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Physical Hazards of Space Exploration and the Biological Bases of Behavioral Health and Performance in Extreme Environments
Published in Lauren Blackwell Landon, Kelley J. Slack, Eduardo Salas, Psychology and Human Performance in Space Programs, 2020
Julia M. Schorn, Peter G. Roma
Microgravity also affects bones and muscles, both of which atrophy from disuse in microgravity environments. This characteristic bone loss is referred to as spaceflight osteopenia. On Earth, the elderly lose on average 1% of bone mass per year. In space, astronauts lose on average 1% of bone mass per month. Some astronauts have lost as much as 20% of bone density, while others are less affected. Bone and muscle atrophy are mitigated by exercise and physical activity (Sibonga et al., 2017). In space, exercise is essential—indeed prescribed as a mission-critical activity—to mitigate bone and muscle degradation caused by microgravity. Fortunately, this countermeasure to microgravity effects also provides neurobehavioral benefits, with evidence showing that physical activity can alleviate depression, enhance memory performance and motor acquisition, and improve sleep quality (Chang, Labban, Gapin, & Etnier, 2012; Cooney, Dwan, & Mead, 2014; Reid et al., 2010; Roig, Skriver, Lundbye-Jensen, Kiens, & Nielsen, 2012). Exercise also directly improves brain function by regulating brain-derived neurotrophic factor, insulin-like growth factor 1, and vascular endothelial-derived growth factor (Cotman, Berchtold, & Christie, 2007). These growth factors have been shown to lessen depression, increase learning, and enhance the growth and repair of blood vessels and brain tissues (Silverman & Deuster, 2014).
Body Systems: The Basics
Published in Karen L. LaBat, Karen S. Ryan, Human Body, 2019
Exercise programs can be tailored to keep muscles in good working condition or to produce muscle bulk and firmness. Body building programs can create visible definition of separate muscles (Figure 2.8). Working the rectus abdominis muscles creates the abdominal “six-pack.” A person who works to build upper body strength can so change the configuration and bulk of muscles of the neck, shoulder, and arms that standard shirt/blouse sizes do not fit well. Increased deltoid muscle volume broadens the shoulders; pectoralis major development enlarges the chest. Inactivity in the extreme, from paralysis or prolonged periods of time in bed due to illness, can result in muscle atrophy (muscle wasting or deterioration).
Skeletal Muscle
Published in Nassir H. Sabah, Neuromuscular Fundamentals, 2020
The increase in fiber size is called hypertrophy. Muscle disuse and loss of innervation, as in paralysis, causes a severe loss of muscle tissue, referred to as muscle atrophy. The increase in the number of muscle fibers is hyperplasia. This has been demonstrated in laboratory animals, such as birds, rats, and cats, as a result of some form of exercise or prolonged electrical stimulation. There are claims that hyperplasia also occurs in humans through two possible mechanisms: (i) splitting of large fibers into two or more smaller fibers, and (ii) fusion of myoblasts to form a new fiber. The myoblasts arise through cell division of satellite cells that are involved in the repair of muscle tissue, as mentioned earlier.
Characteristics of effective home-based resistance training in patients with noncommunicable chronic diseases: a systematic scoping review of randomised controlled trials
Published in Journal of Sports Sciences, 2021
Roseanne E Billany, Noemi Vadaszy, Courtney J Lightfoot, Matthew Pm Graham-Brown, Alice C Smith, Thomas J Wilkinson
Noncommunicable, often termed “chronic”, diseases (NCDs) are the most common causes of death and morbidity. Accountable for 71% of worldwide deaths, they have a significant socioeconomic burden. (WHO, 2014) Four NCDs (cardiovascular disease, cancer, diabetes, and chronic respiratory disease) are prioritized in the World Health Organisation’s (WHO) ‘Global Action Plan (GAP) For Prevention and Control of Noncommunicable Diseases 2013–2020ʹ (WHO, 2013) because together with chronic kidney disease (CKD) they share key behavioural risk factors amenable to public health action and contribute to a major portion of global NCD burden. (Couser et al., 2011) Furthermore, skeletal muscle atrophy, dysfunction, and weakness are well-documented consequences of these conditions which result in exercise and functional limitations, and contribute to poor quality of life (QoL). (Powers et al., 2016) Driven by a complex torrent of factors such as inflammation, disuse, ageing and malnutrition, loss of skeletal muscle has been observed in multiple chronic conditions including heart failure, (Springer et al., 2017) cancer, (Powers et al., 2016) diabetes, (Perry et al., 2016) chronic respiratory diseases (Barreiro & Jaitovich, 2018) and CKD. (Wang & Mitch, 2014) Studies have shown that skeletal muscle atrophy is independently associated with increased mortality of patients with chronic disease. (Powers et al., 2016)
Resistance training with blood flow restriction: Impact on the muscle strength and body composition in people living with HIV/AIDS
Published in European Journal of Sport Science, 2021
Thiago Cândido Alves, André P. Santos, Pedro P. Abdalla, Ana Cláudia R. Venturini, Priscila S. Angelotti, Franciane Góes Borges, Henrique D. O. Reis, Valdes R. Bollela, Jorge Mota, Dalmo R. L. Machado
Our results provide some practical insights that should be considered. Both training methods are capable of increasing MS and promote desirable changes in body composition. However, the RTBFR may be a more positive alternative targeting PLWHA individuals who have a greater degree of physical weakness than the general population. For strength training programmes, the RTBFR method uses loads close to the intensities of activities of daily living (Loenneke et al., 2010), providing relevant gains of muscular strength, similar to traditional programmes. Additionally, early intervention with strength training groups can attenuate or prevent muscle atrophy (Hughes et al., 2017). This low training load leads to muscle hypertrophy, which, alongside with gains in muscle strength, may prevent the development of frail conditions, which can lead to prevention of morbidity and mortality in PLWHA.
Melatonin therapy for blunt trauma and strenuous exercise: A mechanism involving cytokines, NFκB, Akt, MAFBX and MURF-1
Published in Journal of Sports Sciences, 2018
Gerald J. Maarman, Russel J. Reiter
Muscle injury due to trauma or strenuous exercise and sport activities, like many muscle disorders, leads to muscle atrophy pathways and protein degradation (Bonaldo & Sandri, 2013; Fanzani et al., 2012) that contribute to the extent of muscle injury (Aarimaa et al., 2004; Lowe, Warren, Ingalls, Boorstein, & Armstrong, 1995; Tsuang et al., 2007). If a treatment limits atrophic processes during trauma/exercise, it may in turn limit the extent of the muscle injury. Many experimental studies demonstrate that melatonin limits injury to skeletal muscle (Beck et al., 2015; Borges et al., 2015; Hong et al., 2014; Maarman et al., 2016; Stratos et al., 2012). However, the underlying mechanisms are not well understood and yet to be delineated.