Background The relationship between the Body Mass Index (BMI) with physical fitness in children and adolescent populations from diverse regions are consistent. However, the relationship between the Ponderal Index (PI) with physical fitness, based on what is known to date, has not been examined in depth. The objective was to evaluate the relationships between BMI and PI with three physical fitness tests of students living at moderate altitudes in Peru. Methods A descriptive correlational study was carried out with 385 adolescents, between the ages of 10.0 to 15.9 years old, from the province of Arequipa, Peru. Weight, height, and three physical fitness tests (horizontal jump, agility, and abdominal muscle resistance) were evaluated. BMI and PI were calculated, and they were, then, categorized into three strata (low, normal, and excessive weight). Specific regressions were calculated for sex, using a non-lineal quadratic model for each item adjusted for BMI and PI. Results The relationship between BMI and PI with the physical tests reflected parabolic curves that varied in both sexes. The regression values for BMI in males oscillated between R2 = 0.029 and 0.073 and for females between R2 = 0.008 and 0.091. For PI, for males, it varied from R2 = 0.044 to 0.82 and for females, from R2 = 0.011 to 0.103. No differences occurred between the three nutritional categories for BMI as well as for PI for both sexes (p range between 0.18 to 0.38), as well as for low weight (BMI vs PI), normal weight (BMI vs PI), and excessive weight (BMI vs PI) (p range between 0.35 to 0.64). Conclusions BMI showed inferior quadratic regressions with respect to the PI. In addition, physical performance was slightly unfavorable when it was analyzed by BMI. PI could be a useful tool for analyzing and predicting physical fitness for adolescents living at a moderate altitude since it corrects for the notable differences for weight between adolescents.

A soccer player should possess a reasonable level of different skills and abilities, so the playing position, level of training, style of play, physical and physiological demands can influence his performance. The objective was to identify the intervention programs that have been applied in search of generating positive effects on explosive strength and speed in young soccer players, as well as to identify the percentage of improvement among soccer players. A bibliographic study of systematic review was carried out. Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement, bibliographic searches were performed in the PubMed database. The following descriptors were used: Explosive Strength, soccer players, jump performance, CMJ, SJ, VJ, Plyometrics, power, speed, sprint, kicking speed, change of direction speed, soccer player, football and training, intervention. Articles were included only if they were original articles, studied populations of young soccer players and showed an intervention program related to explosive strength and speed. Six studies were identified that applied intervention programs to look for changes in speed and explosive strength in young soccer players. In the 5m speed tests, significant changes were observed, improving from (0.26 to 0.53m/s), 10m speed (0.07 to 0.27m/s), 20m speed (0.08 to 1.92m/s) and 40m speed (0.25 to 0.62m/s). In explosive strength, performance in the test squat jump SJ (4.1 to 8.6cm), countermovement jump CMJ (1.0 to 8.8cm), horizontal jump HJ (12.17 to 24.4cm) and vertical jump VJ (5.0 to 11.0cm). Speed and explosive strength are relevant components of athletic performance and can be improved through training programs that include 20 to 40min sessions, training two to five times per week over a period of approximately 6 to 9 weeks.

ObjectiveKnowledge of the biological parameters of pubertal growth spurt allows verification of secular changes and exploration of the timing of puberty. The aim of the study was to estimate final height, age at peak height velocity (APHV), and peak height velocity PHV (cm/y) in children and adolescents living at moderate altitude in Colombia.MethodsA cross-sectional study was designed in 2.295 schoolchildren from Bogotá (Colombia) with an age range from 5.0 to 18.9 years. Height (cm) was assessed. Preece–Baines model 1 (1PB) was used to make inferences about mathematical and biological parameters.ResultsThe five mathematical parameters estimated in general have reflected quality in the fit to the model, reflecting a small residual error. Final height was reached in boys at 170.8 ± 0.4 cm and in girls at 157.9 ± 0.2 cm. APHV was estimated at 12.71 ± 0.1 years in boys and 10.4 ± 0.2 years in girls. Girls reached APHV 2.2 years earlier than boys. In relation to PHV (cm/y), boys reached higher growth speed in height (7.4 ± 0.4 cm/y), and in girls it was (7.0 ± 0.2 cm/y).ConclusionIt was determined that final height was reached at 170.8 ± 0.4 cm in boys and 157.9 ± 0.2 cm in girls, and APHV (years) and PHV (cm/ye) were reached relatively early and with average peak velocity similar to Asian and Western populations. A large-scale longitudinal study is needed to confirm these findings.

Objectives: This study's purpose was to compare physical growth (PG) patterns of children and adolescents living at high elevations with those of other geographic regions, relate body adiposity indicators, and develop percentile reference tables for assessing physical growth and body adiposity. Methods: The sample included 1536 children and adolescents ages 5.0 to 17.9 years from Puno (Peru) located between 3821 and 4349 m above sea level. Weight, height, arm and waist circumferences (WC), and three skinfolds measurements were recorded. Body mass index (BMI) and waist-height Index (WHI) were calculated. Results: PG patterns for children living at a high altitude reflected similar values for weight, height, and arm circumference (AC) to those of their counterparts living in Puno (Peru) and La Paz (Bolivia). When compared with children living at moderate altitudes in Peru, they showed slightly lower PG values. BMI explained between 41% and 64% of the variance in sum of the skinfolds, while WC explained between 47% and 66%. HWI was not a strong predictor of variation in sum of skinfolds. Percentiles were generated for WC and the sum of skinfolds. Conclusion: Weight, height, and, arm and waist circumference patterns for children and adolescents living at high altitudes were similar to those of La Paz (Bolivia). WC and the sum of the skinfolds were better indicators for analyzing abdominal obesity compared to BMI and WHI. The percentiles proposed may be a useful tool for identifying high risk of developing overweight disorders in pediatric populations living at high altitudes.

Background and Objectives: The presence of the new SARS-CoV-2 virus is causing enormous threats to people’s health and lives, so quantifying the scientific productivity on mental health in times of pandemic is an urgent need, especially to expand the degree of knowledge on mental health problems in regions of low scientific productivity. The aim was to characterize the bibliometric indicators of scientific productivity on mental health during the pandemic in the PubMed Identifier database of the National Library of Medicine in the United States. Materials and Methods: A documentary study (bibliometric) of the scientific productivity on mental health in times of pandemic from January 2020 to June 2021 was carried out. The PubMed database was used to abstract the information from the original scientific articles. The data abstracted were: authors, year of publication, journal name, country, and language of publication. Results: We identified 47 original articles worldwide, which were published in 29 journals and in three languages (English, Spanish, and German). We observed three groups of countries that published on mental health topics. The first group comprised the largest number of publications, which were multicenter studies (six studies), followed by India (five studies), and Italy (four studies). A second group comprised Bangladesh, China, USA, and Spain, with 3 studies each; and a third group comprised 13 countries (Albania, Saudi Arabia, Argentina, Brazil, South Korea, Denmark, Ecuador, Egypt, Greece, Japan, Jordan, Kuwait, and New Zealand) with one study each. Conclusions: Bibliometric indicators of scientific productivity on mental health during the COVID-19 pandemic have ostensibly increased. We verified 47 studies in PubMed, which could serve to improve the understanding and management of COVID-19, as well as serve as a thought-provoking means for other countries and researchers to publish on the state of mental health during and post pandemic.