The compound is betaine – something the kidneys produce naturally and a nutrient you also get from foods like spinach or beets. Researchers found that betaine levels not only rose during long-term exercise, but that the molecule seemed to carry many of the same benefits as training itself.

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The kidney steps into the spotlight

To get there, the team followed 13 healthy men for six years. They measured everything they could: genes, proteins, gut bacteria and even how the body behaved after a single 5 km run versus nearly a month of steady training. The kidney kept showing up as the quiet control centre, Science Daily said.

During sustained exercise, the body ramped up betaine production through an enzyme called CHDH. That spike sent protective signals across the body, improving immune strength, calming inflammation, and stabilising age-linked changes in T cells.

Short-term workouts, on the other hand, told a different story. A single hard run stirred inflammation and what the researchers called “metabolic chaos.” But once exercise became a habit, the system settled. Gut bacteria improved while antioxidant defences rose.

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Why betaine may matter more than expected

The biggest twist came when the team tested betaine on its own. Giving the molecule to older mice mirrored many of the effects of training – better metabolism, sharper cognitive function, lower inflammation, and even fewer depressive-like behaviours.

A big part of that comes down to inflammation control. The researchers found betaine binds to TBK1, a kinase that fuels inflammatory pathways. By blocking TBK1 and its IRF3/NF-κB signalling route, betaine quieted the chronic low-grade inflammation tied to ageing – a process often called “inflammaging.”

Co-corresponding author Dr Liu Guang-Hui called the findings a shift in how we understand exercise medicine. “This redefines ‘exercise as medicine’,” he told Science Daily.

“This study gives us a fresh way to turn how our body works into something we can target with chemicals. It opens the door to geroprotective treatments that can tweak how multiple organs work together,” he added.

Betaine is already considered safe, which makes its potential even more intriguing – especially for people who cannot train consistently. The molecule may never replace movement, but it points to a future where exercise benefits might not rely on exercise alone.

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.