Heavy Singles in Training: The Devil is in the Dosage
Proceeding the introduction post to this series on the implementation of “heavy” singles in powerlifting training, which I posted on the Collaborative Strength Instagram, I decided to write this article instead of just creating a shorter post. I can get much more in-depth on the subject matter, hopefully without confusing, or, boring all of you too much. You might even enjoy reading this [fingers crossed].
According to the SAID principle (Specific Adaptations to Imposed Demands), in order to build maximal strength in a single repetition, and the skill necessary to do so in an effective manner, we need somewhat regular exposure (to be imposed) to intensities as close to 1RM (specific demands) as possible to elicit the desired adaptations. To, 1) develop efficient intra and intermuscular coordination under maximal weight, and 2) develop the mindset needed to approach that weight with confidence.
But what about recovery cost; doesn’t maxing out all the time lead to non-functional overreaching and come with high amounts of fatigue? How ever will we manage acute to chronic work ratios? Slow down. As always, it depends, and it’s more complicated than that.
What is fatigue? Often defined as an overwhelming sense of tiredness, lack of energy and feeling of exhaustion, fatigue relates to a difficulty in performing voluntary tasks. There are many different fatigue classification methods. According to its duration, fatigue can be classified into acute fatigue and chronic fatigue. Acute fatigue can be quickly relieved by rest or lifestyle changes, whereas chronic fatigue is a condition defined as a persistent tiredness lasting >months that is not ameliorated by rest. Fatigue can also be classified as mental fatigue, which refers to the cognitive or perceptual aspects of fatigue, and physical fatigue, which refers to the performance of the motor system.
Muscle fatigue is defined as a decrease in maximal force or power production in response to contractile activity. It can originate at different levels of the motor pathway and is usually divided into central and peripheral components. Peripheral fatigue is produced by changes at or distal to the neuromuscular junction. Central fatigue originates at the central nervous system (CNS), which decreases the neural drive to the muscle. Muscle fatigue is a commonly experienced phenomenon that limits athletic performance and other strenuous or prolonged activity.(Wan et al 2017).
But to what extent? We know that there is an intertwined relationship between fatigue, recovery, and performance, but does maxing out a squat and bench every other week really tax the CNS that much? There is minimal evidence to suggest that true overtraining has occurred in strength sports or resistance training based on the current literature (Bell et al 2020). And it is suggested that the CNS can recover from maximum effort activities in 48–72hrs (Thomas et al 2018). There is also a lack of research considering acute fatigue responses to differing resistance training stimuli, and considerations in the context of powerlifting are basically non-existent. A 2017 study by Fisher & colleagues looking at acute fatigue and perceptual responses to resistance exercise found that max voluntary isometric torque decreases with lower loads but induces higher levels of discomfort. And even though lower loads (as low as ~20%) can elicit the same hypertrophic response as higher loads, strength gain is greater with higher loads. Less force production, more soreness, no thanks. The study also encourages the use of higher loads (80% or greater) at lower volumes to “avoid unnecessary fatigue or discomfort,” and another study by Fisher in 2018 supports these findings.
However, while heavy loads at low volumes appear to have little physiological effect on acute fatigue, frequently maxing out can induce high amounts of psychological stress, or mental fatigue, which have been associated with worse recovery(here and here). Stringing together too many consecutive high stress training sessions without adequate recovery can lead to decrements in performance, burnout, and increased injury risk. Not to mention, doing too little in terms of volume and overall work can have negative effects as well. The devil really is in the dosage.
Some traditional periodization models accommodate for this by breaking up training into separate phases that focus on different adaptations for a given period of time. Others break up training into high to low stress training days, disbursing volumes and average relative intensities appropriately across micro, meso, and macro cycles. These top down linear approaches can be based on a lot of assumptions and require time spent away from sport specific training(“heavy” singles), which may be less optimal for powerlifting performance. While three to four weeks away from intensities close to 1RM may have negligible effects on strength, a prolonged lack of exposure to those conditions can lead to loss of skill and lack of confidence; decreasing efficiency of intra and intermuscular coordination under maximal weights.
Some newer models of non-linear periodization, like Daily Undulating Periodization (DUP), attempt to make up for the shortcomings of traditional models by allowing for more day to day flexibility. The same or similar exercises are performed daily at varying intensities, separated into high to low stress days, using percentages based on 1RM or estimated 1RM, and/or autoregulation with RPE. However flawed, periodization is built from general scientific principles which have proven very useful for developing a training plan. We should consider the individual, and apply the principles accordingly. This includes the SAID principle.
As previously stated, for powerlifting competition performance, specific conditions would be considered a one-repetition maximum in the squat, bench, and deadlift. We need exposure to these conditions, or close to these conditions, to improve performance, however, only training heavy loads at low volumes can make for fun training, but it doesn’t make for great athletes. Conversely, only training light loads at high volumes doesn’t make great athletes either. The logical conclusion here, in my opinion, is that varying but maintaining training intensities somewhere between 70–100% of 1RM would address both the mental and physical demands of powerlifting, increasing work capacity and the ability to tolerate stressors. Essentially finding a balance between psychological and physiological stress by combining high load/low volume and low load/high volume training days that build maximal strength, increase work capacity, stress tolerance, and allow for proper recovery to take place.
Many great coaches have filtered general principles through their own creative processes and developed some of the best systems powerlifting has ever seen. Boris Sheiko, Louie Simmons, and Mike Tuscherer, to name a few, and I think we can learn a lot from the different programming styles of these legendary coaches. In our next installment of this series, we’re going to talk about practical application of high stress singles, including moderate and low stress days, and managing the accompanying fatigue of these differing stressors. All without non-functional overreaching [eye roll].
