endurance-hoz meg még fontos a laktát- és aerob küszöb különbsege (forrás: The Uphill Athlete, ajánlom mindenkinek)

ADS was first described to the author Scott Johnston in 1985 by the coiner of the term, Dr. Phil Maffetone

AEROBIC DEFICIENCY SYNDROME (ADS)
When you exceed the capacity of the aerobic system’s production of ATP, you will be forced to rely upon the anaerobic system to make up the deficit. As you now know, that reliance will be self-limiting and you will have to slow down sooner or later. Athletes who overuse high-intensity training methods will usually have a low AeT because their aerobic metabolism has become detrained while the anaerobic metabolic pathway has become very powerful. We call this condition Aerobic Deficiency Syndrome (ADS). It is reflected in a slow (often shockingly slow) AeT pace. These athletes will be dismayed that despite all their hard training, they still can barely get above a jog or even a walk before exceeding their AeT. These athletes typically respond with disbelief: How can they possibly be getting any training benefit from such a slow (perhaps even walking) pace? This low aerobic capacity has only one cure: a high volume of low- to moderate-intensity training.

Zone 3 training is most effective when the athlete has sufficient basic aerobic capacity; when the vacuum cleaner is big and powerful. How much capacity is sufficient? When you’ve raised your AeT to be within 10 percent (elite athletes can have a Z3 spread of 6–7 percent or only 10 beats) of your LT as measured by either heart rate or pace. With more than a 10 percent spread between thresholds, an athlete still has aerobic deficiency and needs to build more aerobic base. Those who have less than a 10 percent spread between thresholds will need to reduce or even drop Z2 training, substituting Z3 workouts.