Here is the design of a clinical trial:

Official Title: The Effects of a Prehabilitation Exercise Program in Adults Receiving a Hematopoietic Stem Cell Transplant

Included conditions:
- Hematopoietic Stem Cell Transplant
- Hematologic Diseases
- Physical Activity
- Prehabilitation

Study Armgroups:
- {'label': 'Home-Based Prehabilitation', 'type': 'ACTIVE_COMPARATOR', 'description': 'Will be offered an individual one-on-one appointment for an exercise introduction session with an exercise and cancer specialist and periodical phone calls to support and adapt the exercise program. The exercises should be done home-based for 5 times a week until the time of transplant.', 'interventionNames': ['Behavioral: Exercise']}
- {'label': 'Prehabilitation Education', 'type': 'ACTIVE_COMPARATOR', 'description': 'Will be offered a prehabilitation and stem cell education class at the Penn State Hershey Cancer Institute.', 'interventionNames': ['Behavioral: Prehabilitation Education']}

Interventions:
- {'type': 'BEHAVIORAL', 'name': 'Exercise', 'description': 'The exercise intervention is at least 2 weeks lasting (till the day transplant is taking place) 5-times weekly resistance training intervention combined with aerobic exercise (mostly walking).', 'armGroupLabels': ['Home-Based Prehabilitation']}
- {'type': 'BEHAVIORAL', 'name': 'Prehabilitation Education', 'description': 'Participant will receive a prehabilitation and stem cell education class which will be held at the Penn State Cancer Institute.', 'armGroupLabels': ['Prehabilitation Education']}

Primary Outcomes:
- {'measure': 'Feasibility of the exercise intervention: 50% of included patients actually complete at least one third of the exercise sessions', 'description': 'The exercise intervention will be considered feasible if 50% of included patients actually complete at least one third of the exercise sessions prescribed for 2 weeks or more.', 'timeFrame': 'Through study completion, an average of 18 months'}
- {'measure': 'Acceptability of the exercise intervention: more than 50% of the patients approached', 'description': 'The exercise intervention will be considered acceptable if more than 50% of the patients approached agree to receive at least the first exercise session.', 'timeFrame': 'During recruitment'}
- {'measure': 'Safety of the exercise intervention: questionnaire', 'description': 'Within the questionnaire we will assess whether musculoskeletal occur (yes/no; ongoing; location; severity (mild-life threatening); daily activities affected). The intervention will be considered as safe if less than 25% of included patients report mild musculoskeletal impairments and less than 5% experienced musculoskeletal injuries (defined as symptoms lasting a week or longer and or requiring the attention of a medical professional).', 'timeFrame': 'Through the study completion, an average of 18 months'}

Please estimate the sample size based on the assumption: 
A two-sided significance level of 0.05 will be used for all statistical tests. The study will include various clinical covariates to address heterogeneity and will evaluate missing data at the time of analysis.
Statistical analysis and sample size calculations
        Our primary outcomes are descriptive. Acceptability will be defined by the proportion of approached patients who agree to participate and complete at least the prehab counselling session. Our a priori threshold is 50%. We will consider the intervention feasible if 50% of included patients complete at least one third of the prescribed exercise sessions for 2 weeks or more. Safety will be reported by the number of exercise-associated events. Exercise adherence during the prehabilitation period will be calculated as the proportion of completed exercise sessions over the number of prescribed exercise sessions. Summary statistics including mean and SD for continuous variables and frequency with percentage for categorical variables will be reported. We will examine differences within-group and between-group using linear mixed-effects models for physical performance measures, patient-reported outcomes and body composition. A two-sided significance level of 0.05 will be used for all statistical tests. Various clinical covariates including transplant type, prehabilitation duration and baseline differences will be included as statistical covariates to address heterogeneity. Evaluation of missing data will occur at the time of analysis in order to select the best method to evaluate and analyse missing data. This study will provide estimates of mean and SD to support a sample size calculation for a larger, fully powered trial. The anticipated sample size for this pilot trial is 84 participantsâ42 in each intervention armâbased on the PSCI HSCT programme annual enrolment and projected withdrawal rate from similar previous trials within our working group. All data will be entered and stored on secure servers at PSCI. Regular data range checks will be performed to promote data quality.