Saw this from Friel (I'm assuming he's talking about one's theoretical limit for the general population, not the freaks in the Tour):

"Athletes often ask me what their FTP should be. That’s hard to answer because (as usual) there are so many “it depends.” But here’s a quick and dirty way to estimate what your FTP based on body weight, age and gender…
Step 1. Double your body weight in pounds (1 kg = 2.2 lbs). Example: A body weight of 154 pounds (70 kg) estimates an FTP of 308 watts (154 x 2 = 308).
Step 2. Subtract 0.5% for every year beyond age 35. Example: If the above 154-pound rider is 50 years old he would subtract 7.5% from 308 (50 – 35 = 15 x 0.005 = 0.075). This would predict an FTP of 285 (308 x 0.075 = 23.1, 308 – 23.1 = 284.9). "

If I'm doing my math right, that's an FTP of 4.4W/kg less 1/2 percent per year over 35. That is way, way over what I'm hitting right now.

Just curious what folks thoughts are.