couldnt find my extended Q on that, but here are my notes.. hope they're decipherable
TRAINING THRESHOLDS intensity of exercise necessary to cause an improvement in fitness
AEROBIC THRESHOLD: -Min. level of exercise necessary to cause an aerobic fitness improvement (ability to use oxygen during exercise; VO2)
-occurs at about 70% max. heart rate, or approx. 50-60% Max VO2
-training rate at which the baseline lactic acid level starts to rise
-should train between the 2 thresholds (in the Aerobic Training Zone) to obtain improvements in aerobic fitness
ANAEROBIC THRESHOLD: -intensity of exercise necessary to cause an anaerobic fitness improvement (near max. ability to use oxygen during exercise;VO2 MAX)
-intensity where the body has reached the max. level of oxygen that can be used
-the max. intensity an athlete can maintain and still have no increase in lactic acid
-intensity where anaerobic metabolism is increased, and lactic acid starts to accumulate in blood & muscles
-well trained endurance athletes can improve their performance (toleration to lactic acid) by working close to & above (in spurts) the anaerobic training threshold
hope that helps! its hard to explain in simple terms..