Back in 2009, a research team at Bangor University in Wales published a study showing that mental fatigue impairs physical performance. Subjects spent 90 minutes sitting in front of a computer screen either watching a bland documentary or playing a simple but focus-demanding computer game. Afterwards, when they hopped on an exercise bike for a time-to-exhaustion test, those who’d played the computer game immediately reported higher levels of perceived effort, and gave up 15 percent earlier than the documentary watchers.
More here – Outside
