For years I used to puke during most workouts. Not just legs, but biceps, calves, etc. I used to get so nauseous and sick I was having panic attacks during workouts.
I think I figured out why: use of whey protein and protein powders in general. Dropped them and haven't puked since or even felt very sick.
Puking and feeling sick is no goal and not a sign you're progressing. The better you feel, the faster you recover between sets, the better. Means you can push yourself hard(er). You're handling bigger weights, going harder yet feeling pretty good and recovering fast: great!
JMO.