Weekly Head Voices #188: Exercise Canary.

As I mentioned in the last WHV, I am in the midst of trying to end this year on a strong and especially regular note.

So, more on time than the rest of the rest of the year, you are now reading the 188th edition of the Weekly Head Voices. This will most probably be the last WHV of the year 2019, looking back at the week from Monday December 23 to Sunday December 29.

Vacation oscillates between lazing and running.

Topol-Tweets™ for your vacation.

I may have implied before that Prof. Eric Topol's twitter stream is brilliant.

During the past few days he posted two high impact (meta-)analyses on topics that I currently find interesting.

Time-restricted eating.

The first is a New England Journal of Medicine systematic review of time-restricted eating and intermittent fasting:

I was able to download the full-text PDF via a free subscription to NEJM which gives you three free articles per month.

However, I feel it's my civilly disobedient duty to inform you that the PDF is now also available via Sci-Hub. (Future readers, if that link disappears, try Where Is Sci-Hub.)

Anyways, you can read the full article, or read the twitter discussion embedded above.

The TL;DR is that fasting's benefits have been clinically shown “for many health conditions such as obesity, diabetes mellitus, CVD, cancers” mostly for “overweight young and middle-age adults”.

Although long term benefits in otherwise healthy humans still have to be shown, texts like the following (and more parts of the article's introduction) make me hopeful:

Periodic flipping of the metabolic switch not only provides the ketones that are necessary to fuel cells during the fasting period but also elicits highly orchestrated systemic and cellular responses that carry over into the fed state to bolster mental and physical performance, as well as disease resistance.

Amount and Intensity of Leisure-Time Physical Activity and Lower Cancer Risk.

The second Topol-Tweet I wanted to single out was this gigantic study with data pooled from 9 cohorts, totalling more than 750000 people, in which the data showed that 2.5 to 5 hours per week of moderate-intensity [leisure-time] activity was associated with significantly lower risk for seven different types of cancer:

This the full-text PDF of this Journal of Oncology article is fortunately available thanks to open access!

Intriguingly, the study also found that (page 8):

There was evidence of nonlinear u-shaped associations with vigorous-intensity activity for colon and endometrial cancer such that the protective associations observed at intermediate activity levels were eroded at higher levels of activity (ie, 30 v0 MET hours/week).

This either does mean that too much exercise indeed brings us right back to no protective effect from colon and endometrial cancer relative to no exercise, or that the data in this case (n = 309881) is still somehow misleading the analysis.

The (middle-aged) Exercise Canary™.

On Friday, during the second part of my morning run, the first part being together with GOU #1 (running with your genetic offspring is amazing on more than one level), I had an exercise-related realisation which I thought was worth sharing with you peeps.

Another important but indirect reason to exercise (I'm extrapolating from running here, please correct me if you can) is the following:

Performing some activity at the edge of one's athletic capability, be it endurance or intensity, enables one to detect with much more sensitivity than normal, anything negatively impacting one's functioning and hence the status of one's health.

For example, when I've lost an hour of sleep for whatever reason, or I've had as little as a drink or two the previous day, or, as is often the case, I've sinned on both dimensions, my legs, lungs and other grit-related organs will notify me in no uncertain terms, during my run, that they are not happy.

On a rest day, I might experience a spot of brain fog, but mental performance is already so complicated that it could be a host of other contributing factors.

A gaggle of cognitive biases (you heard it here first) means that I usually ascribe it to everything but my behaviour the previous day.

Fortunately friends, the exercise canary does not lie.

Unlike when we were still invincible, here at middle-age I prefer being reminded early and regularly of the consequences of my daily life choices.

Friendly wishes.

Highly valued reader peeps, I wish you much wisdom and kindness as we round out the last few days of 2019, and usher in the brave new 2020.

I look forward to our next meeting, either on this blog in the soon-to-be-written traditional 2019-2020 transition post, or at whichever other point we might become entangled.

Contents