AB Machines dont work!?!?!?!?

[brianb1998]

So I have been trying to get in shape with my girlfriend and we just got our first gym memberships. We are currently doing 15 minuted of cardio then hitting the weights then about 10 more minutes on a bike.

anyway my main question is:
Everything I read online tells me ab machines in the gym dont work. then why is it the after doing about 30 crunches on this machine set to 90 lbs my abs are burning like hell?

oh and its the machine where you sit down, rest your chest on a padded bar, and push down with a certain amount of weight.

 

[Coach Palfrey]

They don't work for what exactly? What are your goals?

 

[SXIPro]

They work for increasing your ab muscles strength and strengthening your core. They do not work if your goal is simply to have six pack abs. Your six pack will only show if you get your body fat low enough. In other words, spot reduction is a myth. Working one part of your body and expecting to burn fat off that specific area ain't gonna happen.

 

[jakenash]

I'm personally a free weight and body weight junky and avoid most machines, but I have to admit (shh, don't tell anyone) that there are a couple of ab machines that seem to do a very good job for me. Being able to increase the weight progressively is a good thing in any rep range, and for whatever reason, they seem to bother my old lower back injuries (herniated disk) less than many traditional core exercises, probably because they force me not to hyperextend.