I actually use both Jack3d and Xtend for my workouts. After experimenting, I found that the best way to use these was to drink Jack3d 30 minutes prior, and the Xtend during my training. This has given me by far the best energy and endurance I have ever had. Another thing to try would be tossing 2-3 scoops of Glycergrow in each drink for pumps and water retention.
I'm mixing Jack3d with RecoverPRO right now
It seems to really be helping reduce the over all fatigue from my new workout. Hooked up with a friend who was overseas for a few years training military in physical fitness and the first two weeks I woke up and went to bed tired as hell. Since I started the stack it's helped put more drive in the gym and actually feel somewhat normal againStrength is picking up gradually too.