I have been running for a few months (34m), and I can feel I have become more fit when it comes to how I feel and achieve while running. Now my session is more than double the time than when I started, and even when I end it, I would still be in zone 2 as my heart rate and breath rate are lower, unlike when I began running and I would always find myself at zone 4 by half the time (similar pace). Even when I try to run faster, I can do so for longer than before.

Yet, my VO2 max has dropped from 39.8 to 37.8! I would get very surprised every time I see it drop. Why would that be?

  • RunningM8@alien.topBEnglish
    1·
    1 year ago

    It depends on how hard you’re pushing. The higher your heart rate goes above a certain average across the total distance VO2Max may decrease because you’re pushing harder than you’re running farther.

  • Newtronic@alien.topBEnglish
    1·
    1 year ago

    I’ve been increasing my running over the last 4 months. Most practice runs are slow, zone 2, heart rate 125. Sometimes I run the first 5k fast or mix it up by HIIT runs. The watch says my VO2Max has consistently increased and my last practice run, 5 days ago, hit a new personal high. 4 miles. So then two days ago, I’m at an actual 5k run, which is only 3 miles. I go all out, heart rate 157 average, time significantly faster than practices. My VO2Max goes down.

    I know it’s just an estimate, but this peeves me. I have two theories:

    • distance matters. The real race was shorter so I get less credit.

    • Race speed went up, but heart rate went way up. So maybe it’s like in a car if you increased the RPM of the motor but the car speed didn’t go up linearly. Like the transmission is slipping.

  • ermax18@alien.topBEnglish
    1·
    1 year ago

    The Apple Watch likes you to kill yourself every run which isn’t the proper way to train. If you do a lot of zone2 running it will tank your VO2Max. I pay it no attention other than for giggles.

  • scelt@alien.topBEnglish
    1·
    1 year ago

    I think the only useful information for VO2max is when you open the yearly graph and then you can see the trends. Otherwise, day-to-day, not accurate. Needs maybe a month of training to spit out a remotely useful number.

    But speaking of this - VO2max of around 40 sounds about right, if you’re not super active, running a few months. It’s not really an indication of durability, how long you’ve run. The estimate is more about how much energy you can spend for a given heart rate.

    In a year or so, if add some sprints, HIIT, hills, you’ll be 50ish and rising :)