One Step Beyond Multisport Coaching brings you…
The completely unofficial guide to translating various athletic training terms into universal constants
~HR PE/Hellemans Power (% of FT) Friel Byrn Coggan Daniels Gaal Training Goal Tri-Race Pace PhysioSpeak
<70% Easy 55% Z1 AeT-10 1 E schmoozin' recovery/base beginner  
~70 Easy-Mod 55-70% Z1-Z2 AeT 2 L cruisin' endurance base IM VT/LT1 (~2mmol)
70-80% Mod/Steady 70-80% Z2 AeT+5 2 MP groovin' endurance base IM/Half-IM the lactate curve
80-85% Mod-Hard 76-90% Z3 AeT+10 3   movin' tempo/endurance half-IM ""
85-90% Hard 95-105% Z4 AeT+15-25 4 (FT) T bruisin' tempo/threshold OD/Sprint AT/LT2/OBLA (~4mmol)
88-94% Very hard 105-120% Z5a AeT+25 5 I way gnarly threshold/V02 5k lactate increasing
92-97% Extremely hard >120% Z5b AeT+30+ 6 R wicked V02/Power Finish Shute ""
98+% All out 140-250+% Z5c   7   insane Power Cycling applicable ATP-phosphocreatine
PE=Perceived Effort/Exertion E=easy
CP=Critical Power L=long
AeT=Aerobic endurance threshold MP=marathon pace
LT=Lactate threshold T=threshold
VT=Ventilatory threshold I=interval
AT=anaerobic threshold R=repetition velocity
OBLA=onset of blood lactate accumulation
ATP=adenosine triphosphate, the universal energy storage molecule
FT=functional threshold*
*additional notes from Dr. Coggan:
"8 mmol/L is something that many endurance athletes can never achieve, even following a VO2max test."
"One more comment/caution: although they are obviously quite comparable, the notions of "functional threshold power" and "CP60" are not identical, as your conversion table implies."

"For various ways of estimating functional threshold power, you can search the wattage list for a post I wrote titled "seven deadly sins" or some such."
Click here to read that post (I've archived it on this site, hope no one minds).
Sources:
http://www.ultrafit.com/
Book: Triathlete's Training Bible, Joe Friel
 http://www.coachgordo.com/
Book: Going Long, Joe Friel & Gordo Byrn
http://www.cyclingpeakssoftware.com/levels.html
Dr. Andrew Coggan, PhD, Ex. Phys (notes above)
www.coacheseducation.com/endur/jack-daniels-aug-00.htm
Book: Daniel's Running Formula, Dr. Jack Daniels & Alberto Salazar
http://www.osbmultisport.com
Book: Title TBD, Hitting shelves in 10 years or so, Marty G, BS, MA, MBA