Hi Team, and More Experienced Runners, I have a dilemma an am trying to decide what to do. I am a 48 y.o. runner who was a late starter. Have been running regularly for 3 years with up to 3 month breaks, low mileage of 20-49k/week, 2 half marathons and several 10-15k’s. Low on talent but obsessed. Strength training 2x/week. At my age, with my musculoskeletal tweaks and twinges, I feel that 80% of my running should be easy, zone 2. A VO2max test last year has shown this to be at a HR of 128 - surprisingly low for my VO2max of 50.6 mL/kg/min.
The problem is, Athletica has my L2 as up to 142 bpm. (I understand this is calculated based on my threshold). I know both from the VO2max test and by feel that this is too high (my VT1 was at 125 bpm and when running, my breathing is noticeably laboured at 132 bpm, a slow pace of about 8’15-8’30k). What this means is that if I go by feel and HR, which I have been, I cover far less distance than Athletica predicts, or it takes much longer. I am worried if I run at the pace Athletica is asking (i.e. HR up to 142bpm) I am pushing into more glycolytic demand than intended, not targeting fat oxidation preferentially and thus failing to develop a base efficiently. On the other hand, I am concerned that if I don’t follow Athletica’s prescription, and train at a more accuratezone 2, it won’t detect sufficient fitness improvements and will therefore not extend the long runs, increase weekly mileage, etc in an appropriate way getting closer to my September HM. Athletica has given me BOTH messages that I am “at risk of overtraining” AND that I “should run more than the prescribed mileage some weeks as your goal will require this”, so I am getting mixed messages. I am finding it stressful trying to work out how to manipulate my training to try to get closer to what Athletica wants for me when I feel it has made a fundamental error in where it has my zone 2. Or perhaps I’m confused and L2 is not intended to correspond with the physiological zone 2, and that the HIIT philosophy Athletica is based on does not prioritise easy runs targeting fat oxidation. But if I trust the prescription and run my Aerobic Development runs at a HR of up to 142, I am concerned I will risk injury, overtraining and sustained high cortisol (which blood tests showed late last year). I am really confused and would love some guidance. Thanks in advance!
Hey 
sounds like you are doing many things absolutely fantastic!
You are correct in your intuition! Always trust your feel. This is a wonderful example that sometimes we don’t “fit in” and that’s ok. Individual differences exists and I am glad you listened your feel and your test last year.
You could down-adjust your HR zones and keep doing your aerobic runs as you have with lower hr.
When it comes with distance, if you feel good and have no niggles, I would personally extend runs a little bit. If you goal is to run half marathon, I would make sure to get the distance done in training. So practically you would have to extend the time Athletica is prescribing. As it sees you extending, You’ll start to see Athletica give you a little more leash, knowing you can handle more.
When you see overtraining warnings, reflect on your feel, fatigue, sleep, nutritional intake . Is your overall energy good? Staying healthy? When you build up, sometimes overtraining warning pops up - your fell trumps ! Feel fatigued, please allow some recovery. Feel GRrrreat? Keep going!
I hope this helps you,
Let me know.
Fantastic. Thanks so much Marjaana! This gives me confidence to keep using the program making adjustments for feel, bit also to keep the prescribed mileage as my target. Wil see how I go over the next few weeks! Thanks again!
Let us know if you have any questions or concerns in the future, and good luck with the training 