So I found this workout on YouTube. It's called Tiffany rothe workouts. It is fun and I feel good doing it. However, I did it yesterday and now my back muscles are killing me. Is it normal to feel like this? I was running a mile a day four days a week and weights 2 days a week. What is more important? Cardio, weights, or aerobics? Or something else? Any info would help.

yes, thats normal, when u are body is used to a certain routine "running and weight" for a period of time and then you start doing a new routine, it targets new muscle group or a new moving techniques that might leave u sore or hurt for sometime.. My best advice is to keep going so the soreness will go away and automatically you will be elevating ur fitness level, Like when I stop doing lunges and go back to doing them I feel sore again then I keep doing them for about 10 more days and baam the muscles get stronger and the soreness goes away.. so i suggest f u are feeling really hurt that u go to an easy mile run with, slower pace.. and get back to ur routine by the next day.

Cardio is essential on the weight loss phase.. I resort to aerobics when I am just bored with my cardio routine.

Weight training is just as important as cardio, u are building muscles = burning more calories.

I am not a weight training person but now while I am getting closer to goal, I have to try to stick to it, It will help me to tone my body and to maintain on the long run.

I hurt so much that I messed up my back. My back muscles are so sore that I can't move and had to call into work to tell them I can't work cuz I can't move. I hope with time it will get better.