Written by Kiel DiGiovanni | Co-founder
Fact checked by Kirsten Yovino, CPT Brookbush Institute
FACT CHECKED
A constant debate in the fitness world centers around training protocols. An often-asked question is “should I train each muscle group once or twice a week?”. The scientific evidence says that training each muscle group twice a week is optimal. Many in the fitness world still believe that the training frequency of once a week is better. In this article we will look at some studies that have proven the twice weekly protocol is better for muscle hypertrophy and strength. We’ll also give you a few sample programs that fit the 2x/week frequency.
Should I Train Each Muscle Group twice Per Week?
An overwhelming yes! There have been numerous studies conducted to determine the effects of training frequency. There’s a preponderance of evidence that says training each muscle group twice weekly leads to more muscle gains. In 2016 a meta-analysis was done by well-known researchers in the fitness world; Brad J Schoenfeld, Dan Ogborn , James W Krieger. The results were pretty clear. They looked at resistance training frequency and the results on hypertrophic outcomes. They concluded that training each muscle group twice weekly promoted superior hypertrophic results when compared to training each muscle group once a week.
So, does this mean that training each muscle group three times a week is better than twice a week? There’s no evidence to suggest that this is true. It is speculated by researchers that training muscle groups two times a week allows them adequate time to be repaired and recover before stressing them again.
Benefits of Training Each Muscle Group Two Times a Week
Briefly touched on above, there are a number of benefits to training each muscle group twice a week. Let's look at a few of the main benefits below.
- More strength/muscle gain periods: It’s been shown that the higher volume of training a specific muscle group results in more muscle hypertrophy (to a specific degree). Taking this into consideration the high training frequency means your muscles have more chances to be stimulated to grow. If you train a muscle group once a week, you have around 52 possible growth periods yearly compared with 104 growth periods if you train each muscle group twice a week. For most natural lifters, or anyone who lifts weights the best frequency is to work each muscle group twice weekly.
- Variety of Workout Programs: When training each muscle group once per week you’re limited to specific splits. Monday Chest Day, Tuesday Leg Day etc. By hitting each muscle group twice a week you have multiple options of workout programs including; upper/lower body splits, PHUL workouts, PHAT workouts and even full body workouts. This also enables you to perform different types of exercises such as big compound lifts and isolation exercises all at different set and rep ranges. The variety will help to stave off boredom of going through the same routine over and over.
- Increased Muscle Hypertrophy: Studies have shown an increase of 3.1% muscle hypertrophy for lifters hitting muscle groups two times a week compared with those only targeting each muscle group once a week. Over the course of one year this incremental increase compounds, leading to some serious gains.
What is muscle protein synthesis?
Muscle protein synthesis (MPS) is a naturally occurring process of building muscle protein. MPS is increased when you consume protein, it is digested into amino acids. These amino acids are then absorbed by the gut then move into the blood stream. The amino acids are delivered throughout your body where they are used to build muscle tissue protein.
The counteracting side of this process is called muscle protein breakdown or MPB. Also known as muscle proteolysis or muscle degradation, MPB is the process where protein is lost as a result of exercise.
Both muscle protein synthesis and muscle protein breakdown never stop but the speed at which they operate can increase or decrease. If the muscle protein synthesis surpasses muscle protein breakdown, then the muscles will grow. If muscle protein breakdown exceeds muscle protein synthesis, then there will be a loss in muscle mass.
Protein Synthesis and Muscle Hypertrophy
Now that you know a little about protein synthesis, we will show you its relation to muscle hypertrophy and training frequency. This study showed that protein synthesis remained elevated for 36-48 hours then returned to baseline. This period of time tells us that the twice a week training frequency is aligned with protein synthesis. If you are only training each muscle once a week then there’s a five-day lapse of any potential muscle gain.
People often think that muscle soreness means more muscle growth. However, new science suggests that the DOMS (Delayed Onset Muscle Soreness) is pain from connective tissue inflammation and isn’t necessarily related to muscle soreness or muscle tissue damage.
In order for muscle to grow the amount of muscle protein synthesis has to be greater than the amount of muscle protein breakdown. Ideally you should keep muscle protein synthesis at a high level if you want to build muscle.
How to train each muscle group two times a week
There’s a number of workout programs that can fit the bill of training each muscle group twice a week. Below are a few sample workout routines from three day splits up to 6 day splits. The aim should be to get between 10-20 sets per muscle group per week.
|
|
3 Day Split Full Body |
4 Day Split Upper/Lower |
5 Day Split Powerbuilding |
6 Day Split Push Pull Legs |
|
Monday |
Full Body |
Lower Body |
Upper Body Power |
Push |
|
Tuesday |
Rest |
Upper Body |
Lower Body Power |
Pull |
|
Wednesday |
Full Body |
Rest |
Rest |
Legs |
|
Thursday |
Rest |
Lower Body |
Upper Body Hypertrophy (Back/Biceps/Forearms) |
Rest |
|
Friday |
Full Body |
Upper Body |
Upper Body Hypertrophy (Shoulders/Chest/Triceps) |
Push |
|
Saturday |
Rest |
Rest |
Lower Body Hypertrophy |
Pull |
|
Sunday |
Rest |
Rest |
Rest |
Legs |
Training Each Muscle Group Once a Week vs Twice a Week
Many competitive bodybuilders are sticking to their guns about targeting specific muscle groups once a week. However, the truth is that if your end goal is strength and muscle hypertrophy in a shorter time period then training each muscle group once a week just won’t cut it. Your muscles don’t need a week to recover from a workout. The reality is that your muscles will recover within 24 hours from a light workout and within 48 to 72 hours from an intense workout. This time frame closely aligns with peak muscle protein synthesis. There are other factors in determining your recovery time such as nutrition, genetics, overall health, supplementation, stress, training intensity and volume.
Training Frequency FAQs:
What about training each muscle group more than twice a week?
If training each muscle group twice a week is great for muscle hypertrophy then why not up it to three or four times a week? The science is out on this as there is no evidence supporting the idea of training each muscle group 3-4 times a week will lead to positive results. This study compared two groups of people; one group hit each muscle group twice weekly while the other group targeted each muscle group 4 times a week. The results showed no increased muscle hypertrophy by doubling the training frequency.
That said, some people might have the capacity to handle training muscle groups more than twice weekly with positive results. It should also be mentioned that different muscles have different recovery periods. For example, the biceps will recover faster than the quads.
Who should workout each muscle twice a week?
Most people who regularly lift weights should be training each muscle group twice a week. This rings true especially for intermediate and advanced lifters as their bodies are accustomed to higher frequency training regimens and they usually have similar end goals to build muscle or get stronger. The science is clear that targeting the same muscle group twice a week is the best training protocol. The more current successful resistance training programs are centered around this philosophy. Other lifting frequencies might also work but the 2x/week method has the best results for building muscle and increasing strength.
Who shouldn’t train each muscle group twice per week?
Weight lifting newcomers or those just beginning their fitness journey. Instead, beginners should start their fitness journey by doing full body workouts 2-3 times a week. The start to a weight lifting journey is all about getting the technique and form perfected. This will help to forge a muscular foundation to build upon before moving into a more serious training schedule.
Generally speaking, the twice a week frequency of targeting the same muscle groups means there will be bigger compound lifts involved where technique is everything. It’s also worth mentioning that beginners should be able to put on muscle without hitting plateaus relatively easily if training and eating properly. Therefore, there’s less need for them to put their bodies through the same intensity and volume of lifts to see progress. Also, determine how long a workout should be before committing to a plan. If you don't have much time, then a 6-day split will not be the best way to hit your muscle groups twice weekly.
How many exercises per muscle group should I do?
This will depend on your training frequency but we will assume we are following this blog topic and working each muscle group twice a week. If you’re doing 2-3 sets per exercise then you should aim for 5-8 exercises for one workout. The main goal here is to keep the total sets per muscle group around 20 or under per week.
A few variables will determine the number of exercises you will do per muscle group. However, this study showed that larger muscles such as the back and quads require 90-120 total reps weekly.
The smaller muscle groups like biceps or triceps require 50-70 reps weekly. These numbers serve as a baseline because if you’re lifting heavier weights then the number of total reps needed will decrease.
To put this into practice, the best number of chest exercises per workout vs bicep exercises will differ.
Related: How Many Reps, Sets & Exercises Should I do per Muscle Group?
Why do bodybuilders train one body part a day?
Bodybuilders might only train one body part each workout session so that they can hone in on the particular area. By focusing only on one body part at a time they are able to work it with a high volume and at a high intensity. The sport of bodybuilding is based on body composition not necessarily muscle strength. Therefore, they're trying to improve their aesthetics. Although muscles might grow slower by only working them once weekly it will enable them to fix any asymmetries that are present in the musculature. Training one muscle group once per week can still lead to strength and muscle hypertrophy but it will take longer.
How long does it take to build noticeable muscle?
So, just how long does it take for muscles to grow? This is a subjective question so there isn’t a clear-cut answer. The amount of muscle you can gain in a certain time frame is dependent on factors such as sex, age, genetics, diet, training intensity, fitness level and training style. Building muscle isn’t a quick and easy process. On the shorter side it could take a month to see a change but it will take closer to 4 months to see a REAL change.
Conclusion
It might be time to leave the “Bro Split” in the past. There’s been a paradigm shift in recent years moving away from the traditional bodybuilding approach of targeting each muscle group once a week. Time and time again studies have shown that training each muscle group should be done twice a week. If you haven't tried training your muscles twice weekly then it's about time you start.
Workout Programs for Training Muscles Groups Twice a Week:
- Full Body Workout Split
- Upper Lower Split
- PHUL Workout Program
- PHAT Workout Program
- The Ultimate 4 Day Workout Split
- The Ultimate 6 Day Workout Split
Related: Full Body Routine vs Workout Splits
Prepare to maximize your gains with our exclusive 12-week hypertrophy training program. Choose between a 4 or 5 day training split and gain 2-12 pounds of muscle over 90 days...
Kiel DiGiovanni
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