"A high VO2 max is like being tall in basketball. All other things equal, the taller player will fare better ... but all other things never are equal. Lactate threshold and economy, the other primary factors in steady-state endurance performance, may change drastically. VO2 max will change, but not as drastically. This is the situation with the twins. Their VO2 max is the same, but one has a higher LT and better economy (among other factors). I have performed over 6,700 VO2 max tests. Of all the information we provide with the test, VO2 max is the least useful. Knowing your economy (speed or watts per liter of oxygen consumed) the heart rate and speed/wattage of aerobic threshold, lactate threshold, and at peak VO2 is much more useful data that can improve training."