Use it or Lose It

Detraining Results In Rapid Loss Of VO2 Max Fitness Ability 

So you had a vision, a goal, and a point to prove. You pushed your body through hundreds maybe thousands of gruelling hours in the gym. You refused to relent whilst getting stronger, fitter, faster and leaner from consistent training and patient increased goal setting. The reflection in the mirror staring back at you is now unrecognisable from a few years back, and you can hold your own on the Wattbike demonstrating strong VO2 Max and LT levels… Hard works pays off…. But for how long? …

Maybe you feel a pain in your chest, pneumonia?  Your partner has booked the lifelong four-week holiday to the middle of knowhere, or work commitments just got serious and the first casualty is your “ training “ time… But your fit and strong right? It took years to achieve it, so you won’t just lose it? …  Well yeh you will.

Expect rapid loss of your VO2 fitness, lactate threshold and the vanishing of lean muscle mass…



“It takes three times if not longer to gain fitness as to lose fitness”

Let me explain:

Training the body (endurance/cardio/cross-fit/HIIT etc.) Causes a metabolic trigger at cellar level that opens up adaptive pathways that lead to increased levels of VO2 Max, lactate threshold, mitochondrial density and the ability to oxidise fat stores as fuel. Why? In a nutshell training makes the body feel either under threat (avoid predators) or the need to work harder to successfully hunt for food. This trigger is known in part as the“fight or flight” response, which results in the secretion of hormones known as catecholamines.


When we stop training (known as detraining) the body beings very rapidly to feel “safe and secure” so it then begins to “preserve energy”. Understand all the biological factors that increased baseline VO2 Max in the first place, are closely connected, and will fall together like dominos. When you stop training almost immediately your requirement for blood volume decreases, and so does your stroke volume (the amount of blood pumped per heart beat) this increases your heart rate at both rest and during increased intensity demand…this leads to a loss of fitness and the bad news?  Expect within only three weeks of detraining to lose fitness VO2 max levels of near 20%  #Alterations in anaerobic threshold as the result of endurance training and detraining. Ready AE,Quinney HA.

Although elite athletes will experience an even more dramatic initial decline in fitness (peak fitness is always tapering and held up only by extreme training) they will not regress totally over long periods of detraining and hold most of their lifetime aerobic conditioning. Unfortunately non-trained athletes over time will regress completely.

As the body’s ability to consume and process oxygen falls, watch as muscle mass, strength and flexibility all begin to enter atrophy.This will cause your metabolism to change, meaning you will start to burn less fat and store lots more of it!! (Decrease in RMR)

So can you regain all this lost ground?

The simple answer is yes, but the road back will take time, patience and its not going to be easy, whilst you will find a lot of the “fun” is taken away from training. That’s why detraining should where possible be avoided, and it’s worth noting:


 “You don’t need much of a training load to maintain fitness provided you increase the training intensity”. 


My advice when faced with non-injury related time challenges is to always employ the use of a Heart Rate Monitor (HRM) and target the body against progressively increased levels of training intensity to compensate for the decrease in training volume. Short precision powerful bouts of 8-15 min HIIT workouts will provide the body with enough stimuli to keep open the adaptive pathways that provide current fitness levels.


When total detraining has occurred, its important to condition the mind to the long, hard road back to fitness. Motivation is always key to successful training, however time off means previous highs and PB’s which “amped up” your sessions will not apply. The challenge criteria has changed and you will need to evolve your mind-set to beat and defeat smaller milestones… 


Once the correct mind-set is in place, the speed in which fitness levels are re-obtained come down to two main factors:

· Previous training experience, fitness and training lifespan.

· Establishing new fitness baseline levels and employing smart targeted training with progressive challenge that allows for both recovery and growth. Typically you will need to vary workout volume and intensity so that you oxidise fat as fuel (FatMax) increase upper aerobic threshold (70+ % VO2 Max) and strengthen anaerobic capacity and lactate threshold (HIIT/Weights) forcing the body into adaption.


A good tip would be to obtain your new VO2 Max score. However taking the test in a lab is for most not practical, so the alternative would be the 12 min Cooper Test which can be performed on a treadmill and gives a good baseline VO2 score, which taken regularly under the same conditions will provide a solid protocol to monitor real fitness progress)