Can You Lose Fitness During Marathon Training?

I feel so unfit.

I ran a marathon 3 weeks ago and yet I feel like I am more unfit than I’ve been in years! How can that possibly be?

Running the Trick or Treat 5K on Sunday, although I wasn’t wearing a watch, I felt like we were pushing the pace and when Emily forged ahead, I knew I wasn’t going to follow. Yes my knee was hurting, but also my lungs were starting to burn.

Is it the two week taper? Or the two week recovery post marathon that has been detrimental to my fitness?

Chicago marathon mile 13

Obviously when improving your endurance fitness, your speed can suffer. It’s a different kind of pressure on your body, to push it to run 18, 19, 20 miles than to take a HIIT 30 minute cardio and weights session in a gym. It’s aerobic vs anaerobic fitness, plus you’re using your fast twitch muscle fibres used in rapid movements like jumping and sprinting. A HIIT workout is all about your recovery, whilst your endurance tests your ability to find a pace and stick to it for miles and miles.

To improve at a certain type of fitness, you need to train for that type of fitness. Although I included weekly speed session into my marathon training, I know I’ve lost a lot of my anaerobic fitness and strength. Mentally I’m finding it hard to push through these types of workouts too.

Incorporating speed work as well as explosive style movements like squat jumps, burpees, and split lunges into marathon training can help maintain your anaerobic fitness even as the mileage increases. As much as I loved Barre classes while training for Chicago, I think personally I need to add some more weights/HIIT training in there too.


I’m currently making very good use of my Classpass membership and attending classes at Paola’s Body Barre, GymClass, 1Rebel and Boom Cycle last week, and have got workouts booked at Core Collective, Ride Republic and Project Fit this week (along with My November Project). I’ve been thinking about sharing these workouts regularly on here to show you what I’m getting up to – would this be of interest? I currently share most of it on twitter/instagram but am missing the regular workout recaps that come with marathon training!


  1. November 3, 2015 / 8:35 am

    Good post! Sounds like you need to re-train your brain to be able to go back to shorter, faster workouts. If the last run you did was the marathon then the brain is still wired to the endurance runs and/or is possibly still recovering? Enjoy all your new workouts 🙂

    • charlotte
      November 4, 2015 / 7:24 am

      Hmm good thought, I really pushed it hard in yesterdays spin class so maybe mind and body are finally reconnecting!

      • November 5, 2015 / 7:20 pm

        Yeah sounds like your mind and body are returning to what they were doing before you started marathon training 🙂

  2. November 3, 2015 / 8:42 am

    Yeah, I agree – great post! I have struggled with my fitness too over the past few weeks, mainly because I’ve been changing things up and my body isn’t always used to it. Like what has been mentioned, it’s all about doing a variety of workouts to be well balanced, whilst still having the primary focus being the end goal and training specifically for that ie the marathon. It ain’t easy! I have actually just written a blog, inspired by Eternal Glory (the show on iTV), about how including a variety of different intensities and exercises helps the body work at it’s optimum.

    Hope you feel stronger soon!

    • charlotte
      November 4, 2015 / 7:24 am

      ooh I’ll check that out! Thanks, x

  3. November 3, 2015 / 9:21 am

    Hi Charlie, I absolutely know what you mean. I ran my fourth marathon two weeks ago and feel very much the same now. I took one week almost totally off, and last week ramped it up with more yoga, a Boom class as well, and a few short runs, only to wake up with a knee problem a few days ago. So I am back now to taking it easy and feeling blah. I want to join some of your November project runs and also take the opportunity to try fun HIIT classes at Frame and 1Rebel, once my knee feels better. Anyway, I know just how you feel!

    • charlotte
      November 4, 2015 / 7:23 am

      Thanks Kathy, would love some company!! Do take it easy though and make sure you’re getting plenty of sleep! It’s my secret weapon (a 10pm bedtime!)

  4. November 3, 2015 / 11:37 am

    Definitely with you on this one Charlie. I’m just a week out of my first marathon and spent last week recovering and doing very little. I think if you take taper time into account, apart from actually running the 26.2 miles we’ve not actually done that much in the last month or so as we were preparing for race. The key is to not get disheartened, remember that if you were once fit you can be as fit or fitter again and just put in the hard work to achieve that. I also agree that there’s many different types of fitness and your training should be tailored to what you want to get out of it. My focus is XC races and 10k/half marathons over Winter, so I’m upping the interval work to try and get speed back into my legs, and also adding resistance/weights back into my training to improve strength.
    Amy |

    • charlotte
      November 4, 2015 / 7:22 am

      That’s true, enjoy the cross country and shorter races, I think I’m going to be doing the same!!

  5. November 3, 2015 / 12:52 pm

    Definitely feel like I’ve lost speed during my marathon training compared to when I was training for a fast half marathon earlier in the year! As much as I have enjoyed marathon training and taking my long runs nice and slow, I’m almost looking forward to signing up to a spring/summer half marathon and focusing on shorter but faster workouts again – they make me feel so much fitter!
    Keep at it, you know you can do it and it’ll only take a few weeks hard slog!

    • charlotte
      November 4, 2015 / 7:21 am

      I hope so!! I’m thinking of a fun spring half too, want to get my PB down, it’s currently from my halfway point in Chicago which definitely doesn’t feel like my fastest!

  6. November 3, 2015 / 4:29 pm

    I always feel so unfit after a marathon- it’s almost like my body’s gone on strike- which it probably has! I’ve started mixing up my training a lot more since my last marathon and have definitely noticed an overall improvement in my fitness. The only thing that’s suffered is my running… not sure I can win!

    • charlotte
      November 4, 2015 / 7:19 am

      It’s odd isn’t it?! I’d love to do my next marathon for fun and just get the mileage done rather than focusing on pace so that I can mix up the training a lot more and just enjoy it!

  7. November 3, 2015 / 5:32 pm

    I feel this way. I so miss lifting heavy and doing more varied workouts. I feel like I need more strength back now post-marathon!

    • charlotte
      November 4, 2015 / 7:18 am

      Me too, I love fitness classes and really missed HIIT during marathon training!

  8. November 3, 2015 / 5:40 pm

    This is exactly why I’m having a year off marathons in 2016. I’m scared of the impending FOMO that will come when the whole of Twitter starts training for their Spring races, but I need to lose some fat, get fast and feel fit again. I had the run of my life at Brighton this year, but it took me a loooooong time to get back to anaerobic fitness again. Saying that though, ask me to run a half tomorrow and I’d laugh in your face!

    • charlotte
      November 4, 2015 / 7:17 am

      Hahah I know the feeling, it was almost unbearable last year with London/Brighton/Paris etc but fun to cheer others on too!!

  9. November 4, 2015 / 2:47 am

    I just ran the NYC Marathon (my first one!) and will be curious once I get back into strength training how I’ll feel. I was pretty consistent with my cross training during the whole process, but definitely noticed how weak I had become towards the end. Ah the price you pay to work up that endurance.

    • charlotte
      November 4, 2015 / 7:16 am

      Congratulations! That’s my favourite marathon so far, hope you loved it! Enjoy the recovery!

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