Pediatric Weight Management

Pediatrics and Physical Activity


Klentrou, P, Hay, J, & Plyley, M.  Habitual physical activity levels and health outcomes of Ontario youth.  Eur J Appl Physiol 2003;89:460-465.

Study Design:
Cross-Sectional Study
D - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

The purpose of the present study was to investigate the relationship(s) of habitual activity, involvement in sports, attitude toward physical activity, aerobic fitness and body fat with the frequency of upper respiratory tract infection (URTI).

Inclusion Criteria:

The completion of a Physical Activity Readiness questionnaire was required prior to being considered for participation.

Exclusion Criteria:

Absence of chronic medical conditions and smoking.

Description of Study Protocol:

Peak aerobic power was estimated using the 20-m shuttle run. Bioelectrical impedance (BIA) was used to estimate percentage of body fat (from height, mass, sex, frame size, and physical activity levels).  The Habitual Activity Estimation Scale (HAES) was used to estimate the duration of all forms of habitual activity (HPA) per day.  The Participation Questionnaire was used to estimate both the amount of participation in physical activity and the nature of the participation under three categories: free time activity (FTA), organized activity time (OAT), and total time spent in activities (SAT).  The Canadian Scale for Adequacy and Predilection for Physical Activity was used to determine the subjects’ perceptions of the ‘adequacy’ of the physical activity (AdPA), their predilection for the physical activity (PrPA), and their enjoyment of physical education (EPE).  A one month health log was used to record the incidence and duration (number of days) of URTI.

Statistical Analysis

The complete subject pool was divided into two groups:  highly active (HA) and moderately (MA) active based on median value of the HAES and the median score of total time spent in sport activity as determined from the PQ.  One way ANOVA was used to compare the HA with the MA groups in terms of body mass, %BF, predicted aerobic power and URTI symptom days.  Gender specific independent t-tests were performed to examine differences between males and females.  Pearson correlation analysis was used to detect possible relationships among the variables.

Data Collection Summary:

Dependent Variables

  • body fat, peak VO2, upper respiratory tract infection

Independent Variables

  • attitude towards PA, amount of physical activity

Control Variables

  • maturation
Description of Actual Data Sample:


Initial N: 256 adolescents (male n=126; female n=130) participated in the study. Subjects were recruited from 4 out of 104 randomly selected public schools within the Niagara Region in Ontario, Canada.

Age: adolescent

Ethnicity: Not reported

Location: Niagara Region in Ontario, Canada.


Summary of Results:

Percentage body fat and upper respiratory tract infection symptom days were significantly greater in the moderate activity group of the complete cohort. There was a significant difference between the moderate activity and high activity boys in terms of body fat, predicted aerobic power and URTI symptom days while the moderate activity girls differed significantly from the high activity girls only in body fat. 

Significant (P<0.01) relationships were found between each of the three sport activity parameters (FTA, OAT, SAT) and both peak VO2 and %BF. 

In addition, all three indicators of attitude towards physical activity (AdPA, PrPA, EPE) were significantly related to peak VO2, with PrPA and EPE also being significantly (P<0.05) related to body fat.

Author Conclusion:

The present data revealed that during the important developmental years, adolescent females are considerably less active than their male counterparts. The present results showed a significant relationship between predicted peak VO2 and perceptions of adequacy in, predilection for, and enjoyment of physical education. Overall, our findings reveal that those who enjoy physical activity also demonstrate higher levels of physical fitness.  Enjoyment of physical education was also found to be strongly correlated with relative body fat.

Funding Source:
Government: NHLBI
Reviewer Comments:

In the complete cohort and in males, those who spent less time in sporting activities showed significantly (P<0.05) higher %BF. Girls also showed significantly (P<0.05) less enjoyment of physical education than boys, which may explain their lack (P<0.05) of participation in sporting activities.


Reliance of using self-report measures for both infection and physical activity.


Multiple questionnaires.

Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) N/A
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? ???
3. Were study groups comparable? Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? ???
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) N/A
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? Yes
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? N/A
  4.1. Were follow-up methods described and the same for all groups? N/A
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) N/A
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? N/A
  4.4. Were reasons for withdrawals similar across groups? N/A
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
5. Was blinding used to prevent introduction of bias? No
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) No
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? No
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? N/A
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? Yes
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? N/A
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? N/A
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? N/A
  6.6. Were extra or unplanned treatments described? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? N/A
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? N/A
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? Yes
  8.6. Was clinical significance as well as statistical significance reported? No
  8.7. If negative findings, was a power calculation reported to address type 2 error? N/A
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes