Disagree regarding the crash. I've done both and prefer it pre...Matt Jansen advocates for it pre WO so it's there to utilize from the start of your workout (I actually sip it whilst warming up)I use around 25-30g once im warmed up good, probably 20 mins into my workout I start drinking it. I like lots of water with it. Ben pakluski said something about it boosting gh when done this way. If you drink it preworkout you will crash. I can do a longer workout once its in my system it gives me my second wind.
Try it out.