Daniel: Great questions. I’ll reply to them individually.
I have pretty bad ADS with AnT at 190 BPM and aerobic threshold at 135 BPM. I am currently training at 12+ hours per week. How often should I be retesting my aerobic threshold?
At this volume of training you will probably see noticeable gains in both AeT HR and AeT pace within 8 weeks. If you are seeing gains during your routine training on familiar trails like: “OH! I’m 2 min faster to that rock than I was 2 weeks ago and my avg HR was the same and/or my perceived effort was the same or lower” then you’re moving the AeT needle and probably should retest. I normally suggest allowing about 4-6 weeks between tests.
I also have a couple of general questions about metabolism. So to use oxygen to produce energy, you need aerobic capacity – does this mean that VO2max is dependant on an individuals aerobic capacity and will improve with higher aerobic capacity? In this way can an individual with potential for a very high VO2max have that masked by awful aerobic capacity?
Think of maxVO2 as your maximum aerobic power. Aerobic power is a measure the maximum amount of oxygen your body can take in and utilize for work within a short period of time (even elites can’t maintain maxVO2 for more than a minute or two before being forced to slow due to fatigue. During near maximal efforts the anaerobic system is also contributing substantially to the total energy needed to sustain this high speed. The ultimate limit to aerobic power is the cardiac output (stroke volume x heart rate). This can be trained but has severe genetic limits. Read this:
Aerobic Capacity should be thought of as the amount of energy production that can be sustained with the minimal involvement from the anaerobic metabolic pathway. This is often referred to as the cross over point where anaerobic and anaerobic energy production are each contributing 50% of the energy needed. This intensity can be sustained for at least 2 hours and is often referred to as the aerobic threshold. Unlike aerobic power aerobic capacity is highly trainable even in elites. Raising the AeT may or may not increase the maximum aerobic power, maxVO2 but it will increase your maximum SUSTAINABLE power output (~1hr). Read page 47 of our book Training for the uphill Athlete for a real world story of Aerobic Deficiency Syndrome in an elite athlete.
If training results in increased muscle capillirisation and cardiac hypertrophy this should reduce the heart rate required to provide enough oxygen to the working muscles to satisfy their aerobic capacity. Will this essential cause a drop in aerobic threshold effort and require further base building to redevelop capacity to a level to fully utilise this increased oxygen supply? Finally, is that the main purpose of the base phase of a training cycle? To maximise the aerobic potential based on cardiovascular fitness derived from the previous training cycle?
In ADS, during the early stages of aerobic capacity building you will see a drop in HR for the same pace and perceived effort. Once the AeT/AnT get small (<10) you will mainly notice that your pace at AeT increases while AeT HR may not budge. Progress in AeT pace has been recorded for 10 years on one elite athlete. There is a lot of upside here for all of us until we meet our genetic limits.
I hope this helps.
Scott
