Follow up: losing your running fitness


After yesterday’s post about my specific situation with losing vs. retaining running endurance after our two-week trip to Kenya, one of my running role models and blogger-friends, Amanda, sent me a great link. I wanted to share it with you guys.

Via Runners Connect
Via Runners Connect

The article discusses research on the loss of aerobic fitness in cyclists, beginner runners, and “already-fit” runners. I was particularly interested in the latter of the three.

Research studies monitored the effects of de-training with endurance athletes who have a solid base of training and fitness (i.e., if you’ve been a runner for more than just a few months). They found:

  • Initial rapid drop in fitness: after 12 days off…
    • VO2 max had dropped by 7%
    • Immediate gains from training like glycogen storage and muscle efficiency are reduced
    • Enzyme levels in the blood (associated with endurance performance) had dropped by 50%
  • Plateau effect of fitness loss: after 84 days off (12 weeks)…
    • VO2 max had only dropped by 18% of its initial (pre-detraining) level
    • Capillary density (# of small blood vessels that grow into your muscles) did not seem to be affected
  • Bottom line(s):
    • Decline in your immediate fitness is fairly rapid
    • But your cardiovascular fitness (i.e., longer-term fitness gains) remains mostly intact (even after 12 weeks off)

No wonder I was able to jump back into my normal weekly mileage, but speed workouts have been slower than usual! I have some (speed work) catching up to do!

Thanks again for sending me this article, Amanda

Runners: what’s your favorite hard/speed workout? 

5 Comments Add yours

  1. Great info and I’m glad you are not really much worse for the wear!

  2. Morgan says:

    When I was injured for a zillion months back in 2011, it was keeping up the cardio any way I could that helped me jump right back in to running once I was cleared to. Obviously there was still a transition period, but for the most part I was kinda shocked at how easily I got back in to the swing of things and it’s all because of the cross training. So if you can’t run, just staying active will help the you lessen the loss of fitness overall. Great write up Erin!

    1. Beth says:

      Thanks for sending me this Morgan!!!

  3. Beth says:

    So happy to read this. I’ve had to take 6 weeks off and I’m nervous about how hard it’s going to be to start again. Thanks for the research!

    1. Efo says:

      Thanks for stopping by, Beth! Good luck returning back to running! You’ll be great!

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