Supplementing Glutamine for Endurance: 7 Benefits

glutamine for endurance

Endurance athletes (like all athletes) always seek ways to increase performance, enhance recovery, and prevent overtraining and injuries.  Glutamine supplements are extremely beneficial to endurance athletes.  Read on to learn more about the benefits of supplementing glutamine for endurance.

What is Glutamine?

Glutamine is one of 20 naturally occurring amino acids.  It is also a conditionally essential amino acid.  This is just fancy talk that means it is easily made in our bodies, but it is essential during periods of disease and muscle wasting (heavy exercise) and may need to be supplemented during these times.  It may also need to be supplemented if you follow a vegan or vegetarian diet, as glutamine is found in high amounts in meat, eggs, and dairy.

Glutamine is widely used in sports nutrition, partly due to its ability to support and benefit immune function (Coqueiro et al., 2019).  Additionally, glutamine is touted for its other biological functions: cell proliferation, energy production, glycogenesis, ammonia buffering, maintaining acid-base balance, and many others (Coqueiro et al., 2019).  Glutamine is and has been, for some time, a popular supplement.

Many athletes supplement with glutamine in hopes that it will aid them in increasing muscle mass.  But, there is actually little to no scientific evidence that glutamine supplements help with muscle mass gains.

The International Society of Sports Nutrition (ISSN) found from the scientific literature that there does not appear to be any scientific evidence that glutamine supports increases in lean body mass or muscular performance (Kerksick et al., 2018). Therefore, if you have been supplementing with it for that reason, you should probably stop wasting your money.

However, there is evidence that supports supplementing glutamine for endurance.

How Can I Benefit from Taking Glutamine?glutamine for endurance

For all you that don’t like to read summaries of research, let me list out the benefits of glutamine for endurance athletes:

  • Prevents/reduces fatigue
  • Increases/improves recovery
  • Maintains cognitive function during exhaustive exercise
  • Increases time to exhaustion
  • Prevents muscle damage
  • Boosts immune system
  • Reduces exercise-induced intestinal permeability (leaky gut syndrome)
  • Aids in the regulation of cortisol

And if you like to read about scientific studies, this next section is for you:

Studies have supported the claim that taking glutamine can improve fatigue after endurance training by increasing glycogen synthesis and reducing ammonia accumulation (Coqueiro et al., 2019).  Glutamine has also been shown to fight and prevent fatigue (DuBourdieu, 2021).  Moore et al. (2019) found similar results in that glutamine supplementation prevented fatigue in repeated bouts of activity, even on the second day of activity.

Furthermore, McCormack et al. (2015) found that both low-dose and high-dose supplementation of glutamine significantly increased time to exhaustion for endurance-trained athletes.  Time to exhaustion can also be correlated with fatigue levels. So you can get a double bonus in this area with glutamine supplementation!

Another study found that the ingestion of glutamine, along with leucine, increased the rate of recovery after exercise (Waldron et al., 2018).  Who doesn’t want to bounce back quickly after their runs and workouts?  Athletes of all disciplines can reap this benefit.

Endurance athletes that supplemented with glutamine showed increased ability to maintain cognitive function and reaction time during exhaustive exercise (Pruna et al., 2016).  If you’ve read Chase’s blog on some of the key differences between ultra-endurance and endurance sports, you already know that cognitive function can be majorly impacted during extended duration training and racing.  So, this benefit is especially crucial for ultrarunners.

Cordova-Martinez et al. (2021) found that glutamine supplementation attenuated exercise-induced muscle damage.  The same study also found that supplementation reduced levels of ATCH, which is a hormone that stimulates the production of cortisol.  Therefore, it is possible that glutamine supplementation can lower cortisol or at least prevent it from becoming elevated.  If we haven’t already beat that topic to death for you, you should read more about cortisol levels for endurance athletes in Chase’s blog.

Glutamine has been found to decrease the incidence of illness in endurance athletes (Castell, 2002).  Another study found that oral supplementation of glutamine compared with a placebo showed beneficial effects on the number of infections reported by runners after a marathon (Castell & Newsome, 1998).  This benefit is quite important for endurance athletes.  Research has shown a high incidence of infections, especially upper respiratory infections, in athletes that undergo intense and prolonged training and endurance races (Castell & Newsome, 1998).

Pugh et al. (2017) found that athletes benefit from glutamine supplementation to prevent gastric distress, especially in the heat.  Glutamine has also been shown to reduce exercise-induced intestinal permeability (leaky gut syndrome).  This may further prevent GI distress, which is commonly associated with ultra-endurance exercise.  GI distress is one of the most common issues that can lead to a DNF for endurance athletes.

Is Glutamine Safe to Supplement?

Research shows that short-term and long-term glutamine supplementation in healthy athletes does not have significant adverse effects (Davani-Davari et al., 2019).  Studies have found that participants tolerated acute glutamine intake of 20-30g without ill effects.  Furthermore, researchers found no harmful effects in a study where athletes consumed 28g of glutamine daily for 14 consecutive days (Gleeson, 2008).  Additionally, doses of up to .65 grams per kilogram of body mass have been reported to be well tolerated (Gleeson, 2008).

Where Can I Find a Supplement with Glutamine?Terminus

Here at Ultraverse Supplements, we strive to make the most complete and beneficial supplements on the market.  If you haven’t already guessed, we’ve got you covered on finding a glutamine supplement.

In our recovery formula, Terminus, we have included 4 grams of glutamine.  Glutamine was added to our recovery drink to take it to the next level in endurance recovery formulas.

We created Terminus to be the most comprehensive plant-based recovery supplement on the market.  We guarantee you will notice a difference.  Don’t believe me? Look at the reviews, read about our ingredients, and try some for yourself.  You won’t believe the results!


**Use common sense, and always listen to your doctor over a blog post. They know more about your personal health situation than anybody behind a keyboard. If you have underlying medical conditions, always check with your doctor before starting a new supplementation routine.



Castell, L. M. (2002). Can glutamine modify the apparent immunodepression observed after prolonged, exhaustive exercise? Nutrition, 18(5), 371-375. doi:

Castell, L. M., & Newsholme, E. A. (1998). Glutamine and the effects of exhaustive exercise upon the immune response. Canadian Journal of Physiology and Pharmacology, 76(5), 524-532. doi:10.1139/y98-054

Coqueiro, A. Y., Rogero, M. M., & Tirapegui, J. (2019). Glutamine as an anti-fatigue amino acid in sports nutrition. Nutrients, 11(4), 863. doi:10.3390/nu11040863

Córdova-Martínez, A., Caballero-García, A., Bello, H. J., Pérez-Valdecantos, D., & Roche, E. (2021). Effect of glutamine supplementation on muscular damage biomarkers in professional basketball players. Nutrients, 13(6), 2073. doi:10.3390/nu13062073

Davani-Davari, D., Karimzadeh, I., Sagheb, M. M., & Khalili, H. (2019). The renal safety of L-carnitine, L-arginine, and glutamine in athletes and bodybuilders. Journal of Renal Nutrition, 29(3), 221-234. doi:

DuBourdieu, D. (2021). Chapter 61 – glutamine supplementation: Hope, hype, or stay tuned? In R. C. Gupta, R. Lall & A. Srivastava (Eds.), Nutraceuticals (second edition) (pp. 1027-1036) Academic Press. doi: Retrieved from

Gleeson, M. (2008). Dosing and efficacy of glutamine supplementation in human exercise and sport training. The Journal of Nutrition, 138(10), 2045S-2049S. doi:138/10S-I/2045S [pii]

Kerksick, C. M., Wilborn, C. D., Roberts, M. D., Smith-Ryan, A., Kleiner, S. M., Jäger, R., . . . Kreider, R. B. (2018). ISSN exercise & sports nutrition review update: Research & recommendations. Journal of the International Society of Sports Nutrition, 15(1), 38. doi:10.1186/s12970-018-0242-y

McCormack, W. P., Hoffman, J. R., Pruna, G. J., Jajtner, A. R., Townsend, J. R., Stout, J. R., . . . Fukuda, D. H. (2015). Effects of l-alanyl-l-glutamine ingestion on one-hour run performance. Journal of the American College of Nutrition, 34(6), 488-496. doi:10.1080/07315724.2015.1009193 [doi]

Moore, M., Moriarty, T. A., Connolly, G., Mermier, C., Amorim, F., Miller, K., & Zuhl, M. (2019). Oral glutamine supplement reduces subjective fatigue ratings during repeated bouts of firefighting simulations doi:10.3390/safety5020038

Pruna, G. J., Hoffman, J. R., McCormack, W. P., Jajtner, A. R., Townsend, J. R., Bohner, J. D., . . . Fukuda, D. H. (2016). Effect of acute L-alanyl-L-glutamine and electrolyte ingestion on cognitive function and reaction time following endurance exercise. European Journal of Sport Science, 16(1), 72-79. doi:10.1080/17461391.2014.969325 [doi]

Pugh, J. N., Sage, S., Hutson, M., Doran, D. A., Fleming, S. C., Highton, J., . . . Close, G. L. (2017). Glutamine supplementation reduces markers of intestinal permeability during running in the heat in a dose-dependent manner. European Journal of Applied Physiology, 117(12), 2569-2577. doi:10.1007/s00421-017-3744-4

Waldron, M., Ralph, C., Jeffries, O., Tallent, J., Theis, N., & Patterson, S. D. (2018). The effects of acute leucine or leucine–glutamine co-ingestion on recovery from eccentrically biased exercise. Amino Acids, 50(7), 831-839. doi:10.1007/s00726-018-2565-z

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