So I've been doing a lot of cardio lately (over 1 hour sessions) and I need to make sure I don't lose a lot of muscle. I'm getting a lot of protein immediately after the workout but from what I've heard, L-glutamine before a cardio workout can help to prevent muscle loss. Is this true, and how much should I take? And if this is the case, how long can I do moderate-intensity cardio before I start hitting muscle instead of fat stores? BTW, I usually do it at about 150-170 bpm. My max heart rate according to the 220-age method is 204. So apparently I'm usually around 70-80% of my max heart rate.

no, glutamine wont do that. supplement companies use research on HIV patients and burn victims to make those claims.

I disagree with abear...

Glutamine as a a daily supplement will help. WHo cares that it was tested on burn victims??? It slows down "muscle-wasting" and that is the bottom line. Doesn't matter if you suffer from HIV, burns, snake-bite, or intense cardio.

70-80% of glutamine consumed orally doesnt survive the gut. you have been duped by supplement companies using research on the aforementioned individuals. those results could not be replicated in healthy weight trainers.

now since it gets absorbed in the gut, it does make a difference in those who have trouble in that area. also it'll help ppl like pre-contest bodybuilders and endurance trainers. but for the majority of ppl, it serves no purpose.

so is glutamine bad for you?

not at all. i believe glutamine is actually a good supplement, but only for what it can be used for.

for those with some kind of digestive "issues", glutamine can work wonders. for those in an extreme catabolic state like pre-contest bodybuilders or marathon runners, glutamine can work wonders.

cite your source.