Physical Activity Questionnaire for Children: Validity and Cut-Points to Identify Sufficient Levels of Moderate- to Vigorous-Intensity Physical Activity Among Children and Adolescents Diagnosed With HIV.

PURPOSE: To investigate the validity of the Physical Activity Questionnaire for Older Children (PAQ-C) to assess the moderate- to vigorous-intensity physical activity (MVPA) level of children and adolescents diagnosed with HIV and propose cut-points, with accelerometer measures as the reference method. METHOD: Children and adolescents, aged 8-14 years (mean age = 12.21 y, SD = 2.09), diagnosed with HIV by vertical transmission, participated in the study. MVPA was investigated through the PAQ-C and triaxial accelerometer (ActiGraph GT3X+). Receiver operating characteristic curve and sensitivity and specificity values were used to identify a cut-point for PAQ-C to distinguish participants meeting MVPA guidelines. RESULTS: Fifty-six children and adolescents participated in the study. Among those, 16 met MVPA guidelines. The PAQ-C score was significantly related to accelerometry-derived MVPA (ρ = .506, P < .001). The PAQ-C score cut-point of 2.151 (sensitivity = 0.625, specificity = 0.875) was able to discriminate between those who met MVPA guidelines and those that did not (area under the curve = 0.751, 95% confidence interval, 0.616-0.886). CONCLUSION: The PAQ-C was useful to investigate MVPA among children and adolescents diagnosed with HIV and to identify those who meet MVPA guidelines.

Prediction of peak V˙ O2 in Children and Adolescents With HIV From an Incremental Cycle Ergometer Test.

PURPOSE: To examine the capacity of physiological variables and performance to predict peak oxygen consumption (peak V˙ O2) in children and adolescents living with HIV. METHOD: Sixty-five children and adolescents living with HIV (30 boys) aged 8-15 years, participated in the study. Peak V˙ O2 was measured by breath-by-breath respiratory exchange during an incremental cycle ergometer until volitional exhaustion. Information on the time to exhaustion, maximal power output (Pmax), and peak heart rate (peak HR) were also recorded. RESULTS: Predictive models were developed and all equations showed the ability of performance variables to predict peak V˙ O2. However, Model 1 was based only on Pmax by following equation: Y = 338.8302 + (Pmax [W] * 11.16435), R2 = 0.90 and standard error of estimation (SEE) = 180 ml ⋅ min-1. CONCLUSION: The V˙ O2 peak can be predicted simply by the Pmax obtained from the incremental cycle ergometer test. This protocol is a valid and useful tool for monitoring the aerobic fitness of children and adolescents living with HIV, especially in resource-limited settings.

Estimating bone mineral content based on different types of muscle strength tests.

The aims of this pilot study were to verify which muscle strength tests better explain bone mineral content (BMC) of the femoral neck and lumbar spine and to develop predictive equations to estimate femoral neck and lumbar spine BMC. Twenty-nine subjects aged 56-76 years old (12 women and 17 men) participated in the study. Femoral neck and lumbar spine BMC was evaluated by Dual X-ray absorptiometry (DXA). Muscle strength measurements included maximal isometric voluntary contractions of knee extensors and flexors, vertical jump, 5-repetition maximum of the leg press (5-RMLP) and seated leg curl (5-RMLC), and handgrip strength. Women presented a moderate to strong correlation between femoral neck BMC and 5-RMLP (r = 0.819), 5-RMLC (r = 0.879), knee extensors peak torque (r = 0.699), and handgrip strength (r = 0.663), as well as between lumbar spine BMC and the 5-RMLP test (r = 0.845) and manual grip strength (r = 0.699). For females, the 5-RMLP and 5-RMLC tests most fully explained femoral neck BMC (R2 = 0.859) and the 5-RMLP test and body mass explained lumbar spine density (R2 = 0.757) for females. Men did not present correlations between BMC and strength variables. For females, the 5-RMLP and 5-RMLC variables explained the variations of femoral neck BMC, while 5-RMLP and body mass explained lumbar spine BMC. Future studies should evaluate a larger sample size and prioritize the strength tests with a greater predictive capacity.

Low handgrip strength levels among adolescents in a city in southern Brazil.

OBJECTIVE: To estimate the prevalence of low handgrip strength (HGS) levels and sociodemographic characteristics, health behaviours and body fatness status related in adolescents. METHOD: Cross-sectional epidemiological study with 636 adolescents aged 14-19 years in a city in southern Brazil. HGS was measured by dynamometer. Sociodemographic and behavioural data were collected using self-report questionnaires. Body mass and height was measured by Body Mass Index. RESULTS: Prevalence of low HGS levels was 47% (63.5% boys, 37.7% girls). Boys aged 14-16 years were more likely to have low HGS levels. Girls who were of higher socioeconomic status and who were less physically active were more likely to have low HGS levels. Overweight girls were less likely to have low HGS levels. CONCLUSIONS: High prevalence of low HGS levels was observed in adolescents. Increased HGS levels should be focused on younger boys and normal-weight girls with higher socioeconomic status and lower levels of physical activity.

Handgrip strength and associated sociodemographic and lifestyle factors: A systematic review of the adult population.

OBJETIVES: The aim of this study was to identify studies on handgrip strength (HGS) and associations with sociodemographic variables and lifestyle in adults. METHODS: Searches were performed in Scielo, PubMed, EBSCO, Lilacs, Scopus and Web of Science databases. DATA EXTRACTION: Two blinded reviewers independently screened the articles, scored their methodological quality and extracted data. QUALITY ASSESSMENT: The selected studies were analyzed according to the agreement of their findings with the evidence summary. RESULTS: Overall, 18,038 studies were found and 26 articles were selected. Lower HGS levels were found in older individuals (n = 20), females (n = 13) and in those not engaged in physical activities (n = 5). CONCLUSIONS: Older adults, females, those of lower educational level and not physically active had lower HGS levels. The adoption of standardization in relation to specific cutoff points for HGS classification becomes necessary in order to allow better comparison of results.