Davies TB, Tran DL, Hogan CM, Haff GG, Latella C. Chronic Effects of Altering Resistance Training Set Configurations Using Cluster Sets: A Systematic Review and Meta-Analysis. Sports Med. 2021 Apr;51(4):707-736. doi: 10.1007/s40279-020-01408-3. Epub 2021 Jan 21. PMID: 33475986.
When programming we mostly think of a certain set structure in literature that would be considered a traditional set. Cluster sets, while sometimes used in body building as an intensity technique, seems to have some merit for strength and hypertrophy adaptations.
There are several types of cluster sets:
grouping of repetitions for example if I have a set of 8 you could break it into a cluster of 2 or 4, typically this is done with 30 seconds of rest between reps.
Interset rest: where you pause between reps, typically this is seen with shorter rest like 2-10 seconds between each rep
Rest redistribution: where if you say had a set of 3x10 you would do 10x3 instead, or 3x8 you could break it into 6x4 or a similar configuration. Typically, this protocol would be done with taking all the rest you would normally do between sets and just dividing it up into smaller chunks.
Rest pause: typically is the one most people are familiar with already. In this clustering you go until momentary failure and rest briefly, some protocols use 15-30 seconds, and then initiate more reps going again to momentary failure.
This review ultimately found that there was no difference in the type of set configuration performed for adaptations of hypertrophy, strength, power, and endurance. THis again calls into question the constant need to train to failure or using high RPE, as most cluster sets are in set of low RPE. Some cluster sets are as low as RPE 3.
This again would seem to be another data point to support mechanical tensions role in hypertrophy, and the idea that lower in session fatigue generation may be beneficial for development of and expression of absolute strength.
The specific discussion here is that cluster sets seem to help with movement quality, as the technical execution tends to be better due to less in set fatigue, and it is thought this trains high threshold motor units better.
It fuels ongoing debate about the need for metabolic stress and endocrine responses for muscular strength. While for hypertrophy there does seem to be a cap on the response of growth due to mechanical tension alone, but I will save that for another article review.
When clusters are employed there is also an association with higher in set velocities, which seems to be a promising area for development of strength.
It seems that inter rep rest of >10 seconds and interset rest of 30-45 seconds is a sweet spot for application of these clusters as well. Cluster sets are overall not superior to traditional training for developed adaptations, but are not worse. Which gives us another tool to use with our athletes to focus on mitigating fatigue (mental or physical), to allow them to ultimately achieve their desired goals. This will give us some ability to implement some outside the box strategies with some people and salvage situations, or match this with athletes who this style of training might better suit.
Grgic J, Schoenfeld BJ, Orazem J, Sabol F. Effects of resistance training performed to repetition failure or non-failure on muscular strength and hypertrophy: A systematic review and meta-analysis. J Sport Health Sci. 2022 Mar;11(2):202-211. doi: 10.1016/j.jshs.2021.01.007. Epub 2021 Jan 23. PMID: 33497853; PMCID: PMC9068575.
At this point I think it’s well established that training to failure and non-failure seem to produce similar changes in muscle growth. I mostly wanted to cover one of the papers that made this very apparent, as it is something that I have discussed previously.
However, this paper also continues to support the idea that training to failure does not support maximal strength development. For a variety of reasons: training to failure causes more muscular damage which impairs strength due to neural inhibition and down regulation of high threshold motor units. Additionally, the soreness sometimes associated with this results in a lower threshold for tolerance to loads, and volumes that would continue to contribute to strength, and or expression of strength. Additionally, training to failure generates a large amount of fatigue, which impairs our ability to to exhibit strength.
Training volume appears to have a dose dependent effect on strength, but the exact response is very individual. The more we can perform volume in training, and recover from this volume to perform high amounts at each session, the greater the strength adaptations.
Similar changes in muscular size however are seen if someone is training to failure or not. It is important to note that this is most often seen with loads from 60-90% of 1RM. While this is not a rule, there is data that suggests loads under 60% or those in which you can perform 15-20+ reps on a set more often require training to failure to see similar hypertrophy.
This is because loads of 60-90% (they are onset from 60-85% maximally) result in high threshold motor units being recruited from the onset of exercise. These muscle fibers have the highest potential for growth. While other fiber types do hypertrophy, and this usually accounts for mass differences seen between athletes in strength training sports versus bodybuilding. You could round this out primarily by performing sets in 8-15 rep ranges to stimulate factors besides mechanical tension.
While in general it may be beneficial to not train to failure in our day to day training. It may be practical and useful to occasionally taking certain exercises to failure helps us understand where true failure might occur for us. This will help to make sure we are still training “hard enough” to get the most benefit from our work. And can help when you have a lagging body part or weaker mind muscle connection with a particular muscle group.
Jukic I, Van Hooren B, Ramos AG, Helms ER, McGuigan MR, Tufano JJ. The Effects of Set Structure Manipulation on Chronic Adaptations to Resistance Training: A Systematic Review and Meta-Analysis. Sports Med. 2021 May;51(5):1061-1086. doi: 10.1007/s40279-020-01423-4. Epub 2021 Jan 8. PMID: 33417154.
The manipulation of set structure seems to have a negligible effect on strength gains and hypertrophy outcomes. It seems traditional set structures may be more beneficial for the development of muscular endurance but alternatives seem to have a more favorable response towards improving power like jump height. Alternative set structures also appear to help improve velocity profiles.
It has been thought that fatigue is important for the development of strength and hypertrophy, but more new data suggests that volume is more important. And while time under tension doesn’t have no effect toward the goals we look to achieve through coaching, new information suggests that moderating velocity loss during sets is more important for strength gains. And alternative sets seems to help mitigate fatigue allowing for better strength expression and athletic performance.
While this is the case alternative set structures might not always be practical due to time constraints. As many of them can increase the time needed to train. But it does appear that cluster sets and rest redistribution sets do not result in any less hypertrophy than seen with traditional sets. Also at submaximal loads there is greater velocity and power seen with alternative set structures. Which makes sense because you are using a weight for overall less reps at a time resulting in less metabolic, muscular, and perceptual fatigue. This seems to help in the short term allowing for better performance or quality of reps and velocity. The intention to move weight with high velocity appears important. All things that can help with skill acquisition.
This study also throws another one on the pile suggesting when weights are heavy enough training to failure may not be needed and adds to the idea that tension is what is a primary stimulator for hypertrophy. With ASS there is less metabolic stress which doesn’t mean it cannot influence growth but depending on our goals may not be as important to highlight. Because vía tension and accumulation of volume, due to less fatigue, it may be possible to accumulate more total sets via ASS (more to come in a future newsletter discussing mechanisms of hypertrophy)
Further, higher velocities, or consistently moving weights faster when lifting appear to result in better strength adaptations. But should be stated in caution due to small effect sizes.
ASS may also allow for greater tolerance to higher training loads, and total volume within a session. In some protocols rest redistribution allowed participants to perform 5x the number of repetitions as those performing traditional sets. Another study reviewer in this used a protocol comparing 90% using cluster sets versus 70% with traditional sets, finding those using CS had a greater velocity of movement despite a 20% difference in load.
So because there is a dose dependent relationship between volume and size and strength ASS is a viable tool to potentially help someone to tolerate more total volume. Giving more options to coaches and athletes to work on specific goals like: building tolerance to volume, accumulation of volume, reducing DOMs, improving technique, making a daunting session seem less so etc.
Travis SK, Zwetsloot KA, Mujika I, Stone MH, Bazyler CD. Skeletal Muscle Adaptations and Performance Outcomes Following a Step and Exponential Taper in Strength Athletes. Front Physiol. 2021 Oct 21;12:735932. doi: 10.3389/fphys.2021.735932. PMID: 34777004; PMCID: PMC8582352.
Typically tapers are a planned period of time where training volume is manipulated. This entails decreasing the volume (total number of sets and reps and load on the bar) and training load. Although training load is a part of volume most studies still address that load is also manipulated in different ways due to specificity. Most tapers occur over a 1-4 week period as well and in resistance training are not as well studied, as in endurance exercise. This is typically done to reduce fatigue to allow someone to express strength adaptations at a planned competition.
A step taper is seen in this study as a reduction in training volume over 1 week by 50% (the percentage of decrease can vary), and an increase in overall training intensity leading into competition period.
The exponential taper group performed their taper over a 3 week period where the number of sets is less per week but the intensity in most instances, until the final training day, is increased.
Some data suggests that higher intensities and an exponential taper over 2 weeks may be more favorable, others suggest having less than 2 weeks where volume and load is reduced by half might be more beneficial. Most tapers are seen over a 7-10 day period with 41-50% reduction in volume and or load but weight on the bar can reduce by up to 30% in some studies and increase up to 10% in others, and any variation in between.
This study used trained powerlifters, who were a part of the competitive team at a University, and compared step versus exponential tapers. This included a planned overreaching period where volume was increased so that participants were performing 150% of their normal training volume.
Overall this study found that following a planned overreach in training, step and exponential tapering resulted in similar performance for 1RM, but it appeared for the deadlift exponential tapering had a better effect. Overall this adds to our understanding of tapering and might suggest for more people that taking longer to taper on deadlift might be appropriate for many lifters.
More to come on tapering in the coming month.