Saturday, December 30, 2017

Swimming on the Coldest night of the Year

I woke up this morning to a temperature of -12° F (-24° C). It is a good day to stay indoors and sip a warm beverage. This day is following the winter weather pattern here in Minnesota: first it snows and then it gets cold.

The saving grace with such cold weather is that it occurs to a crystal clear sky and bright sunshine reflecting off of the new snow. A newcomer might be caught off guard from the false visualization of outdoor warmth and may even try to take a deep breath; abruptly choking on the arctic flash freezing of the windpipe. Scarves and shallow, deliberate breaths to acclimation are thus quickly learned.

If the wind isn't blowing, one can be quite comfortable in a normal winter attire where body heat and insulation make for a fine cushion. A little labor can even result in the dropping of a layer. However, the slightest breeze will steal that cushion with the comedic sensibility of a practical joke; leaving you to shiver and hasten your pace to get back indoors.

Still, last night was a good evening to take the kids out for an activity and what better activity on a cold winter night that swimming at the local YMCA. Fortunately, the pools are indoors; saving the antics of a cannonball onto ice:

Instead, we were able to jump in in a less YouTube-worthy manner. Much of the time was spent in the vortex pool a shallow oblong loop of a pool with jets that pushed the water; a sort of compact "lazy river". It reminded me of being younger and swimming at my neighbor's above ground circular pool. If you could get everyone going in the same direction a healthy current would be whipped up.

Also, now that my kids are a little older we spent a healthy amount of time in the lap pool actually swimming laps. There are three of us so we would have two of us at one end and one at the other. One of the two would swim down and the lone person would swim back, taking turns.  The kids need a little coaching on their strokes, but they did well.

The thing I enjoy about swimming is that it doesn't feel like a lot of work when you're doing it, but you get out of the water and find that you're winded. It saves on your joints as there is no appreciable impact. It also places a focus on rhythmic breathing and pacing. Here are a couple of articles that extol the merits of swimming:

From my own experience I was swimming laps one to two times a week a few years ago. I recall going in for an exam after maybe six weeks of this routine (Note that other lifting and cardio were also being performed). My blood pressure was at a record low (115/68) and my pulse was 42 beats per minute (bpm). My pulse is currently typically ~60 bpm (63 bpm at the moment on my trusty Galaxy Note 4). The pulse data-point floored me and is something I still aspire to see again, but low 60s bpm is nothing to gripe about according to the Mayo Clinic website.

Still, I recall a bio-physics seminar in graduate school that started off with a back of the envelope calculation of the life span of the heart. I forget the researcher's name, but here is an estimate that the average human heart is good for 2.21 billion beats.

Since I am a fan of back of the envelope calculations here is a graph I made of "heart lifetime" in years as a function of average heart-rate and the above 2.21B number. Note this is totally non-scientific, but provides a trend that makes some intuitive sense.

 There is obviously a lot of "hand-waving" in such analysis and more factors than one can count that weigh into your actual "need a new heart" date. However, the trend of improved cardiovascular efficiency with improved lifespan does seem to be, if only slightly, reinforced.

So one might wonder if artificially lowering the heart-rate would increase lifespan? One way of doing this would be to provide oxygen rich air for breathing. This would improve heart efficiency by increasing the oxygen taken in and circulated. I'll save a rigorous literature study for another day, but there are cases for and against as aging is a complicated process with many factors beyond the heart's ability to function.

Overall, we swam for about an hour before hunger set in. I'm still trying the vegetarian lifestyle. Fortunately, the local Chinese Restaurant chain has a new "firecracker" tofu that was delicious. Although, the counter worker told me, "typically only women order that". All I could say was a mild well now me too.

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