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Andy J. King, Joshua T. Rowe and Louise M. Burke

CHO hydrogel formation and delivery to the small intestine. Despite benefits to gastric emptying with hydrogel-encapsulated CHO, the rate-limiting step of exogenous CHO oxidation lies in the intestinal transport of monosaccharides. CHO = carbohydrate. Methods A search of electronic databases for

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Theodore Tsakiris, Panagoula Angelogianni, Christine Tesseromatis, Stylianos Tsakiris and Kleopatra H. Schulpis

Background:

Forced exercise is associated with oxidative stress, and L-cysteine (L-cys) administration reduces free-radical production.

Aim:

To investigate whether L-cys (5 mg/kg) intraperitoneal administration can ameliorate modulated total antioxidant status (TAS), protein concentration, and the activities of acetylcholinesterase (AChE), (Na+,K+)-ATPase, and Mg2+-ATPase in rat brain after 2 and 3 hr of forced swimming.

Methods:

TAS, protein, and enzyme activities were measured spectrophotometrically before and after 2 and 3 hr of exercise without or with L-cys administration.

Results:

TAS concentration (55.6 ± 1.5 vs. 42.1 ± 1.0 vs. 37.4 ± 1.2 μmol/L, p < .001), protein concentration (5.68 ± 0.36 vs. 5.40 ± 0.18 vs. 4.01 ± 0.16 mg/ml, p < .01), and AChE activity (0.89 ± 0.05 vs. 0.61 ± 0.04 vs. 0.48 ± 0.03 ΔOD/min × mg protein, p < .001) were significantly reduced, whereas Na+,K+-ATPase (6.00 ± 0.36 vs. 10.44 ± 1.04 vs. 11.90 ± 1.21 µmol phosphorus inorganic/hr × mg protein, p < .001) and Mg2+-ATPase activity (7.20 ± 0.65 vs. 10.88 ± 1.08 vs. 11.55 ± 1.22 µmol phosphorus inorganic/hr × mg protein, p < .001) were statistically significantly increased after 2 and 3 hr of forced exercise. Post-L-cys administration, AChE activity was decreased (0.90 ± 0.04 vs. 0.47 ± 0.02 ΔOD/min × mg protein, p < .001) and remained unaltered (0.64 ± 0.04 vs. 0.67 ± 0.04 ΔOD/min × mg protein, p > .05) 2 and 3 hr postexercise (0.47 ± 0.02 vs. 0.54 ± 0.02 ΔOD/min × mg protein, p > .05). Na+,K+-ATPase was decreased and remained unchanged (1.85 ± 0.17 vs. 1.77 ± 0.19 µmol phosphorus inorganic/hr × mg protein, p > .05) 2 and 3 hr postswimming (1.91 ± 0.19 vs. 2.06 ±0.17 µmol phosphorus inorganic/hr × mg protein, p > .05). Mg2+-ATPase activity was similar with L-cys supplementation pre- vs. postswimming.

Conclusions:

L-cys administration might ameliorate modulated rat brain enzyme activities induced by free-radical production during forced swimming.

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Ulrika Andersson-Hall, Stefan Pettersson, Fredrik Edin, Anders Pedersen, Daniel Malmodin and Klavs Madsen

In order to maximize the adaptive response to endurance training among athletes and/or to promote healthy living in the general population, there has recently been interest in ways to increase the capacity of fat oxidation during exercise. As glycogen stores are limited, a higher reliance on fat

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Mark Elisabeth Theodorus Willems, Mehmet Akif Şahin and Matthew David Cook

reported health benefits of regular intake of green tea such as a reduced risk for some cancers ( Guo et al., 2017 ) and cardiovascular and ischemic-related diseases ( Pang et al., 2016 ). Green tea has also been implicated in body weight management ( Janssens et al., 2016 ) by promoting fat oxidation

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Nicola Giovanelli, Lea Biasutti, Desy Salvadego, Hailu K. Alemayehu, Bruno Grassi and Stefano Lazzer

running on muscle oxidative functions in rats were investigated by Kano et al. 12 These authors observed that 1 and 3 days after a downhill run to exhaustion, capillary hemodynamic and Q ˙ O 2 / V ˙ O 2 matching were still compromised. Moreover, Kano et al 12 suggested that the fiber damage after

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Sang-Ho Lee, Steven D. Scott, Elizabeth J. Pekas, Jeong-Gi Lee and Song-Young Park

weight over a short period of time prior to competition. 4 This rapid weight change with high-intensity exercise training may result in the deterioration of the health and sports performance of these athletes, as it can lead to an abrupt disturbance of metabolism and increased oxidative stress, which

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Francisco J. Amaro-Gahete, Lucas Jurado-Fasoli, Alejandro R. Triviño, Guillermo Sanchez-Delgado, Alejandro De-la-O, Jørn W. Helge and Jonatan R. Ruiz

energy storage is effectively unlimited during prolonged exercise. 3 Therefore, the capacity to adapt fuel oxidation to fuel availability (known as metabolic flexibility) is a key determinant of endurance sport performance. 4 Therefore, the maximal fat oxidation (MFO) capacity during a graded exercise

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Nathan A. Lewis, Andrew J. Simpkin, Sarah Moseley, Gareth Turner, Mark Homer, Ann Redgrave, Charles R. Pedlar and Richard Burden

-performance support team. Oxidative stress (OS), historically and simply defined as a disturbance in the prooxidant to antioxidant balance in favor of the former, 4 is evident in athletes diagnosed with overtraining syndrome 5 , 6 . Indeed, increases in biomarkers of OS correlate strongly with increases in training

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Steven K. Malin, Brooke R. Stephens, Carrie G. Sharoff, Todd A. Hagobian, Stuart R. Chipkin and Barry Braun

Exercise and metformin may prevent or delay Type 2 diabetes by, in part, raising the capacity for fat oxidation. Whether the addition of metformin has additive effects on fat oxidation during and after exercise is unknown. Therefore, the purpose of this study was to evaluate the effect of metformin on substrate oxidation during and after exercise. Using a double-blind, counter-balanced crossover design, substrate oxidation was assessed by indirect calorimetry in 15 individuals taking metformin (2,000 mg/d) and placebo for 8–10 d. Measurements were made during cycle exercise at 5 submaximal cycle workloads, starting at 30% peak work (Wpeak) and increasing by 10% every 8 min to 70% Wpeak. Substrate oxidation was also measured for 50 min postexercise. Differences between conditions were assessed using analysis of variance with repeated measures, and values are reported as M ± SE. During exercise, fat oxidation (0.19 ± 0.03 vs. 0.15 ± 0.01 g/min, p < .01) and percentage of energy from fat (32% ± 3% vs. 28% ± 3%, p < .01) were higher with metformin than with placebo. Postexercise, metformin slightly lowered fat oxidation (0.12 ± 0.02 to 0.10 ± 0.02 g/min, p < .01) compared with placebo. There was an inverse relationship between postexercise fat oxidation and the rate of fat oxidation during exercise (r = –.68, p < .05). In healthy individuals, metformin has opposing actions on fat oxidation during and after exercise. Whether the same effects are evident in insulin-resistant individuals remains to be determined.

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Alan J. McCubbin, Anyi Zhu, Stephanie K. Gaskell and Ricardo J.S. Costa

-associated gastrointestinal symptoms (GIS; Jeukendrup, 2014 ). More recently, there has been a focus on additional ingredients in CES to further improve gastric emptying, minimize GIS, and enhance carbohydrate absorption and oxidation during exercise ( Sutehall et al., 2018 ). Through the addition of alginate and pectin