Functional Training Institute

Use it or lose it

In the previous weeks’ articles, we have looked at how much exercise we really need to do, combining weights and cardio and exercise and ab myths. Given the emphasis on how to get fit, we now need to turn our attention to the other side of the coin, what happens when we stop exercising?  This is a very common question that trainers and coaches get asked by their clients as they approach the holiday season or an overseas trip. Think about the amount of hard work and dedication it takes to actually get fit, particularly in those clients who initially present in bad shape. Armed with this important question in mind, we now need to look through the lens of exercise detraining, to see what research has to say on this topic. 

Let’s start with the good news, it certainly takes less work to maintain your fitness levels, than it takes to actually improve it!  Research has consistently shown this over the years, maintaining your fitness can be achieved with very short, but intense workouts. For example, aerobic fitness can be maintained with as little as 2 x 20-minute high-intensity sessions, or put another it only takes 40-minutes a week to maintain peak aerobic fitness. In contrast, strength is a little bit different, with most research suggesting strength can be maintained with just one high intensity (heavy load) session per week. The maintenance requirements for other training modalities are somewhat similar, including hypertrophy where research suggests the maintenance of muscle size can also be maintained with 1-2 shorter workouts per week.  

So if we know how to maintain our fitness, what should we know about completing stopping training. As most of the research in this area has been completed with athletes, we will look at what happens to a group of world-class kayakers when they are given a 5-week break from both endurance and strength training. Researchers from the University of Murcia, Spain reported after 5-weeks of complete rest and no training, the group of elite level kayakers demonstrated a: 

  • 8.9% reduction in bench press strength  
  • 7.8% reduction in prone row strength 
  • 11.3% reduction in aerobic fitness 

For the average client who is not a completive athlete, these reductions might not seem so bad, but for an elite athlete where the difference between gold and silver medals lies in the difference of 100th of a second, these detraining effects would be catastrophic!  The health benefits of exercise, such as insulin sensitivity and the ability to burn fat start to become affected after 2-3 weeks of reduced physical activity.  The effect of detraining effect different bodily structures very differently. For instance, in the first few weeks of detraining, muscles lose stored carbohydrate (glycogen), causing the appearance of reduced muscle size. A good rule of thumb for endurance or cardio training is your fitness level will be minimally affected by a break of two weeks, if your client is already fit. If your client, is just starting out, a 2-week break will have a much greater effect on their aerobic fitness levels.  On the other hand, strength can be positively affected by a 2-week break, however after 2-week both strength and muscle mass progressively declines. Thus we can advise our clients with a reasonable degree of certainty, up to a 2-week break in training is unlikely to have a detrimental effect on their endurance, strength, muscle size and general health and wellbeing. The only caveat here, is these recommendations apply to the low to moderately trained, the effects of detraining in highly to elite trained individuals  



García-Pallarés, J., García-Fernández, M., Sánchez-Medina, L., & Izquierdo, M. (2010). Performance changes in world-class kayakers following two different training periodization models. European journal of applied physiology110(1), 99-107. 

Hickson, R. C., Foster, C., Pollock, M. L., Galassi, T. M., & Rich, S. (1985). Reduced training intensities and loss of aerobic power, endurance, and cardiac growth. Journal of Applied Physiology58(2), 492-499. 

Mujika, I., & Padilla, S. (2000). Detraining: loss of training-induced physiological and performance adaptations. Part I. Sports Medicine30(2), 79-87. 

Mujika, I., & Padilla, S. (2000). Detraining: loss of training-induced physiological and performance adaptations. Part II. Sports Medicine30(3), 145-154. 

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