Ask any runner who has “hit the wall” and they will tell you that it’s not just a metaphor, but an actual insurmountable obstacle. It feels as if your body is crying out: “No mas!” According to this new piece, however, the feeling might be rooted in your brain’s predictive power: “A New Theory Explains Why Exercise Makes Us Tired.” A framework led by researcher Jeanne Dekerle suggests that perceived fatigue is the brain’s “diminishing confidence in its own ability to exert control over the body.” Essentially, your brain predicts your ability to maintain homeostasis (a stable internal state), and when vitals like heart rate and blood acidity get too out of whack, the brain expects trouble. That’s when it signals “fatigue” to slow us down, protecting our body from this state of uncertainty. But this in-the-moment sensation is only part of the puzzle. How do all our efforts, from long runs to stressful workdays, add up to tiredness? That’s where a system detailed in “How Does WHOOP Strain Work?” provides a broader view. WHOOP quantifies total cardiovascular and muscular load on a 0-21 logarithmic scale, where it becomes harder to build strain the higher you go. The average daily strain for members is around 11.0, with a one-hour run clocking in at about 12.0. By tracking your total daily strain, not just individual workouts, you get a clearer picture of your body’s cumulative stress, helping you understand why the same run might feel tougher on a low-recovery day.

#StrainAndGain