Hello JoAnna,   It isn't bad for you typically, however there are exceptions. If you are an otherwise healthy individual and you want to do a little aerobic in the mornings and anaerobic in the evenings then you should expect nothing but benefits. Everyones limit to working out is different but your body will tell you what yours is. Plenty of people will work out for three or more hours in a day and be all the more healthy because of it. Many professional athletes will work out 6 hours a day (3 in the morning and 3 in the afternoon). If you have the energy, splitting up your work out (in any order you choose) is fine. typically the aerobic/anaerobic debate is referring to doing one right after the other...   I hope this was helpful.