Here is the design of a clinical trial:

Official Title: Tai Chi for Patients With Essential Hypertension: Study Protocol of an Open-label Single-center Randomized Controlled Trial

Included conditions:
- Hypertension

Study Armgroups:
- {'label': 'Tai Chi', 'type': 'EXPERIMENTAL', 'description': '3 sessions of Tai Chi per week for 12 weeks', 'interventionNames': ['Behavioral: Tai Chi']}
- {'label': 'Walking', 'type': 'ACTIVE_COMPARATOR', 'description': '3 sessions of walking per week for 12 weeks', 'interventionNames': ['Behavioral: Walking']}
- {'label': 'Waiting-list', 'type': 'NO_INTERVENTION'}

Interventions:
- {'type': 'BEHAVIORAL', 'name': 'Tai Chi', 'description': 'Tai Chi is a traditional Chinese mind-body exercise, which combines deep-breath relaxation and gentle movements in sequence with meditation. Each session of Tai Chi will last 60 minutes, including a 10-minute warm-up, a 40-minute Tai Chi practice and a 10-minute cool-down.', 'armGroupLabels': ['Tai Chi'], 'otherNames': ['Tai Ji Quan']}
- {'type': 'BEHAVIORAL', 'name': 'Walking', 'description': 'Each session of walking will last 60 minutes, including a 10-minute warm-up, a 40-minute walking and a 10-minutes cool-down.', 'armGroupLabels': ['Walking']}

Primary Outcomes:
- {'measure': 'average 24-h Systolic Blood Pressure (SBP)', 'timeFrame': 'change from baseline to 12 weeks after intervention'}

Please estimate the sample size based on the assumption: 
The sample size calculation used One-Way analysis of variance, F-Tests with PASS 15.0 software. The study aims for a power of 80% at a significance level of 5%. A 20% dropout rate is considered.
Sample size
          This study is an RCT, the intervention group is the Tai Chi group, and the control groups are walking group and waiting-list group. The reduction of Systolic Blood Pressure (SBP) is set as the primary outcome. According to previous study [31], the mean difference and standard deviation of SBP was ââ13.33âÂ±â46.73, ââ12.46âÂ±â33.37 and 3.37âÂ±â46.01 for Tai Chi compared with walking and waiting-list control. The sample size was calculated using One-Way analysis of variance, F-Tests with the PASS 15.0 software. The standard deviation is set as 20. A total of 65 participants per arm are needed to achieve a power of 80% at a significant level of 5%. A sample size of 195 participants is required to sufficiently detect a target effect size. Considering a 20% drop-out rate, we intend to enroll a total of 234 participants, with 78 participants in each group.