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Gregory A. Hand, Robin P. Shook, Daniel P. O’Connor, Madison M. Kindred, Sarah Schumacher, Clemens Drenowatz, Amanda E. Paluch, Stephanie Burgess, John E. Blundell and Steven N. Blair

and energy stores. Methods Participant Recruitment Sedentary men and women aged 21 to 45 years with a body mass index (BMI) of 25 to 35 kg/m 2 were recruited. Inclusion and exclusion criteria (Table  1 ) were designed to select healthy individuals with no major acute or chronic conditions, no recent

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M. Travis Byrd, Jonathan Robert Switalla, Joel E. Eastman, Brian J. Wallace, Jody L. Clasey and Haley C. Bergstrom

measure of whole-body metabolism (CP) and local muscle energy stores (AWC), respectively. 2 , 14 , 15 Methods Experimental Design This study involved 2 testing sessions separated by 24 to 72 hours. During the first testing session, the %BF, LBM, and TLM of each subject were estimated from a total

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Richard Latzel, Olaf Hoos, Sebastian Stier, Sebastian Kaufmann, Volker Fresz, Dominik Reim and Ralph Beneke

Purpose: To analyze the energetic profile of the Basketball Exercise Simulation Test (BEST). Methods: Ten male elite junior basketball players (age 15.5 [0.6] y, height 180 [9] cm, and body mass 66.1 [11.2] kg) performed a modified BEST (20 circuits consisting of jumping, sprinting, jogging, shuffling, and short breaks) simulating professional basketball game play. Circuit time, sprint time, sprint decrement, oxygen uptake (VO2), heart rate, and blood lactate concentration (blc) were obtained. Metabolic energy and metabolic power above rest (W tot and P tot), as well as energy share in terms of aerobic (W aer), glycolytic (W blc), and high-energy phosphates (W PCr), were calculated from VO2 during exercise, net lactate production, and the fast component of postexercise VO2 kinetics, respectively. Results: W aer, W blc, and W PCr reflect 89% (2%), 5% (1%), and 6% (1%) of total energy needed, respectively. Assuming an aerobic replenishment of PCr energy stores during short breaks, the adjusted energy share yielded W aer 66% (4%), W blc 5% (1%), and W PCr 29% (1%). W aer and W PCr were negatively correlated (−0.72 and −0.59) with sprint time, which was not the case for W blc. Conclusions: Consistent with general findings on energy system interaction during repeated high-intensity exercise bouts, the intermittent profile of the BEST relies primarily on aerobic energy combined with repetitive supplementation by anaerobic utilization of high-energy phosphates.

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Jaak Jürimäe

Physical exercise is known to regulate energy balance. Important to this regulatory system is the existence of several peptides that communicate the status of body energy stores to the brain and are related to the body fatness including leptin, adiponectin and ghrelin. These hormones assist in regulating energy balance as well as somatic and pubertal growth in children. It appears that rather few studies have investigated the responses of leptin, adiponectin and ghrelin to acute exercise and these studies have demonstrated no changes in these peptides as a result of exercise. Leptin levels are decreased and may remain unchanged advancing from prepuberty to pubertal maturation in young male and female athletes. A limited number of studies indicate that adiponectin levels are not different between prepubertal and pubertal athletes and untrained controls. However, in certain circumstances circulating adiponectin could be increased in young athletes after onset of puberty as a result of heavily increased energy expenditure. Ghrelin levels are elevated in young sportsmen. However, pubertal onset decreases ghrelin levels in boys and girls even in the presence of chronically elevated energy expenditure as seen in young athletes. Ghrelin may also be used as an indicator of energy imbalance across the menstrual cycle in adolescent athletes. There are no studies with high-molecular-weight adiponectin and only very few studies with acylated ghrelin responses to acute exercise and chronic training have been performed in young athletes. Since these forms of adiponectin and ghrelin have been thought to be bioactive forms, further studies with these specific forms of adiponectin and ghrelin are needed. In conclusion, further studies should be conducted to investigate the response of these hormones to acute and chronic negative energy balance to better understand their role in regulating energy balance during growth and maturation in young athletes.

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Marco J. Konings and Florentina J. Hettinga

the available energy resources against possible tactical advantages or disadvantages. 18 As a result, each race may not require the use of all available energy stores, and finishing times are irrelevant as long as you finish in front of your opponents. 18 , 19 Indeed, in sports such as cross

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Brian Hanley, Trent Stellingwerff and Florentina J. Hettinga

the race. In championship racing, where multiple rounds are negotiated and finishing position is more important than time taken, 6 , 13 successful pacing in qualifying is not about using all possible energy stores by the finish line, 14 but where resources are preserved 15 and psychological efforts

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Justin J. Merrigan, James J. Tufano, Jonathan M. Oliver, Jason B. White, Jennifer B. Fields and Margaret T. Jones

neuromuscular fatigue induced from high-volume training protocols. Anaerobic glycolysis is likely prevalent during high-volume training (multiple high-repetition sets), and thus, fatigue may result from a reduction of immediate energy stores (adenosine triphosphate and phosphocreatine [PCr]) and accumulation of

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Matthew Zimmermann, Grant Landers, Karen Wallman and Georgina Kent

reserve, 32 or sparing of energy stores, 12 with ice ingestion, allowing for an increase in exercise intensity. Moreover, both thermal sensation 33 and aerobic efficiency 7 have previously been indicated as modulators of self-selected exercise intensity. Therefore, during post-CTT in the precooling

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Anne Z. Beethe, Elizabeth F. Nagle, Mita Lovalekar, Takashi Nagai, Bradley C. Nindl and Christopher Connaboy

others, while seeking to preserve energy stores in an attempt to ensure the remainder of the mission is successful. 11 , 12 Operators are known to swim up to 11 km wearing military clothing (fatigues), boots, fins, load carriage equipment (webbing), weapons, and a buoyant-weighted rucksack while

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Harry G. Banyard, James J. Tufano, Jose Delgado, Steve W. Thompson and Kazunori Nosaka

This energy system typically lasts for up to 10 seconds of maximal effort and, when depleted, coincides with rapid decreases in movement velocity. 27 If energy stores are depleted without sufficient recovery, it is speculated that training under energy depletion and excessive velocity loss could