Maintaining the half sit-up position while performing any movement with the arms will challenge the abs, hip flexors, and even the neck musculature.
Anchor your feet under something stable and lean back until you feel your abs turn on. Try to keep your spine and neck as neutral as possible. You can go light and do the exercise for 60 seconds, or use heavier weights and shoot for 10-15 reps.
When I look at all the questions that people send me, one of the more common themes I notice is confusion around the topic of putting together your weekly training cycle. So for my first edition of The Staley Strategies, I thought I'd elaborate on one of my all-time favorite strategies (this one being a tactic, technically speaking): the A-B split.
The Bent-Over Barbell Row is a great exercise, but hardly anybody does it correctly. Most people look like they're having relations with a small farm animal when they do BB rows. Hence the Incline Bench Dumbbell Row.