The Digest - Feb 23

A recap of some of the interesting studies and articles I read over the past few days:  

  • I've brought up probiotics in the past in relation to overall gut health and as a means to boost your immune system and prevent gut permeability and food intolerances. New studies over the past 2 years have also revealed a relationship between the health of your intestinal microbiota (the health of the bacteria living in your GI tract) and weight gain/loss. In fact, there was a recent media circus around the story of a woman who suddenly became obese after altering her gut microbiome through fecal transplant. On the flip-side, a study was published in the British Journal of Nutrition this month in which subjects who were given probiotics showed lower insulin resistance and other Type II Diabetes risks when provided with probiotics on conjunction with a 50%(!!!) increase in caloric intake. ^


  • My favorite protocol with people who suffer from generic symptoms of fatigue, trouble sleeping, muscle aches, etc is the "auto-immune diet protocol". This protocol (which I adapted from the Paleo Auto-Immune Protocol) aims atminimizing any foods which may trigger an inflammatory response in the body, over-activating the immune system and keeping it engaged at full throttle 24/7. This study published in the British Journal of Nutrition looked at specific inflammatory markers (C-reactive protein-CRP, Homocysteine, Interleukin-6 and Fibrinogen) in response to the consumption of foods deemed "inflammatory" based on an inflammatory index. These are the same inflammatory markers I ask athletes I work with to test regularly to assess general levels of inflammation in the body. The results were conclusive: the higher the inflammatory index of a food, the higher the levels of inflammatory markers IL-6 and homocysteine (less so with CRP and fibrinogen). I personally use an iPhone app called IF Tracker (Android version, sorry Pat no Bberry version!) which provides the inflammatory index of most foods & ingredients. ^


  • If there is one "nerdy" term our performance-obsessed endurance community is fixated on it's "Lactate Threshold-LT" (or Anaerobic Threshold). To put it in simple terms, it's the level of effort (heart rate, pace or Watts) at which your muscle are unable to clear the build-up of lactic acid fast enough, so it starts accumulating in the blood, causing an increase in acidity and a significant drop in performance. Accurately detecting an athlete's LT & training zones is somewhat cumbersome and expensive, and requires blood testing at various levels of effort (usually taken from a prick to the index finger during a treadmill or stationary bicycle session). Well a new study published in the Journal of Strength and Conditioning Research identified a much cheaper and easy way to calculate LT with a reasonable level of accuracy: moderately experienced athletes can estimate their LT and Zones with reasonable accuracy by simply calculating it based on the Rate of Perceived Exertion (RPE) using the following formula: RPE = 1.092 x BLC + 2.143, where BLC = blood lactate concentration. Have fun with that one and send me some feedback... ^


  • I've always sought simple ways to explain in simple terms how various forms of stress (physical, mental, emotional) affect our bodies on a biochemical level, resulting in a wide range of problems, from hormonal imbalances, to weight gain, fatigue, suppressed immune system, sexual dysfunction etc.This article by renowned functional medicine practitioner Chris Kresser does just that: explaining in simple terms what happens inside your body when you get stressed, and how in many people, stress suppresses Thyroid function which is not detectable in your average doctor-recommended blood test. ^


  • I was involved in some recent Facebook discussions surrounding sudden cardiac death (SCD) among endurance athletes, and how many well-known professional endurance athletes from the past 2 decades have recently suffered potentially fatal heart pathology. Coincidentally, this study was just published and revealed that in most instances of SCD, the victims were found to have a "structurally normal heart". In other words, there were NO congenital heart defects which would have put them at exceptionally high risk. This supports my argument (which stems from various studies I've read, and also common sense) that large volumes of "chronic moderately intense cardiovascular exercise" put abnormally large strains on the human heart, which is not designed to cope with such circumstances. To put it simply, yes the human heart is designed for endurance, but not 15-20hrs/week!There are ways to achieve the same athletic goals while reducing the strain on the heart, primarily by shifting the focus from "cardiovascular endurance" to "muscular endurance" in training, something I firmly believe in. ^