The Key to Speed is – Through Your Gut?

Adaptations to running and aerobic exercise in general take a variety of forms, ranging from large scale changes like increases in bone mineral density, to smaller scale shits such as enzyme development and muscle capillarization.

Lactate is a byproduct of fuel (carbohydrate) metabolism during exercise, and certain adaptations to aerobic exercise improve our body’s ability to recycle and utilize lactate during exercise. While it is accepted that different organs and muscles themselves can either recycle lactate into glucose or oxidize it for ATP production, new research shows that our gut bacteria play a significant role in lactate recycling.

A study published back in June 2019 analyzed stool samples from runners that had just completed a marathon, and found that the samples contained elevated levels of the bacteria Veillonella atypica. Furthermore, when they inoculated mice with this strain of bacteria, their times to exhaustion on a treadmill significantly improved.

The presence of this bacteria among others is upregulated through aerobic exercise, and the researchers went on to investigate the exact mechanism through which the presence of this bacteria and others like it improve performance.

What they found is that these bacteria are responsible for the production of short chain fatty acids from their consumption of lactate, which in turn provide fuel for the muscle to oxidize for ATP.

As stated before, lactate can travel from working muscles to the liver to be recycled into glucose that can again be used as fuel, or to other working organs that oxidize the lactate directly. In this new case however, the researchers found that due to the ability of lactate to permeate the lumen of the gut, the bacteria were able to metabolize the lactate and provide fuel for the muscles to use during exercise, in turn improving performance.

Surely this isn’t the final discovery of the gut’s influence on athletic performance, but it provides further insight as to the bodily circumstances that yield high performance.