Here is the design of a clinical trial:

Official Title: Cardiopulmonary Capacity and Quality of Life in Patients With Chronic Heart Failure Submitted to Functional Training - a Randomized Clinical Trial

Included conditions:
- Heart Failure

Study Armgroups:
- {'label': 'Functional Training', 'type': 'EXPERIMENTAL', 'description': 'Patients in the functional training group, in addition to maintaining their usual care, will perform functional training including exercises for core strength, power training, knee dominance, hip dominance, horizontal pressure, vertical pressure, horizontal pull and vertical pull, using unstable surfaces.', 'interventionNames': ['Other: Functional Training']}
- {'label': 'Strength Training', 'type': 'ACTIVE_COMPARATOR', 'description': 'These group, in addition to maintaining their usual care, will perform the exercise protocol as recommended by the American Heart Association.', 'interventionNames': ['Other: Strength Training']}

Interventions:
- {'type': 'OTHER', 'name': 'Functional Training', 'description': 'Exercises performed in circuit, using weights, elastic bands, suspension tapes, cones and on unstable surfaces.', 'armGroupLabels': ['Functional Training']}
- {'type': 'OTHER', 'name': 'Strength Training', 'description': 'Exercises carried out using weights and involving the main muscle groups.', 'armGroupLabels': ['Strength Training']}

Primary Outcomes:
- {'measure': 'Cardiopulmonary Capacity', 'description': 'Cardiopulmonary capacity assessed by peak oxygen consumption in treadmill cardiopulmonary exercise test.', 'timeFrame': 'After 12 weeks of training.'}
- {'measure': 'Quality of life', 'description': "Quality of life assessed by the Minnesota Living With Heart Failure Questionnaire. It is composed of 21 questions about limitations that are often associated with how heart failure interferes with patients' quality of life. The patient should consider the last month to answer the questions. The scale of responses for each question varies from 0 (zero) to 5, where 0 represents without limitations and 5, maximum limitation. These questions involve a physical dimension (from 1 to 7, 12 and 13 questions) that are highly interrelated with dyspnea and fatigue, an emotional dimension (17 to 21 questions) and other issues (8, 9, 10, 11, 14, 15 and 16 questions) which, added to the previous dimensions, form the total score. The scale totals 105 points. Higher values indicate maximum limitation and poorer quality of life.", 'timeFrame': 'After 12 weeks of training.'}

Please estimate the sample size based on the assumption: 
A power of 80%, a significance level of 5%, and a 20% estimated participant loss or refusal rate.
Sample size
        Our sample size calculation was based on Feiereisen et al., who enrolled subjects with HF with reduced ejection fraction to assess the effect of strength in comparison with aerobic and combined aerobic-strength training on their peak VO2 [31]. Considering a power of 80%, a significance level of 5% and an effect size of 0.2 for the peak VO2, a total sample size of 32 subjects was estimated, including 16 in each study group. To account for a 20% estimated participant loss or refusal rate, we defined that 19 patients should be enrolled in each group, totalizing 38 subjects.