Our physical energy level and running performance do not depend solely on our willpower, but on a combination of lifestyle factors and mental state: sleep duration, nutrition, hydration, and emotional load or stress.

noli's read

This multifactorial view of our physical fitness level is solidly validated by sports science research. Regarding sleep, a 2022 meta-analysis published in the journal Sports Medicine demonstrates that a lack of sleep directly decreases endurance performance, especially for efforts lasting more than 30 minutes. As for nutrition and hydration, scientific literature reviews confirm that a deficit in water or carbohydrate fuel increases the perception of effort and depletes muscular energy reserves. Regarding emotional impact, a 2017 systematic review in Sports Medicine explains that mental fatigue or cognitive stress reduces endurance by increasing perceived effort, even if the muscles are fresh. The creator's discourse is therefore perfectly accurate and avoids the pitfall of a guilt-inducing narrative focused solely on mindset. Willpower nonetheless remains a useful tool for adaptation, but it cannot indefinitely compensate for a biological or emotional deficit.

the sources

No named source held this one up — that absence is part of the verdict.