Not sure what's happening, but after making a conscious decision to work out harder (and hopefully smarter), it seems that I've been gaining weight (and no it's not muscle weight).

My usual routine looked something like this:

Mon: Cardio-treadmill 20 min., stairs 10 min.
Tue: Weights- Chest (bench: 3 sets, incline bench: 3 sets)
Biceps (preacher curls: 3 sets, hammer curls: 3 sets)
Wed: Cardio-treadmill 20 min., stairs 10 min.
Thur: Weights-Shoulders (dumbbell military press: 3 sets, standing dumbbell
'lifts': 3 sets)
Triceps (skullcrushers: 3 sets, cable pulldowns: 3 sets)
Fri: Cardio-treadmill 20 min., stairs 10 min.
Sat: Weights-Legs (squats: 3 sets, deadlifts: 3 sets, leg presses: 3 sets)
Back (upright rows: 3 sets, pullups: 3 sets)

I think this is a pretty good routine...however, I still did not achieve the results I was looking for. Size has never been too much of an issue, it's always been more an issue of trying to get 'cuts' and definitions. To use the terminology, I would be described as a classic "endomorph" body type.

The changes I made:

1) stop lifting heavy weights w/ low reps and switch to low weight w/high reps.
2) Add 3 sets of decline bench on chest days.
3) Add 3 sets of a back exercise on back days.
4) Add 20 min. of cardio on my lift days (tues, thurs, sat) that is done after lifting.

And yet I seemed to have achieved no results, except to have gained 5 lbs of fat. With 6 days of cardio, I thought I would begin to see some tangible results. I'm still in my 20's so it's not like I should have an unbelievably slow metabolism. Add to all this that I generally follow a low carb diet. Admittedly I havent' been as vigilant about the diet as I used to, but I still never eat pasta, white flour, bagels, potatoes, and rarely have anything with refined sugar.

Can anyone help? I'm really out of ideas as to what i'm doing wrong.