scholarly journals The Road to the Beijing Winter Olympics and Beyond: Opinions and Perspectives on Physiology and Innovation in Winter Sport

2021 ◽  
Author(s):  
Jun Wang ◽  
Hongwei Guan ◽  
Morten Hostrup ◽  
David S. Rowlands ◽  
José González-Alonso ◽  
...  
Keyword(s):  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Ambient Temperatures ◽  
Winter Olympics ◽  
The Road ◽  
Cold Environments ◽  
Winter Sport ◽  
Innovation Potential ◽  
And Performance ◽  
Exercise Induced

AbstractBeijing will host the 2022 Winter Olympics, and China strengthens research on various aspects to allow their athletes to compete successfully in winter sport. Simultaneously, Government-directed initiatives aim to increase public participation in recreational winter sport. These parallel developments allow research to advance knowledge and understanding of the physiological determinants of performance and health related to winter sport. Winter sport athletes often conduct a substantial amount of training with high volumes of low-to-moderate exercise intensity and lower volumes of high-intensity work. Moreover, much of the training occur at low ambient temperatures and winter sport athletes have high risk of developing asthma or asthma-related conditions, such as exercise-induced bronchoconstriction. The high training volumes require optimal nutrition with increased energy and dietary protein requirement to stimulate muscle protein synthesis response in the post-exercise period. Whether higher protein intake is required in the cold should be investigated. Cross-country skiing is performed mostly in Northern hemisphere with a strong cultural heritage and sporting tradition. It is expected that innovative initiatives on recruitment and training during the next few years will target to enhance performance of Chinese athletes in classical endurance-based winter sport. The innovation potential coupled with resourcing and population may be substantial with the potential for China to become a significant winter sport nation. This paper discusses the physiological aspects of endurance training and performance in winter sport highlighting areas where innovation may advance in athletic performance in cold environments. In addition, to ensure sustainable development of snow sport, a quality ski patrol and rescue system is recommended for the safety of increasing mass participation.

scholarly journals Exercise-Induced Vascular Adaptations under Artificially Versus Pathologically Reduced Blood Flow: A Focus Review with Special Emphasis on Arteriogenesis

Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 333
Author(s):  
Johanna Vogel ◽  
Daniel Niederer ◽  
Georg Jung ◽  
Kerstin Troidl
Keyword(s):  
Blood Flow ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Venous Blood ◽  
Underlying Mechanism ◽  
Arterial Disease ◽  
Lower Limbs ◽  
Vascular Effects ◽  
External Application ◽  
Exercise Induced

Background: The vascular effects of training under blood flow restriction (BFR) in healthy persons can serve as a model for the exercise mechanism in lower extremity arterial disease (LEAD) patients. Both mechanisms are, inter alia, characterized by lower blood flow in the lower limbs. We aimed to describe and compare the underlying mechanism of exercise-induced effects of disease- and external application-BFR methods. Methods: We completed a narrative focus review after systematic literature research. We included only studies on healthy participants or those with LEAD. Both male and female adults were considered eligible. The target intervention was exercise with a reduced blood flow due to disease or external application. Results: We identified 416 publications. After the application of inclusion and exclusion criteria, 39 manuscripts were included in the vascular adaption part. Major mechanisms involving exercise-mediated benefits in treating LEAD included: inflammatory processes suppression, proinflammatory immune cells, improvement of endothelial function, remodeling of skeletal muscle, and additional vascularization (arteriogenesis). Mechanisms resulting from external BFR application included: increased release of anabolic growth factors, stimulated muscle protein synthesis, higher concentrations of heat shock proteins and nitric oxide synthase, lower levels in myostatin, and stimulation of S6K1. Conclusions: A main difference between the two comparators is the venous blood return, which is restricted in BFR but not in LEAD. Major similarities include the overall ischemic situation, the changes in microRNA (miRNA) expression, and the increased production of NOS with their associated arteriogenesis after training with BFR.

Leucine-stimulated mTOR signaling is partly attenuated in skeletal muscle of chronically uremic rats

2011 ◽  
Vol 301 (5) ◽  
pp. E873-E881 ◽  
Author(s):  
Yu Chen ◽  
Sumita Sood ◽  
Kevin McIntire ◽  
Richard Roth ◽  
Ralph Rabkin
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Signaling Pathway ◽  
Muscle Wasting ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Mtor Signaling ◽  
Mtor Signaling Pathway ◽  
Exercise Induced ◽  
Rps6 Phosphorylation

The branched-chain amino acid leucine stimulates muscle protein synthesis in part by directly activating the mTOR signaling pathway. Furthermore, leucine, if given in conjunction with resistance exercise, enhances the exercise-induced mTOR signaling and protein synthesis. Here we tested whether leucine can activate the mTOR anabolic signaling pathway in uremia and whether it can enhance work overload (WO)-induced signaling through this pathway. Chronic kidney disease (CKD) and control rats were studied after 7 days of surgically induced unilateral plantaris muscle WO and a single leucine or saline load. In the basal state, 4E-BP1 phosphorylation was modestly depressed in non-WO muscle of CKD rats, whereas rpS6 phosphorylation was nearly completely suppressed. After oral leucine mTOR, S6K1 and rpS6 phosphorylation increased similarly in both groups, whereas the phospho-4E-BP1 response was modestly attenuated in CKD. WO alone activated the mTOR signaling pathway in control and CKD rats. In WO CKD, muscle leucine augmented mTOR and 4E-BP1 phosphorylation, but its effect on S6K1 phosphorylation was attenuated. Taken together, this study has established that the chronic uremic state impairs basal signaling through the mTOR anabolic pathway, an abnormality that may contribute to muscle wasting. However, despite this abnormality, leucine can stimulate this signaling pathway in CKD, although its effectiveness is partially attenuated, including in skeletal muscle undergoing sustained WO. Thus, although there is some resistance to leucine in CKD, the data suggest a potential role for leucine-rich supplements in the management of uremic muscle wasting.

scholarly journals Branched-Chain Amino Acid Plus Glucose Supplement Reduces Exercise-Induced Delayed Onset Muscle Soreness in College-Age Females

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Danielle T. Leahy ◽  
Stephen J. Pintauro
Keyword(s):  
Muscle Soreness ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Recovery Period ◽  
Delayed Onset Muscle Soreness ◽  
Male And Female ◽  
Delayed Onset ◽  
Branched Chain ◽  
Exercise Induced ◽  
Female Subjects

Supplementation with branched-chain amino acids (BCAAs) has been used to stimulate muscle protein synthesis following exercise. The purpose of this study was to determine if supplementation with BCAAs in combination with glucose would reduce exercise-induced delayed onset muscle soreness (DOMS). Using a double-blind crossover design, 20 subjects (11 females, 9 males) were randomly assigned to either BCAA () or placebo () groups. Subjects performed a squatting exercise to elicit DOMS and rated their muscle soreness every 24 hours for four days following exercise while continuing to consume the BCAA or placebo. Following a three-week recovery period, subjects returned and received the alternate BCAA or placebo treatment, repeating the same exercise and DOMS rating protocol for the next four days. BCAA supplementation in female subjects resulted in a significant decrease in DOMS versus placebo at 24 hours following exercise (). No significant effect of BCAA supplementation versus placebo was noted in male subjects nor when male and female results were analyzed together. This gender difference may be related to dose per body weight differences between male and female subjects.

scholarly journals Exercise-Induced Muscle Damage and Hypertrophy: A Closer Look Reveals the Jury is Still Out

2018 ◽  
Author(s):  
Brad Jon Schoenfeld ◽  
Bret Contreras
Keyword(s):  
Skeletal Muscle ◽  
Protein Synthesis ◽  
Resistance Training ◽  
Muscle Damage ◽  
Muscle Hypertrophy ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Skeletal Muscle Hypertrophy ◽  
Exercise Induced

This letter is a response to the paper by Damas et al (2017) titled, “The development of skeletal muscle hypertrophy through resistance training: the role of muscle damage and muscle protein synthesis,” which, in part, endeavored to review the role of exercise-induced muscle damage on muscle hypertrophy. We feel there are a number of issues in interpretation of research and extrapolation that preclude drawing the inference expressed in the paper that muscle damage neither explains nor potentiates increases in muscle hypertrophy. The intent of our letter is not to suggest that a causal role exists between hypertrophy and microinjury. Rather, we hope to provide balance to the evidence presented and offer the opinion that the jury is still very much out as to providing answers on the topic.

Resistance Exercise–induced Regulation of Muscle Protein Synthesis to Intraset Rest

2020 ◽  
Vol 52 (5) ◽  
pp. 1022-1030
Author(s):  
AMADEO F. SALVADOR ◽  
ANDREW T. ASKOW ◽  
COLLEEN F. MCKENNA ◽  
HSIN-YU FANG ◽  
SARAH K. BURKE ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Resistance Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Exercise Induced

Legal nutritional supplements during a sporting event

2008 ◽  
Vol 44 ◽  
pp. 45-62 ◽  
Author(s):  
Ceri Nicholas
Keyword(s):  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Scientific Evidence ◽  
Endurance Performance ◽  
Nutritional Supplements ◽  
Electrolyte Solutions ◽  
Exercise Duration ◽  
Nutritional Supplement ◽  
Branched Chain ◽  
And Performance

Nutrition significantly influences sports performance; however, the efficacy of any nutritional supplement or strategy should be carefully considered in relation to the event and the sex, training and nutritional status of the participant. The causes of fatigue, mechanism of action, safety and legality of the supplement, together with the scientific evidence from studies with an appropriate experimental design, should all be taken into account before incorporating into the training and/or competition diet. The efficacy of ingesting nutritional supplements immediately before and/or during endurance exercise (duration 45–180 min) is reviewed in this chapter. The ingestion of CES (carbohydrate-electrolyte solutions) have been shown to improve both exercise capacity and performance, either due to the maintenance of euglycaemia throughout exercise or the sparing of muscle glycogen early on in exercise. The addition of caffeine to CES may improve endurance performance as a consequence of a reduced perception of effort. Research suggests that the addition of protein to CES may only be effective when a suboptimal amount of CHO (carbohydrate) is ingested during exercise (<60 g of CHO⋅h−1); however, recovery of performance may be enhanced due to a reduction in subsequent muscle soreness and the promotion of muscle protein synthesis after exercise. The findings from studies investigating the effects of ingesting MCTs (medium-chain triacylglycerols) and BCAAs (branched-chain amino acids), either on their own or in combination with CES, on endurance performance have been equivocal and therefore would not be recommended. Any nutritional strategy should be practised in training before being used during a competition.

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