Central vs Peripheral Fatigue

“Give it 48 hours.” It’s the most repeated number in strength training — repeated in gyms, on forums, in programmes, and by coaches who mean well. Heavy lifting “fries your CNS,” and the CNS apparently needs two days to reboot. The advice lands on the right answer through the wrong mechanism. Which matters, because if you recover on a timeline you can actually measure, you recover differently. This post is the third in a short series on central fatigue. The primer on what CNS fatigue is and how HRV catches it gives you the framework. The myth put on trial handles whether heavy lifting “fries” anything at all. This one answers the question both of those raise but don’t settle: how long does it actually take to recover, hour by hour? ...

Type “does heavy lifting fry your CNS?” into Google and you’ll get a wall of confident answers. Yes, obviously — that’s why you need 48 hours between heavy sessions. Your central nervous system is a battery, and every hard set drains it. It’s one of the most repeated claims in the gym. It is also, as a mechanistic claim, substantially wrong — and the way it’s wrong matters, because it leads men over 40 to train around a threat that isn’t the real one. ...

Here’s a feeling every lifter over 40 knows, even if they’ve never named it. You show up. Your muscles don’t even hurt. Your warm-up feels fine. Then you get under a bar that you moved easily last week — and it feels like it’s bolted to the floor. Your coordination is slightly off. Your drive is gone. You grind through it anyway, because that’s what men do, and the number still won’t budge. ...