Herrero 2006.

Study characteristics
Methods	Study design: RCT Number randomized: 20, 10 to the exercise group and 10 to the control group Study start and stop dates: recruitment was from November 2003 to April 2004 Length of intervention: 8 weeks Length of follow‐up: to end of the intervention
Participants	Type cancer: Stage I or II ductal breast cancer, stage at diagnosis not reported Time since cancer diagnosis: not reported Time beyond active treatment, mean (SD) months: exercise group: 36 (13) months control group: 35 (12) months Inclusion criteria: postmenopausal women surviving breast cancer 2 to 5 years post‐treatment 40 to 60 years old previous anticancer treatment consisting of surgery with axillary lymphadenectomy and both postsurgery radiation therapy and chemotherapy Eligibility criterion related to interest or ability to exercise, or both: physical activity level: walking less than a total of 30 to 60 minutes 3 days per week performing no strenuous exercise such as running, cycling, swimming, or resistance training Exclusion criteria: cardiac disease (NYHA II or greater) uncontrolled hypertension (blood pressure > 160/90 mmHg) uncontrolled pain, or any other condition that contraindicated exercise training in cancer patients or survivors, for example increased risk of bone fractures severe anemia (< 8 g/dL) platelet count lower than 50 x 109/μL lymphedema Gender: female Current age, mean (SD) years: exercise group: 50 (5) years control group: 51 (10) years Age at cancer diagnosis: not reported Ethnicity/race: not reported Education level: not reported SES: not reported Employment status: not reported Comorbidities: not reported Past exercise history: limited by exclusion criteria On hormone therapy: not reported Body mass and BMI, mean (SD): exercise group: body mass, 66.7 (10.5) kg; BMI, 24.0 (3.2) kg/m2 control group: body mass, 67.7 (8.9) kg; BMI, 25.1 (3.5) kg/m2
Interventions	10 participants assigned to an exercise group, including: 10‐minute warm‐up and cool‐down period, consisting of: cycle‐ergometer pedaling at very light workloads stretching exercises for all major muscle groups 70‐minute core portion of the training session resistance training with 11 exercises engaging the major muscle groups (chest press, shoulder press, leg extension, leg curl, leg press, leg calf rise, abdominal crunch, low back extension, arm curl, arm extension, and lateral pull‐down) exercises performed through the full range of motion normally associated with correct technique for each exercise stretching of muscles involved in an exercise performed at the end of each set of resistance exercise blood total creatine kinase levels were measured every week to ensure that the training program did not induce excessive muscle damage, that is levels < 167 International units Type exercise (aerobic/anaerobic): aerobic and anaerobic Intensity of experimental exercise intervention: not reported Frequency: 3 times per week Duration of sessions: 90 minutes Duration of program: 8 weeks Total number of exercise sessions: 24 Format: not reported Facility: community fitness club (Miranda de Ebro, Spain) Professionally led: supervised by experienced investigator Adherence: mean (SD) % = 91.1% (6.9%); Control group: 10 participants assigned to: usual activities with no moderate to heavy exercise Contamination of control group: not reported
Outcomes	Primary outcome: physical and QoL outcomes, including: cardiorespiratory test to measure peak oxygen uptake (peak VO2) dynamic strength endurance test, maximum number of repetitions for chest and leg press exercise at 30% to 35% and 100% to 110% of body mass sit‐stand test, frequency count per time EORTC QLQ‐C30 questionnaire, a 30‐item questionnaire on physical, role, social, emotional, cognitive and functioning, and a global scale of QoL (maximum score of 100). The physical and global scores were assessed hematocrit and hemoglobin level Secondary outcomes, included: body composition, assessed indirectly through changes in body mass and subcutaneous skinfolds. Skinfold measurements were made at 3 sites (triceps, abdominal, and supra iliac) to estimate percentage of body fat total muscle mass (kg), estimated from anthropometrical data following the prediction equation using multislice magnetic resonance imaging Outcomes were measured at baseline and 8 weeks (end of the intervention): exercise group: n = 10 at baseline, n = 8 at 8 weeks control group: n = 10 at baseline, n = 8 at 8 weeks Adverse events: none reported
Notes	Country: Spain Funding: Universidad Europea de Madrid
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	The generation of the random sequence was not described
Allocation concealment (selection bias)	Low risk	"The treatment allocation system was set up so that the researcher who was in charge of enrolling participants did not know in advance which treatment the next person would get"
Blinding of participants and personnel (performance bias) All outcomes	High risk	Owing to the nature of the intervention, masking or blinding of study participants was not possible; however, it is unclear whether the lack of masking could influence the outcomes
Blinding of outcome assessment (detection bias) All outcomes	Low risk	"Research assistants (exercise physiologists) with no knowledge of group assignments were designated to measure the outcome variables"
Incomplete outcome data (attrition bias) All outcomes	High risk	2 participants in each group withdrew. No information provided on withdrawals
Selective reporting (reporting bias)	Low risk	There appears to be no selective reporting of outcomes
Other bias	Low risk	The trial appears to be free of other problems that could put it at a high risk of bias