Body Stuff Condicionamento Geral e Fitness bibligrafia

: Physical fitness effect on bone mass is mediated by the independent association between lean mass and bone mass through adolescence: a cross-sectional study.

Vicente-Rodríguez G, Urzanqui A, Mesana MI, Ortega FB, Ruiz JR, Ezquerra J, Casajús JA, Blay G, Blay VA, Gonzalez-Gross M, Moreno LA; AVENA-Zaragoza Study Group.

University School of Health Science and Pediatrics Department, University of Zaragoza, C/Domingo Miral s/n, 50009, Zaragoza, Spain, gervicen@unizar.es.

We studied 278 adolescents (169 females) aged 13.0-18.5 years to elucidate whether an independent effect of physical fitness and lean mass in the differences between male and female bones can be detected. Lean and fat masses and bone mineral content (BMC) were measured with DXA. Physical fitness was evaluated with six different tests included in the EUROFIT test battery (flexibility, isometric, dynamic and endurance strength, speed, and cardiovascular fitness). To test the independent relationship between physical fitness and bone mass, multiple regression analysis was applied, including lean mass, age, and Tanner development as covariates. The males had a 43% lower fat mass and 40% and 16% higher lean mass and total BMC compared with the females (all P < 0.05). After adjustment for differences in body size and lean mass, the females exhibited a 7.4% higher BMC than the males (P < 0.05). The multiple regression analysis showed that lean mass had an independent relationship with bone mass (P < 0.001), explaining 67% of the total variance in whole-body BMC. In males, change in R (2) was 0.658 for hand grip and 0.035-0.151 for the rest of physical fitness-related variables; but 0.019-0.042 in females (all P-0.001); however, the independent relationships between physical fitness and bone disappeared after controlling for lean mass. In conclusion, it is likely the differences between male and female in bone mass could be explained by differences in lean mass and physical fitness.

PMID: 18470671 [PubMed - in process]

: Relationships among Fitness, Body Composition, and Physical Activity.

Lohman TG, Ring K, Pfeiffer K, Camhi S, Arredondo E, Pratt C, Pate R, Webber LS.

1Department of Physiology, The University of Arizona, Tucson, AZ; 2Department of Biostatistics, University of North Carolina, Chapel Hill, NC; 3Department of Kinesiology, Michigan State University, East Lansing, MI; 4Department of Kinesiology, University of Maryland, College Park, MD; 5School of Public Health, San Diego State University, San Diego, CA; 6National Heart, Lung, and Blood Institute, Division of Epidemiology and Clinical Applications, Bethesda, MD; 7Department of Exercise Science, University of South Carolina. Columbia, SC; 8Department of Biostatistics, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA.

PURPOSE:: This study was designed to examine the associations of physical activity and body composition with cardiorespiratory fitness in eighth grade girls. METHODS:: A random sample of 1440 eighth grade girls at 36 schools participated in this cross-sectional investigation, which represented an ethnically and geographically diverse group. Cardiorespiratory fitness was assessed using a modified physical work capacity test on a cycle ergometer that predicted workload at a heart rate of 170 beats.min. Physical activity was assessed over 6 d in each girl using an accelerometer and body composition was estimated from body mass index and triceps skinfolds using a previously validated equation. Pearson correlations and multiple regression analyses were used to determine the relationships among fitness, physical activity, and body composition. RESULTS:: Significant linear relationships among cardiorespiratory fitness, body composition, and physical activity were found. The combination of fat and fat-free mass along with racial group and a race by fat-free-mass interaction accounted for 18% (R) of the variation in physical fitness. Adding moderate-to-vigorous physical activity to the regression model increased the R to 22%. Black girls had somewhat lower fitness levels (P < 0.05) especially at higher levels of fat and fat-free mass than other racial/ethnic groups. CONCLUSIONS:: Physical activity, fat-free mass, and the interaction between fat-free mass and racial group are significantly associated with cardiorespiratory fitness in adolescent girls.

PMID: 18460987 [PubMed - as supplied by publisher]

: Sense of coherence and physical health. A "Copenhagen interpretation" of Antonovsky's SOC concept.

Endler PC, Haug TM, Spranger H.

Interuniversity College for Health and Development Graz, Castle of Seggau, Austria. college@inter-uni.net

According to Antonovsky's (Aaron Antonovsky, 1923-1994) sense of coherence (SOC) model, persons with a high SOC have the ability to benefit from their general defense mechanisms in order to overcome stressful situations. In a health-disease continuum, this leads to the development towards health. However, Antonovsky's global hypothesis that the strength of the SOC may influence the physical health status of a person could not be proven. Flensborg-Madsen et al. from Copenhagen were able to provide a new access regarding SOC and health. They investigated the mixture of emotional aspects and mental constructions as a possible cause for fairly low correlation between SOC and physical health. Thus, in an empirical way, they described "emotional coherence" in relation to physical health, while "mental coherence" was linked to psychological health. These authors introduced the idea of applying a shortened version of the original 29-item SOC questionnaire, but have not yet developed or tested the shortened questionnaire. Backed by their important findings, it appears to be promising to consider the use of the SOC questionnaire as standardized by Antonovsky, but cleared of the items regarding "predictability", i.e., Flensborg-Madsen et al. suggested that the items on "predictability" be excluded from the SOC scale when a correlation to physical health is to be investigated. Further investigations in this area of research will be of high impact, not only for health sciences, but also for medical practice.

PMID: 18454255 [PubMed - indexed for MEDLINE]

: The long-term effects of progressive resistance training on health-related quality in older adults.

Inaba Y, Obuchi S, Arai T, Satake K, Takahira N.

Graduate School of Medical Science, Kitasato University, Sagamihara, Kanagawa, Japan. yasuko178@h3.dion.ne.jp

This study examined the persistence rate of resistance training after intervention with progressive resistance training and the long-term changes in self-perceived function as Heath-related quality of life (HRQOL) between a maintaining group (TR) and a detraining group (DT) after the intervention.One hundred sixty-seven persons aged 65 and older participated in this study. We measured SF-36 as indices of HRQOL before intervention (T1), after intervention (T2), and 1 year later (T3).We assessed 135 participants at T3, and, of these, 58 were in TR and 77 were in DT. In TR, T2 scores significantly improved over T1 scores for Physical Functioning, Role Physical, and Mental Health (p<.05-.01). Moreover, in T3 scores, Physical Functioning (p<.01) and Role Physical (p<.05) significantly improved over T1 scores. In DT, T2 scores were significantly higher than T1 scores for Vitality and Mental Health (both p<.01), while T3 scores significantly decreased from T2 scores for Physical Functioning, General Health, Vitality, and Mental Health (p<.05-p<.01). Only Physical Functioning of TR was significantly higher than that of DT in T2. However, Physical Functioning, Role Physical, General Health, Vitality, and Mental Health of TR were significantly higher than that of DT in T3 (p<.05-.01). No subscale scores at T3 were significantly lower than at T1.Our findings suggest that for the elderly, voluntarily continuing training after the structured program has beneficial effects for HRQOL, and the differences in HRQOL with regard to how to spend time after the intervention over the long term. However, it was possible for the HRQOL of the participants to deteriorate, though not significantly, at 1 year after the intervention in comparison to the baseline. This result suggests that the significant HRQOL gains of the DT group for the intervention period are very important.

PMID: 18379162 [PubMed - indexed for MEDLINE]

: Physical activity, physical fitness, and risk of type 2 diabetes mellitus.

Hu G, Lakka TA, Barengo NC, Tuomilehto J.

Department of Epidemiology and Health Promotion, National Public Health Institute, Helsinki, Finland., Department of Public Health, University of Helsinki, Helsinki, Finland.

Type 2 diabetes mellitus (DM) is a common chronic disease. Cardiovascular disease is the most prevalent complication of DM. In the past decade, the associations of physical activity, physical fitness, and changes in lifestyle with the risk of type 2 DM have been assessed by a number of prospective epidemiologic studies and clinical trials. Several studies also evaluate the joint associations of physical activity, body mass index, and glucose levels with the risk of type 2 DM. The results of 21 prospective studies and four clinical trials demonstrated that moderate or high levels of physical activity or physical fitness, as well as changes in lifestyle (dietary modification and enhanced physical activity) could prevent type 2 DM.

PMID: 18370708 [PubMed - in process]

6: Rev Esp Cardiol. 2008 Feb;61(2):108-11.

[Relationship between physical activity and physical fitness in children and adolescents]

[Article in Spanish]

Martínez-Vizcaíno V, Sánchez-López M.

Publication Types:

PMID: 18364177 [PubMed - in process]

7: J Endocrinol Invest. 2008 Feb;31(2):138-45.

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Young elite athletes of different sport disciplines present with an increase in pulsatile secretion of growth hormone compared with non-elite athletes and sedentary subjects.

Ubertini G, Grossi A, Colabianchi D, Fiori R, Brufani C, Bizzarri C, Giannone G, Rigamonti AE, Sartorio A, Muller EE, Cappa M.

Endocrinology Unit, Children Hospital Bambino Gesù, IRCCS, Rome, Italy.

Acute exercise is a well-known stimulus for GH secretion but the effect of chronic training on GH secretion still remains equivocal. The aim of our study was to analyse spontaneous pulsatile GH secretion (during a period of 2 hours in the morning) in a group of young elite athletes (EA) compared with non-elite athletes (NEA), and sedentary subjects (SS). Mean and peak GH levels proved significantly higher in EA than in NEA and SS (p=0.0004 and p<0.0001, respectively). The same differences in mean and peak GH levels were also demonstrated in males and females when considered separately (males: p=0.0062 and p=0.0025; females: p=0.0056 and p=0.0032). In addition, GH levels (mean and peak) were higher in females than in males in SS while no differences were demonstrated between the 2 sexes in the EA and NEA groups. IGF-I levels were within the normal range for age in all the subjects with no difference between the 3 groups. Body mass index (BMI) exhibited no difference between groups, while EA showed higher lean mass (p=0.0063) and lower fat mass (p=0.0139) than NEA and SS measured by dual-energy x-ray absorptiometry. A strong positive correlation between GH levels (mean and peak) and hours of training a week was demonstrated (p=0.0101; r2=0.1184; p=0.0022; r2=0.1640, respectively). In conclusion, GH levels were higher in EA than NEA and SS without any modification of IGF-I levels; a strong positive correlation was present between GH levels and intensity of training. An increase in the knowledge of the effect of chronic training on GH secretion could improve the training programme to elicit the greatest exercise- induced GH response.

Publication Types:

PMID: 18362505 [PubMed - indexed for MEDLINE]

8: Appl Physiol Nutr Metab. 2008 Feb;33(1):191-9.

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Resistance training, sarcopenia, and the mitochondrial theory of aging.

Johnston AP, De Lisio M, Parise G.

Department of Kinesiology, McMaster University, Hamilton, ON L8N 3Z5.

Skeletal muscle aging is associated with a significant loss of muscle mass, strength, function, and quality of life. In addition, the healthcare cost of aging and age-related disease is growing, and will continue to grow as a larger proportion of our population reaches retirement age and beyond. The mitochondrial theory of aging has been identified as a leading explanation of the aging process and describes a path leading to cellular senescence that includes electron transport chain deficiency, reactive oxygen species production, and the accumulation of mitochondrial DNA deletions and mutations. It is also quite clear that regular resistance exercise is a potent and effective countermeasure for skeletal muscle aging. In this review, we discuss age-related sarcopenia, the mitochondrial theory of aging, and how resistance exercise may directly affect key components of the mitochondrial theory. It is clear from the data discussed that regular resistance training can effectively disturb processes that contribute to the progression of aging as it pertains to the mitochondrial theory.

Publication Types:

Review

PMID: 18347672 [PubMed - indexed for MEDLINE]

1: Exp Gerontol. 2008 Jan;43(1):24-33. Epub 2007 Oct 4.

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The role of mitochondrial DNA mutations in aging and sarcopenia: implications for the mitochondrial vicious cycle theory of aging.

Hiona A, Leeuwenburgh C.

Department of Aging and Geriatrics, Division of Biology of Aging, Biochemistry of Aging Laboratory, Genomics and Biomarkers Core of the Institute on Aging, College of Medicine, University of Florida, Gainesville, FL 32611, USA. cleeuwen@aging.ufl.edu

Aging is associated with a progressive loss of skeletal muscle mass and strength and the mechanisms mediating these effects likely involve mitochondrial DNA (mtDNA) mutations, mitochondrial dysfunction and the activation of mitochondrial-mediated apoptosis. Because the mitochondrial genome is densely packed and close to the main generator of reactive oxygen species (ROS) in the cell, the electron transport chain (ETC), an important role for mtDNA mutations in aging has been proposed. Point mutations and deletions in mtDNA accumulate with age in a wide variety of tissues in mammals, including humans, and often coincide with significant tissue dysfunction. Here, we examine the evidence supporting a causative role for mtDNA mutations in aging and sarcopenia. We review experimental outcomes showing that mtDNA mutations, leading to mitochondrial dysfunction and possibly apoptosis, are causal to the process of sarcopenia. Moreover, we critically discuss and dispute an important part of the mitochondrial 'vicious cycle' theory of aging which proposes that accumulation of mtDNA mutations may lead to an enhanced mitochondrial ROS production and ever increasing oxidative stress which ultimately leads to tissue deterioration and aging. Potential mechanism(s) by which mtDNA mutations may mediate their pathological consequences in skeletal muscle are also discussed.

Publication Types:

PMID: 17997255 [PubMed - in process]

PMCID: PMC2225597

2: J Gerontol A Biol Sci Med Sci. 1995 Nov;50 Spec No:113-9.

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Strength and aerobic training attenuate muscle wasting and improve resistance to the development of disability with aging.

Tseng BS, Marsh DR, Hamilton MT, Booth FW.

Department of Integrative Biology, University of Texas-Houston Health Science Center, Medical School, USA.

By the age of 50 yrs old, humans become aware that they are losing muscle strength (mass) and endurance (mitochondria). A frequent symptom of neuromuscular disorders is muscle weakness (Walton, 1988). We define the aging-associated muscle wasting as a progressive neuromuscular syndrome that will lower the quality of life in the elderly by (1) decreasing the ability to lift loads (progressing to difficulty arising from a chair), and (2) decreasing endurance (leading to an inability to perform the activities of daily living, which increases health care costs). Campion (1994) states that the most successful outcome would be for the very elderly to take control of the last stage of their life and make it worth living. To obtain this goal, prevention of muscle wasting is an absolute requirement. Muscle mass and motor unit number, activation, and synchronization are highly related to strength; both decrease with aging (Rodgers and Evans, 1993). Resistance-training is the best way to increase muscle mass, neural coordination, and strength. Mitochondrial concentration is highly related to endurance capacity in young and old (Holloszy and Coyle, 1984). Both muscle contractile and mitochondrial protein decrease with aging in sedentary humans (reviewed by Rodgers and Evans, 1993). Endurance training, which is the best exercise to increase/maintain mitochondrial concentration with aging, has generally resulted in relatively small functional benefits to nursing home patients (Fiatarone et al., 1994).(ABSTRACT TRUNCATED AT 250 WORDS)

Publication Types:

PMID: 7493203 [PubMed - indexed for MEDLINE]

3: J Gerontol A Biol Sci Med Sci. 2003 Oct;58(10):M918-22.

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Exercise, aging, and muscle protein metabolism.

Yarasheski KE.

Washington University School of Medicine, St Louis, Missouri 63110, USA. key@im.wustl.edu

Age-associated alterations in muscle protein quantity and quality that adversely affect muscle structure, composition, and function have been referred to as sarcopenia. Muscle protein is metabolically active, and the age-associated loss of muscle protein mass is related to a loss of physical function and an inability to perform activities of daily living (physical frailty). It is important to maintain adequate reserves of muscle protein and amino acids as we age. As in all cachectic conditions, sarcopenia can be explained by an imbalance between the rates of muscle protein synthesis and muscle proteolysis, in which net muscle protein balance is negative. This review summarizes evidence that supports the notion that: (a). advancing age and physical frailty are associated with a reduction in the fasting rate of mixed and myosin heavy chain protein synthesis, which contributes to muscle protein wasting in advancing age; (b). this impairment can be corrected because resistance exercise acutely and dramatically increases the rate of muscle protein synthesis in men and women aged 76 years and older; and (c). resistance exercise training maintains a modest increment in the rate of muscle protein synthesis and contributes to muscle hypertrophy and improved muscle strength in frail elderly men and women. The cellular mechanisms responsible for these adaptations, as well as the role of nutrition and hormone replacement in reversing sarcopenia, require further investigation.

Publication Types:

PMID: 14570859 [PubMed - indexed for MEDLINE]

4: Exp Physiol. 2006 May;91(3):483-98. Epub 2006 Feb 9.

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Myotendinous plasticity to ageing and resistance exercise in humans.

Reeves ND, Narici MV, Maganaris CN.

Institute for Biophysical and Clinical Research into Human Movement, Manchester Metropolitan University, MMU Cheshire, Alsager Campus, Hassall Road, Alsager, Cheshire ST7 2HL, UK. n.reeves@mmu.ac.uk

The age-related loss of muscle mass known as senile sarcopenia is one of the main determinants of frailty in old age. Molecular, cellular, nutritional and hormonal mechanisms are at the basis of sarcopenia and are responsible for a progressive deterioration in skeletal muscle size and function. Both at single-fibre and at whole-muscle level, the loss of force exceeds that predicted by the decrease in muscle size. For single fibres, the loss of intrinsic force is mostly due to a loss in myofibrillar protein content. For whole muscle, in addition to changes in neural drive, alterations in muscle architecture and in tendon mechanical properties, exemplified by a reduction in tendon stiffness, have recently been shown to contribute to this phenomenon. Resistance training can, however, cause substantial gains in muscle mass and strength and provides a protective effect against several of the cellular and molecular changes associated with muscle wasting and weakness. In old age, not only muscles but also tendons are highly responsive to training, since an increase in tendon stiffness has been observed after a period of increased loading. Many of the myotendinous factors characterizing ageing can be at least partly reversed by resistance training.

Publication Types:

PMID: 16469817 [PubMed - indexed for MEDLINE]

: Sarcopenia--exercise as a treatment strategy.

Taaffe DR.

School of Human Movement Studies, Faculty of Health Sciences, The University of Queensland. dtaaffe@hms.uq.edu.au

BACKGROUND: Sarcopenia, the age related decline in muscle mass, is associated with a reduction in muscle function, physical performance, quality of life, and loss of independence. Exercise, specifically resistance (weight) training, has been shown to be an effective countermeasure, arresting decline and substantially improving physical function. OBJECTIVE: This article reviews the prevalence of sarcopenia, underlying processes, and the role of exercise as a treatment strategy. Practical guidelines are provided for prescribing exercise to older patients. DISCUSSION:The aging neuromuscular system is highly responsive to resistance training. Resistance can be applied using specialised weight training machines, elastic bands, objects around the home, or body weight. Training once or twice a week targeting the major muscle groups at moderate intensity is sufficient for improvement.

PMID: 16525526 [PubMed - indexed for MEDLINE]