Thinking Hard Burns Almost No Calories–But Destroys Your Next Workout
8 days ago
- #mental fatigue
- #brain energy
- #exercise performance
- The brain uses 20-25% of the body's energy at rest, but intense thinking only increases this by about 5%, burning just 100-200 extra calories per day.
- Mental fatigue from prolonged cognitive work reduces endurance performance by 15%, not due to physical limitations but because the brain perceives effort as harder.
- Adenosine accumulation in the brain, particularly in the anterior cingulate cortex (ACC), is responsible for increased perceived exertion after mental fatigue.
- Caffeine can counteract mental fatigue by blocking adenosine receptors, improving endurance by about 14% in mentally fatigued individuals.
- Scheduling high-intensity workouts on days with lower cognitive demand or using caffeine strategically can help mitigate the effects of mental fatigue on training.
- Mental fatigue primarily affects endurance performance, not maximal strength or short anaerobic bursts, by making sustained efforts feel harder.
- Recovery involves not just physical rest but also reducing cognitive load to lower adenosine levels in the brain, improving workout performance and adaptation.