Your abs have a key role in maintaining posture so they are capable of tolerating a much higher volume and/or with less rest. Hence you'll find that most people can happily work their abs 3+ times per week and still make progress.(Original post by Peace0fM1nd)
My response in a single word. Overtraining.
Its far too common with abs. The abs are a muscle, just like all other muscles. For example, would you apply the same routine you described to your biceps, back, legs etc.?
In the same way, if your overtraiing the abs - your muscle will simply not grow. In other words, no matter how much further training you do, the muscle has given up growing. This means visually, you will not see any results, even though the strength may have increased.
If we delve into the OP's history it becomes evident that he isn't training properly and he isn't eating properly - his lack of progress isn't down to him not training in the 8-12 rep range, overtraining or him not getting enough rest between sets.You can gain size and strength across any rep range as long as you add more weight to the bar over time. As for this 'optimum rep range' it varies depending on the person, the bodypart, the exercise, etc.All muscle responds in the same way, i.e. fast twitch, slow twitch is the same in the abs as in the biceps and so on. The basics of muscle training applies to the abs as it does to all other muscles. When you train the biceps, you will roughly do 5 sets of heavy loads (~8-12 reps) which is the optimum combo to trigger new muscle growth - any more or less will fail to trigger new growth.Overtraining is the process by which your training exceeds your capacity to recover between workouts, muscle strains are caused by over-reaching and/or poor technique and increased protein turnover is a natural response to exercise. Working outside of the 'magic' rep range won't suddenly induce a state of overtraining or cause muscle strain, likewise training in this window will not prevent muscle catabolism.In the same way, once you've reached the trigger point - any further training will tend to strain your muscles and a process of protein breakdown begins - i.e. your muscle will eat itself to maintain function (this is overtraining).It's a long standing myth that high repetition work improves definition.On other occasions, do high volume abs training, similar to what your doing atm, this should give the sharp and crisp definition of the abs to complement the muscle growth.
Some of your advice has an element of truth to it but a lot is very muddled.He isn't doing anything strenuous enough to need a dedicated warmup and cool down likewise it's unlikely to have any effect on his progress in this situation. Sure if he was following a decent routine centred around the main compounds and he was putting up big numbers he'd need a warmup and cool down but at the moment you couldn't be further from that.(Original post by HarryA)
There was a typo there, sorry. The last sentence was a statement, it wasn't meant to be a question. While he needs to improve, his warm-up and cool-down sessions are just as important as his diet and routine.
Challenging the body is only 1 part of it, rest and warm-up/cool-down is another.
... and the ones that won't