Detraining Quickness and Maintaining Fitness

Detraining Quickness and Maintaining Fitness

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What happens when you stop riding for 5 days? The detraining timeline is important to understand, as is knowing how to maintain fitness when you can’t train like usual. I cover both these topics in this episode.



Maintaining Fitness and Detraining Quickness: What Happens to Your Fitness When You Stop Training and How to Maintain It?

  1. First week:
    1. Aerobic capabilities drops by 5%
    2. Reduced fatigue
  2. Second week:
    1. VO2 max drops by 4-10%
    2. Body’s metabolic rate begins to drop
    3. Muscle tone sees the first appreciable loss
  3. Third week
    1. Loss of muscle mass and metabolic rate occurs
    2. Strength is still maintained
  4. Fourth week
    1. VO2 max has dropped by about 20-25%
    2. Loss of strength comes more loss in force of around 16%
    3. muscle glycogen concentration decreased by 20%
  5. Eighth week
    1. Strength loss of 7% at this stage.
    2. V02 max remains at 20%
  6. Twelfth week
    1. Strength 12 % loss


We all worry about time off the bike. The effort it takes to get fit and stay fit seems like nothing compared to get fit again. There is a lot of urban myths when it comes to the what, how and when of losing fitness.


So today I’m trying to clear it up for you. It may give you some peace of mind the next time you decide to take time off mid-season, or if you’re forced off the bike involuntarily either through injury, family or work commitments.

Technically the name of this is detraining. Sounds a bit funny considering it’s a technical term for doing nothing. But it links into the idea that you are a full-time athlete, semi-pro or not. We are on 24/7. Every decision we make affects your riding. Food, sleep etc etc. So looking at a year like this, it makes perfect sense to think about any time off the bike as detraining.


Having planned detraining is an important part of your yearly schedule, and yes that plays a part in resetting for a new season. But it also works when talking about the unplanned 3 day, 5 day 10 day periods when we can’t train. Or even longer 2 week, 4 week etc.


It’s also related to tapering, but that’s a discussion for another day. I’ll file that one under. Form = Fitness + Freshness.


Detraining is defined as the partial or complete loss of anatomical, physiological and performance adaptations induced by training, as a consequence of training reduction or cessation. It’s also not solely limited to physical abilities, but also affects technical skills.


What Happens When You Don’t Train?


I have gone through a lot of studies to come up with a guide to what happens during detraining. Noting the major changes usually in terms of percentage loss. There are a couple of things to keep in mind here. The studies do not agree, like most scientific studies there is a discrepancy between their reported findings. I have either taken a range or average approach. Also, these ranges apply to individuals. It’s hard to give you a concrete number since we are all so different.


Using the numbers as a guide would be a good way to benchmark your actual results if you could ever get them tested.

Days 2-3

  • Two or three days should have little impact and may even result in slight improvements as your body recovers from hard training.
  • When you are in hard training you are perpetually fatigued, so a short break allows your body to recover and adapt to your previous training.
  • Beta-endorphin and adrenaline levels drop. Mood is affected negatively.

Days 3-5

  • Muscles lose elasticity.
  • Aerobic capabilities drop off 5% by the fifth day off.

Days 7-9

  • Performance in endurance and fatigue are affected by the first week of inactivity. Specifically cardiovascular and muscular endurance.
  • Body’s ability to use oxygen (VO2 max) drops by 4-10% in well-trained athletes declines in a roughly linear fashion. Therefore less oxygenated blood is pumped with each beat.
  • Force 8% loss.

Day 10

  • Body’s metabolic rate begins to drop which means eat less or you’ll gain weight.

Days 11-13

  • Muscle tone sees the first appreciable loss.

Days 14-16

  • Mitochondrial activity (energy production) in muscle cells begins to decrease rapidly. Loss of muscle mass, strength, and metabolic rate occurs.

Days 17-19

  • The body becomes less efficient at thermoregulation. You are forced to spend excess energy cooling off.

Days 20-21

  • VO2 max has dropped by about 20-25%.
  • Strength is still maintained at this point though.

Days 27-29

  • Studies have shown that strength gains are largely retained for about four weeks with no training. Strength decreases from the 4th week. So with the loss of strength comes more loss in force of around 16%.
  • Lactic anaerobic metabolism stable for first 4 weeks
  • Metabolic downturns can also occur quite quickly. Glycogen is the key here as it’s the primary fuel source for exercise. By ceasing to train, you attack your metabolism from two sides. Firstly the body stops becoming so effective at converting glucose to glycogen, muscle glycogen concentration decreased by 20% after just four weeks of inactivity in trained athletes.

8 Weeks

  • Strength loss of 7% at this stage.
  • Vo2 max remains at 20 percent after eight weeks.
  • Metabolic and structural – muscle fibre distribution remains unchanged for the first few weeks after stopping. It takes up to eight weeks for the slow-twitch fibres – so important for endurance athletes – to start to convert to fast-twitch.

12 Weeks

  • Strength 12 % loss.


I’m not sure if you can get a clear picture out of all that. Overall though, it’s not as bad as I certainly thought.


Yes you will get zapped of your vo2max goodness if you’re are super fit, but most other elements will stick around for at least 4 weeks. You’re not losing strength for 4 weeks, which also means that you should be maintaining some sort of strength work before your peak. But depending on what you are doing, there are ways to maintain fitness over short periods of time, even if you don’t have access to a bike. The bottom line is that if you can maintain some type of fitness over the time periods when you are less able to train, you will be able to maintain fitness.

How To Maintain Fitness?

Depending on why you aren’t training will depend on how to maintain fitness. I will just stick to some basic guidelines.


There is not a lot of information out there regarding volume of training because it’s more widely accepted that intensity is the key. It’s claimed that fitness losses can be minimised if you can keep the intensity of your training going, even if you have to drastically cut the volume.


If you go on a holiday in a base or build phase of your training than a few weeks of fewer hours is fine so long as you do high-intensity short rides to compensate.

At this point, it’s not about getting fitter through, but you shouldn’t lose much fitness. It also might leave you refreshed for another bout of hard training for more gains.

Here is an important point though. Decreasing volume is fine, but you should take care not to decrease training frequency by more than 20 to 30 percent. So if you normally train 6 days a week, you’re better off riding 4 short sharp rides per week or 5 to 3.

Running is also another option, as are other winter sports in the off-season. The closer that your cross-training activity simulates cycling, the more slowly you will lose your cycling fitness. Running three times per week for around 20 minutes to one hour—through in some harder efforts to push your HR and breathing levels up. Will keep your body ticking over.

In conclusion:

  • Reduce the amount of training volume.

  • By maintaining some measure of intensity and decreasing frequency only moderately, many of the negative effects of detraining can be avoided.

  • Cross train in sports that are similar and even dissimilar can still have crossover aerobic benefits.


How about a 14-year difference in detraining?


Mujika I. The cycling physiology of Miguel Indurain 14 years after retirement. International Journal of Sports Physiology and Performance 7: 397-400, 2012.


So if you’re listening to this and you’re thinking about getting on the bike again. It will hurt at first but overall it may not be as bad as you think.


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[email protected]: Deskbound by Kelly Starrett

  1. Water (a lot of water) with salt for better absorption
  2. Lacrosse ball – Glutes, hamstrings, feet
  3. Executive Stretches – Minimum Therapeutic Dose





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Build fitness on a realistic schedule with this time-saving planner.

Get your free copy of The Weekly Workout Stack™

Build fitness on a realistic schedule with The Weekly Workout Stack™

Get your free copy of this time-saving planner.
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