Hello: Newbie to the group but an oldie as far as fitness goes. I used to run Marathons but my left knee told me it was time to quit. Now, I'm a gym rat. I'm 67 y/o 6'1" tall and 178#. I'm in the gym 5 days a week on average and lift, as well as cardio and aerobics. 

My issue is with doing crunches/situps on the reverse incline station. It seems if I do more than 100 reps, I get a blister at my tailbone (coccyx) area from abrasion against the padded bench. I've used extra padding such as a towel but it doesn't help much. Today, I did 220 reps and am now suffering from an open blister. I can do more, but the blister/spore gets worse. I do other ab/core stuff to compensate (usually 4 different exercises per workout) but I don't like not being able to do the crunches without the blister. I've asked a few people at the gym but no one can offer anything but(t) sympathy. Any clues or suggestions will be greatly appreciated. Thanks in advance. David