Our ancient ancestors weren't jacked, They were energy savers

There's a cost to keeping your body running. For every five breaths you take, one is paying for your brain, one is paying for your liver, and another is paying for your muscles.

On average, your body spends about 1,400 calories per day just keeping you alive, even if you're doing nothing else. This helps explain why we tend to avoid unnecessary physical activity.

For our ancestors, finding food could be incredibly difficult, so they didn't waste energy. Today, even though have energy sources ready at our fingertips, we still naturally protect how we spend that energy.