Welcome to the third in this mini series on muscle power as we build up to the release of the Making Sense of Muscle Power online course in a few weeks’ time. We’ve discussed the training of muscle power and how power performance changes across the lifespan, but we’re yet to consider detraining. I’m often asked how quickly power performance degrades once you stop training? So let’s look at the reversibility of muscle power training.
Reversibility of training
Reversibility is the loss of training adaptations as a person ceases training. As I’ve discussed before, particularly during the COVID pandemic (here), the extent of losses and deconditioning following cessation of training can depend on several things, including exercise history, previous length, duration and intensity of training, initial strength and fitness levels etc.
When we provide a training stimulus to the body, something that presents a challenge (the overload), the body adapts to be able to manage that overload. From a power training perspective, this might represent lifting weights with explosive intent (more on that here). If we remove that stimulus, the body also adapts; the challenge is no longer there and as such the training adaptations are progressively lost. BUT, how long does this take?
Why is reversibility of power training important?
First of all why do we need to consider detraining, reconditioning and reversibility? Well, I’m sure most of you reading this are involved in rehabilitation.
Rehabilitation: the process of returning to a healthy or good way of life, or the process of helping someone to do this after they have been in prison, been very ill, etc.Cambridge Dictionary: https://dictionary.cambridge.org/dictionary/english/rehabilitation#
Loss of physical qualities such as strength, power, balance etc. can occur for all manner of reasons, for example as a result of injury, illness, surgery, or simply cessation of training, and of course as a result of ageing. If we understand how these processes impact the extent and rapidity of loss of performance we can start to understand the characteristics of the training and rehabilitation programmes necessary to restore these qualities.
Of course, there’s another application here too, that of periodisation. What happens if we need to swap from training or rehabilitating strength for example to power, or vice versa? Will we loose all the performance gains?
Reversibility of training in athletes
Understanding what happens in elite athletes can be difficult. This is because not many elite athletes will voluntarily stop training so that you can test them. So, much of the data here is shaped around the off-season or during a period of alternative training.
Understanding the decay rates of strength and power when resistance training is ceased in sporting settings is important to moderate the periodisation of training. For example, to calculate the minimum and maximum duration that strength and power training can be ceased before another training stimulus is required.
Reversibility in Rugby
I want to highlight here a really information-packed systematic review by McMaster et al. (2013), which sought to evaluate the development, retention and decay rates of strength and power in elite rugby and American football. There’s a hell of a lot of data in the paper than I’m going to present her, so I encourage you to read it, but from a strength perspective, pooled data (n = 155) showed that a decrease in strength of 14.5 ± 14.3 % was found when players ceased strength training for a mean duration of 7.2 ± 5.8 weeks.
Put another way, based on the 6 studies included in this particular analysis, ‘detrained’ athletes were able to maintain the majority of their pre-season strength levels with no resistance training over periods of 2–3 weeks – during the competitive season.
Right, what about power performance, as that’s what we’re focussing on here? Well, things were less clear. Vertical jump performance (VJP) was used as the measure of power across most studies. Data showed reductions and improvements in VJP following detraining. Odd. However, there were only 3 studies that investigated power decay rates over the competitive season. Furthermore, different methodologies, length and specificity of training and indeed fluctuations in body mass could all contribute to the heterogeneity of findings. Answer is here that we don’t quite know.
What about other athletes? Kayaking
Garcia-Pallares et al. (2009) studied a group of elite Kayakers to investigate the effects of training cessation vs. reduced training volume on various elements of performance. So unlike the studies included in the above systematic review, here training was completely stopped, well in one group.
The typical training volume of these athletes comprised of 7 hours of cardiovascular work and 2.5h of strength work per week, representing 10-15 and 3 sessions, respectively. Following the completion of the competitive season, training was completed stopped for 5 weeks in one group of athletes, in the other group athletes performed a reduced volume of training. This represented 5 weeks of only 1 session of strength: 3×10 reps (of 12RM load) on the bench press, prone bench pull and squat exercises, and 2 endurance sessions (1 kayak, 1 run) each of 40 mins.
What happened? Stopping training resulted in a loss of upper body strength and stroke power output of approximately 8% each index over the 5 weeks. Interestingly, this was halved (3-5% losses) in those who performed a reduced volume. For more discussion about retaining performance with minimal training see here.
So, from this and associated literature, do we have an idea of what to expect in terms of decay rates of power in athletes? Possibly. It’s likely that muscle power gains will be lost more quickly if training and competition is completely ceased compared to continuing to exercise with some degree of explosiveness (sprinting, jumping etc). By how much is difficult to tell as there are many ways of measuring power and many ways of training.
Could we estimate similar changes on the basis of muscle strength decay rates? Perhaps a retention of power performance for 3-5 ish weeks during competition…?
Reversibility of muscle power training
– in older adults
A more controlled way of looking at detraining and reversibility is to provide a standardised conditioning response and then remove it for a period of time, track performance changes throughout. We’re going to take a look at older adults here, and yes, muscle power is important in this population (see discussion here).
A great study by Blocquiaux et al (2020) sought to investigate the knee extension strength and power changes in older men (n = 30; 55-77 yrs) and controls (n = 10) before and after 12 weeks of resistance training, detraining and retraining of similar lengths. Resistance training was progressed over the 12 week periods: 4 weeks 60%1RM, 2X15 reps; 4 weeks 2 X 13 @70% 1RM 4 weeks 3 X 8 @80% 1RM.
They observed ~11% increase in muscle power after 12 weeks of training, which is great. Cessation of training for 12 weeks resulted in losses or around half the adaptations (see graph below). So, not all is lost and this mimics what be see this in strength performance in these types of studies.
What happened when they recommenced training? Check out the figure below, we can see that 12 weeks of the same type of training resulted in almost full restoration of power performance. What does this mean? Well it’s interesting to note that whilst restoration of power performance is possible, the rate of change in the second period of training is reduced.
Are these data similar to what we see in strength performance? Well, perhaps not entirely. In the same study (see figure below) the authors reported losses to strength performance of about half the gains achieved, but that it took less time to regain performance to initial post-training levels. In fact after the 12-weeks of retraining participants strength performance exceeded post-training levels.
Specificity of training
We see this profile of decay and restoration in muscle strength performance in a number of studies (see here), and on balance we might conclude that during a detraining period, approximately half or the gains achieved in strength and power would be lost over an equivalent period. Given the data above, we might also conclude that restoration of muscle power might take a little longer than strength when training recommences.
This could be correct, however, we need to be mindful of the types of training undertaken. It’s not clear whether or not preservation and restoration of muscle power performance would be different if the specificity of training was honed to optimise power performance.
Furthermore, duration of training might play a role. Yang et al. (2021) recently showed that retention of training adaptations is superior following high-intensity resistance training programmes of >24 weeks in older adults.
What else influences reversibility?
Clearly and as discussed above there are a multitude of factors that could moderate performance decay rates, but I just wanted to leave you with this. What happens if you think about your performance?
A really interesting recent study by Dello Iacono et al. (2021) showed that mental imagery (MI) of strength-loaded (85%1RM) and in a separate group power-loaded (optimal power load) exercises during 6-weeks of detraining (during the COVID-19 pandemic) in professional basketball players was sufficient to maintain and in some cases increase physical performance. What? Discussion of this paper is a bit out of scope of this post, but compared to a control group who did no MI and lost performance it could highlight the integral role of neural parameters in the modulation of performance.
So, what can we conclude from all of this?
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- McMaster et al (2013). The development, retention and decay rates of strength and power in elite rugby union, rugby league and American football: a systematic review. Sports Med. 43(5):367-84. [Abst]
- Garcia-Pallares et al. (2009). Post-season detraining effects on physiological and performance parameters in top-level kayakers: comparison of two recovery strategies. J Sports Sci Med. 1;8(4):622-8.[Full text]
- Blocquiaux et al (2020). The effect of resistance training, detraining and retraining on muscle strength and power, myofibre size, satellite cells and myonuclei in older men. Exp Gerontol. 133:110860 [Abst]
- Yang et al. (2021). Training Session and Detraining Duration Affect Lower Limb Muscle Strength Maintenance in Middle-Aged and Older Adults: A Systematic Review and Meta-Analysis, Journal of Aging and Physical Activity, 30(3), 552-566. [Abst]
- Dello Iacono et al. (2021). Ain’t Just Imagination! Effects of Motor Imagery Training on Strength and Power Performance of Athletes during Detraining. Med Sci Sports Exerc. 1;53(11):2324-2332.[Abst]