The driver of all size and strength development is progressive overload. It’s the most important thing you will ever come across in the world of lifting. It’s so important, that without it, you will never be able to achieve the size and strength you want. No matter how much tweaking you make to your training and nutrition.
If you are looking for more size and strength over time, then any resistance training program that you follow, must incorporate progressive overload at its core. Progressive overload ensures that you are doing more work over time, thus pushing your muscles beyond their current limits. By pushing your muscles more, and stressing them to new heights, you force them to adapt in order to withstand and overcome these new training stressors. What follows? As a result of this adaptation, your muscles become stronger and bigger, thus priming them to withstand and successfully overcome the next stimulus. This progressive overload cycle is what guides you to your ultimate size and strength goals.
An important question to ask is: How do I utilise my training in order to overload over time?
So What Are The Progressive Overload Variables?
♦More weight: This is the most obvious one. By keeping the reps, and sets the same and trying to increase the amount of weight you shift over time, you are overloading more. But you can’t just keep increasing the weight indefinitely over time. It’s just impossible! Your body won’t let you.
♦More Repetitions: By keeping the weight the same, and the number of sets. This is also a manner of overload. However, there are so only so many repetitions before you start wasting too much time and energy and, the exercise set is no longer challenging.
♦More Sets: By keeping the reps the same and the weight the same. This is overloading too! However, there are only so many sets you can do per session before this variable starts losing its effectiveness.
♦More Frequency: By increasing the number of times you work each muscle group per week. Increasing the frequency for each muscle group worked, leads to increases in protein synthesis during the entire week. Potentially increasing muscular hypertrophy.
The Case For Training Frequency?
While increasing the number of sets in a given workout counts as progressive overload (keeping reps and weight the same), it might not actually be the best method of doing so, especially past a certain point. It has been suggested that there may be an ‘upper limit’ to the number of effective sets one can do in a given training session. In other words, you reach a point where the anabolic response to your training volume is maximised. Any more, and you are essentially wasting energy, increasing potential times for recovery and, gaining no further increases in muscle growth.
⇒In a study published by Kumar et al (2012), it was found that in 6 young UNTRAINED men, increasing the number of training sets from 3 to 6 (while keeping reps and intensity the same), produced no significant changes in muscle protein synthesis (MPS).
⇒In a study by Hernandez et al (2012), 39 UNTRAINED males underwent 5 weeks of blood flow restricted resistance training (BFRT). They were split into 4 groups: BFRT low-volume, low-intensity (BFRT LV), BFRT high-volume, low-intensity (BFRT HV), traditional high-intensity (HIT) and a control group (CON). The BFRT LV group carried out 3 working sets of 15 repetitions leg extensions, while the BFRT HV group carried out DOUBLE the volume (6 working sets of 15 repetitions leg extensions). After 5 weeks, it was found that the muscle thickness increases of the rectus femoris and vastus lateralis muscles were SIMILAR for both the BFRT LV and HV groups.
⇒In another study by Ostrowski et al (1997), 27 TRAINED men underwent either 10 weeks of LOW volume (3 sets per muscle group per week), MODERATE volume (6 sets per muscle group per week) or HIGH volume (12 sets per muscle group per week) resistance training. In all groups, the exercises, number of training days and intensity were THE SAME. The only thing that changes, was the number of SETS. After the 10 weeks, it was found that muscle size increases were SIMILAR between all three volume groups. Here, increasing the number of sets from 3 to 12 had no additional benefit on increasing muscle size.
♦The bottom line: Increasing the number of training sets in a session may provide increases in muscle size up to a certain point. After this point, more sets (termed here ‘wasted sets’) does not lead to further increases in muscle size. These wasted sets would simply be deleterious to recovery times without providing greater increases in muscular hypertrophy.
Evidence For Increasing Training Frequency
Resistance training is important for size and strength development because it provides the necessary stimulus for growth. Following resistance training there are acute increases in MPS and it is believed these post-exercise increases in MPS are important for supporting protein remodelling in damaged muscle tissue and eventual muscular hypertrophy (McGlory et al, 2016). Furthermore, this post-exercise MPS response seems to differ in magnitude and duration between untrained and trained individuals (this is important for planning frequency!). In untrained individuals, the post-exercise MPS response is longer lived and peaks later than for trained individuals (Damas et al, 2015).
Damas et al (2015). Shows the magnitude and duration of post-exercise MPS in untrained (UT) and trained (T) individuals. Following resistance training, the MPS of the UT peaks later and lasts longer than that of the T individual. A higher training frequency in T individuals will allow for more MPS during the week, while a higher frequency is not needed for UT individuals.
From McGlory et al (2016). Following resistance training there is an increase in translational capacity (cellular mechanisms in muscle cells) as seen from (1). This supports an increase in post-exercise MPS (2). This elevation is MPS plays (short-term effect) a role in protein remodelling (4) (muscle repair) (long-term effect).
This is interesting because it basically tells us that the potential for further muscular hypertrophy is smaller in trained individuals because the extent of protein development in response to a single resistance training session, is now significantly limited. Given that only a small number of sets (~4) are required to elicit a large increase in post-exercise MPS, a smaller number of sets per session will allow for potentially higher training frequencies across the week (Burd et al, 2011).
⇒In a study by Hakkinen and Kallinen (1994), female athletes underwent two resistance training periods. The first 3 week period (first period) consisted of normal intensive strength training, while the following 3 week period (second period) consisted of splitting the same training volume now across TWO DAILY training sessions. At the end of each period, it was found that muscle cross sectional areas and maximal strengths exhibited in the trained muscles during period 2, were significantly GREATER than period 1.
⇒This suggested that splitting your training volume up across more sessions (then all in one session) may provide a more potent hypertrophy and strength-inducing stimulus. It’s likely that by splitting your total volume up across sessions, you avoid the so-called wasted sets that could occur if volume in one session is too high and you exceed the maximal anabolic response.
Modelling Training Frequency In Trained And Untrained Individuals
It’s possible to show how training frequency could be effectively programmed for both trained and untrained individuals in order to optimise muscular hypertrophy. Since trained individuals need to do more work to stimulate further gains in hypertrophy than in untrained individuals, it requires a little more creativity with different training variables to do that successfully (e.g. balancing overload with recovery). As proposed by Dankel et al (2017), trained individuals could benefit from increasing their frequency, by working each muscle group more times per week. Given that post-exercise MPS is shorter in duration in trained individuals, an increased weekly frequency for each muscle group, would lead to more post-exercise MPS. This would increase the time spent in net positive-protein balance (when MPS is greater than muscle protein breakdown). This balance would allow for more protein accretion in trained individuals and thus potentially more hypertrophy over time.
From Dankel et al (2017). Increasing frequency and spreading total volume among more training sessions in a late-intermediate/advanced lifter, would allow for increased MPS during the week (black line), while avoiding ‘wasted sets’ (dotted line) and issues with recovery. If a late-intermediate/advanced lifter was to train with reduced frequency (2x per week), with 9 sets per session, this would likely cause ‘wasted sets’ and increase recovery times (grey line). Resulting in less MPS during the week.
From Dankel et al (2017). In late-intermediates/advanced lifters the anabolic potential is greater when a frequency of 6 days per week is adopted with 3 sets per muscle group in each session (black area). Why? More MPS during the week, less wasted sets, and better recovery, thus overall, more potential for protein accretion and muscular hypertrophy over time.
In order to increase the frequency, overall training volume needs to be considered in order to prevent fatigue and recovery issues. Given that there appears to be an upper-limit for the number of effective training sets in one session (anabolic limit), and that splitting a given training volume across multiple sessions seems to provide a more effective hypertrophic stimulus, then weekly frequency could be increased by performing fewer sets per session (all while providing a better stimulus for hypertrophy).
The benefits of utilising fewer sets in a given training session is two fold:
⇒It prevents TRAINED individuals from exceeding this anabolic limit in a given session (through wasted sets)
⇒Fewer training sets provides for less fatigue and better recovery in time for the next session.
Since the post-exercise MPS is shorter in duration in trained individuals, if their recovery time after a session is extended, they risk a period of time when there is NO MPS occurring (due to not being able to train again until recovered). Over the course of a week then, this can reduce the chances of them being in a net protein balance, thus reducing protein accretion and hypertrophy over the longer-term.
What Happens When Training Frequency Becomes Too High?
Increasing the number of times per week a muscle group is trained might be an effective way to further stimulate hypertrophy in trained individuals (provided total training volume is controlled for). But, what happens when you can’t really increase the frequency anymore? For instance, say you work each muscle group 3 times per week, do you bump that up to 4 times per week? Well, you could! But then your total weekly volume would also go up. The problem is, that might start to really eat into your ability to recovery optimally, negating any potential increased benefits from higher training frequencies. So, what can you do?
⇒Interestingly, Dankel et al (2017) suggest that after training at higher frequencies for a while, it might be possible to drop back down for an extended time, WITHOUT losing the current muscle mass you have built up.
⇒In a study by Bickel et al (2011), seven adults underwent a resistance training protocol that consisted first, a 16-week training period (3 days per week) followed by a 32-week detraining phase. It was found that the hypertrophic benefits gained in the 16-week training period were maintained during the 32-week detraining phase.
⇒In another study by Ogasawara et al (2013), 14 young men underwent either a periodic resistance training program (PTR) or a continuous resistance training program (CTR). Both groups performed HIGH-INTENSITY benchpress at an intensity of 75% 1RM, 3 sets of 10 reps, 3 days per week. The PTR group performed 6 weeks resistance training, followed by 3 weeks of detraining. It was found that the extents of hypertrophy gained in both programs were similar.
⇒In attempting to explain these results, Ogasawara et al (2013) investigated the effects of ANABOLIC SIGNALLING in response to continuous resistance training and detraining in rats. It was found that levels of PHOSPHORYLATION* of various anabolic signalling proteins in response to repeated bouts of resistance training, were significantly reduced. However, after detraining, these levels of phosphorylation were actually restored. This suggested that after periods of high frequency training, dropping back to lower levels might actually serve to re-sensitise muscles to an anabolic stimulus.
*Phosphorylation of these anabolic signalling proteins increases their activity, thus leading to higher levels of protein synthesis. Greater anabolic potential.
So What Is The Verdict On Training Frequency?
As a beginner, it’s pretty simple: you keep a given number of sets and reps and you work on increasing only the weight on the bar for your core compound movements. This you can get away with for 6-12 months before things start slowing down (approaching end of the ‘beginner gains’). As you enter the intermediate stages of training, you will have to start further increasing volume and intensity in order to further stimulate hypertrophy. This will come through a mix of increasing weight, sets and repetitions. Typically for beginners and most intermediates, the post-exercise MPS following training will be elevated and will return back to base levels within 24-48 hours (even less in advanced trainees). For most beginners (and early intermediates), working each muscle group 2/3 times per week is considered optimal training frequency. This can be done through full body workouts, push-pull legs or upper-lower body type training plans. For early intermediates, the focus should be on increasing volume as well as intensity over time (while keeping with a training frequency of 2/3 times per week).
However, you may reach a stage in your lifting career where you need even more volume to push these hypertrophic responses higher. But, there is only so much volume you can do in a single session (e.g. sets) before the law of demising returns start to kick in and recovery and fatigue issues become a problem and start impacting your subsequent sessions. In this case, rather than try to push volume even higher in your training sessions, it might actually be better to increase the weekly frequency at which you work each muscle group, and spreading your current weekly volume across these sessions. Not only would this prevent the law of demising returns, it would allow you to stimulate weekly post-exercise MPS more for each muscle group, thus increasing the potential for hypertrophy. In terms of training, a training split working 1-3 muscle groups per session at this point will more applicable to allow higher training frequencies to be utilised.
Once it no longer becomes feasible to increase frequency anymore, then it might be the case of alternating between periods of high frequency and low frequency for each muscle group in order to re-establish optimal anabolic responses to training stimuli. At this point, you have probably reached an ‘upper threshold’ for volume that you can handle in a given training session and now it’s a case of alternating between high/low training frequency cycles to push out any extra gains before you hit your ‘genetic ceiling’ (but honestly, most of you will never hit it so I wouldn’t worry too much about this!)
♦In my opinion, training frequency seems like a valid way of progressive overload. But ONLY for those of advanced and late-stage intermediate lifters. For most, you won’t be utilising anywhere near enough training volumes in a given session to warrant increasing the training frequency for each muscle group. So, unless you have 10+ years of training experience and more volume in a given training session is just no longer feasible or sensible, I wouldn’t make changing training frequency a priority. For you beginners and intermediates, working on building up more volume and intensity in your sessions, is your key for now! You won’t need to work your muscle groups more than 2/3 times per week at this stage.
Any questions, ask away!