Yep, you read it here. Exercise good: Sugar…Not so good for your brain

“Thus, BDNF appears to be released from the human brain, and the cerebral output of BDNF is negatively regulated by high plasma glucose levels, but not by high levels of insulin”

Let us boil it down to two simple equations for you:

Exercise = More BDNF

Sugar (Glucose) = Less BDNF

So what is BDNF? It stands for “Brain Derived Neurotrophic Factor”. It’s the stuff that makes our brain grow.

Neurotrophins are a family of structurally related growth factors, including brain-derived neurotrophic factor (BDNF), which exert many of their effects on neurons in the brain, but also many other metabolic processes in the body.

Brain-derived neurotrophic factor has been shown to regulate neuronal
development and to modulate synaptic plasticity (ie it is a mind expanding compound; literally). Recent studies show that BDNF is also expressed in non-neurogenic tissues, including skeletal muscle. BDNF has also been identified as a key component of the hypothalamic pathway that controls body weight and energy homeostasis and it appears to
be a major player not only in central metabolic pathways,but also as a regulator of metabolism in skeletal muscle.

So, before you replenish those glycogen stores with some simple sugars post run or workout; remember that it may be at the expense of your brain function. Are we saying not to replenish? No, we are saying stick to lower glycemic choices, which yes, will fill the glycogen stores slower, but can help preserve your noggin. Glucose IS the preferred fuel of the brain, but it can make it from fats and proteins as well; remember something called gluconeogenesis from physiology class? Some of the latest studies show that ketosis isn’t as bad as we previously thought, but that is the subject of another post…

We are The Gait Guys and we are all things gait; even those that are peripherally related.



Krabbe KS, Nielsen AR, Krogh-Madsen R, Plomgaard P, Rasmussen P, Erikstrup C, Fischer CP, Lindegaard B, Petersen AM, Taudorf S, Secher NH, Pilegaard H, Bruunsgaard H & Pedersen BK (2007). Brain-derived neurotrophic factor (BDNF) and type 2 diabetes. Diabetologia 50, 431–438.