[Jack213]

I have recently done two AeT treadmill tests, 9 weeks apart, and an AnT test and have a few questions on how to interpret the results.

 

Background: (Male, 34yo) I’ve been an active outdoor person for 7 years – mountaineering, rock climbing, trail running, backcountry skiing and hiking. I regularly do large objectives, 12-15 hours in the mountains, and am doing some sort of long run/hike/rock climb every weekend like 2-3 hour trail runs, 5 hour easy hikes, or alpine approaches to glacier climbs or rock climbs. These activities feel pretty good and I’m not dead tired afterwards so I like to think I have some level of aerobic fitness. Twelve months ago I took a serious fall while scrambling and broke my arm and multiple vertebrae and had zero activity for 4 months. I gradually worked back up and after 6 months I was able to catch the second half of the ski season and did lots of backcountry skiing. Since then I’ve been very fortunate to recover and complete a few big objectives like a 20 mile trail run, skied Mt Hector in the Canadian Rockies, and I’m rock climbing harder than I was before the injury.

 

When I felt like I was back to full time activity I decided to assess where I was aerobically, so the first AeT test in May (10 months post-accident) was on a treadmill at 11:19 min/mile, at 2% incline. I used a Garmin chest strap to record heart rate. After a 15 min warmup on the treadmill, I ran continuously for an hour. The first 30min average HR was 143bpm and the second 30min average HR was 150bpm. 150/143 = 4.9% drift. Therefore I set my top of Z2 at 143bpm.

 

In Feb this year, I did an AnT test while skinning uphill. Following this article (https://evokeendurance.com/resources/our-latest-thinking-on-aerobic-assessment-for-the-mountain-athlete/), I just went as hard as possible for the entire hill, climbing 1,250ft in 31:08 so 2,400ft/hr. Average HR over the 30 min was 171bpm.

 

After these two tests, my AnT/AeT was 171/143 = 120%, therefore leading to self-diagnosing ADS. I decided to do 6 weeks of very structured aerobic training to see if I could improve my AeT – I did every road and trail run in Z1/2 using the Garmin chest strap. During these 6 weeks, I averaged 6.5 hours of running per week spread out over 3-4 runs per week with 91% of the time spent in Z1/2, and 9% in Z3 according to Trainingpeaks. There were a couple hikes and bike rides as well as a long 10-hour multi-pitch sport climbing day during that period, and if I include all aerobic activities I spent 9.5 hours per week in low-intensity training with 92% in Z1/2.

 

During these six weeks, I was also going rock climbing 3 times per week and strength training twice per week. The strength sessions were 15-20 min each and at a pretty low intensity because of my injury and I’m increasing the deadlift & squat weights very slowly.  All-in-all, I was doing some form of activity 7 days per week, varying in intensity with one short & easy 30-45 min flat road run one per week, a couple 1hr runs, and one long 2-3hr run on the weekend. I took one rest week in Week 4 with a total of 6 hours of activity at a reduced intensity for running, climbing, and lifting. While doing all this training I was feeling very good and energized and not feeling any soreness/tiredness into the following day. Honestly it was feeling pretty easy.

 

After the six weeks, I took two days of rest and I did another AeT test at the same gym (unfortunately the same treadmill as the first test was occupied), and at the same pace and incline. Result was 4.8% drift (152bpm/145bpm). So both of the HR numbers are 2 bpm higher than the first test at the same intensity.

 

Question 1: I interpret the 2 bpm difference in HR from the two AeT tests as just simple variation due to sleep/nutrition/stress/air temp/HR sensor variation and therefore cannot draw any meaningful conclusion. Should I conclude that my AeT was unchanged from test 1 to 2?

 

Question 2: I assumed that if my aerobic capacity had improved, then when I perform the test again at the same pace & incline then my HR would be lower and the drift would be lower, is that right?

 

Question 3: The lack of improvement of my AeT is rather disappointing, so what should I do differently? Should I simply continue the same training program for another 8-16 weeks and check again? Should I spend more focused time in Z2 road/trail runs with runs 6 or 7 days per week and less time spent rock climbing? Or should I incorporate one or two days of high intensity work like tempo runs and VO2 max runs?

 

Thank you for any feedback!

[Scott Johnston]

Jack:

Thanks for writing in with your questions.  Hope the following helps.

I would recommend that you do the AeT and AnT using the same modality rather than one running and one skinning uphill.  I also recommend that you use the starting HR not the avg of the first half as the denominator.  Since you didn’t have much drift this will probably only result in change of a a couple of bpm.

1)You are correct that these are insignificantly small differences between tests and could be due to fatigue or even differences in treadmills.  But you can probably count these results as valid on the day.

2) Yes, I would have expected that in 9 weeks of 6.5hrs/wk of Z2 training you would have seen a change in HR drift.  Was the speed of the belt the same?  If you were moving faster that in itself is the actual goal and would indicate the even with the same drift your aerobic capacity ha increased.

3) if the answer to 32 is that the speed was the same then your suggestion to increase Z2 volume/week is direction I would recommend you take.  4 months lay off is a long time and it may just take more time to move the aerobic needle.  However it seems like you are experiencing good results in the mountains. A 20 mile run is nothing to sneeze at.  Were you able to recover pretty quickly from that?  Real world performance and your perception counts for a lot in assessing fitness gains.

I know this is not a black and white answer but I wish you luck. Clearly something you have been doing has been working.  So don’t loose faith.

Scott

[charlotteemma]

You can interpret improved aerobic capacity through subjective feelings of increased stamina and decreased fatigue, objective physiological markers like a lower resting heart rate and improved VO2max, and enhanced performance in endurance activities. A combination of these factors, such as being able to exercise longer, faster, and with less effort,Increasing aerobic capacity can  spacebar clicker  help improve the flow of oxygenated blood to muscle tissue, which, in turn, can improve mitochondrial density. Mitochondria are the organelles of a muscle cell that use oxygen to help produce adenosine triphosphate (ATP), which is the actual fuel that supplies muscle contractions.

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