Chubak 2006.

Methods	Study design: randomised controlled trial Location, number of centres: Fred Hutchinson Cancer Research Center and the University of Washington Country: USA Study period: 12 months Methods of analysis: "at baseline and 3, 6, 9 and 12 months, participants completed self administered questionnaires, modified from established, validated instruments on the number of episodes of allergies, upper respiratory tract infections (colds and flu) and other infections over the past 3 months" Statistical analysis: "Poisson regression allowed for use of data from all available time points without eliminating individuals with some missing data. We assumed an unstructured working correlation matrix, computed robust standard errors and performed an intention‐to‐treat analysis, with P < 0.05 being considered statistically significant. Results were identical or stronger when restricted to women who had assessments at all 4 time points. We also evaluated whether the exercise effect differed by age (< 60 versus ≥ 60 years) or regular multivitamin use, assessed by abstraction of vitamin bottles brought into the clinic at baseline (see Shade et al for details). All analyses were performed using SAS 8.0 (SAS Institute, Cary, NC) and Stata 8 (StataCorp, College Station, Tex) statistical software. All P values are 2‐sided"
Participants	Recruitment means: mass mailings and media placements Target participants: postmenopausal women, overweight/obese, non‐smoking, sedentary N randomised: 115 adult postmenopausal women N completed: 115 postmenopausal women: 53 (exercise) and 62 (control) Gender F = 115: exercise 53, control 62 Age: exercise 60.5 (7), control 60.9 (6.8) Inclusion criteria: "post‐menopausal; age, 50 to 75 years; in good health; non‐smoking; sedentary (< 60 minutes/week of moderate and vigorous‐intensity recreational activity and maximal oxygen consumption < 25.0 mL/kg per minute during a VO₂ test); not taking hormone replacement therapy in the past 6 months; alcohol consumption of fewer than 2 drinks per day; body mass index (BMI) between 25 and 40 or BMI 24.0 to 24.9 if body fat > 33%; no history of invasive cancer, diabetes, cardiovascular disease, asthma; no current serious allergies; no regular (≥ 2 times/week) use of aspirin or other nonsteroidal anti‐inflammatory medications; not using corticosteroids or other medications known to affect immune function. Women were ineligible if they were volunteering for the study to lose weight, had a history of surgery for weight loss, or were currently attempting, or planning to attempt, weight loss by taking diet pills or entering a structured weight loss programme. Participants had been weight stable for at least 3 months" Baseline details: demographic information, medical history, health habits, reproductive history, physical activity, diet, and anthropometric variables
Interventions	Setting of intervention: Fred Hutchinson Cancer Research Center and the University of Washington Description of intervention: "the exercise intervention consisted of at least 45 minutes of moderate‐intensity exercise 5 days/week for 12 months. During months 1 through 3, participants were required to attend 3 sessions per week at 1 of the study facilities and to exercise 2 days/week at home. For months 4 through 12, participants were required to attend at least 1 session per week at the facility and to exercise the remaining days on their own for a total of 5 days/week (participants were allowed to exercise additional days at the facility if they chose). The training programme began with a target of 40% of maximal heart rate for 16 minutes per session and gradually increased to 60% to 75% of maximal heart rate for 45 minutes per session by week 8, at which point it was maintained for the duration of the study. Participants wore heart rate monitors (Polar Electro Inc, Woodbury, NY) during their exercise sessions. Facility sessions consisted of treadmill walking and stationary bicycling. Strength training, consisting of 2 sets of 10 repetitions of leg extension, leg curls, leg press, chest press and seated dumbbell row, was recommended but not required to decrease risk of injury and maintain joint stability. A variety of home exercises were suggested and encouraged, including walking, aerobics and bicycling. Participants were encouraged to wear their heart rate monitors when exercising at home. Women randomly assigned to the control group attended weekly 45‐minute stretching sessions for 1 year and were asked not to change other exercise habits during the study. Exercise and control participants were asked to maintain their usual diet" Delivered by: not stated Follow‐up period: 12 months Co‐interventions: none
Outcomes	Multivitamin, number of colds before baseline, number of URTIs, allergy episodes, influenza immunisation Prespecified: 3 months before baseline Follow‐up period: 12 months
Notes	Study funding: "National Cancer Institute (NCI) (R01 CA 69334). Ms. Chubak was supported by grant T32 CA09168 from the NCI. The contents of this publication are solely the responsibility of the authors and do not necessarily represent the official views of the NCI or National Institutes of Health. Dr. Wener was supported in part by the University of Washington Clinical Nutrition Research Grant (DK35816)"
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Participants were enrolled in a randomised trial...". Insufficient information provided to assess this domain.
Allocation concealment (selection bias)	Unclear risk	No information regarding allocation concealment was provided in the text.
Blinding of participants and personnel (performance bias) All outcomes	High risk	The participants could not be blinded due to the characteristics of the intervention.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Outcomes are by participant self‐report. Information was obtained by telephone for outcomes ARI episodes and URI.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Authors reported missing data on colds or other URTI episodes at 6 and 9 months (result: < 10%).
Selective reporting (reporting bias)	Low risk	The study protocol was not available, although all outcomes relevant to this review were reported.
Other bias	Low risk	The study seems to be free of other sources of bias.