Ha, surprised this thread is still going, but let's keep it alive.
Best of luck with sub 60! Next year make sure to post here if you do. Us middle aged guys and former couch potatoes can still hold our own, with some motivation.
It's both surprising how out of shape a person can get by not trying, as well as surprising how in-shape the same person can get with even a modest level of trying.
Best of luck also with the sub 20 5K. For me the 5K isn't yet on my radar, but it's surprising how working at one distance can help others, like better endurance for shorter races. Eventually, I'll give it a go, having low expectations for good times (since endurance=kryptonite for me).
My flat-course version of the 400m is 63 seconds, but my main workout is going over a elevation-challenging course, where the first 400 m requires two quick vertical changes of about 25-30 feet. After the first hill, running at a sprinting pace, it feels like you weight 500 pounds fighting (fast) against gravity, and after the second hill (top of hill is exactly at the 400m mark) it's very draining on the gas tank.
That 400m hilly version, I'm at 74 seconds now. Last year my best time, even after getting into better shape 4 months from the couch, was 16 seconds slower than it is now. I can't believe this time keeps going down nearly every time I run.
After training this torturous 400m (and 800m, 1mi continuing w/ hills like this), the flat 400m is like a dream tour.
Not fitting any particular stereotype, almost no one would pick me out of a crowd and think I was athletic. I once walked onto the field of the ISU Cyclones practice during their 40yd times (I drove an ISU linebacker to practice), and asked if I could give it a shot, where the players were laughing when they let me run one. Even with a stumble at the start, I topped the fastest time on the team. When I walked back after the run, no one was laughing any more :)
Sub 60 or better 2019!!!
For me, non-ridiculous mile in 2019 also.
Here's to resurrecting our inner athleticism.
As a data scientist I will be tracking this resurrection metric for sure :)