Anaerobic Threshold Test Gone Terribly Wrong

  • Creator
  • #72293

    Howdy folks!

    I’m about 6 weeks into the 16 week Big Mountain training plan, and I just took the Anaerobic Threshold Test as described on Training Peaks. I followed the set up instructions pretty much exactly. My set up was this:
    * slowly warmed up for 15 minutes, increasing speed until I broke a sweat (hit about 3 mph). Incline was set to a 15% grade this entire time.
    * At this point, I increased the intensity to around 4.5 mph, keeping the same 15% grade. After around 10 minutes, I realized this speed was unsustainable so i bumped the speed a bit back down to around 3.8 mph.

    What’s strange is that, this entire time, my heart rate did not even CLOSE to my AeT of 160 bpm (determined by a MET test in a lab). In fact, according to my Garmin, my average heart rate for this effort was 108 bpm. You should know that I was trying – HARD. Especially when I saw my heart rate not getting close to AeT, I bumped the speed back up a bit. No good.

    What I found was that by far, what felt like my limiting factor in this test was my calf/ankle endurance. when I was going 4.5 mph, my heart rate was around 125 bpm, but my calves were absolutely on FIRE.

    Does this mean my limiting factor is my calf/ankle endurance, and my aerobic system is leagues ahead of what my calves/ankles can handle going uphill? And if so, how should I adjust my training to correct this? Add as much vert as possible to all my aerobic base building runs?

    I should note that I, for the most part, notice this similar effect when I do my long “Zone 2 Hike on Hilly Terrain”. I usually do these in tall high rise stair wells with a bunch of vert gaing over several hours, and my HR is much below my AeT while my legs slowly give out first.

    Thank you so much for any help and advice! Cheers.

  • Participant
    Richard Abbott on #72296

    I can’t really answer your important questions, but I will say that 3.5-4.5 mph for me is a bit of a “no man’s land” where I struggle to efficiently walk/hike or run so I might suffer similarly in that situation. If I feel like I’m going to be at that speed for a particular target HR, I generally have to adjust elsewhere (incline/weight/etc.) to hit it.

    ryanarifin134 on #72308

    That totally makes sense!

    It’s just strange, as Training Peaks recommends to set the grade at 15% (steep) and keep it there.

    Overall (even with my normal aerobic base training), I usually have better luck getting my HR closer to AeT on flatter/milder terrain – there comes a point in steepness where I noticed my heart rate actually chills out but my legs start to give out. So I’m guessing what’s happening there is a similar phenomenon as what I saw at my attempt at the Anaerobic Threshold Test.

    On a side note – reading some of the pinned posts revealed to me that I need to get a HR chest strap! I don’t think using a wrist HR monitor completely explains what happened with my Anaerobic Threshold Test, but more accurate date can never hurt.

    rcj on #72313

    This sounds like your heart rate monitor wasn’t right. There’s no way you averaged only 108 at that pace and incline unless you stopped almost immediately is my guess, so something was off. The chest strap probably solves this.

    ryanarifin134 on #72315

    Definitely agree the chest strap will help – but I don’t think the inaccuracy of a wrist HR monitor explains a 60+ bpm discrepancy… unless it does.

    Just from everything I’ve read online, the accuracy of the wrist HR monitor can be about 7% or so. But I could definitely be wrong here.

    Cory from Wisconsin on #72316

    I too would lean toward HR monitor issue. Just a thought: Do you have a trace of the HR for the full duration? I’ve seen issues at times when I used my Apple Watch (series 6) without the chest strap and for some reason due to tightness or too much movement or the like, the watch only grabbed partial HR data and then when it averages its something completely off. But for me it was because the only good data it had to average was at the start during warm up, not during the actual activity.

    ryanarifin134 on #72341

    Looking at the HR graph on Garmin Connect, looks like my HR was a more reasonable (although still lower than I expected) BPM. (min of 110 bpm and max of 140 bpm).

    Like you mentioned though, around the 10 minute mark, my HR just drops (even though I’m definitely more gassed). This could also be correlated with me dialing the speed way back, but I do wonder if what happened to you is also what happened to me.

    Either way – looking forward to getting some better training data when my chest strap monitor comes in!

    Dada on #72397

    There is a saying at this forum: we don’t troubleshoot wrist HR training results here ?

    ryanarifin134 on #72402

    Apologies – I’m new around here! But I’m still appreciative of all of y’all helping point a total rookie in the right direction!

    I just got my chest strap HR monitor and will report back with the results.

    Vw2s4 on #75264

    Did the chest strap solve your issue?

Viewing 9 replies - 1 through 9 (of 9 total)
  • The forum ‘General Training Discussion’ is closed to new topics and replies.