A thought-provoking review on low carbohydrate diets and substrate oxidation rates was recently published in the journal Frontiers in Physiology (10). The author list includes a couple of the big names in low carbohydrate research, Tim Noakes and Jeff Volek. In this blog, I will summarise some of the key messages and takeaways from the review.

The traditional model of exercise and substrate oxidation

During prolonged, endurance exercise, we primarily use two fuels to support our metabolism and keep us moving. We have carbohydrates, which are stored as glycogen in muscles and in the liver, and we have fat, stored in fat cells and in muscle. The rate at which we use carbohydrates and fats to support metabolism changes with things like exercise intensity and duration (14, 17), heat stress (6), and recent diet (2, 16). As our carbohydrate stores are relatively modest, we can become carbohydrate-depleted, and fatigued as a result, after exercise of sufficiently demanding intensity and...

We all love a good "pain face" and we all know how much those high intensity interval sessions hurt! Such big sessions, require big recovery; and recovery optimization is always a key question for athletes, sports scientists and coaches looking for a performance advantage. With media reports circulating that many elite road cycling teams are investing huge sums of money in exogenous ketone supplements for their athletes (7), many of us in endurance sport – including the scientists – are asking if exogenous ketones are the next magic bullet in sports nutrition (4). We blogged about exogenous ketones recently, specifically using some of our own data and a recently published review (8) to survey the evidence for supplementing with exogenous ketones during a long-distance triathlon. In this blog, we are going to focus instead on the possible benefits of exogenous ketone supplementation for recovery.

Background

Before diving into specific original studies assessing...