4 red bulls worth of caffeine??? I'm fairly sure that's insanly unhealthy. 320mg of caffeine in that alone. That's like having 4 cups of coffee in one hit!
Thats an artery clogging heart attack waiting to explode mate.
Theres nothing wrong with it, the purpose of caffeine pre-workout is stimulate the mind and cause a blood sugar spike that, mixed with the aminco acids, provide the perfect reaction for any weightlifting regime.
Caffeine is not as bad as people think and it as a lot of beneifts; its like eggs, people are scared of eggs from the 'saturated fat' rubbish of the 70's, when in all honesty the yolk of an egg is beneficial and filled with nutirients that ren't founf in many other food sources.
Anyway, Havard researches have been doing some studies on caffeine and found that men who drink 4 cups of caffeinated coffee a day, or equivelant, are half as likely to develop Parkinson's disease as those who don't; this is due to the fact that caffeine keeps dopamine molecules active. What's more, blocking adenosine may slow the buildup of amyloid-beta, a toxic brain plaque that's associated with Alzheimer's disease