Category Archives: Science

Fitbit (and other optical/LED-based devices’) HR Accuracy

Reposted here from Facebook for reference:

Not sure how many out there are Fitbiters but I believe this applies equally to all wrist/LED-based HR monitors (e.g. Apple Watch, Garmin devices, and other trackers). My own anecdotal testing corroborates this study as does DC Rainmaker’s review of the Garmin 235, i.e. they are good at low intensity but get less accurate as intensity increases.

NB: The study referenced was commissioned by the plaintiffs in a class action lawsuit agains Fitbit, so bias is a strong possibility. The descriptive language could be more neutral but it’s hard to deny the data.

NYT Article
Just How Accurate Are Fitbits? The Jury Is Out

Validation of the Fitbit® SurgeTM and Charge HRTM Fitness Trackers

DC Rainmaker Review of Garmin 235 (HR Accuracy)
Garmin Forerunner 230 & 235 In-Depth Review

Myth of High-Protein Diets

This is a GREAT read! Many research papers sited. I highly suggest you read the entire article but here’s the key excerpt:

What that means in practice is little or no red meat; mostly vegetables, fruits, whole grains, legumes and soy products in their natural forms; very few simple and refined carbohydrates such as sugar and white flour; and sufficient “good fats” such as fish oil or flax oil, seeds and nuts. A healthful diet should be low in “bad fats,” meaning trans fats, saturated fats and hydrogenated fats. Finally, we need more quality and less quantity.


Kaley McKean


Original article by DEAN ORNISH, MARCH 23, 2015 NYT.

Pi Day!!!

As you probably have seen, tomorrow, March 14, 2015, when written using the standard US (short) notation 3/14/15, spells out the first 5 digits of Pi. As it turns out, you can go even further down the Pi “number” hole. Here are a couple of good references:

Vox has a good (layperson) explanation of Pi Day

Jeff Rosenthal has a detailed explanation of the Pi Instant

You can also find your birthday “spelled out” WITHIN the digits of Pi using this cool Wolfram site!  Here is mine:



Vernal Equinox – March 20, 2015

The 2015 Vernal Equinox, which marks the first day of Spring for Northern Hemisphere dwellers, is almost upon us. This is the (one of 2) point(s) in the Earth’s orbit when the tilt of its axis (e.g. the North Pole) is neither pointing toward nor away from the Sun. In this situation, virtually all parts of the Earth receive (approximately) equal amounts of day and night (12 hours each). It’s also the point at which the increasing amount daylight (or night-time in the case of the Autumn Equinox) is at a maximum! Here are a few links if you’d like to learn more about equinoxes:


Time and Date

The Old Farmer’s Almanac