Training frequency is defined as the number of sessions a given body part is trained per week. Traditional bodybuilding workouts have you training each muscle group just once a week. For example.
Mon: Chest, Shoulder and Triceps
Wed: Back and Biceps
Friday: Legs and Abs
In this post we’ll highlight some reasons as to why this method of training each muscle just once a week is sub-optimal.
But before we begin, here are a few thought experiments:
1) If your family was kidnapped and you were told, that you need to add 100 pounds to your squat max within two months, would you squat just once per week?
2) Would you be stronger and build more muscle performing the bench press 52 times a year or 104 times a year?
3) If you had to add an inch to your arms in the shortest time possible, would you train them just once a week?
Intuitively you would answer,
1) No 2) 104 3) No
Yet, that’s not how you train, is it?
“Right, I get what you’re trying to say, we should train our muscles more often instead of the traditional one muscle a week protocol. But what about the research? Thought experiments are cool, but is there any evidence to support this theory”
Yes there is. But let’s establish a few things first.
The Law of Practice:
We often see Olympic Weightlifters train each lift 6 times a week. The law of practice suggests that the more frequently you perform a movement, the better your body becomes at performing it. If you want to play better soccer, you don’t just play more soccer. You play more soccer, more OFTEN. You don’t say, “I’ll just play soccer once a week and spend the rest of the week doing other forms of exercise”.
Think of resistance training as a skill. If you want to get better at a skill, you practice it more often. In every other sport, we encourage practice. Why make weight training an exception?
“But training for strength and muscle is not the same as Olympic Weightlifting”
Yes that’s true, it’s important to look at different sports on a case by case basis instead of making general recommendations for sport as a whole. But as you’ll see, there’s more to this than just practice.
Increased Muscle Protein Synthesis (MPS):
To build more muscle, you need to increase Muscle Protein Synthesis (MPS). In 1995, J.D. MacDougall and his team showed that after a weight training session, MPS remained elevated for approximately 36 to 48 hours, after which it returned back to baseline (1). In essence, if you train your Chest on Monday, you can be rest assured that MPS in your Chest muscles would increase for a couple of days, following which it would return back to baseline by around Wednesday.
Logic would dictate that training your Chest muscles again on Thursday would be more beneficial for muscle growth, than training them after an entire week’s rest.
“What about more volume per session?”
A study published in 2000 showed that increasing volume per workout did not have any additional effect on MPS (2). It’s safe to say, that blasting through each muscle group once a week by performing high number of sets and reps in the typical bodybuilding routine does not lead to more growth through increased MPS. Dividing your volume into smaller, more frequent sessions per week seems like the logical way to go.
The Repeated-Bout Effect:
DOMS (Delayed Onset of Muscle Soreness) is the pain or stiffness felt in the muscles, a few hours or days after performing a stressful activity which the body isn’t used to. DOMS can be an unpleasant experience, and one of the ways to reduce their occurrence and improve recovery is through increasing training frequency.
This seems counter intuitive but can be explained through an interesting phenomenon known as the repeated-bout effect. After performing an unaccustomed activity and developing soreness, muscles rapidly adapt to reduce further damage from the same exercise. This protective effect is called the repeated-bout effect. Interestingly, this effect gradually decreases as the time between sessions increases (3).
Although the mechanisms behind this effect aren’t well understood, this is yet another reason to perform the same exercises more often.
Along with practice, another advantage of a high frequency program is quality repetitions which help in improving technique. Training more frequently increases the opportunity to train fresh under an improved state of neuromuscular activation with minimal fatigue (4). As a workout progresses from set to set, you accumulate fatigue which can lead to a breakdown of technique. This is especially true if you are training just one muscle group. Repetitions of the exercises performed towards the end of a workout tend to get sloppy. Also, you will not be able to move the same poundage on the last few exercises as you would, had you approached those exercises fresh. Besides muscular fatigue you also accumulate neural fatigue, so the same applies for strength training.
“Some of the best bodybuilders in the world train each muscle only once a week. How do you explain that?”
Can you build size and strength by training each muscle just once a week? Of course you can. Is this form of training effective? Yes it is. Is it optimal? We don’t think so, and the current research on muscle growth supports our stance.
Another thing to keep in mind is that given enough time, one can develop a lot of muscle using less effective training methods. Professional bodybuilders have decades of training experience, amazing genetics and they dedicate a lot of time to exercise, nutrition and recovery.
Also, most elite bodybuilders use some form of pharmaceutical enhancement. It is no secret that anabolic steroids and performance enhancing drugs are extensively used, and play a huge role in increasing muscle growth.
In 1997, a study demonstrated a significant increase in strength for individuals training two or three times per week, compared to individuals training just one time per week (5).
In 2000, a study examined the effects of training frequency on muscle growth. Even though volume was kept constant, spreading the training frequency to three sessions per week produced superior results in both strength and muscle growth compared to just one session per week (6).
Perhaps the most intriguing study to demonstrate this is the Norwegian Experiment, also known as the Frequency Project. There was a dramatic difference in both strength and muscle mass for competitive Powerlifters who trained six days per week versus those that trained three days per week. Again all other training variables were kept constant. In fact, the total strength increase in the six days a week group was DOUBLE compared to those training three days a week (7).
And finally Brad Schoenfeld and his team recently demonstrated a significant increase in muscle growth from performing full body workouts three times a week versus the traditional one muscle per week bodybuilding split (8).
In a nutshell, if you’re someone who has been following the traditional one body part per week routine, you may want to try out something like an Upper/Lower split. Don’t go overboard and jump straight into full body workouts every single day. Be patient, assess your recovery potential, understand your limitations and program your workouts intelligently.
1. JD MacDougall et al., “The time course for elevated muscle protein synthesis following heavy resistance exercise,” Canadian Journal of Applied Physiology 1995 Dec;20(3):480-6
2. MJ Gibala et al., “Myofibrillar disruption following acute concentric and eccentric resistance exercise in strength-trained men,” Canadian Journal of Physiology and Pharmacology, 2000 Aug; 78(8):656-61
3. Nosaka, Ken. “Muscle Soreness and Damage and the Repeated-Bout Effect”. In Tiidus, Peter M. Skeletal muscle damage and repair. Human Kinetics, 2008, pp. 59–76. ISBN 9780736058674
4. Hartman MJ, Clark B, Bembens DA, Kilgore JL, Bemben MG.: Comparisons between twice-daily and once-daily training sessions in male weight lifters. Int J Sports Physiol Perform. 2007 Jun; 2(2):159-69
5. DeMichele, P. L., Pollock, M. L., Graves, J. E., Foster, D. N., Carpenter, D., Garzarella, L., Brechue, W., & Fulton, M. Isometric torso rotation strength: effect of training frequency on its development. Archives of Physical Medicine and Rehabilitation, 1997 78(1), 64-69
6. McLester, J., Bishop, E., & Guilliams, M. Comparison of 1 day and 3 days per week of equal-volume resistance training in experienced subjects. The Journal of Strength and Conditioning Research, 2000 14(3)
7. Raastad T, Kirketeig, A, Wolf, D, Paulsen G. Powerlifters improved strength and muscular adaptations to a greater extent when equal total training volume was divided into 6 compared to 3 training sessions per week (abstract). Book of abstracts, 17th annual conference of the ECSS, Brugge 4-7 July, 2012
8. Schoenfeld, BJ, Ratamess, NA, Peterson, MD, Contreras, B, and Tiryaki-Sonmez, G. Influence of resistance training frequency on muscular adaptations in well-trained men. J Strength Cond Res 29(7): 1821–1829, 2015