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G. Gregory Haff, Alexander J. Koch, Jeffrey A. Potteiger, Karen E. Kuphal, Lawrence M. Magee, Samuel B. Green and John J. Jakicic

The effects of carbohydrate (CHO) supplementation on muscle glycogen and resistance exercise performance were examined with eight highly resistance trained males (mean ± SEM, age: 24.3 ± 1.1 years, height: 171.9±2.0 cm, body mass: 85.7 ± 3.5 kg; experience 9.9 ± 2.0 years). Subjects participated in a randomized, double blind protocol with testing sessions separated by 7 days. Testing consisted of an initial isokinetic leg exercise before and after an isotonic resistance exercise (IRT) session consisting of 3 leg exercises lasting ~39 min. Subjects consumed a CHO (1.0 g CHO ·kg body mass−1) or placebo treatment (PLC), prior to and every 10-min (0.5 g CHO ·kg body mass−1) during the IRT. Muscle tissue was obtained from the m vastus lateralis after a supine rest (REST) immediately after the initial isokinetic test (POST-ISO) and immediately after the IRT (POST-IRT). The CHO treatment elicited significantly less muscle glycogen degradation from the POST-ISO to POST-IRT (126.9 ± 6.5 to 109.7 ± 7.1 mmol·kg wet weight−1) compared to PLC (121.4±8.1 to 88.3±6.0 mmol·kg wet weight−1). There were no differences in isokinetic performance between the treatments. The results of this investigation indicate that the consumption of a CHO beverage can attenuate the decrease in muscle glycogen associated with isotonic resistance exercise but does not enhance the performance of isokinetic leg exercise.

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Javier T. Gonzalez, Martin J. Barwood, Stuart Goodall, Kevin Thomas and Glyn Howatson

Unaccustomed eccentric exercise using large muscle groups elicits soreness, decrements in physical function and impairs markers of whole-body insulin sensitivity; although these effects are attenuated with a repeated exposure. Eccentric exercise of a small muscle group (elbow flexors) displays similar soreness and damage profiles in response to repeated exposure. However, it is unknown whether damage to small muscle groups impacts upon whole-body insulin sensitivity. This pilot investigation aimed to characterize whole-body insulin sensitivity in response to repeated bouts of eccentric exercise of the elbow flexors. Nine healthy males completed two bouts of eccentric exercise separated by 2 weeks. Insulin resistance (updated homeostasis model of insulin resistance, HOMA2-IR) and muscle damage profiles (soreness and physical function) were assessed before, and 48 h after exercise. Matsuda insulin sensitivity indices (ISIMatsuda) were also determined in 6 participants at the same time points as HOMA2-IR. Soreness was elevated, and physical function impaired, by both bouts of exercise (both p < .05) but to a lesser extent following bout 2 (time x bout interaction, p < .05). Eccentric exercise decreased ISIMatsuda after the first but not the second bout of eccentric exercise (time x bout interaction p < .05). Eccentric exercise performed with an isolated upper limb impairs whole-body insulin sensitivity after the first, but not the second, bout.

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Andrzej Gawrecki, Aleksandra Araszkiewicz, Agnieszka Szadkowska, Grzegorz Biegański, Jan Konarski, Katarzyna Domaszewska, Arkadiusz Michalak, Bogda Skowrońska, Anna Adamska, Dariusz Naskręt, Przemysława Jarosz-Chobot, Agnieszka Szypowska, Tomasz Klupa and Dorota Zozulińska-Ziółkiewicz

There is limited data concerning the glycemic changes during mass sporting competitions for children and youth with diabetes. In general, aerobic exercise is associated with decreasing glucose values, whereas brief, very high-intensity or anaerobic exercise is related to increasing glucose values

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Yuri Alberto Freire, Geovani de Araújo Dantas de Macêdo, Rodrigo Alberto Vieira Browne, Luiz Fernando Farias-Junior, Ágnes Denise de Lima Bezerra, Ana Paula Trussardi Fayh, José Cazuza de Farias Júnior, Kevin F. Boreskie, Todd A. Duhamel and Eduardo Caldas Costa

light physical activity can reduce postprandial glucose, insulin, triglycerides, and blood pressure (BP) levels. 8 – 12 These benefits seem to be less robust in individuals without cardiometabolic risk factors or diseases. 9 , 10 Inconsistent results have been reported in young healthy adults

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Alaaddine El-Chab and Miriam E. Clegg

avoid vigorous exercise on the morning of the test, as it has been shown to raise whole-body glucose uptake and glucose area under the curve (GAUC; Rose et al., 2001 ). This will result in an increase in coefficient of variation (CV) between trials and possibly exceed the acceptable level of

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Keith Tolfrey, Julia Kirstey Zakrzewski-Fruer and Alice Emily Thackray

Citation 1 Fletcher EA, Salmon J, McNaughton SA, et al. Effects of breaking up sitting on adolescents’ postprandial glucose after consuming meals varying in energy: a cross-over randomised trial. J Sci Med Sport . E-pub ahead of print. doi: 10.1016/j.jsams.2017.06.002 Objectives : To explore the

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Stephen A. Mears, Kathryn Dickinson, Kurt Bergin-Taylor, Reagan Dee, Jack Kay and Lewis J. James

subject sat for 5 minutes, and resting HR was recorded. At the end of the rest period, a capillary fingertip blood sample (20 µL) was collected and later analyzed for whole blood lactate and glucose concentrations. Subjects were also asked to rate their gastrointestinal (GI) comfort (1 = neutral and 12

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Emily Arentson-Lantz, Elfego Galvan, Adam Wacher, Christopher S. Fry and Douglas Paddon-Jones

, 1999 ; Suesada, Martins, & Carvalho, 2007 ). Investigators recently demonstrated that reducing and limiting step count to 1413 ± 110 steps/day for 14 days had a negative effect on myofibrillar protein synthesis, lean leg mass, and glucose tolerance in a cohort of free-living, healthy older adults

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Alexei Wong, Marcos A. Sanchez-Gonzalez, Won-Mok Son, Yi-Sub Kwak and Song-Young Park

the study. Blood Sampling and Analysis Venous blood samples were obtained from an antecubital vein around 8 AM following an overnight fast. Blood glucose was measured using an automated analyzer (120-FR; Toshiba, Tokyo, Japan). Blood was centrifuged and stored at −80°C for future analysis. To assess

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Peter T. Katzmarzyk and Amanda E. Staiano

triglycerides and glucose were obtained on a Beckman Coulter DXC600 (Beckman Coulter Inc, Brea, CA). A continuous cardiometabolic risk score was computed following the recommendations of Eisenmann 13 as follows: BMI, mean arterial pressure (MAP = [(2 × DBP) + SBP]/3), HDL-C, fasting blood glucose, and