Phase Angle and Body Composition as Predictors of Fitness and Athletic Performance in Adolescent Boxers.

Background: Phase angle (PhA) is an indicator of cellular health, function, and integrity. PhA has been considered an indicator of nutritional and health status, but it is uncertain whether it could be used as a fitness or athletic performance indicator.

Objective: To analyze the relationship between PhA and the fitness and athletic performance of adolescent boxers and to know whether this association is independent of body composition.

Energy Expenditure in Free-Living Physical Activities and Sedentary Behaviors in Mexican Schoolchildren.

Metabolic equivalents for youth (METy) are derived using the estimated basal metabolic rate (BMR). However, is unknown whether this METy can be different when measured resting energy expenditure (REE) is used. The purposes of this article are to: (a) To determine whether there is equivalence between METy values calculated using measured REE (METy-mea) and METy using predicted BMR (METy-est).

Differences in blood pressure according to physical fitness and body mass in a sample of Mexican schoolchildren.

Background: Physical fitness is the ability to perform activities of daily living without excessive fatigue. The potential protective role of fitness against high blood pressure in childhood is relevant to diminish the risk of hypertension in adulthood. A negative association between cardiorespiratory fitness (CRF) and hypertension has been found in the pediatric population.

Validity of equations for estimating aerobic fitness in Mexican youth.

The purpose of this study was to evaluate the validity of prediction equations for estimating maximal oxygen uptake (VO) based on the PACER test and different adiposity indicators in Mexican youth. A convenience sample of youth aged 9-18 years from schools in Mexico City was recruited. VO was evaluated with a laboratory exercise test on a treadmill and using a gas analyser and with the 20-m PACER test guidelines.

[Accelerometry does not match with self-reported physical activity and sedentary behaviors in Mexican children].

Background: An accurate assessment of physical activity in schoolchildren is necessary to implement strategies that promote active lifestyles. The objective of this study was to validate a self-administered questionnaire to assess physical activity and sedentary behaviors and to analyze differences in the validity according to nutritional status in Mexican schoolchildren.

Methods: Schoolchildren of 8-12 years of age answered a self-report physical activity and sedentary behaviors questionnaire to evaluate sedentary and light physical activity (SLPA) and moderate to vigorous physical activity (MVPA).