If you've spent any time learning about strength and conditioning you're almost certainly familiar with the "energy systems" framework. In this episode we're breaking down why the way these concepts are widely understood isn't supported by the evidence. And don't worry, we're not just here to criticize, we also explore an alternative model that's more up to date.

Evan Peikon is back for his second episode (if you missed his first, check it out here). He is a physiologist and bioscientist who focuses on human performance, including consulting for elite athletes and military special operations. He has a particular focus on understanding and monitoring how the body utilizes oxygen during exercise.

He the co-founder and lead physiologist at NNOXX, where he and his team developed the first and only wearable device to non-invasively measure muscle oxygenation (SmO2) and nitric oxide (NO) release from red blood cells in real-time.

If you're not familiar with the traditional energy systems model, I made this Instagram post about it in the early days of MOPs & MOEs.

You can even find this energy systems model on the Army's official page.

Evan cited three studies that collectively shatter the fundamental assumptions behind the traditional energy systems model, here are each of those studies:

The "glycogen shunt" in exercising muscle

Metabolic fluctuation during a muscle contraction cycle

Simultaneous in vivo measurements of HbO2 saturation and PCr kinetics after exercise in normal humans