I did the 30 Day Shred back in January and got awesome results! I lost inches like crazy and boosted my energy level tremendously.
I started out on day one only doing about 1/2 of the repititions and was somewhat sore the next day but still able to do the workout. i usually do this with any workout I start though. I think I actually started out only using 2 lb weights so my muscles didn't shake much. I gradually increased to 5 lbs then 8 lbs. I felt strong after about the third week. I started noticing my triceps about the third week into it. My arms toned up a lot along with my legs, buttocks and abs ( well everywhere really).
I've had better results with the 30 DS than any other workout I've tried and I've tried several. I can't say enough good things about it. Hang in there, it'll be worth it!