here you are branching out into the controversial field of supplementation. Since BCAAs have some positive research behind them (http://www.ncbi.nlm.nih.gov/pubmed/18974721) I would print the information off for the clients and suggest to them to discuss this with their doctor or an RD.
Whenever I find something that works for me, I share the information but only inform, not advise.
I have read some good and some bad things about BCAAs. They have been around for a long time, like 50 years or more. There isn’t a lot of sound research on them. The majority of the research was paid for by companies producing BCAAs. Many independent studies showed no definitive effects. There were reports of less fatigue and of more fatigue, increased strength and decreased strength, etc. And no one has done a follow up study on the long term outcome that I can find so far. There is no money in bad news, so companies don’t pay for long term studies unless they know the outcome in advance.So no long term study usually means no good news.
But to me it is just another attempt to bypass eating properly and training properly. Another “magic pill” for the masses. Usually it is used by the people who want big muscles or instant results. I can also tell you that the products that usually get you fast results end up costing you fast loses when you stop using them or down the road. Sensible eating and training have never been shown to have side effects or future health bad impacts.
If you had to chose between powder protein and BCAAs, I would go with the later. If it works for you then you should continue taking them. As for suggesting them to clients, I would leave that to a RD, just as any other supplementation intake. Beware of the many companies out there that claim their products are better than others. Do your own research and always question the “findings” that a certain company claims to have/present.
If your client is eating a balanced protein diet (plant and animal based) and maybe even supplementing with protein powders, it would truly shock me if they weren’t getting enough BCAA’s in their diet. Adding more BCAAs isn’t really going to give them any pronounced results and is going to cost money they should be spending on good food.