Symptoms really run the gamut, and there is no rhyme or reason to it. I have seen Army Rangers get laid out for two days, and then guys in only average shape are hardly fazed. I would avoid taking any pain killers beforehand (and preferably none at all), but definitely drink more water than usual 48 hours prior and avoid booze.Yah, the second round should be interesting. The first? Less than nothing for me. I feel slightly fatigued when getting an annual flu shot, but that's it. This one didn't even do that.