[Poli1979]

Hi,

early this week a did a lab test in order to measure my LT1 and LT2 and now I received the results which are kind hard to believe for me. The test itself was conducted that I started running at 8km/h for 10 minutes as a warmup, incline was set to 0% for the whole duration of the test. After that the test began with 9km/h for 4 minutes. After that blood was taken from my finger and speed reduced to 3 km/h. During blood sampling I stood still on the sides of the treadmill. The next round was at 10km/h again for 4 minutes (each round the speed was increased for 1km/h) and so on until I could no longer maintain the speed for 4 minutes (I think that the final speed was 16km/h which I managed to sustain for 2 minutes). Blood lactate measurements showed that my LT1 is at 156 BPM (speed 5:13 min/km) and LT2 is at 171 BPM (speed 4:30 min/km). During the last round my highest heartrate was 184 BPM. I am 45 years old and training with Scott’s principles (lots of Z2) more or less for the past 5-7 years.

And now to what puzzles me the most. In report there is also a table of training zones with corresponding heartrate based on my test results:

Z1/recovery = min – 119 BPM

Z2 = 120 – 156 BPM

Z3 = 157 – 164 BPM

Z4 = 165 – 176

Z5 = 177 – 184

What puzzles me the most is the high number of my top Z2. Up until now I was made to believe that my upper Z2 limit was around 140 BPM and planed my training around that value. OK, I have to admit that the number 140 was based more on my feel when I ran at that intensity rather than specific test. I did some heartrate drift tests in the past, but did not check that on a regular basis. I was more listening to my body and how I felt after a 3h run in Z2. I was tired, but not devastated and could easily do it again the next day. Even after a 5-6h run/walk in the mountains I was still able to operate in the afternoon and in the evening.

So my question is: is the calculation of the zones right? Can you give me any insights on that? I really don’t want to start training in higher intensities than what my body and system is able to sustain in the long run. As I am a time constraint athlete (work, family…) I really need to use my training time as wisely and as efficiently as possible.

Thanks for any thoughts you might have on this. And if any additional data from the test is needed, I’m more than happy to share it with you.

Pete

[Scott Johnston]

Pete:

Sorry to be slow getting back to you.  We’ve been swamped.  There is a lot to unpack here but I will try to be succinct.

The test itself sounds like it was conducted using a pretty standard protocol.  However, I can’t see the data or even the lactate numbers so don’t know what they were doing to determine those zones for you.

I value field tests and experience in everyday training far more than lab tests. These values change based on recovery state on the day. They are not fixed in stone.  This lab test is like a snapshot on a single day.  IMHO your experience out training and using the simple field tests we recommend which can be repeated for free anytime you see changes in performance outweigh the lab unless you can get into the lab regularly.

For determining the second threshold  I MUCH prefer to use a field test like a 30-45min time trial to find the average speed/average HR the athlete can maintain for the duration top determine AnT/LT2.  This is an actual performance test and your average speed and/HR are a true indication of your maximum sustainable output.  Where as in that lab you are transitioning through that intensity for only 4 minutes.  That may coincide with your maximum stainable pace but in my experience is over estimates it because you can be comfortable for 4 min at a higher speed than for 40min.

In your case the Z3 spread is only 7 bpm which is outstanding but comes with a significant caveat.  No doubt your paces at AeT and AnT are also quite similar.  This means that while the metabolic load at the top of Z2 is still quite aerobic the neuromuscular load is almost the same as at AnT.  Check the paces you are running at these two points during the test and see if they are also only a fe percent different.  The well aerobically trained can’t constantly train at AeT because of this mechanical stress from the high speed.  Z2 training needs to be more carefully controlled and applied for these fit athletes as opposed to the less well aerobically developed who can train a very high volume of Z2 because they are moving much slower and the mechanical stress is a lot lower.

Now, this is not a definitive diagnosis because I do not have all the information. But, it might help you understand the test better.

From what you say, chances are that you can’t run daily for hours at a time at this new AeT they have assigned you.  While that HR/pace may indeed reflect your metabolic state that corresponds with the top of Z2 you would become overtrained in a couple of weeks training in that Zone.

This is something I have spoken and written about extensively but with all the hype around Z2 these days I have no heard one of the ‘influencers’ mention this little but crucial detail.

I hope this helps and sorry again for the slow reply.

Scott

 

 

[Poli1979]

Hi Scott, thanks for the reply, very much appreciated as I was entering the lab test hoping to get a more precise readings of my thresholds and it seems that this might not be the case. However, below are the results from the test:

Pace (mim/km) – Heartrate (bpm) – Blood lactate (mMol)

7:30                                           128                                   1.10

6:40                                           135                                   0.90

6:00                                           145                                   1.20

5:27                                            151                                    1.20

5:00                                           163                                    2.00

4:37                                            169                                   2.80

4:17                                            173                                    5.00

4:00                                           182                                    7.10

3:52                                            184                                    9.80

 

Would you say that it is safe to assume that my LT1 more or less correlates to AeT? Because it this is not the case than lab testing is not so helpful in determining ones thresholds. Or is it? During the past few weeks I was training with heartrate zones adjusted and can confirm that a 3 hour hilly run @150 bpm average is more taxing that before running @135-138 BPM average. Afterwards I feel tired (not destroyed) but it would be hard to do it again the next day. And I can imagine what would happen after a few weeks. However, my breathing was still somewhat easy in terms that I could speak to myself in short sentences (something like in these video https://www.youtube.com/watch?v=1RqY5EYOM0k). It is not comfortable to speak would rather just breathe but if I need to I can speak/talk. So I’m guessing that I was/am still in aerobic zone.

Regarding AnT I will be doing an uphill run in duration of 45-60 min going as hard as I can for the duration as in the testing report there is a footnote that my LT2 (171 BPM) does NOT represent the intensity that I can sustain for 1 hour.

 

Thanks for you valuable feedback!

 

Best, Pete

 

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