qt it really depends on the person. I take one
Atomic Tab about 30 minutes before I get to the gym, mainly because that's about how long it takes me to get out the door and get there. My gym is less than 10 minutes away, but I usually chew a tab before I make my shakes and apply my skeletal balm for my elbows or knees. Then I warmup for 10 minutes or so at the gym. By my workout I am definitely feeling it though.
Latest I would take them would be around 5-6pm. I can put myself to sleep easily though, and after the gym I am usually tired because I lift heavy and go balls to the wall. 5-6 should be a safe time though.
You can gauge yourself too. See how you respond. IMO different things factor in and people respond differently. If I am already exhausted and I take a tab, I still get
energy, but it may not last as long as if I were not exhausted. Sometimes I can get 6-7 hours before I start to feel tired, and sometimes I only get 3-4 hours. If I've been up late or didn't sleep well/had to get up during the night a few times, etc., then one
Atomic Tab will make me feel "normal". If I got decent rest and already feel "normal" then one
Atomic Tab will make me feel "supercharged". lol. I like that about them. If I'm dragging ass tired I can take two if I need to and still not get jittery and anxious. If you do take two I recommend having some food in your stomach though. Just in case.