Here is the design of a clinical trial:

Official Title: FitMum: Fitness for Good Health of Mother and Child

Included conditions:
- Pregnancy Related
- Physical Activity

Study Armgroups:
- {'label': 'Structured exercise training (EXE)', 'type': 'EXPERIMENTAL', 'description': 'Structured supervised exercise training (EXE) contains three weekly one-hour exercise sessions at moderate intensity, more specifically one water exercise session and two land exercise sessions. The training will be supervised, held in teams, and both water and land exercise sessions will consist of a combination of aerobic and resistance training.', 'interventionNames': ['Behavioral: Structured supervised exercise training']}
- {'label': 'Motivational counseling (MOT)', 'type': 'EXPERIMENTAL', 'description': 'Motivational counseling supported by health technology (MOT) contains four individual and three group counseling sessions taking place from randomization until GA week 33+6 and aim to motivate the participants to increase their physical activity level at moderate intensity. During individual sessions, feedback on physical activity performance will be provided based on activity data acquired from the activity tracker and further, MOT-participants will receive weekly SMS-reminders about physical activity.', 'interventionNames': ['Behavioral: Motivational counseling supported by health technology']}
- {'label': 'Control group (CON)', 'type': 'NO_INTERVENTION', 'description': 'Control group receiving standard treatment.'}

Interventions:
- {'type': 'BEHAVIORAL', 'name': 'Structured supervised exercise training', 'description': 'EXE contains three weekly one-hour exercise sessions at moderate intensity, more specifically one water exercise session and two land exercise sessions. The training will be supervised, held in teams, and both water and land exercise sessions will consist of a combination of aerobic and resistance training.', 'armGroupLabels': ['Structured exercise training (EXE)'], 'otherNames': ['EXE']}
- {'type': 'BEHAVIORAL', 'name': 'Motivational counseling supported by health technology', 'description': 'MOT contains four individual and three group counseling sessions taking place from randomization until GA week 33+6 and aim to motivate the participants to increase their physical activity level at moderate intensity. During individual sessions, feedback on physical activity performance will be provided based on activity data acquired from the activity tracker and further, MOT-participants will receive weekly SMS-reminders about physical activity.', 'armGroupLabels': ['Motivational counseling (MOT)'], 'otherNames': ['MOT']}

Primary Outcomes:
- {'measure': "Min/week of moderate-to-vigorous-intensity physical activity from randomization to GA week 28+0-6 determined by a Garmin Vivosport activity tracker [ Time Frame: Continuously 24/7 from inclusion (at latest GA week 15+0) to GA week 28+0-6 ]'", 'description': 'Physical activity level from randomization to GA week 28+0-6 determined by a wrist-worn activity tracker, Garmin Vivosport, with built-in heart rate monitor and accelerometer. The activity tracker is to be worn continuously by the women from inclusion until delivery. After inclusion baseline physical activity level will be measured for one week, followed by randomization to one of the three study groups and continuous monitoring of physical activity level by the activity tracker. Preferably, the activity tracker is also worn continuously from delivery and one year ahead. The activity tracker determines the frequency, duration and intensity of activity periods on a minute-to-minute basis and data from the activity tracker is wirelessly synced to its associated smartphone application, Garmin Connect, and research platform, Fitabase.', 'timeFrame': 'Continuously 24/7 from inclusion (at latest GA week 15+0) to GA week 28+0-6'}

Please estimate the sample size based on the assumption: 
The study is powered to achieve 80% power with a family-wise significance level of 5% and accounts for a 20% lost to follow-up rate.
Sample size
        FitMum RCT has been powered to detect an overall significant difference in the primary outcome between the three groups as well as a significant difference between the two intervention groups (EXE vs MOT) with average activity levels of 210 (EXE), 150 (MOT) and 60 (CON) min/week. The SD was set at 116âmin/week and based on the results from Oostdam et al.51 The required sample size is determined to obtain a power of 80% with a family-wise significance level of 5%. The sample size calculation showed that the required number of participants is 35 in CON and 70 in each of the two intervention groups due to the randomisation ratio of 1:2:2 to CON, EXE and MOT, respectively. Based on an expected lost to follow-up rate of 20%, as seen in similar exercise studies in pregnant women,28 32 33 51 we plan to include 44 participants in CON and 88 participants in each of the two intervention groups, making a total of 220 participants.