The most critical time is 15 minutes after your Jiu Jitsu training because at this point the body is better prepared to receive and store carbohydrate than at any other time during the day. There are five goals for this brief but important window:
1. Replace expended carbohydrate stores
About 1.5 gm of carbohydrate per Kg of body weight from a mixture of glycaemic load sources. You should take in 50 gm of high glycaemic load carbohydrate for example glucose powder and the rest from low-moderate glycaemic load, for example fruits or fruit juices.
In the most severe conditions you may lose up to 1.8l of sweat per hour, to replenish fluid levels begin by taking 1.1l of liquid for every Kg lost during exercise. You can find this out by weighing yourself before and after exercise.
3. Provide amino acids for resynthesis of protein
Protein should be taken in at a carb-to-protein ratio of between 4:1 and 5:1. You can use protein powder made from whey or eggs, it is important to read the labels as many manufacturers add artificial sweeteners and flavours. If you prefer whey protein then I would recommend using whey isolate.
4. Begin replacing electrolytes
These are the salts; sodium, chloride, potassium, calcium, and magnesium lost through sweat. Most of the electrolytes are found in abundance in natural food, which makes their replacement fairly easy. Drinking juice or eating fruit will easily replace salts with the exception of sodium. Two or three pinches of salt must be added to a post exercise recovery drink.
5. Reduce the acidity of body fluids
During exercise body fluids shift towards an acidic state. The problem is that your body neutralises this acid by releasing minerals into the blood that have a net alkaline enhancing effect. Calcium from the bones and nitrogen from the muscle meet this need. Research has shown that fruits and vegetables have a net alkaline effect. Raisins, spinach and bananas all perform well at this task.