is inclined bench better than flat bench press

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are situps even worth it, even with weights or on an incline

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any exercises good for chests/stomach that you could suggest

Incline and flat bench suck. Decline is where it's at.

Stomach, I dont like them or do them. I work my core with heavy dead lifts and squats.

So, decline bench press, and dips for chest.
Squats and Dead lift for abs.