How Frequently Should You Exercise to See Muscle Growth?

"How frequently should you exercise to see muscle growth?" is arguably one of the most commonly asked questions by gym-goers. See what the science has to say!

There are two parts to this question:
  1. How many days per week should you train in the gym?
  2. How many times per week should you train each muscle group?


First things first, how many days per week do you need to train to build muscle?

The answer is, it depends. You can build muscle effectively training 3 times a week. You can also, if you choose, train every day of the week and build muscle. There is no set in-stone, one size fits all, best training split. The number of days you train in the gym depends on various factors. For example:
  • Your work schedule
  • Family commitments
  • Travel itinerary
  • Training experience
  • Goals
  • How important your gym-based goals are relative to other goals/hobbies/activities in your life

With all that said, let me give you some guidelines to work from. With these in place you can then begin to put a plan in place that is specific to your needs.
  • Beginners: Training 3 days per week is ideal for the beginner
  • Intermediates: 3-5 days per week
  • Advanced: 4-6 days per week

As a beginner, you should grow from almost any training program. Even better, you don’t need to do that much to grow. At this stage in your lifting career, building muscle is the easiest it will ever be. You can get a very high return (muscle and strength gains) on your investment (time spent in the gym).

That’s why so many experienced lifters go misty-eyed when reminiscing about the “newbie” gains stage. Sadly, the newbie gains don’t go on forever. The repeated bout effect kicks in and your rate of gains slow down.

The Repeated Bout Effect AKA Diminishing Returns
The repeated bout effect is basically a training specific way of describing the law of diminishing returns. For every training session you repeat, there is a lesser and lesser response from the body. The body is an incredible adaptive mechanism.

As such, a workout that forced it to adapt by building bigger and stronger muscles will become progressively less effective as the body adapts to it. It’s for this reason that your workout routine needs to change from time to time. Training frequency is one such way to create this change.

As you become more advanced and need to do more training to keep growing, adjusting the number of days per week you train is one way of achieving this. It’s for that reason that I have suggested intermediates train a bit more often than beginners and, on average, advanced lifters should train more often than intermediates. It takes more effort to build the final 5 pounds of muscle to reach your genetic ceiling than it does to build the first 5 pounds.

Within each stage of your lifting career you will have to balance all the lifestyle factors I previously mentioned when determining your weekly training schedule, but the fact is, to build muscle your training has to be hard and it needs to get harder over time. This means that in all likelihood you’ll have to train more often to keep progressing as a lifting veteran than you did as a wide-eyed novice.

How Many Times Per Week Should You Hit Each Muscle Group?
Training frequency has traditionally been associated with how many days a week you train. When it comes to building muscle, the number of times a given muscle group is trained per week is probably a more important consideration.

The classic “Bro-split” of blasting a muscle once per week has built a lot of muscle for a lot of lifters, but is it optimal?

The science would indicate it is not. According to the research, splitting the same training volume into more frequent training sessions is superior for hypertrophy. This is likely because the muscle building stimulus is distributed more optimally over the course of the week in higher frequency training approaches.

Based on the weight of evidence it would seem that hitting a muscle group two or three times per week will build a bit more muscle (especially in advanced lifters) than training it once.

Schoenfeld et al. (2016) meta-analysis identified that training a muscle twice per week is better than once per week for hypertrophy. Schoenfeld and colleagues conducted a follow meta-analysis last year after a boom in the number of training frequency studies and hypertrophy.

Their 2019 paper has identified that the difference between training a muscle once, twice, or three times per week was modest. They stated that training frequency was less important than training volume for hypertrophy. This fact has meaningful practical applications.

Given you can build muscle training each muscle group once, twice or even three times per week, your personal preference should be a consideration. From a practical perspective coaching hundreds of clients, I have found that an individual’s motivation to train hard on a given training program is crucial to their success.

If they are excited to train and willing to push themselves to their limits, their results will drastically outperform the most “scientific” program that bores them and they simply go through the motions on.

So, when setting out your training split, be sure to honestly assess if you’re excited and motivated by the prospect of training with this frequency.

Symmetry is Not Always Achieved with a Symmetrical Split
Up to this point, the discussion on training frequency per muscle group has treated every muscle group the same. It would lead you to a symmetrical training split. If quads are hit twice per week, so are hamstrings, chest, back, and all the other muscle groups. I think this is a mistake.

SRA – The Missing Link in the Frequency Puzzle
A muscle goes through a series of processes between training sessions. This can be described by the SRA curve. SRA stands for Stimulus-Recovery-Adaptation.

The straining session is the stimulus, immediately after training the recovery processes begin. Recovery has been achieved when the muscle has returned to baseline levels of capacity. Assuming sufficient rest and nutrients are taken, it will then adapt to new levels of size and strength. These adaptations are miniscule session to session, but they add up over time. This repeated adaptation process is what causes you to build bigger and stronger muscles.

There are numerous factors which come into play when determining a muscle’s SRA curve. These include the muscles:
  • Function
  • Architecture
  • Fiber type ratio
  • Size
  • Amount of damage caused when training it
  • Capacity to tolerate stretch under load
  • Its range of motion
  • How close to failure it is trained

Each individual muscle has its own specific SRA curve. As a result, I think your training frequency should reflect this.

For example, you probably find that your quads take several days to recover after a tough leg workout. They probably won’t have been through the full SRA cycle in under 48 hours. Perhaps it’s more like 72, or even 96 hours before they have recovered and adapted. Your biceps or rear delts, however, are probably good to go within 48 hours of even the toughest upper body session.

Here are some guidelines on training frequency for each individual muscle group that I have found very effective:
  • Chest: 2 x week
  • Quads: 2 x week
  • Hamstrings: 2 x week
  • Back: 3 x week
  • Triceps: 3 x week
  • Biceps: 3 x week
  • Calves: 3 x week
  • Lateral delts: 4 x week
  • Rear delts: 4 x week

As you can see, if you train using the above frequencies your program will not be symmetrical, but your physique might well be.

The Interplay Between Frequency, Volume, and Intensity
Another factor to consider when planning your training frequency is how the other training variables are organized in your training. The other two key variables to consider are training volume and intensity.

Research indicates that adjusting training frequency appears less of a powerful determinant of muscle gain than your overall training volume. As a result, your training frequency should probably be a function of your training volume. Think of frequency as the faucet that allows volume to flow sufficiently to maximize your muscle building. The more volume you need to grow the more frequently you’re likely to need to train (I’ll expand on this later in the junk volume section).

Intensity also has a bearing on how often you can train a muscle. If you always train at very high percentages of your 1-rep max (e.g. 85+%), you might well find that you can’t train muscles as often as another lifter who predominantly trains using their 15-rep max (approximately 65% of 1-rep max).

Another consideration on the intensity front is your relative intensity. Relative intensity is a measure of how close to failure you go. If you take every set to failure then, you will probably be better off using a lower training volume and frequency. On the other hand, if you tend to leave a few reps in the tank on most sets you will likely respond better to higher training frequencies.

Frequency is a Key Tool to Avoid Junk Volume
Junk volume is any training volume that has no additive effect on your results. Several studies have indicated that once enough training has been done in a session to maximize the anabolic pathways doing more is not better.

It appears that adding more training at this point simply increases fatigue and the risk of injury. So, once the muscle building threshold of a session has been met, you’re better off finishing the session or moving on to another muscle group.

The current consensus is that between 5-12 sets per body part per muscle group is enough to max out the anabolic pathways (in beginners this threshold is even lower). Meanwhile, several studies have indicated that muscle growth is enhanced by training a muscle with 10 or more sets per week. Many studies have shown benefits to weekly training volumes well north of 20 sets per muscle group (one even had subjects performing 45 sets per muscle group!).

It is likely that the more advanced you become the more sets per week you will need per body part. Consequently, it seems logical to split the total weekly training volume into as many sessions is needed so as to maximize the muscle building response to each session while avoiding junk volume.

For this reason, your training frequency might well have to increase throughout your career to reflect the need for more overall training volume while eradicating junk volume.

Frequency Should Not Be Set In-Stone
As I have mentioned multiple times, I don’t think training frequency is a fixed, one-size fits all deal. Over the course of your career I think it should change. Even within certain stages of your career I think it should change.

Training frequency is just one of many variables you have available to adjust your training over the long-term to maximize results. Just like you might periodize specific phases of your training to be higher in intensity or volume you can do the same with frequency. For example, a recent training study found increased muscle gains when participants trained each muscle five times per week.

This study was only 8 weeks long so, it would be premature to suggest that always training 5 times a week is best. It might however, provide a very good indicator that training muscles with very high frequencies as part of an overreaching or specialization phase could be very effective.

Key Takeaways:
  • The exact number of training sessions you do per week will be determined by many lifestyle factors and how high a priority you place upon training relative to other activities in your life.
  • You can build muscle training 3-7 days per week.
  • When it comes to hypertrophy the key question is not, how many times per week should I train, but how many times per week should I train each muscle?
  • It seems wise to use a default training frequency of training each muscle 2 times per week.
  • Taking a muscle specific approach to training frequency (based on the SRA curve) might increase your rate of gains.
  • Periods of more frequent training strategically and sparingly used might help to bust through a plateau or specialize on a specific muscle.


References:
Dankel SJ, Mattocks KT, Jessee MB, Buckner SL, Mouser JG, Counts BR, Laurentino GC, Loenneke JP.. Frequency: The Overlooked Resistance Training Variable for Inducing Muscle Hypertrophy? Sports Med. 2017 May;47(5):799-805
Schoenfeld BJ, Contreras B, Krieger J, Grgic J, Delcastillo K, Belliard R, & Alto, A. Resistance Training Volume Enhances Muscle Hypertrophy but Not Strength in Trained Men. Medicine and Science in Sports and Exercise. 2019; (51(1): 94-103
Schoenfeld BJ, Ogborn D, Krieger JW. Effects of resistance training frequency on measures of muscle hypertrophy: a systematic review and meta-analysis. Sports Med. 2016; 46(11):1689-1697
Schoenfeld BJ, Grgic J, Krieger JW. How many times per week should a muscle be trained to maximize muscle hypertrophy? A systematic review and meta-analysis of studies examining the effects of resistance training frequency. Journal of Sports Sciences. 2019; 37 (11): 1286-1295
Zaroni RS, Brigatto FA, Schoenfeld BJ, Braz TV, Benvenutti JC, Germano MD, Marchtti PH, Aoki MS, & Lopes CR. High resistance-training frequency enhances muscle thickness in resistance trained men. The Journal of Strength & Conditioning Research. 2019; 33: 140-151