Explain why participants in the Pfizer-BioNTech vaccine trial recorded information in an app after receiving injections. No links plz

In the essay section of this assignment make a list of 5 of your favorite physical activities. do you like swimming, rollerblading, riding your bicycle, hiking, or playing a sport? maybe you like to go walking around your neighborhood or around the mall. even dancing to music in your room counts as a physical activity. if you can't think of five activities you like to do, list as many as you can think of and write down things you would like to try in the remaining spaces. now that you've written down some of your favorite activities, set a schedule for when you will participate in these activities. try to do each one at least one time this week for a duration of at least 30 minutes. observe how you feel while you are participating in each activity, directly after you finish with the activity, two hours after the activity, and the day after the activity. do you feel better than you did last week when you weren't as active, or do you feel the same? do you have more energy during the day? can you sleep better at night? do you have the urge to be more active? do you feel more relaxed? record any changes to your mood that occur during this time