I just go by how I feel. I really ought to start counting grams, I could probably do better.
When I'm low on protein, I'm sorer longer after easier workouts, and I don't gain strength or heal as quickly. Back in the fall when I was in marathon training, my nails got so brittle that I literally could not cut them without them splintering (and I keep them very short regardless). I was downing piles of protein powder (about 20g/day from powder alone), eating beans pretty much every day, plenty of vegetables, occasional fish, dairy and eggs (like once or twice a week of each), and it just obviously wasn't nearly enough.
When I've been sick it's a whole 'nother story. I just really, really crave meat to build myself back up. I think I would've eaten my husband's arm the other night if he hadn't been able to track down that steak for me. 
ETA: Read the labels on your B-complex and make sure it's really balanced. A lot of them say "balanced" on the label when what they mean is they've got, say, 50g of everything. That's like saying a garment fits because it's a cylinder the diameter of your hips... Solaray's formula is the only one I've found that's actually balanced based on the RDAs.
Last edited by OakLeaf; 03-05-2011 at 06:27 PM.
Speed comes from what you put behind you. - Judi Ketteler