How intense workouts keep food cravings in check, the science explained

Ever finished a killer HIIT session or a grueling spin class and realized you weren’t even thinking about food? It’s not your imagination—science backs up this surprising effect of intense workouts. While moderate exercise might leave you daydreaming about pizza mid-plank, intense exercise can actually suppress your appetite. Let’s break down why pushing yourself harder might keep you away from the snack drawer longer.

Scientists at the University of Virginia dove deep into this phenomenon, publishing their findings in the Journal of the Endocrine Society. Their study explored how different exercise intensities impact levels of ghrelin—the hormone responsible for triggering hunger—and what that means for appetite control.

The power of high-Intensity workouts

The researchers discovered that high-intensity workouts are particularly effective at reducing appetite, more so than moderate exercise or even resting. “Our research suggests that high-intensity exercise may be important for appetite suppression, which can be particularly useful as part of a weight loss program," explained the lead researcher Kara Anderson in a statement.

Ghrelin: The hunger hormone

Inside your body, ghrelin exists in two forms:

Acylated ghrelin (AG): The "I’m hungry" hormone, responsible for signaling hunger to your brain. It makes up about 22 per cent of total ghrelin. Deacylated ghrelin (DAG): The appetite-neutral form, which either suppresses appetite or has no effect. It accounts for the remaining 78 per cent.

Beyond controlling hunger, ghrelin also influences energy balance, blood sugar control, immune function, sleep, and memory. Understanding how exercise impacts these different forms can help tailor workouts for better weight management.

Your body multitasks well, and during intense exercise, it knows exactly where to focus its energy. Instead of powering your digestion, it shifts blood flow to your muscles to help you push through. The result? Your stomach takes a backseat, and you’re left feeling less interested in food—at least for a little while.

Endorphins: Your post-workout mood boosters

Ever feel a rush of happiness after a tough workout? That’s the magic of endorphins, the feel-good hormones your body releases during intense exercise. They don’t just elevate your mood—they also suppress hunger.

Moderate workouts tell a different story

Gentler activities, like a casual jog or yoga session, don’t have quite the same impact on appetite. They’re easier on your body, so the hunger hormone ghrelin stays, making you more likely to think about that post-workout snack even before you finish stretching, according to the study.

How long does it last?

Here’s the thing: That appetite-suppressing effect isn’t permanent. A couple of hours later, your hunger is likely to return as your body starts looking for fuel to recover. But there’s a silver lining—you’re more likely to crave something nutritious, like protein or complex carbs, instead of a sugary treat.

Should every workout be intense?

Not at all. Mehul Jadhav, a Dubai-based fitness nutritionist and trainer says, "While intense workouts are good for curbing hunger in the short term, they’re just one piece of the fitness puzzle. Moderate workouts come with their own benefits, like stress relief and sustained energy, so it’s all about finding the right balance for your goals. And don’t skip meals—your body needs proper fuel to recover and thrive."

By understanding how different types of exercise affect your appetite, you can make smarter choices about your workouts and nutrition, helping you feel great and stay on track with your goals.