After looking at various fitness trackers to see about tracking more details of my activity, I mentioned the tracking to my step-daughter and how I wasn't sure exactly what I wanted for $50 to $150 just to track my activity. She pointed me to Samsung Health on our cell phones using Android.
For us, Samsung Health tracks from midnight to midnight whether or not we have the application up and running. I have checked the app in the evening when it hasn't even been on and have seen how many steps I took and so on.
We can set limits and goals along with weight, heart rate (which the phone can provide through a sensor in the Galaxy S7 on up), and our stress levels. We can record food, water, and caffeine intake. It will keep track of inactivity, which can be manually altered to match sleep time or whatever. For activity, modes can be set manually to match types of exercise - walking, running, biking, paddling, and so on. It also links to various articles about staying healthy.
The app also lets the user connect with others using the app for friends (it shows over 1.2 million participants today) and challenges. A quick look just now, my first look at that part of the app, told me that my step count over the last 7 days is below average for those using the app. I've been quite a slacker lately.
I am barely more than a beginner using Samsung Health, so I only know that it does much more than I have listed.
The one thing it doesn't do is synchronize with AARP. If this is an issue for you, then Samsung Health is probably not for you.
If you have a Samsung cell phone, check the store for this free application.
We do have choices.
Stay well, and enjoy!
P.S. If you have an Apple cell phone, I can't help you.