I don't know if I would want to take Niacin preworkout. The Niacin flush can be an uncomfortable feeling. I have to wonder if the sick feeling you get is from the stims in many of the the preworkout powders out there today. L-Arginine should work well, without causing upset. Citrulline malate might be another supp to consider using. Personally, I use a traditional pre-workout drink that contains a stim about 30 min before training. I usually change the brand every few wks. On back day or quad day, I like to use a stronger pwo, as they are usually more intense training days. Then during my workout, I sip on an intra workout drink, using a high molecular weight carb like Karboload or HBCD, along with some EAA and Citrulline malate. When dieting, I reduce and eventually eliminate the intraworkout drink, but in the off season and pre season, I get great pumps using this combo. I get good sustained energy and I feel that it helps me recover faster