Hypertrophy training manual an evidence based guide to maximise muscle growth (2nd edition)

BazValle, E., FontesVillalba, M., SantosConcejero, J. (2021). Total Number of Sets as a Training Volume Quantification Method for Muscle Hypertrophy: A Systematic Review. Journal of Strength Conditioning Research, 35(3), 870878.2.3. Brigatto, F. A., Lima, L. E. M., Germano, M. D., Aoki, M. S., Braz, T. V., Lopez, C. R. (2019). High Resistance Training Volume Enhances Muscle Thickness in ResistanceTrained Men. Journal of Strength Conditioning Research.4. Duchateau, J., Semmler, J. G., Enoka, R. M. (2006). Training Adaptations in the Behaviour of Human Motor Units. Journal of Applied Physiology, 101(6), 17661775.

AN EVIDENCE-BASED GUIDE TO MAXIMISE MUSCLE GROWTH

HYPERTROPHY

PROXIMITY TO FAILURE - - - 5

QUANTIFYING PROXIMITY TO FAILURE - - - 6

ACCURACY - - - 6

TECHNIQUE - - - 7

SET BY SET - - - 7

MOTOR UNIT RECRUITMENT - - - 8

‘ALL OR NOTHING’ PRINCIPLE - - - 8

SIZE PRINCIPLE - - - 9

PROXIMITY TO FAILURE & HYPERTROPHY - - - 9

FAILURE VS NON-FAILURE - - - 10

REP RANGES & LOAD - - - 10

EXERCISE SELECTION - - - 11

REP RANGES & LOAD - - - 13

MOTOR UNIT RECRUITMENT - - - 14

TOO LIGHT & TOO HEAVY - - - 15

COMPOUND VS ISOLATION LIFTS - - - 15

JOINT HEALTH - - - 16

VOLUME - - - 17

QUANTIFYING VOLUME - - - 18

VOLUME LOAD - - - 18

NUMBER OF SETS - - - 18

VOLUME & HYPERTROPHY - - - 18

INDIVIDUAL RESPONSE - - - 20

LIMITING FACTORS - - - 21

JOINT TOLERANCE - - - 21

SYSTEMIC FATIGUE - - - 22

PRACTICALITY - - - 22

VOLUME ALLOCATION - - - 22

FREQUENCY - - - 24

CONTENTS

FREQUENCY & VOLUME - - - 25

DIRECT VS INDIRECT TRAINING - - - 25

FREQUENCY & HYPERTROPHY - - - 25

INDIRECT INFLUENCE - - - 26

VOLUME - - - 26

LIFTING PERFORMANCE - - - 27

INJURY RISK - - - 28

EXERCISE SELECTION - - - 29

ANATOMY & BIOMECHANICS - - - 30

COMPOUND VS ISOLATION LIFTS - - - 30

COMPOUND LIFTS - - - 30

ISOLATION LIFTS - - - 30

STIMULUS-TO-FATIGUE RATIO - - - 31

STIMULUS - - - 32

FATIGUE - - - 32

MUSCLE RANGE OF MOTION - - - 32

MUSCLE LENGTH - - - 33

TENSION CURVES - - - 34

PERSONAL PREFERENCE - - - 34

EXERCISE ORDER - - - 36

ACUTE EFFECTS - - - 37

EXERCISE ORDER & HYPERTROPHY - - - 37

COMPOUND VS ISOLATION LIFTS - - - 37

LARGE VS SMALL MUSCLES - - - 37

PRE-EXHAUSTION - - - 38

INDIRECT EFFECTS - - - 39

LIFTING PERFORMANCE - - - 39

JOINT STRESS - - - 40

STRENGTH GAINS - - - 40

INTERSET REST - - - 41

INTERSET REST & HYPERTROPHY - - - 42

LIFTING PERFORMANCE - - - 42

METABOLIC STRESS - - - 43

ANABOLIC HORMONES - - - 45

PRACTICAL CONSIDERATIONS - - - 45

TIME EFFICIENCY - - - 45

JOINT STRESS - - - 46

EXERCISE SELECTION - - - 46

REFERENCES - - - 48

PROXIMITY TO FAILURE

Proximity to failure in the simplest sense refers to how close a set is taken to failure This can be quantified using the Reps in Reserve (RIR) or Rate of Perceived Exertion (RPE) scales (Table 1.1) These are subjective scales that require trainees to judge how many reps they could have performed before failure Therefore, it is a subjective estimation of proximity to failure and may be influenced by many individual factors Both scales quantify proximity to failure in the same way, they are just different numerical systems

RATE OF PERCEIVED EXERTION (RPE) REPS IN RESERVE (RIR) MEANING

10 0 NO MORE REPS COULD HAVE BEEN

PERFORMED

9 1 1 MORE REP COULD HAVE BEEN PERFORMED

8 2 2 MORE REP COULD HAVE BEEN PERFORMED

7 3 3 MORE REP COULD HAVE BEEN

PERFORMED

6 4 4 MORE REP COULD HAVE BEEN PERFORMED

5 5 5 MORE REP COULD HAVE BEEN

PERFORMED

4 6 6 MORE REP COULD HAVE BEEN PERFORMED

3 7 7 MORE REP COULD HAVE BEEN

PERFORMED

2 8 8 MORE REP COULD HAVE BEEN

PERFORMED

1 9 9 MORE REP COULD HAVE BEEN PERFORMED

Several studies have investigated the validity of these scales with all studies finding positive results This study (Zourdos et al., 2021) found that when performing the squat with 70% 1RM to failure, trainees were accurately able to predict repetition

in reserve using the RPE scale It was also found that as trainees got closer to failure, repetition in reserve predictions were more accurate There also seemed to be some

ACCURACY

TABLE 1.1: RPE & RIR SCALES

individual variation in how accurate trainees were able to judge proximity to failure, which was not related to training experience

Furthermore, this study (Helms et al., 2017) explored the accuracy of using the RPE scale in powerlifters performing the squat, bench press, and deadlift Overall, trainees could accurately self-select loads to meet a prescribed RPE It was also found that the accuracy of these predictions was increased when sets were taken closer to failure, and when trainees had been using the scale for multiple successive weeks

Therefore, the RIR and RPE scales seem to be valid tools to assess proximity to failure It also seems that estimations are more accurate as sets are taken closer to failure, and as trainees accumulate experience using the scales

Proximity to failure also depends on lifting technique For hypertrophy training, trainees generally want to use a technique that maximally stresses the target muscle, not necessarily the technique that allows us to lift the most weight Therefore, if technique deviates, trainees can probably perform more reps or load compared with strict technique For example, when a trainee is getting close to failure in a set of biceps curls with strict form, if they start to swing the weight using momentum, then they can probably perform more reps than if they kept the technique strict This has implications for proximity to failure as it is relative to the technique used In other words, trainees should never break their form at the expense of increasing reps performed

Proximity to failure is also independent of each set This is because workouts are not performed in a ‘vacuum’ so to speak One set will induce fatigue, which will impact the following sets and following exercises Therefore, performance will likely decrease from set to set, and throughout the course of a workout

For example, let’s say a trainee performs three sets of bench press with a load of 70kg and takes each set to a proximity to failure of two reps in reserve In their first set, 10 reps may be performed in a fresh state In the second set, 9 reps may be performed with the same load with two reps in reserve In the third set, they may only perform 8 reps with the same load and same proximity to failure As the trainee becomes more fatigued with each set, performance starts to decline (Table 1.2) If this trainee were to perform 10 reps on each set, they would end up training at a TECHNIQUE

SET BY SET

‘Motor unit’ is a collective term to describe a motor neuron and the muscle fibres that it innervates Each muscle generally has multiple thousand muscle fibres and hundreds of motor neurons Each motor neuron is responsible for the control and contraction of the specific muscle fibres that it innervates

Some muscle fibres are larger and stronger which are often referred to as ‘fast-twitch’ or

‘type 2’ fibres Other fibres are smaller and weaker but have greater endurance capacity, which are often referred to as ‘slow-twitch’ or ‘type 1’ fibres Fast-twitch fibres and their associated motor neurons are referred to as ‘high-threshold’ motor units, while slow-twitch fibres and their associated motor neurons are referred to as ‘low-threshold’ motor units

Motor units are recruited based on force requirements Greater force demands require more motor units to be innervated, while lower force demands require fewer motor units to be innervated The strength of the neural impulse does not change with the magnitude of force requirements, rather the number of motor units recruited will be adjusted This is known as the ‘all or nothing’ principle of motor unit recruitment

This has implications for resistance training and hypertrophy adaptations When a lighter load is used, a smaller portion of motor units will be recruited since force demands are lower When a heavier load is used, a larger portion of motor units will

be recruited since force demands are greater Therefore, fewer muscle fibres are initially trained using lighter loads, while more muscle fibres are initially trained using heavier loads

‘ALL OR NOTHING’ PRINCIPLE

TABLE 1.2: PERFORMANCE DECLINE WITH SUBSEQUENT SETS

The order of motor unit recruitment follows what is known as ‘Henneman’s Size Principle’ According to this research review (Mendell, 2005), the size principle suggests that low-threshold motor units are always recruited first, while high-threshold motor units are only recruited when required Therefore, if a submaximal exercise is performed until exhaustion, only low-threshold motor units will be recruited initially, and high-threshold motor units will contribute more as the exercise nears exhaustion By the end of the exercise bout, all motor units will be recruited

to contribute to force production (Figure 1.1)

Concerning resistance training, this determines the amount and type of muscle fibres that are trained According to this research review (Duchateau et al., 2006), all motor units are recruited from the first repetition with loads of approximately 85% 1RM and greater, although this varies between muscles This means that when loads are lighter than this approximate threshold, not all muscle fibres will be involved from the start of the set

However, this study (Morton et al., 2019) showed similar type-2 muscle activation when performing leg extension with 30% or 80% 1RM, when sets were taken to failure This suggests that although heavier loads will recruit more muscle fibres initially, all muscle fibres will eventually be recruited and trained when sets are taken close enough to failure

SIZE PRINCIPLE

FIGURE 1.1: HENNEMAN’S SIZE PRINCIPLE

First, is a simple binary decision: should we take sets to complete failure, or should

we leave reps in reserve? This meta-analysis (Grgic et al., 2021) found no significant difference in muscle growth when comparing training to failure versus non-failure Although these results were non-significant, there did seem to be a slight benefit in favour of training to failure on a set-by-set basis

When all other variables are equated, training to failure seems to be more hypertrophic than non-failure training However, in practice, trainees generally perform an entire workout in the gym rather than a single exercise Therefore, the indirect influence of training to failure on muscle growth should also be considered Frequent or inappropriate training to failure may result in excessive fatigue For example, training to failure with exercises performed at the beginning of the session may carry fatigue into the rest of the workout This may lead to a less productive training session and may inhibit the performance of subsequent sessions

How close a set is taken to failure will also depend on the rep ranges and loads used According to the principles of motor unit recruitment, heavier loads will involve more muscle fibres earlier in the set, while lighter loads will only recruit slow-twitch muscle fibres initially However, to maximise hypertrophy, all muscle fibres need to

be recruited and trained to induce adaption

This study (Lasevicius et al., 2019) compared performing leg extensions with different loads and different proximities to failure Subjects trained one limb to failure and the other limb with approximately 3-4 repetitions in reserve One group of subjects used a load of 30% 1RM and another group used a load of 80% 1RM It was found that training to failure with either load resulted in similar hypertrophy Similar hypertrophy was also seen between the limbs using 80% 1RM despite the difference in proximity to failure However, the limb training to failure using 30% 1RM saw significantly greater muscle growth than the limb training further from failure (Figure 1.2) It therefore seems that when training with heavier loads, sets

do not need to be taken as close to failure to elicit significant muscle hypertrophy Alternatively, lighter loads probably need to be taken closer to failure to ensure all muscle fibres are stressed, thus maximising hypertrophy adaptations

FAILURE VS NON-FAILURE

REP RANGES & LOAD

As a result of such outcomes, this research review (Schoenfeld & Grgic, 2019) suggests that when training in the approximate 6-12 rep range, stopping several reps before failure doesn’t seem to compromise muscle growth compared with training to failure However, when training with lighter loads in the 12-20+ rep range, sets should be taken between 0-2 reps in reserve to ensure the highest threshold motor units are recruited

Certain exercises may be more suited to different proximity to failure ranges This is more of a practical consideration, rather than a scientifically based theory

It is probably more appropriate to train further from failure with heavy, compound, free-weight lifts that are highly centrally fatiguing Exercises like squat variations, weighted pull-ups, military press, and deadlift variations involve many accessory and stabiliser muscles This will be more taxing on the cardiovascular and respiratory systems, and fatigue accessory and stabiliser muscles resulting in greater total fatigue with each set Consequently, if sets are taken very close to failure, the performance of subsequent sets and subsequent exercises may be compromised Furthermore, these exercises are generally performed with lower rep ranges and heavier loads, which means the hypertrophic effect will be similar, even if several repetitions are left in the tank For these reasons, it seems more appropriate to train EXERCISE SELECTION

FIGURE 1.2: CHANGE IN QUADRICEPS CROSS-SECTIONAL AREA (LASEVICIUS ET AL., 2019)

In opposition, it seems more appropriate to perform lighter isolation lifts closer to failure This is because isolation lifts involve movement of only one joint, and only one primary muscle is being trained Therefore, fatigue is localised to the target muscle, while central fatigue is minimal Consequently, the target muscle will almost always be the limiting factor to performance Furthermore, isolation lifts are generally performed with higher rep ranges and lighter loads This means that sets need to

be taken closer to failure to maximise the hypertrophic stimulus For these reasons,

it seems more appropriate to train slightly closer to failure with lighter isolation exercises

• When training in the 6-12 rep range, sets should mostly be taken around 1-3 reps in reserve

• When training with greater than 12 reps, sets should mostly be taken to around 0-2 reps in reserve

• Only a small portion of a trainee’s total number of sets should be taken to failure These sets should be performed at the end of the session to prevent reductions in training quality for the rest of the session

• Training to failure should be mainly performed in isolation exercises rather than compound lifts, to avoid excessive systemic fatigue

PRACTICAL GUIDELINES

REP RANGES & LOAD

The rep ranges used will determine what loads are used and vice versa This is because there is an inverse relationship between the load used and how many reps can be performed (Figure 2.1) In other words, lighter loads allow higher rep ranges to be used, while heavier loads limit rep performance potential

As previously discussed, motor unit recruitment follows the size principle, where low threshold muscle fibres are recruited first, and high threshold muscle fibres are recruited last (see ‘Proximity to Failure’ chapter) It was also established that heavier loads recruit

a higher number of muscle fibres from the start of the set, while lighter loads only exhaust the high threshold motor units by the end of the set

With this principle in mind, it seems that a large spectrum of rep ranges can be used for hypertrophy training since all rep ranges will eventually train all muscle fibres if taken close enough to failure This meta-analysis (Schoenfeld et al., 2017) showed that hypertrophy

FIGURE 2.1: RELATIONSHIP BETWEEN LOAD LIFTED & REPETITION PERFORMANCE

can be equally achieved using a spectrum of different rep ranges and loading zones when sets were taken very close to failure

It has been established that hypertrophy can be achieved using a large spectrum of rep ranges and loads, however, is it possible for loads to be too light or too heavy for optimal hypertrophy gains?

This study (Lasevicius et al., 2018) showed that training with loads of 20% 1RM was not

as effective for muscle growth as heavier loads However, the subjects who used loads of 20% 1RM performed around 60-70 reps per set on average, making it very impractical to perform anyway Therefore, it seems that very light loads may be inferior for muscle growth compared with moderate and heavier loads

While it seems that loads can be too light to maximise hypertrophy adaptations, can loads also be too heavy? This study (Schoenfeld et al., 2016) compared the effects of training

in the 2-4 rep range compared with the traditional 8-12 rep range on hypertrophy outcomes With the total number of sets equated, the group training in the 8-12 rep range saw superior muscle growth Therefore, it seems that if loads are too heavy, hypertrophy adaptations may also not be ideal This could theoretically be because very low rep ranges may not provide enough total mechanical tension and metabolic stress to fully exhaust the muscles being trained

The nature of the lift should also be considered when selecting rep ranges and loads Compound lifts involve movement of multiple joints and require active contraction of more total musculature This increases the likelihood of other systems limiting performance before the target muscle The cardiorespiratory system, or accessory and stabiliser muscles may fatigue before the target muscle Since higher rep ranges require sets to be taken close to failure, this may not be achieved with compound lifts However, during isolation lifts, the target muscle will almost always be the limiting factor regardless of the rep ranges employed This is because there are minimal other muscle groups involved, and the cardiorespiratory system will not be significantly fatigued Furthermore, it may be advisable

to limit the load used on isolation lifts because stress will be concentrated on a single joint, which may increase the risk of pain or irritation over time Therefore, compound lifts may

be better suited to lower rep ranges, while isolation lifts may be better suited to higher rep ranges

Another consideration when selecting loads and rep ranges is their effect on joint health Anecdotally, heavier loads generally tax the joints to a more significant degree than lighter loads, meaning that high volumes of heavy load training may cause joint irritation over time This is probably due to the higher force demands incurred when using heavier loads, resulting in greater joint stress It is therefore important from a longevity standpoint, to avoid excessive training with heavy loads

VOLUME

The next variable that will be discussed is training volume More specifically, the influence

of volume on hypertrophy adaptations will be discussed, and how much volume may be best to maximise muscle growth

First, volume needs to be defined and quantified Volume for resistance training is a measure of how much work we perform over a given period This is usually measured over the time course of one microcycle because this is the shortest repeatable cycle in a training plan In most cases, the microcycle is one week long, which means volume is generally measured over the time frame of one week Two primary methods can be used to quantify volume for resistance training which we will now cover

Volume load is the most accurate definition of work performed and is calculated by multiplying reps x sets x load x distance that the weight has moved Volume load might be a somewhat useful metric for strength training; however, it is probably not the most useful method to quantify volume for hypertrophy training This is because

it is clear from scientific research, that hypertrophy can be equally achieved across

a spectrum of different rep ranges and loads, different exercises, and different techniques Therefore, volume load won’t provide a metric that can be used to compare different training strategies, it can only be used to compare the same training style with itself

It is understood that muscle hypertrophy can be equally achieved using a variety of training styles This has led to the development of using number of sets as a method

to quantify volume for hypertrophy training This systematic review (Baz-Valle et al., 2021) concluded this is certainly a viable method when sets are taken close to failure within the 6-20 rep range Trainees can therefore use the number of sets performed per muscle group per week as a method to quantify volume This allows trainees to compare and manipulate volume using different styles of hypertrophy training Therefore, for the rest of this book, volume will refer to the number of sets performed per muscle group per week

The volume-hypertrophy relationship is not completely clear, and more research is required

to further understand how volume influences muscle growth The most comprehensive evidence exploring the influence of volume on hypertrophy is this meta-analysis

(Schoenfeld et al., 2017) This meta-analysis demonstrates a dose-response relationship between training volume and muscle growth In other words, the more volume that was performed, the more muscle growth that was induced However, this analysis grouped studies into categories of 5, 5-9, 9+ and 10+ sets per muscle group per week From a practical perspective, 10 sets per muscle group per week is generally not considered a very high training volume in most hypertrophy-based training communities Therefore, it should be considered if training with more volume than this would continue this dose-response relationship

Since that meta-analysis was published, further research explored the effects of much higher training volumes This study (Brigatto et al., 2019) compared the hypertrophic effects of training with 16, 24, and 32 sets per muscle group per week (Figure 3.1) Like the initial meta-analysis, a dose-response relationship was found, where more volume resulted in greater growth at all sites measured

Furthermore, this study (Schoenfeld et al., 2019) compared performing the same program with different volumes Subjects were allocated to one of three groups using a low-, moderate- and high-volume program In the group that trained with the highest volume, some muscle groups were trained with up to 45 sets per week Once again, the same dose-response relationship was seen, where more volume even up to these extreme levels resulted in greater muscle growth in all muscles measured

From the current research, it certainly seems that hypertrophy can be achieved even with

FIGURE 3.1: CHANGE IN MUSCLE THICKNESS (BRIGATTO ET AL., 2019)

Another factor to consider is the individual response to training volume While the research on volume clearly shows that more volume results in greater growth, these results are presented as average values Therefore, it seems that the response to different training volumes may be somewhat individual

Going back to the study (Schoenfeld et al., 2019) using extremely high training volumes of up to 45 sets per muscle group, the individual response of each trainee was presented In this figure (Figure 3.2) we can see the change in muscle thickness for the biceps and triceps for each trainee Each line shows the muscle thickness from pre- to post-training, for each individual subject Although we can see that there are general trends, there is certainly some individual variation in the growth response Some trainees saw more growth than others with different volumes, and some trainees saw decreases in muscle size This data suggests that there is likely to be some variation in the individual response to different training volumes

One factor influencing this individual response may be the subjects training history This interesting study (Scarpelli et al., 2020) explored the effects of increasing training volume with consideration for prior training history The subjects performed different volumes of leg extensions for each limb One limb was assigned an arbitrary

22 sets per week, while the other limb was trained with an individualised training volume This volume was 20% more than whatever training volume they had previously been training with for the quads The arbitrary 22 sets were more volume than some trainees had been previously training with and less for others However, for the individualised training limb, the volume performed was slightly more than INDIVIDUAL RESPONSE

FIGURE 3.2: INDIVIDUAL CHANGES IN MUSCLE THICKNESS (SCHOENFELD ET AL., 2019)

they had been training with for every single individual Although both training interventions used a similar average volume, the individualised limb saw significantly greater muscle growth than the arbitrary 22 sets This indicates again that increasing training volume seems to result in greater muscle growth, although increasing volume relative to prior training history may be more effective

As it seems from the scientific research, more volume appears to result in greater growth, especially when this increase is relative to training history However, all these studies use relatively short-term interventions Most of them are between 4 to 8 weeks long, and at maximum 12 weeks long Furthermore, these results don’t include subjects that dropped out or any negative consequences of the training intervention Trainees need to manage training volume for months and years on end, rather than looking at training in a vacuum

of 4-8 weeks There are inevitably limitations to how much volume can be performed at any given point in time

Ultimately, there is a limit to how much stress each joint can handle over any given time frame Training with volumes beyond this threshold will result in joint pain or irritation in the short term and may result in chronic injury if this stress persists Joint tolerance will vary between individuals and between different joints for the same person based on factors such as anatomical structure, training history, injury history, perception of pain, exercise selection, and external load

Furthermore, the acute risk of injury is elevated when we experience sudden changes in workload This study (Hulin et al., 2014) found that cricket players who experienced drastic increases in bowling load in a short timeframe were associated with higher injury rates This study (Hulin et al., 2016) found a similar result in rugby players, where sudden spikes in running workload were associated with increased injury risk Furthermore, this same study (Hulin et al., 2016) found that high chronic workloads were associated with greater resilience to injury Therefore,

it seems that tissues can adapt over time to tolerate more stress

Although these studies were not conducted in a resistance training context, the principles of workload are likely universal to all forms of physical stress From this data, we can extrapolate some recommendations for resistance training First, trainees should avoid sudden changes in training volume over short timeframes as this will increase the likelihood of joint pain Second, tissues can adapt over time to

JOINT TOLERANCE

is ultimately a limit to how much stress each tissue can handle each week, and trainees must stay below this threshold

The second factor which may limit total volume is systemic fatigue Systemic fatigue

is a very vague and non-specific concept This refers to the recovery capacity of the entire organism, including all forms of stress Like the principles of joint tolerance, there is only a finite amount of stress individuals can handle at any given point in time, and breaching this threshold will have negative health and performance consequences Breaching systemic capacity will increase the risk of illness, inhibit lifting performance, and may have negative effects on hormone regulation and essential bodily functions Total workload is one contributor to systemic fatigue, but other stressors include work stress, family and relationship stress, sleep (or lack thereof), and other physical activity

Inevitably, there is a threshold of how much volume each trainee can handle before breaching this systemic threshold and experiencing negative outcomes This is generally something that accumulates over a chronic period rather than an acute timeframe This means trainees may be able to handle a certain level of stress for a short time frame, but it may only result in negative effects after multiple weeks or months Like any other human system, our systemic capacity can likely increase over time, allowing trainees to tolerate greater training stress This may allow more volume to be performed over time before breaching the systemic capacity However, there is ultimately still a threshold of what is too much and, trainees should avoid performing so much volume that they breach this capacity

The last factor that could potentially limit training volume is practicality This refers

to the constraints of each trainee’s lifestyle This is influenced by factors such as time available to train, willingness to train, participating in other forms of exercise, and personal preference These constraints may limit how much volume we can perform in any given week For example, a trainee may only be able to train 3 times per week for around one hour due to their lifestyle and preference Therefore, there

is only so much volume that that can be performed within these time constraints

As it is understood, more volume generally results in greater muscle growth, especially when it is individualised based on training history However, volume is likely to be limited

by one of three factors previously discussed Ultimately, there is only a finite amount of

SYSTEMIC FATIGUE

PRACTICALITY

volume each trainee can perform each week Therefore, it is recommended that volume is allocated based on preference In other words, more volume should be allocated to muscle groups that the trainee wants to specifically develop, and less volume to muscles that they aren’t as concerned with developing These preferences can also be changed over time based on the individual’s specific goals and rate of progress As more volume is allocated

to certain muscle groups, they are more likely to experience a faster rate of growth

• If the goal is to increase volume, trainees should very gradually increase this over time, avoiding sudden spikes

• There are multiple factors which are likely to limit our total weekly workload, including joint tolerance, systemic fatigue, and practical limitations, and trainees should maximise volume within their own personal constraints

• Allocate volume based on personal preference, to emphasise certain muscle groups over others

• Continuously adjust training over time based on the individual response to different volumes

PRACTICAL GUIDELINES

FREQUENCY

Training frequency refers to how often a muscle is trained This is usually quantified as the number of times a muscle is trained per week since most people follow the same training split each week Therefore, for the remainder of this chapter, frequency will refer to the number of times a muscle is trained per week

When discussing frequency, a major caveat needs to be clarified When comparing different training frequencies, it is assumed that volume is equated More specifically, the total number of sets must be equated between conditions This is because it is quite clear that volume has a significant influence on muscle growth, so changes in volume as a result of changes in frequency will likely influence hypertrophy outcomes Therefore, for the remainder of this chapter, it is assumed that volume is equated between different frequencies

When discussing frequency, it is generally applied to how many times a muscle group is trained directly However, it is often the case that muscles can be trained indirectly through exercises in which the muscle is not a prime mover The muscle will not be stressed to the same extent as when it is trained directly, but it may still receive a slight hypertrophy stimulus While this is not a significantly important consideration, it should just be understood that frequency is not a black and white topic However, for this chapter frequency will only refer to direct training for each muscle group

Several studies have investigated the influence of frequency of muscle growth The latest meta-analysis on this topic (Schoenfeld et al., 2019) concluded that training frequency had no significant influence on muscle growth However, this was under the condition that volume – as calculated by the number of sets per muscle group – was equated between frequencies Therefore it seems that if the same total weekly volume is performed, it doesn’t make much difference how many times this is distributed throughout the week (Figure 4.1)