Most people load up on protein after a workout and stop there — but protein alone doesn’t address everything your body needs to recover. Glutamine, the most abundant amino acid in the human body, gets used up fast during intense training, and replenishing it can make a real difference in how you feel the next day.

During hard training, your body’s glutamine stores drop as your muscles and immune system draw on them for repair and defense. This is one reason athletes in heavy training blocks sometimes feel run-down or catch colds more easily — glutamine is a primary fuel source for immune cells, and when reserves run low, immune function can dip along with it.

Beyond immunity, glutamine plays a supporting role in gut health by helping maintain the intestinal lining, which affects how well you absorb nutrients from the food and supplements you’re already taking. A stressed gut lining can undercut recovery even when everything else in your routine is dialed in.

The simplest way to support this is a clean, single-ingredient glutamine supplement taken post-workout or before bed — no need for a complicated stack when one ingredient, dosed properly, does the job.

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