This article is written by Mobiefit’s nutrition expert, Shwetha Bhatia. She is also the founder of Gym & Tonic, where she can easily customize workouts according to the needs and requirements of her clients.
Originally classified as a non-essential amino acid, Glutamine has been found to contribute to 61 percent of skeletal muscle. It has been recently categorized as “conditionally essential” since it consists of 19 percent of nitrogen, making it the primary transporter of nitrogen to your muscles.
During intense training, the Glutamine levels in the body are greatly depleted leading to a decrease in strength, stamina, and recovery. It can take up to 6-days for your Glutamine levels to return to normal and hence Glutamine supplementation becomes important in recovery as it can minimize muscle breakdown and improve protein metabolism.
Let’s look at the benefits:
An intense bout of exercise (heavy workload resistance training, marathon) can be considered a “stressful event”, where a significant decrease in plasma glutamine has been observed during and post-exercise. The reduction in plasma glutamine levels following very prolonged exercise may result from an increased demand and uptake of glutamine by the tissues that require it (muscle, adipose tissue, liver, kidney and immune cells). Glutamine is also utilised as fuel by the small intestine and hair follicles. Dietary glutamine could thus spare muscle protein while providing fuel for other cells and tissues.
Consequently, glutamine levels can be significantly reduced, remaining low for several weeks. This can increase susceptibility to infection and the overtraining syndrome where recovery is insufficient. This may be of importance to athletes for whom recovery time is essential for maximizing muscular strength and improving performance.
It is reasonable then to suggest that the provision of glutamine may elicit a positive effect, if ingested during or after an intense bout of high-intensity exercise, to enhance recovery. As a result of supplementation, glutamine will be available to important fuel sites and may decrease the severity of the inflammatory response, resulting in less muscle damage post exercise.
Glutamine has shown to increase the time to exhaustion and aid recovery, following only 6 days of supplementation.
3. Ammonia disposal and acid-base regulation
Glutamine plays an important role in the regulation of acid-base balance. During and after exercise, acidosis can arise from increased lactic acid production, accumulation of free fatty acids, and consumption of a high protein diet. The production of ammonia in the kidneys protects against acidosis. Glutamine is capable of elevating the blood’s alkaline reserve.
Glutamate acts as a sink for ammonia in the form of glutamine during enhanced ammonia production in high-intensity exhaustive exercise. During a liver failure, glutamine uptake by the kidneys and subsequent urinary ammonia excretion could be an important alternative pathway of ammonia disposal.
Cortisol is a stress hormone which is known to be elevated during periods of catabolic stress and increases glutamine output from muscle. The depletion of muscle glutamine is associated with increased muscle catabolism. Glutamine supplementation can have an anti-catabolic effect.
Oxidative stress increases post workout as metabolism is boosted, nutrients are processed and free radicals are generated. Glutamine can combat this by increasing the production of the body’s internal antioxidant called glutathione.
5. BCAA-glutamine connection
The branched-chain amino acids (leucine, isoleucine and valine), appear to stimulate the release of glutamine. They are preferentially used by the muscle during intense exercise and form glutamine in the process which escapes from the muscle. Thus, both are depleted and supplementation may compensate the depletion, saving muscle from being broken down.
Arginine is a precursor to creatine, growth hormone and nitric oxide. Providing glutamine increases citrulline production in the intestines and this, in turn, leads to increased arginine production in the kidneys.
7. Protein synthesis
Glutamine serves a significant role in the regulation of muscle protein level, even in the absence of insulin. The hydration state of cells is a critical factor influence metabolic processes within a cell. An increase in cellular volume or hydration status acts as an anabolic signal while a decrease in cellular volume acts as a catabolic signal. Glutamine is known to enhance cell hydration and thus signal protein synthesis.
8. Hormone balance
A decrease in the testosterone to cortisol ratio is one of the key indicators of an over-trained state. Glutamine has shown to improve this ratio. The role of glutamine in lessening insulin resistance secondary to a high fat intake might be important in the prevention of excess fat gain. A small oral glutamine load is capable of elevating plasma growth hormone.
Glutamine has shown to promote the accumulation of muscle glycogen and increase peak power after recovery from intense exercise.
A high C-reactive protein (CRP) level is an indicator of inflammation of the heart muscles. High CRP levels are correlated with increased incidence of heart attacks, even when blood lipids such as cholesterol, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) may be normal. It has been seen that glutamine supplementation may be beneficial in maintaining or possibly lowering the CRP levels.
Bottomline: Glutamine supplementation becomes essential to athletes and bodybuilders. The same goes for individuals who are training intensely and need an aid in muscle recovery and protein synthesis. Many protein supplements already contain a feasible amount of Glutamine mixed into them. In case you want to take it separately, take around 5 grams of L-Glutamine after a workout or during training.