H/A: Physical Activity (2009)

Study Design:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:

Women infected with HIV increasingly demonstrate abnormalities in fat distribution and metabolism. However adherence to organized outpatient programs is often poor and may limit the efficacy of these strategies in HIV-infected women. To increase adherence, the purpose of this study was to design and evaluate a novel home-based, supervised aerobic and resistance training program.

Inclusion Criteria:
  • HIV-infected females
  • Between 18 and 60 years of age
  • Waist-hip ratio of 0.85 or more
  • Self-report and physical evidence of fat redistribution.
Exclusion Criteria:
  • Use of megestrol acetate, androgens, growth hormone or glucocorticoid therapy
  • Significant liver or kidney disease or severe anemia
  • Receiving current therapy with insulin
  • History of diabetes mellitus
  • Fasting glucose level of 126mg/dL (7.0mmol/L) or more
  • Actively engaged in substance abuse
  • Pregnant, actively seeking pregnancy or breastfeeding
  • Acute infection
  • Initiated a new anti-retroviral therapy regimen within one month of the study.
Description of Study Protocol:


Subjects recruited through community advertisement and primary care provider referral


  • Randomized controlled trial: Randomization to the exercise program was performed by the General Clinical Research Center Biostatistics Center, using a permuted block algorithm
  • Registered clinical trial: Clinicaltrials.gov identifier: NCT00111332.

Blinding used

Implied for laboratory measures


Home-based, supervised progressive resistance training and aerobic exercise program

Statistical Analysis

  • Demographic variables were compared by unpaired, two-tailed T-test for continuous variables and the x2 test for noncontinuous variables
  • Treatment effects over time were compared between exercise and non-exercise study groups by analysis of covariance with the baseline value as a covariate
  • Use of HIV medication was tested for significance in the analyses of covariance and did not affect the results
  • The primary analysis was per protocol, but a confirmatory intent-to-treat analysis was performed carrying forward last available data on the two dropouts, with similar results (data was not shown)
  • With 40 patients, the study was powered at 85% to detect a treatment effect of 1.0 SD on clinical end points between the exercise and non-exercise groups. The study was powered to detect a difference of 3.4mL*Kg-1*minimum-1 in VO2maximum between the groups.
  • Six-minute walk data excluded one patient unable to perform the test adequately
  • The analysis of waist circumference excluded data from a single patient that did not fulfill the Dixon and Massey criteria.
Data Collection Summary:

Timing of Measurements

  • October 21, 2002 to March 2, 2005
  • 16-week study.

Dependent Variables

  • Fitness measures: VO2max; sub-maximal bike exercise time; six-minute walk distance
  • Strength measures: Knee extensors; pectoralis; knee flexors; shoulder abductors; ankle plantar flexors; elbow flexors (right and left arms)
  • Body composition: BMI; waist circumference; total muscle area; total muscle attenuation; total fat; SAT; VAT
  • Biochemical indexes: Total cholesterol; triglycerides; LDL cholesterol; HDL cholesterol; fasting glucose; two-h glucose
  • Clinical measures: Blood pressure
  • Immune measures: HIV viral load; CD4 count
  • Dietary measures: Total caloric intake; total fat intake; total carbohydrate intake; total protein intake.

Independent Variables

  • Exercise: Supervised home-based progressive resistance training and aerobic exercise program
  • Control: Were encouraged to maintain their normal activities without further prescription as to activity.

Control Variables

  • Use of HIV medication(s)
  • Current smoking history as well as total duration and amount of smoking (in pack-years) was recorded.
Description of Actual Data Sample:

Initial N

47 subjects screened; 42 eligible

Attrition (final N)

  • Two subjects who were eligible withdrew related to illness prior to randomization
  • 40 enrolled and randomized into the two groups
  • One dropout from each group due to unwillingness to complete study
  • 19 completed in both groups for a total of 38 subjects.


  • Exercise (mean ± SEM): 43± two years
  • Control: 40± two years.


Ratio of white to non-white

  • Exercise 7:13
  • Control 4:16.


  • African American: Exercise 10; control 12
  • Hispanic: Exercise two; control four
  • Other: Exercise one; control zero.

Other relevant demographics

  • Current smoking, number (percentage): Exercise seven (35); control 11 (55)
  • Eumenorrheic, number (percentage): Exercise 16 (80); 13 (65).

Disease and medication information

  • Duration of HIV: Exercise 11±1; control 9±1
  • Current retrovirals, number (percentage): Exercise 17 (85); control 16 (80)
    • Protease inhibitor: Exercise 11 (55); control 10 (50)
    • Nucleoside reverse transcriptase inhibitor: Exercise 17 (85); 12 (60) P=0.07
    • Non-nucleoside reverse transcriptase inhibitor: Exercise six (30); control eight (40)
  • Anti-hypertensive agent, number (percentage): exercise three (15); control three (15)
  • Lipid-lowering agent, number (percentage): Exercise two (10); control zero
  • Estrogen use, number (percentage): Exercise two (10); control zero.


Waist-hip ratio: Exercise 0.98±0.02; control 0.94±0.02 P=0.09


  • General clinical research center for a baseline visit; eight-week safety visit; 16 weeks 
  • Home-based.
Summary of Results:


Variables Exercise Group
(change at 16 weeks)
Control Group
(change at 16 weeks)
P-value for Treatment Effect*
Fitness measures      
VO2 max  1.5±0.8 -2.5±1.6  <0.001 
Sub-maximal bike exercise  time, minutes 1.0±0.3 -0.6±0.3  <0.001 
Six-minute walk distance, m 34±11  -6±15  0.009 
Body composition      
Waist circumference, cm -1.0±0.6 1.5±1.0  0.03 
Total muscle area, cm2 6±1 2±1 0.02
Total muscle attenuation, HU 2±1 -1±1 0.03
Immune Function      
Log HIV viral load, copies/uL; baseline (change at 16 weeks) 2.3±0.2 (0.1±0.1) 3.0±0.3
0.06 (0.28)
CD4 counts, cells/uL 539±78 (8±37)

419±63 (11±38)

0.24 (0.94)

*By analysis of covariance.

Other Findings

  • No difference at baseline in VO2max between the groups; however among the HIV-infected subjects, VO2max was markedly lower at baseline (median [95% confidence interval], 15.4 [8.3 to 25.2] mL*kg-1*minimum-1) than reported values for healthy female subjects (26 to 35 mL*kg-1*minimum-1)
  • Endurance (sub-maximal bike exercise time) and knee flexor strength differed at baseline
  • Body composition (29.3 exercise; 28.6 control), biochemical, immune and dietary characteristics were similar between study groups at baseline
  • All strength measures measured by change in one RM increased significantly for the exercise group at 16 weeks versus the control group
  • Subjects randomized to the exercise regimen completed 96% of sessions
  • Body mass index, abdominal fat, and total fat did not change between the groups
  • No significant difference was seen in lipid levels, glucose, CD4 count viral load or blood pressure
  • Dietary intake (baseline values) of total calories (exercise 1,708±109; control 1,547±130), fat, carbohydrate, and protein (exercise 66.6±4.2; control 65.0±5.6) did not differ over time between the treatment groups
  • In response to the exit question, "In the past four months, have you noticed any change in your cardiovascular health?" 89% of the exercise group answered yes vs. 16% of the control group (P<0.001). Of the patients in the exercise group answering affirmatively, 76% reported increased energy, 35% reported increased strength, and 41% reported increased endurance.
  • The total score for self-assessment of fat distribution improved in the exercise group (-1.4±0.3 vs. 0.3±0.1, P<0.001). The most significant effect seen was in the self-reported appearance of the abdomen (-0.8±0.2 vs. 0.0±0.0; P<0.001). A significant effect was also reported for the extremities (-0.7±0.2 vs. 0.2±0.1; P<0.001).
  • The exercise program was well tolerated. Few adverse events occurred, and none was related to the exercise protocol or study participation. One patient in the exercise protocol had exacerbation of asthma related to the development of bronchitis. One patient in the non-exercise groups experienced chest pain at the baseline visit, but myocardial infarction and ischemia were ruled out. No changes in menstrual function were seen.


Author Conclusion:

A 16-week, supervised, home-based exercise regimen improved measures of physical fitness in HIV-infected women. The effects on strength were most significant, but improvements in cardiorespiratory fitness, endurance, and body composition were also seen.

The observed changes may make patients more compliant with anti-retroviral medications associated with negative effects on body image.



Funding Source:
Government: NIH
Reviewer Comments:

Limitations as reported by the authors:

  • We did not measure oxygen consumption directly, but instead used a prediction equation not previously validated in a population with HIV infection, which may be a limitation of the study
  • The lack of effects on lipid levels and glucose may also have been due to small sample size and degree and limited aerobic stimulus.
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? 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) Yes
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? Yes
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) Yes
  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? N/A
  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? Yes
  4.1. Were follow-up methods described and the same for all groups? Yes
  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%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? Yes
  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? Yes
  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.) Yes
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  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? Yes
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? N/A
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? Yes
  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? Yes
  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? Yes
  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)? Yes
  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? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? Yes
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