BCAAs are also called catabolism protection. Catabolism is a state of breakdown of muscle cells, so it is definitely useful to take a supplement that protects against catabolism.
BCAAs consist of three amino acids; isoleucine, leucine and valine, and these are essential amino acids that the body cannot synthesize on its own, so they must be taken in with food or supplements.
About 35% of the total share of BCAAs in the body can be found in the muscles. They are the only amino acids that are directly broken down in the muscles. They stimulate the production of insulin (from leucine) and increase the production of growth hormones. They serve as a source of energy in a situation of lack of carbohydrates. They prevent the breakdown of their own muscle mass during high-intensity training.
There are BCAAs in the form of tablets, capsules and pure powder, added to sprint gels and energy bars and in various combinations with creatine and glutamine.
There is a recommendation that for every 10 kg of body weight you should take 0.825 g of BCAAs.
This means that an athlete weighing 80 kg needs 6.6 g of BCAAs, which seems too little to me.
An athlete weighing around 80 kg should take 5g before and 5g after training and then he/she will feel the real effects. Athletes weighing 100 kg can easily take 10g of BCAAs before and 10g of BCAAs after training since they have a significant proportion of muscle in their body mass.