How Long Does it Take to ‘Lose’ Your Fitness?


Stopping exercising completely can have big implications. This process is called ‘detraining’ in the fitness world.

Let’s take a peek at some typical results during a period of downtime and how to combat the unwanted effects that detraining can bring about.

Aerobic fitness and cardio

Drops can start after 1-2 weeks of total rest with significant loss after 3-4 weeks of no activity.

What happens:

  • Less blood being pumped to the heart per beat
  • Decreased performance and endurance
  • The amount of blood available for your heart starts to decline
  • Decrease in the body’s ability to use fuel effectively
  • Enzymes in the muscles that aid your metabolism start to decline, creating shifts in metabolism
  • Endorphin and adrenaline levels drop which turns moods in a downward direction

Also read: What Your Metabolism is Trying to Tell You

Anaerobic fitness and strength

Typically a fairly small drop after 2 weeks, approx. 70% drop after 3 months.

What happens:

  • Visible muscle mass drops
  • Strength can be maintained for up to 4 weeks, but aesthetic shifts to muscle mass can be apparent much sooner
  • Changes to muscle fibre types
  • The nervous system slows down using the pathways responsible for muscle contractions
  • Drop in mood due to less endorphins being released during exercise
  • Shifts in metabolism


Obvious decrease of suppleness after 1-2 weeks of no work.

What happens:

  • Muscles start to become tighter
  • Message between the brain and muscles become less frequent/strong in communication and the brain starts to protect the muscles by switching on preventative action when we start to lengthen or stretch our muscles.

Other factors

  • Unhelpful changes to diet
  • Poor sleeping patterns
  • Increased blood pressure
  • Goals can seem harder to achieve
  • Health factors can change and overall mood can be compromised due to less oxygen to the brain and the ability to suppress the chemicals that cause irritability, depression and low self-esteem etc

How to prevent detraining

By performing a fitness test at regular intervals, you can keep things honest and make any necessary adjustments to your training.

Aim to stay reasonably active during a break and add in some moderate exercise such as walking, outdoor activities or simply cut back the intensity of your current program.

Incorporate some light cardio and basic resistance activity if you are going to be taking an extended break from your usual pace.



Louise McDonald, Cert III & Cert IV Fitness
Louise has been a Trainer and Wellness Coach for almost 20 years and is one of our experienced Support Crew members in Fitness, as our Lean and Strong Captain! Louise has worked passionately with all levels of fitness over the years across both Australia and the UK, where she has specialised in competition training with athletes for the last decade. She has worked closely with top level competitors and even our own 12WBT peeps to bring home a National Trophy! She lives, breathes, eats and sleeps weight training and is super passionate about teaching others how to reach their full potential.

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