protein Intake ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Weight Ratio ◽  
Energy Systems ◽  
International Federation ◽  
Carbohydrate Restriction ◽  
Specific Strength ◽  
Sport Climbing ◽  
Anaerobic Energy

Bouldering competitions are held up to International level and governed by the International Federation of Sport Climbing. Bouldering has been selected to feature at the 2020 Olympic Games in Tokyo, however, physiological qualities and nutritional requirements to optimize performance remain inadequately defined due to large gaps in the literature. The primary goals of training include optimizing the capacity of the anaerobic energy systems and developing sport-specific strength, with emphasis on the isometric function of the forearm flexors responsible for grip. Bouldering athletes typically possess a lean physique, similar to the characteristics of sport climbers with reported body fat values of 6–12%. Athletes strive for a low body weight to improve power to weight ratio and limit the load on the extremities. Specialized nutritional support is uncommon and poor nutritional practices such as chronic carbohydrate restriction are prevalent, compromising the health of the athletes. The high intensity nature of bouldering demands a focus on adequate carbohydrate availability. Protein intake and timing should be structured to maximize muscle protein synthesis and recovery, with the literature suggesting 0.25–0.3 g/kg in 3–4 hr intervals. Supplementing with creatine and b-alanine may provide some benefit by augmenting the capacity of the anaerobic systems. Boulderers are encouraged to seek advice from nutrition experts to enhance performance, particularly important when weight loss is the desired outcome. Further research is warranted across all nutritional aspects of bouldering which is summarized in this review.

scholarly journals Surface damage mitigation of titanium and its alloys via thermal oxidation: A brief review

2019 ◽  
Vol 58 (1) ◽  
pp. 132-146 ◽  
Author(s):  
Naiming Lin ◽  
Ruizhen Xie ◽  
Jiaojuan Zou ◽  
Jianfeng Qin ◽  
Yating Wang ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Thermal Oxidation ◽  
Chemical Industry ◽  
Friction And Wear ◽  
Weight Ratio ◽  
High Strength ◽  
Surface Damage ◽  
Damage Mitigation ◽  
And Performance

AbstractTitanium (Ti) and its alloys have been extensively applied in various fields of chemical industry, marine, aerospace and biomedical devices because of a specific combination of properties such as high strength to weight ratio, exceptional corrosion resistance and excellent biocompatibility. However, friction and wear, corrosion which usually occur on the surfaces of Ti-base components can lead to degradation in both properties and performance. Thermal oxidation (TO) of titanium and its alloys under certain conditions can accomplish significant improvements both in wear resistance and corrosion resistance, without special requirements for substrate geometries. In this review, the studies and applications of TO process in surface damage mitigation titanium and its alloys were reviewed and summarized.

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