Pediatrics and Physical Activity

Study Design:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To determine the effects of a two-year physical education program, project SPARK (Sports, Play and Active Recreation for Kids) on indicators of relative weight and adiposity in elementary school children.
Inclusion Criteria:
None provided
Exclusion Criteria:
None provided
Description of Study Protocol:


Of 16 elementary schools in district, 12 principals agreed to participate

Intervention Groups:

  • Group 1 – certified PE specialists implemented program (2 schools)
  • Group 2 – trained classroom teachers implemented program (2 schools)
  • Group 3 – usual PE (control; 3 schools)

SPARK Curriculum:

  • PE – to promote PA in school
    • Three 30-min classes per week
    • Rotating units (4 weeks/unit) and progression within each unit
    • Three class segments – (1) brief warm-up and daily conditioning exercise to improve muscle strength and endurance, (2) health fitness activities to promote cardiovascular fitness (e.g., walk/run, aerobic dance), (3) sports skills focusing on skills development rather than competition, followed by cool-down with stretching
    • Sufficient equipment provided to schools (including controls)
    • Self-management – to promote PA outside of school
    • One 30-min class per week
  • Skills taught – self-monitoring (e.g., keeping daily log of PA), self-evaluation (e.g., weekly goal setting and discussion of progress & problems), self-reinforcement (e.g., self-praise and other low-cost methods), positive self-talk, making time for PA, making PA more enjoyable, and increasing social support
    • New skill taught each week with game format or small group interaction
    • Tangible incentives provided for reaching weekly goals (e.g., pencils, sports water bottles)
    • Parental involvement stimulated through monthly newsletters and parental signatures on weekly goal sheets


baseline, end year 1, beginning year 2, end year 2

Statistical Analysis

One-way ANOVA

Data Collection Summary:

Dependent Variables

  • Physical fitness (FITNESSGRAM protocol)
  • Physical activity? (8-page survey)
  • BMI (measured weight & height)
  • Sum of skinfolds (measured calf and triceps)

Independent Variables

SPARK Program (see above)

Control Variables

Gender (separate analyses), baseline value

Description of Actual Data Sample:

Initial N:

All 4th grade students from 7 elementary schools invited to participate; 98% of students provided informed consent though a passive consent procedure.

740 children completed anthropometric evaluations and 745 completed surveys at baseline


196 children; characteristics not described

Final Sample:

549 children (305 boys, 244 girls; 74% of original sample) provided data at all 4 timepoints (beginning and end of each school year)

Mean age 9.25 y at baseline


2 school y (˜18 mo), Fall 1990 – Spring 1992

85% White, 6% Asian and Pacific Islander, 7% Latino, 1% African American, 1% other

Other relevant demographics:

SES:  Not described

Location: San Diego County, CA

Summary of Results:

Baseline: Initial differences in BMI and skinfolds noted (but data not provided); f/u analyses therefore adjusted for baseline values.


BMI –  boys

  • Group 3 < Group 2 at end of year 1 (p<.05)
  • Group 3 < Groups 1 and 2 at beginning of year 2 (p<.05)
  • No differences by end of year 2

BMI – girls

  • Group 3 < Groups 1 and 2 at end of year 2 (p<.01)
  • No differences for other timepoints

Sum of skinfolds – boys

No differences at any timepoints

Trend toward lowest in Group 1 and highest in Group 3

Sum of skinfolds – girls

No difference at any timepoints

Trend toward lowest in Group 2 and highest in Group 3

Author Conclusion:

These results indicate that two years of participation in a special physical activity promotion program did not produce significant reductions in children’s body mass index or adiposity. It may not be appropriate, however, to conclude that the program has no effect on the prevention of childhood obesity.

The present findings suggest that PA alone is not sufficient to reduce adiposity in children over a two-year period (i.e., dietary modifications are required).

There is reason to believe that the increase PA in the intervention conditions could have stimulated greater bone density and more muscle mass, and these changes could be responsible for the higher levels of BMI in the intervention conditions.

The size of the group differences presented here is not trivial.  At the last measurement in the spring of 1992, the mean intervention skinfold score was 4.5% lower than the controls’ scores for boys and 4.8% lower for girls.

Funding Source:
Government: NIH
Reviewer Comments:

Strengths: Described measurer certification procedure at baseline, quality of measure assessment during study and specialist and teacher training program, 2 y duration.

Limitations:  No inclusion or exclusion criteria provided, no blinding of measurers, no provision of fitness or physical activity data (in discussion merely state that intervention students did improve in some fitness components), no evaluation of intervention implementation (in discussion stated that group 1 had 16 more minute/wk of moderate to vigorous PA in PE classes than controls and that difference was 13 minutes in group 2), no comparison of groups at baseline on most factors and data not provided for anthropometry, statistical procedures not well described, no power calculations provided.

Other Comments:

Interim report based on the first of two consecutive cohorts of children in the same schools; final sample expected to be roughly double in size. Intended to be 3 y intervention?

SPARK was not designed to be an obesity prevention program.

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) Yes
  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? ???
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? ???
  1.3. Were the target population and setting specified? ???
2. Was the selection of study subjects/patients free from bias? No
  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? No
  2.2. Were criteria applied equally to all study groups? ???
  2.3. Were health, demographics, and other characteristics of subjects described? ???
  2.4. Were the subjects/patients a representative sample of the relevant population? ???
3. Were study groups comparable? No
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) ???
  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.) ???
  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? ???
  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.) ???
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? ???
4. Was method of handling withdrawals described? No
  4.1. Were follow-up methods described and the same for all groups? ???
  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%.) ???
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? ???
  4.4. Were reasons for withdrawals similar across groups? ???
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? ???
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? ???
  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.) ???
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? ???
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? ???
  5.5. In diagnostic study, were test results blinded to patient history and other test results? ???
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? ???
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? ???
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? ???
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? ???
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? ???
  6.6. Were extra or unplanned treatments described? ???
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? ???
  6.8. In diagnostic study, were details of test administration and replication sufficient? ???
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? ???
  7.2. Were nutrition measures appropriate to question and outcomes of concern? ???
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? ???
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? ???
  7.5. Was the measurement of effect at an appropriate level of precision? ???
  7.6. Were other factors accounted for (measured) that could affect outcomes? ???
  7.7. Were the measurements conducted consistently across groups? ???
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? No
  8.1. Were statistical analyses adequately described and the results reported appropriately? ???
  8.2. Were correct statistical tests used and assumptions of test not violated? ???
  8.3. Were statistics reported with levels of significance and/or confidence intervals? ???
  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)? ???
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? ???
  8.6. Was clinical significance as well as statistical significance reported? ???
  8.7. If negative findings, was a power calculation reported to address type 2 error? ???
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? ???
  9.2. Are biases and study limitations identified and discussed? ???
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? ???
  10.2. Was the study free from apparent conflict of interest? ???