Detraining And Defending Your Physiology
Article by Tait Hearps of Sweat Elite
We all know the feeling of coming home from holidays, feeling refreshed but also apprehensive about that first workout on the road back to fitness. You know it will hurt, and you’ll probably feel demoralised at how much hard-earned progress you’ve lost. Taking time off from training is a regular part of the cycles most athletes go through each year, focusing on a period of recovery and regenerating motivation for another tough cycle of training and racing. This concept is known as detraining, which can be defined as the loss of physiological adaptations and athletic performance when training is reduced or stopped completely.
Training is reduced or stopped completely… does that ring a bell? This topic came up on the most recent episode of The Real Science of Sport Podcast – “Sport, Exercise and Health in the Age of Corona” – which addressed the hindered training capacity many of us are faced with in the current pandemic. Sports scientist Ross Tucker and journalist Mike Finch have a fascinating conversation in the podcast, albeit via video chat as they are both in a strict lockdown in Cape Town, South Africa. Some of the key points are summarised below, however I highly recommend listening to the full episode.
The physiological changes referred to in the definition of detraining are essentially the reversal of all the metrics that improve in the process of becoming fitter. In a review of detraining published in Sports Medicine journal by Mujika and Padilla, these changes (decompensations, in the mind of the athlete) are summarised. “Short term cardiorespiratory detraining is characterised in highly trained athletes by a rapid decline in maximal oxygen uptake (VO2 max) and blood volume.” Further changes include increased resting heart rate, decreased cardiac stroke volume, decreased ventilatory efficiency, an increased reliance on carbohydrate metabolism (due to poorer oxidation of fats), a lowered lactate threshold and decreases in mitochondrial and capillary density in the muscles.
Ross brings up a number of studies that have examined detraining in athletes and enacted interventions to compare the effects of complete training cessation to a highly reduced training load. These are all relatively small studies looking at elite athletes, but despite the small study populations the referenced results are statistically significant, and very substantial in the context of performance and returning to training after taking a break, whether that break is voluntary and planned, or unforeseen.
One study looks at elite kayakers from the Spanish national team. After their final competition of a long season they have five weeks off to rest and recuperate. Athletes are either randomised to a group that does no training (NT), or a group that does reduced training (RT). This reduced training is significantly reduced. From around sixteen hours per week down to three 40-minute sessions (two cardio training sessions, one resistance training session).
The results? The athletes that maintained a low level of training had significantly less of a decline in lean mass (-3.0% NT vs 0.1% RT), 1 rep max for bench press (-8.9% NT vs -3.9% RT), VO2 max (-11.3% NT vs -5.6% RT). By doing a very low training load compared to what they normally would be doing, the athletes managed to retain a significant amount of the physiology they had developed during the previous training block.
Similar results were found when looking at cyclists. In one study looking at a five-week detraining period in elite young male road cyclists, significant declines were measured in VO2 max, peak power output and haematological parameters such as haematocrit and red cell count. Conversely, another study put in place measures to attenuate the deterioration seen with detraining, taking highly trained cyclists (normally training upwards of sixteen hours per week) and shifting them to only two hours of training per week for three weeks. Here there were no significant changes in VO2 max, resting heart rate and efficiency of fat oxidation.
Now you must be wondering, does this principle hold true for runners? YES. This isn’t discussed so much in the podcast but Ross recently uploaded an insightful video to Youtube going through a few more studies. In a 1990 study Houmard et al looked at detraining of experience endurance runners who were averaging 81km per week in training (~60km at ~75% VO2 max and 21km at ~95% VO2 max). Over a three-week period of detraining the athletes cut their volume by 70% to 24km, maintaining the intensity distribution with 17km at ~75% of VO2 max and 7km at ~90% VO2 max.
The participants in the study had an increase in maximum heart rate (2.3%), and plasma volume decreased (-5.6%) during the period of reduced training, so some physiological adaptations regressed. However, performance saw no change, with VO2 max and 5km time trial results holding steady. Another significant finding in this study was also that time to exhaustion during VO2 max testing increased by 9.5%, suggesting that the decreased training left the athletes much fresher. These results indicate that being smart with limited time or training capacity can still help massively in maintaining running performance.
These changes also appear to be less pronounced in older athletes and athletes who have trained for a longer time. Which makes sense, the accumulated progression and adaptations from consistent training over a long time are more entrenched, and therefore more resistant to deterioration than acute improvements in performance from relatively shorter training blocks.
As Ross puts it, defending physiology requires much less work than earning that physiology, and a little goes a long way. With races off and freedom of movement restricted in many places, despondency is pervasive. But lamenting the situation and the certainty of your lost fitness gains won’t serve you well. These studies highlight that even though it may be difficult to stick to training plans and complete hard sessions, a significantly reduced load of training still goes a very long way to preserving the physiological adaptations for which you have laboured.
Exercise is also highly beneficial for immune function and overall health. Probably quite important given the rapid spread of a highly infectious virus, right? Well this is only true up to a certain point. Whilst going out in the sun (or in your apartment, or basement, or bathroom… anywhere you can really) and doing some exercise is beneficial for maintaining fitness, mental health and immunity, prolonged periods of strenuous exercise can place unnecessary strain on the immune system.
With all the extra time some are finding themselves with in this lockdown, it may be tempting to devote exorbitant amounts of time to exercising… Maybe for the fitness gains, maybe to take your mind off the stress of the whirlwind sweeping us all off our feet, or maybe just to escape the tedium of being inside your own head all day. This is not advisable. Ross cites a number of studies suggesting that after a marathon race athletes are more prone to succumbing to illness. Exposing yourself to increased risk is not a good idea at this point in time – it is definitely advisable to be training for maintenance and stress relief rather than pushing your limits.
The novel coronavirus has changed the way a lot of us live on a day to day basis, it has altered our notion of what the future may hold and stripped a great deal of our sense of control over our own lives. However, there is much cause for optimism here. Pandemics are nothing new, and probabilistically we will certainly see more within our lifetimes. I’m sure you’ve heard reference to historic icons who accomplished some of their most notable work during the isolation of a pandemic, such as Sir Isaac Newton. In 1665, as the black plague ravaged Europe and killed over a quarter of London’s population, Newton was isolated at his family farm near Cambridge and used the time to develop what became early calculus and theories on optics. The time he spent in isolation was later referred to as his annus mirabilis, ‘year of wonders’.
This is not the end of the world, things will eventually come to resemble what was “normal” before. Some countries are already beginning to loosen the grip of their lockdown measures. Races will be happening again soon enough. The importance of what we have looked at in this article is clear: even if you can’t train as you normally would, you can still do a lot to preserve what you have worked for and make returning to training much more seamless.
These studies give credence to the mantra consistency is key. Mitigating the effects of detraining is so relevant right now, but it also applies to any interruptions to your normal training load. Whether they come in the form of a planned holiday with the family, an intense period of work, or an abrupt fall from grace due to injury, illness or other circumstances, periods of detraining will incur a much smaller cost to your physiology and performance if small amounts of maintenance work are done.
I must reiterate that the full conversation between Ross and Mike is worth listening to, as it gives a context for what is happening to sport right now. This article comes on the heels of our most recent article which looked at strength training in the context of the effects the COVID-19 pandemic is having on the running community. The conclusion of the last article is too relevant to the topic of detraining to not repeat it here…
To finish I leave you with the words of Knox Robinson, from his recent GQ article about Kipchoge’s training and philosophy. “His secret is that there are no secrets. You just put in the work, season after season. The things worth focusing on are the simplest: the steady accumulation of miles underfoot.” Stay safe, stay sane, and keep accumulating those miles, even if it’s only metaphorically for the moment.
