I get questions on a regular basis about ab training. People wonder why some say to train them just like any other muscle group, while others say hit the abs every day. I usually work abs almost daily. Here's why.
Abs are skeletal muscles, just like the others, but they are considered tonic muscles, meaning that they are typically undergoing some degree of contraction throughout the day, vs phasic muscles, which are used intermittantly for actities
requiring powerful contractions for short periods of time. Tonic muscles are typically composed of primarily slow twitch fibers, meaning that they can't exert as much force as the more fast twitch fiber rich phasic muscles, however, they can
exert force over a much longer period of time.
In order to progressively overload the abs, which typically have an abundance of slow twitch fibers, it may be necessary to increase the volume of work--notice I say "may" here--either by more reps per set, more sets per exercise, or more
frequent training sessions per week.
For me, I prefer sets of 20-25 repetitions, increasing the intensity by adding outside resistance or lengthening a lever arm when the 20-25 reps aren't challenging me. There are some very advanced exercises that I may only be able to do 10 or so reps of--I'll throw them in the mix, too.
Some people see the results they want with lower reps and sets and higher resistance levels only. I tend to do better with a mix. Either way, you need to use an advanced enough version of an exercise or outside resistance so that at the end of a 25 rep set, you are thoroughly fatigued. If you can go on forever, the intensity level isn't high enough that you will see results you want.
Maribeth
Abs are skeletal muscles, just like the others, but they are considered tonic muscles, meaning that they are typically undergoing some degree of contraction throughout the day, vs phasic muscles, which are used intermittantly for actities
requiring powerful contractions for short periods of time. Tonic muscles are typically composed of primarily slow twitch fibers, meaning that they can't exert as much force as the more fast twitch fiber rich phasic muscles, however, they can
exert force over a much longer period of time.
In order to progressively overload the abs, which typically have an abundance of slow twitch fibers, it may be necessary to increase the volume of work--notice I say "may" here--either by more reps per set, more sets per exercise, or more
frequent training sessions per week.
For me, I prefer sets of 20-25 repetitions, increasing the intensity by adding outside resistance or lengthening a lever arm when the 20-25 reps aren't challenging me. There are some very advanced exercises that I may only be able to do 10 or so reps of--I'll throw them in the mix, too.
Some people see the results they want with lower reps and sets and higher resistance levels only. I tend to do better with a mix. Either way, you need to use an advanced enough version of an exercise or outside resistance so that at the end of a 25 rep set, you are thoroughly fatigued. If you can go on forever, the intensity level isn't high enough that you will see results you want.
Maribeth
Lots of good info.