fatburners or pre-work out drink and cymbalta

Hi,
I was wondering if I took a fatburner early in the morning to get through a work out at least 3 hours before I took my cymbalta would that interfere with the meds? I have just started the cymbalta today. I have been dealing with the pain now for about ummmm 4 years. I pretty much kept myself amped on fatburners at work because I had a VERY physical job andthe strong fatburners kept my adrenaline so high I could not feel the pain until of course they wore off and then I could not move from all the abuse I did to my body during the day and the fm, anyway I am not working now but I do need to exercise but I have not had any fatburners for 3 months since I stopped working and I can hardly even do 30 minutes at 4mph on the treadmill. So I was wondering if I could either drink a pre-workout drink or something to at least get me through 60 minute work out... I am really not used to being like this. The pain is horrible, but I am sure you all know that. Anyway any suggestions would be helpful even if you tell me to shut up and stop whining....thanks :)