Glutamine accounts for more than 60% of the total intramuscular free amino acid pool, and because skeletal muscle represents such a large mass of tissue, it is the most important site for glutamine synthesis.
It is considered that intense exercise causes a significant reduction in skeletal muscle and plasma glutamine concentration.
Low levels of plasma glutamine due to intense or prolonged exercise training increased susceptibility to infection and may result from impaired immune function.
Glutamine supplementation stimulate faster recovery time, prevent Over Training Syndrome (OTS), and allow an individual to participate in multiple bouts of exercise more frequently and prolonging time to fatigue.
L-glutamine supplementation slow down DOMS (Delayed onset muscle soreness) effects.

Doses Approx 0.65 g/kg body Weight of Glutamine 

Antioxidants and Micronutrients
Micronutrients and antioxidants are nutrients that dose not yields energy but plays very important role in energy production and other biochemical reactions of the body.

Micronutrients work interactively to:

Antioxidants, Multivitamin and multi-mineral supplements, rather than single micronutrient supplements, may be needed to protect harmful effects of  high energy exercise side effects of higher free radicals  ​​

During exercise your muscles work hard and also got damaged and exposed to some harmful biochemical like lactic acid and free radical. Faster Recovery of muscles is very important. 

Goals of post workout nutrition
Post Exercise, Recovery is a complex processes that include:

  • Top up the muscle and liver glycogen stores with carbohydrate.
  • Replacing the fluid and electrolytes lost in sweat.
  • Build-up new muscle protein, red blood cells and other cellular components as part of the repair and adaptation process.
  • Make immune system strong enough to handle the damage and fight against infections caused by the intense exercise.

So, post workout you need
Sufficient fluid, Electrolytes, Energy and carbohydrates to replace muscle glycogen stores
Very important is Protein to provide amino acids for the maintenance and repair of muscle protein.
Skeletal muscle is the primary site for protein metabolism and is the tissue that regulates protein breakdown and synthesis throughout the body. In prolonged endurance exercise, approximately 3 to 5 percent of the total energy used by muscle is provided by amino acids.
To increase skeletal muscle mass, the body must be in positive nitrogen balance, which requires an adequate amount of protein and energy (calories).
The daily recommended protein intake for strength athletes is 1.5 to 2.0 grams per kilogram body weight, twice that recommended for endurance athletes.
Strength athletes usually need protein supplements because it is difficult to obtain a sufficient amount of protein from food alone.
It is advisable to take Whey Protein within 30 min of workout and Casein at bed time for best recovery
(Most popular is Whey protein because of its anabolic properties. But for complete recovery alone whey is not sufficient as amino acid level in blood after taking whey remains only for 3 hours. So either you have to take Whey after 3 hours or you have to take Casein that gives sustainable amino acids in blood for more than 8 hours.)
Muscles are ‘anabolically sensitive’ for up to 24 hours after resistance exercise, maximal increases in MPS and muscle size and strength are seen when long duration protein like Casein is taken immediately.
Casein protein is effectively digested and absorbed resulting in a rapid rise in circulating amino acid levels.
Sustained blood amino acids as result of Casein ingestion throughout night Protein ingestion before sleep increased whole-body protein synthesis rates and improved net protein balance (61 ± 5 vs -11 ± 6 μmol·kg per 7.5 h).
Muscle protein synthesis rates were ∼22% higher.
ISSN recommendation for recovery.
Add protein to carbohydrates at 0.5 g per kg Body Weight protein and least 30-40 g high glycaemic carbohydrates to restore muscle glycogen and promote protein synthesis.
Adding a small amount of creatine (0.1g/kg BW) to the carbohydrate and protein mixture improves adaptations of resistance training.
Protein must offer 6-20 g Essential amino acids (EAA) and it should be of high biological value.
There is consensus from the ACSM, ISSN and IOC on the beneficial effect of the ingestion of ~20 g protein with carbohydrates within 30 minutes post exercise.

​Sane Science Nutritions