The Best Answer
I'm assuming you mean Glut-4 post meals and to remember when to do them. I write down when I eat. So when I look at a clock I kind of just remember. I might use a timer on my computer if I'm at a computer. http://e.
But mostly, I go off of if I start to feel a little tired or feel/think my blood sugar level is dipping. (Which is usually right around the 1 hr/ 1.5 hr mark)
If you mean time 60-90 seconds, I just go by reps.
Join the 4 Hour Body Superhumans!