Condición física de escolares chilenos de 8° año básico y su relación con el rendimiento académico

Indexación: Scopus.Good physical fitness (PF) is related, among many benefits, to functional and structural brain changes that favor learning. Objective: To analyze the association between PF and academic performance (AP) in Chilean schoolchildren according to sex, and to determine if the kind of school dependency influences this association. Subjects and Method: Cross-sectional study analyzing population data of 8th-grade students evaluated by the SIMCE-2011 test. The sample included only 13 and 14 years old students, of both sexes, with all PF and AP tests taken. The results of PF and AP tests were categorized as poor, regular, and good. A binary logistic regression was performed explaining a good AP from the PF categories according to sex, and kind of school dependency, adjusting for age, nutritional status, parents’ educational level, and school socioeconomic level. Results: Out of 19,929 records, 12,338 schoolchildren were considered, where 47.9% were female. 33.4% of girls and 49.5% of boys presented good PF, and 16.9% and 21.5% presented good AP respectively. Schoolchildren with good PF had more chances of achieving good AP than those with poor PF (girls 84% and boys 78%, both p < 0.001). Considering the kind of school dependency, good PF in girls attending public schools increased the chances of achieving good AP by 334% (p < 0.001) and in boys attending subsidized private schools by 91% (p = 0.01). Conclusion: Both girls and boys with good PF have more chances of achieving a good AP. By including the kind of school dependency, the association persists in girls attending public schools and boys attending subsidized private schools.https://www.revistachilenadepediatria.cl/index.php/rchped/article/view/114

Are ‘Endurance’ Alleles ‘Survival’ Alleles? Insights from the ACTN3 R577X Polymorphism

Exercise phenotypes have played a key role for ensuring survival over human evolution. We speculated that some genetic variants that influence exercise phenotypes could be associated with exceptional survival (i.e. reaching ≥100years of age). Owing to its effects on muscle structure/function, a potential candidate is the Arg(R)577Ter(X) polymorphism (rs1815739) in ACTN3, the structural gene encoding the skeletal muscle protein α-actinin-3. We compared the ACTN3 R577X genotype/allele frequencies between the following groups of ethnically-matched (Spanish) individuals: centenarians (cases, n = 64; 57 female; age range: 100–108 years), young healthy controls (n = 283, 67 females, 216 males; 21±2 years), and humans who are at the two end-points of exercise capacity phenotypes, i.e. muscle endurance (50 male professional road cyclists) and muscle power (63 male jumpers/sprinters). Although there were no differences in genotype/allele frequencies between centenarians (RR:28.8%; RX:47.5%; XX:23.7%), and controls (RR:31.8%; RX:49.8%; XX:18.4%) or endurance athletes (RR:28.0%; RX:46%; XX:26.0%), we observed a significantly higher frequency of the X allele (P = 0.019) and XX genotype (P = 0.011) in centenarians compared with power athletes (RR:47.6%; RX:36.5%;XX:15.9%). Notably, the frequency of the null XX (α-actinin-3 deficient) genotype in centenarians was the highest ever reported in non-athletic Caucasian populations. In conclusion, despite there were no significant differences with the younger, control population, overall the ACTN3 genotype of centenarians resembles that of world-class elite endurance athletes and differs from that of elite power athletes. Our preliminary data would suggest a certain ‘survival’ advantage brought about by α-actinin-3 deficiency and the ‘endurance’/oxidative muscle phenotype that is commonly associated with this condition

Health enhancing strength training in nonagenarians (STRONG): rationale, design and methods

<p>Abstract</p> <p>Background</p> <p>The Health Enhancing Strength Training in Nonagenarians (STRONG) is a randomised control trial to assess the effectiveness of an aerobic and strength training program for improving muscle strength, functional capacity and quality of life in nonagenarians.</p> <p>Methods</p> <p>Sixty (51 women) nonagenarians (age range: 90–102 years) who live in a geriatric nursing home will be randomly assigned to either a usual care (control) group (n = 30) or an intervention (training) group (n = 30). Participants allocated in the usual care group will receive general physical activity guidelines and participants allocated in the intervention group will also enrol in three weekly non-consecutive individualized training sessions (~45–50 min each) during 8 weeks. The exercise program will consist of muscular strength [with a special focus on leg press at 30% (start of the program) to 70% 1 repetition maximum (end)] and aerobic exercises (cycle-ergometry during 3–5 to 15 minutes at 12–14 points in the rate of perceived exertion scale).</p> <p>Results</p> <p>Results from STRONG will help to better understand the potential of regular physical activity for improving the well-being of the oldest population groups.</p> <p>Conclusion</p> <p>The increase in life expectancy together with the dramatic decrease in birth rates in industrialized countries calls the attention to health care systems and public health policymakers to focus attention on promoting healthy lifestyle in the highest sector of the population pyramid. Our study attempts to improve functional capacity and QOL of nonagenarians by implementing an individualised aerobic and strength training program in a geriatric residential care. Results from STRONG will help to better understand the potential of regular physical activity for improving the well being even in persons aged 90 years or over.</p> <p>Trail Registration</p> <p>ClinicalTrials.gov ID: NCT00848978</p

Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

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