There are many different training splits for lifting weights. You can train using a traditional bodybuilding split where Monday is "international chest day" and you only train each muscle group once per week, you can follow an upper/lower body split, or you can even train using full-body workouts.
But which is the best workout routine for building muscle? Let's dive in.
Muscle Training Frequency
Each of these training splits has a different training frequency. Training frequency refers to the number of times that you train a muscle each week. For example, if you follow a traditional bodybuilding split and you only train your chest on Mondays, then that means your training frequency for the chest (pectorals) is once per week. On the other hand, if you perform three full body sessions per week (hitting every muscle on every workout), then each muscle would have a training frequency of 3x per week.
What is the best workout routine for building muscle?
To answer the question of which is the best routine for muscle gain, we need to look at some research. Thankfully we have dozens of resistance training studies to look at that use different training protocols with different frequencies.
For example, a 2016 meta-analysis by Brad Schoenfeld included data from over 10 resistance training studies that directly compare the effects of higher versus lower training frequencies on muscle growth. The results indicated that training each muscle at least twice per week resulted in significantly greater muscle growth than training them just once per week. Additionally, training muscles more than twice per week did not result in any additional benefits.
It's funny, because traditional bodybuilding splits that train each muscle just once per week are some of the most popular types of training splits amongst people looking to build muscle. However, according to this meta-analysis, that type of workout routine probably isn't optimal for muscle growth. In fact, most people would likely make better progress in the gym if they simply trained each muscle at least twice per week.
In other words, according this scientific analysis, a workout routine that trains each muscle twice per week is the best weekly workout routine for building muscle.
Training Frequency vs Training Volume
Now the question that we need to ask is whether the benefits of training a muscle twice per week are inherently due to the effects of training frequency or is it because of other variables like volume?
Thankfully we also have research that gives us insight into this question. For example, a 2019 systematic review showed that training a muscle three or more times per week isn't superior to training it only once per week when the total volume is the same. In other words, when training volume is equated, training frequency does not seem to substantially affect muscle growth. However, when the researchers looked at the effects of training frequency without training volume being equated, they did find a modest benefit for higher training frequencies.
Overall, what these studies really tell us is that training frequency itself doesn’t inherently affect muscle growth. But what they do tell us, is that higher training frequencies allow us to train with more volume which results in better muscle growth. There's ample research showing a positive relationship between training volume and muscle growth , so it makes sense that training a muscle twice per week would be better for muscle growth than training a muscle once per week, if you perform more overall volume.
For example, let's say that you train your chest only once per week on Mondays and you're completely gassed after 10 hard sets for your chest. So your weekly training volume for chest is 10 sets. Now, let's say you start training your chest on Mondays and Thursdays and you perform six or seven sets on each of those workouts. Now your training volume has jumped from 10 sets per week to 12-14 sets per week. Since you're doing more overall hard sets when you train your chest twice per week, you're going to experience better muscle growth!
If you’re someone who really likes traditional bodybuilding splits, you might be thinking, “ok great, but what if I just do 12 to 14 hard sets in one day, would that be the same as performing it in two days?”
And the answer is... no, not really.
Keep in mind that your performance is also incredibly important for muscle hypertrophy. If you've been training for several years and you really push yourself when you're in the gym, then your muscles are probably pretty gassed after seven or eight intense sets. Think about it. If you perform two to three sets of the bench press followed by two to three sets of dumbbell chest presses and then finish that off with two sets of cable chest flies to failure, your chest is going to be pretty pumped and fatigued.
Could you still do more?
Maybe, but your performance is going to suffer because you're already fatigued from the work that you've done. There’s no way that your 15th set of chest for the day is going to be as high quality as your 1st set. You won’t be able to use as much weight and you won’t be able to perform as many reps compared to doing that exercise when you’re fresh. So instead of doing 15 sets of chest in one day, you'd be better off doing fifteen sets for the week and splitting them up into two workouts so that you're fresher and perform better on each individual set.
How often should you lift weights?
In general, training each muscle group at least two times per week is going to be extremely beneficial for building muscle compared to training each muscle group only once per week. If you currently train each muscle group just once per week, then simply split your workouts in half so that you can train each muscle twice per week.
This doesn't mean you have to go to the gym twice as many times as you usually do. You can do this by spending the same amount of time at the gym every single week. For example, let's say you train your chest on Mondays and you train your back on Thursdays and you perform about 12 sets for each. Well, instead try training both back and chest on Mondays and Thursdays, performing about 6 sets for each on both days. By training the muscle groups more frequently (with the same number of total sets), you'll be able to train them with more intensity during each session.
Best weekly workout routine for building muscle
Below are some of our favorite training splits to work each muscle twice per week:
- Going to the gym 3x/week: 1x full body, 1x upper body, 1x lower body
- Going to the gym 4x/ week: 2x upper body, 2x lower body
- Going to the gym 5x/ week: 1x upper, 1x lower, 1x upper push, 1x upper pull, 1x lower
- Going to the gym 6x/ week: 2x upper push, 2x upper pull, 2x legs
Each of these training splits is designed to target every single muscle group twice per week, independent of how many times you go to the gym. Keep in mind that training frequency is not talking about how many times you go to the gym in a week, but rather it refers to how many times you train a particular muscle in a week.
So, whether you go to the gym three times per week, four times per week, or even six times per week, you can design your training program in a way that will allow you to target each muscle twice per week to optimize hypertrophy.
What about overtraining?
For those of you that are absolutely obsessed with the gym, you might be thinking, “well if a frequency of twice per week is better than once per week, then I'm going to train each muscle three or four times per week and make even better gains!” This might sound logical, but all of the available data suggest that a training frequency greater than 2x per week for each muscle doesn’t really result in superior muscle growth.
Let's explore some potential reasons why this is the case.
If you’re somebody who's been training for several years and you really know how to push yourself in the gym, then seven or eight sets per session should be more than enough to truly stimulate and fatigue a muscle group. Ideally, you perform about seven or eight hard sets per muscle group per session, which means that you're doing anywhere between 14 to 16 sets or per muscle per week. Remember, the benefit of greater training frequencies is that they allow you to train with more volume. So in theory, if you take those fourteen or sixteen sets and break them up over three or four sessions, it's not going to provide a much better stimulus for growth than training twice per week because you're still doing the same number of total hard sets per week.
Now, if you want to do significantly more volume and instead of doing two sessions with seven or eight hard sets, you want to do three or four sessions with seven or eight hard sets each, you might run into issues with your recovery.
There are a ton of different variables that influence your ability to recover and some people can definitely handle more training volume than others. However, most people won’t be able to properly recover if they’re trying to perform 20+ sets for every single muscle group. It's just going to be way too much total work. You're better off training with slightly less volume so that you can train intensely and still properly recover.
- Scientific studies show us that training a muscle 2x per week is superior to 1x per week for hypertrophy (muscle growth)
- You can create a workout routine that allows you to train each muscle 2x per week, regardless of how many days per week you go to the gym
- You need to balance your training volume and intensity with your ability to properly recover
1. Schoenfeld, Brad J et al. “Effects of Resistance Training Frequency on Measures of Muscle Hypertrophy: A Systematic Review and Meta-Analysis.” Sports medicine (Auckland, N.Z.) vol. 46,11 (2016): 1689-1697. doi:10.1007/s40279-016-0543-8
2. Schoenfeld, Brad Jon et al. “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 vol. 37,11 (2019): 1286-1295. doi:10.1080/02640414.2018.1555906
3. Baz-Valle, Eneko et al. “A Systematic Review of The Effects of Different Resistance Training Volumes on Muscle Hypertrophy.” Journal of human kinetics vol. 81 199-210. 10 Feb. 2022, doi:10.2478/hukin-2022-0017
4. Schoenfeld, Brad J et al. “Resistance Training Volume Enhances Muscle Hypertrophy but Not Strength in Trained Men.” Medicine and science in sports and exercise vol. 51,1 (2019): 94-103. doi:10.1249/MSS.0000000000001764
5. Baz-Valle, Eneko et al. “Total Number of Sets as a Training Volume Quantification Method for Muscle Hypertrophy: A Systematic Review.” Journal of strength and conditioning research vol. 35,3 (2021): 870-878. doi:10.1519/JSC.0000000000002776