IT’S NOT MY FAULT! Nobody told me concentrated sugar water would erode my noodle.

Oh, they told me it would keep me awake until it made me crash. They said it would confuse my pancreas and distort my skinny jeans.

But only now, well past the point of no return, do they tell me it’s eating away at my brainpower!

Well that’s just great. I didn’t have gray matter to spare in the first place, and now this: According to researchers at the University of California-Los Angeles, a steady diet of high-fructose corn syrup saps lab rats’ memories.

And you know what that means! Yep! Oh … I forgot. It’ll come to me. Just hang in.

In a diabolical experiment, the university rats first completed a five-day training session in a complicated maze. That’s right. A little rat boot camp with UCLA “scientists” as drill sergeants.

“Where are you going Ratzo? To the left? To the left? To the left, Sir! I can’t HEAR you! Drop and give me twenty!”

Then these sickos fed the rats a solution containing high-fructose corn syrup (HFCS) — a common ingredient in processed foods — as their drinking water for a full six weeks! One group of rats was supplemented with brain-boosting omega-3 fatty acids; the other group was not.

Then, after a month and a half of nonstop rodent Gatorade, the rats were placed back in the maze to see how they fared.

Well how would you do? Six steady weeks in a syrup-induced stupor without so much as a spin on the exercise wheel before being herded back into a labyrinth by a tormentor with a spotlight, a stopwatch and a little rat whip!

“The omega-3-deprived animals were slower and their brains showed a decline in synaptic activity,” said professor of neurosurgery Fernando Gomez-Pinilla at the David Geffen School of Medicine at UCLA while clicking his tongue, shaking his head and making a little checkmark on his clipboard.

Thank you, Fernando! They were tubby too, I’ll bet. No wonder they were slow — wobbling through that warren in a sugar-saturated haze! And their little rat teeth were probably rotten. Really!

But OK. Point taken. I will curtail my maze-running.

Ha ha! I’m kidding! Of course! I’ll cut back on my Powerade. My All Sport. My Cytomax.

All right. I don’t drink any of those things because I don’t work out hard enough to elevate my metabolism, let alone require enhanced levels of carbohydrates.

I mean Pilates, really. Hardly a sweat drencher.

Still, I’ve learned my lesson. All that Christmas candy must be the reason I can’t do the math required to raise my heart rate.

Oh yeah. You can’t just hit the rat maze, er, treadmill and expect results! You have to do some calculating to make your time at the gym worthwhile.

All the experts say to get a heart rate monitor — HRM. Your HRM tracks exercise intensity and can motivate you to work harder.

“Most people don’t work out as hard as they think they do,” says Tom Holland, Connecticut-based running coach and author of “Beat the Gym: Personal Trainer Secrets — Without the Personal Trainer Price Tag.

And in order to use the HRM, you have to figure out your MHR (maximum heart rate). To do that, you subtract your age from 220. Why? No one knows and it’s just as well. No one really cares either. It’s a magic number, OK?

Once you have your MHR, use it to vary your workouts by plugging it into your HRM. I mean duh!

“You want to vary your intensity throughout the week,” says Holland. “Most days should be easy/endurance days where you hit 50 to 60 percent of your MHR.

“But make sure you sprinkle in a few hard days where you bring your heart rate up to 75 to 80 percent of your MHR.”

So let’s see, that’s, 220-63 x 80% = easy peasy lemon squeezy. Then enter that into the equation; divide by pi; square it; round it up to the nearest decimal; do-si-do and there you go!

But I drank all that HFCS for all that time! And now my HRM’s shorted out trying to calculate my MHR.

No wonder I’m out of shape.

Carolyn Plath is a Benicia resident and retired high school principal. Read her blog at thinkdreamplay.blogspot.com.