Athlete Mode Values Too Good To Be True?

I consider myself pretty fit, but not really an "athlete." In other words, I hike a few days a week for about an hour at a time. I do body weight (push ups, pull ups, squats, planks) exercises for about 20-30 minutes almost every day. My resting heart rate is 48-50. I am also in my late 50s, 6.1 and 147lbs.

I looked at the suggestions for switching to "athlete mode" and I kind of fit the profile. So, I switched.

And wow! "Body fat" shows at less than 3%. Muscle mass is to the right of the "normal" line, at 133lbs (bone mass is at 6.5 - 6.6).

I don't think I I am that much of an "athlete." In regular mode my "body fat was between 9% and 11.5%.

What is mode I should chose based on the above? Is it possible that these numbers are anywhere close to real?