That coincidentally means working each of back, hamstrings, abdominals, and thighs to exhaustion levels for today.
I like to think of this combination as "fronts and backs", because of their bodily proximity. The leg biceps (Known also as hamstrings) to the quadriceps, and of course the back muscles to the abdominals, i.e., the core muscles.
~ Ab workout ~
There is no secret to working these muscle groups, and there is no prioritized order of importance. I have at it in a natural way, for example, such laying on my back and raising my legs in several angles and positions to thoroughly squeeze my ab muscles. Every time I find a position point that really stresses my target I hold that pose and flex as hard as I can while doing it. Then, when it feels like that position is no longer as stressful I then "ratchet" my raised legs slightly to a different angle and hold that position in order to flex the muscle fibers even more. I change positions and hold/flex the muscle contractions several times before a short rest. For me, "ratcheting" is the best way to hit the fibers from many angles. I also change my upper torso position and do the same leg raises. It totally changes the angle of attack.
You should try this. I think you'll like the workout feeling you get from it.
Stay tuned for future blogs on what I do for the other muscle groups.