FITMAG ELITE FEATURE
Stijn van Willigen is an online coach with a bachelor’s degree in Human Movement Sciences and 8 years of experience in the world of weight training and nutrition. His passion is to empower people to get the results they want with scientific fitness principles. A portfolio of his work can be viewed on his Instagram profile @fitfographs (www.instagram.com/fitfographs
This is Part I of this two-part informative research article by Stijn. Part II coming soon!
How often should you train your Glutes?
What you’re getting yourself into:
The best training frequency for muscle growth is a controversial topic. Most elite bodybuilders swear by training a muscle only once a week (Hackett et al., 2013). A recent meta-analysis concluded that working a muscle group twice per week was superior for hypertrophy compared to once per week (Schoenfeld et al., 2016). Still, modern progressive lifters argue that training a muscle multiple times per week gives better results. Bret’s client Erin is a perfect example of this. She’s seen amazing results training the Glutes a whopping 6 times per week!
So, how often should you train the glutes for maximum results? The short answer is 2-6 times per week. The long answer requires you to read on, as there are variables you will need to adjust in order to optimize your recovery and ability to train effectively at a given frequency.
Read the full article on BretContreras web.
“training with a specific volume-matched frequency might be more effective than another volume-matched frequency because the distribution of the hypertrophic stimuli over the course of a training week are optimal in one case and not in the other.”
Basically, it’s saying that spreading out 15 sets for a muscle over several workouts during the week might grow more muscle than doing all 15 sets in one go. Some well-respected experts in the field hypothesize there’s indeed a maximum growth stimulus a muscle can get per workout (Dankel et al., 2016). Say for example the maximum growth stimulus would happen at 6 sets. Any sets beyond that point could be regarded as ‘wasted sets’.
Going from this logic, with a traditional ‘bodybuilding’ split (frequency of training a muscle 1x per week) a lot of these 15 sets would be wasted. Full body routines typically spread the 15 sets out over several days. This may results in less wasted sets per workout. ‘Wasted’ might not be the best terminology for these sets. They could even be labeled as counterproductive, as the extra sets might hamper your recovery from the growth stimulus! More on that later.
If indeed it’s more optimal to train a muscle multiple times per week, over how many days should these 15 sets be spread? 2? 3? 4? 5? 6 days?
According to science, it depends on multiple factors. In this article, I’m going to primarily talk about one of those factors: Exercise Type. By the end of this article, you will understand how exercise type influences and how often you should train the Glutes. I will end by giving some practical advice on how to apply this knowledge to your training.
First, we have to understand the primary underlying concept that dictates the relationship between Exercise Type and training frequency: muscle SRA.
The muscle SRA curve
The S in muscle SRA is for Stimulus. During a training session you break down the muscle, the Stimulus for growth. Because of this, the muscle’s functional size – the part of the muscle that’s still able to contract – decreases. The body will then rebuild the broken down muscle. This is called Recovery, the R in SRA. After the body is done rebuilding, it prevents future breakdown of the muscle from happening. It does this by building the muscle bigger than before. This is called Adaptation, the A in SRA. The muscle is now more resistant to a future Stimulus (a thicker wall needs a bigger sledgehammer to break it down). The following image illustrates this process.
However, if this sledgehammer is too big, it can cause trouble in the recovery/adaptation process. I briefly talked about this in the introduction: doing too many sets per workout might not only be a waste of effort, it might even hamper your overall muscle growth (Dankel et al., 2016). The image below shows how too big of a stimulus can potentially deform the SRA curve, removing the adaptation part.
Finally, the SRA principle doesn’t exclusively apply to muscle. For example, the nervous system and connective tissues (such as muscle tendons), also have SRA curves. However, that’s beyond the scope of this article. Here, I will focus on muscle SRA.
Muscle Protein Synthesis
In scientific terms, the rebuilding (recovery) and ‘building bigger’ (adaptation) of the muscle happens through muscle protein synthesis (article by Trommelen, 2016; Damas et al., 2016). During the course of the muscle SRA curve, muscle protein synthesis is constantly elevated (Brook et al., 2015; Damas et al., 2016; Franchi et al., 2015). When it gets back down to baseline, recovery and adaptation are completed. That is the perfect time to stimulate the muscle again to restart the muscle SRA curve. This is illustrated in the image below.
When should you train again?
Muscle SRA partly answers this question: when the muscle SRA curve is completed.
Train too frequently, and the muscle will actually decrease in functional size over time, because you constantly stimulate before the muscle has completed recovery and adaptation. Train too infrequently, and you are unable to use the peak of the SRA curve as a new starting point for further muscle growth. You can see both situations in the image below.
So, ideally you want to train again as soon as recovery and adaptation of the muscle is completed. This will grow them as fast as possible.
How long does the Glute SRA curve take to complete?
With a new technique to measure long-term muscle protein synthesis, researchers have shown that muscle protein synthesis can remain elevated for a maximum of 72 to 96 hours (3 to 4 days) (Damas et al., 2016; Miller et al., 2005). As we now know, muscle protein synthesis underlies the rebuilding (recovery) and building bigger (adaptation) of muscles.
Now let’s focus on the muscle group of our interest: the Glutes. It takes a maximum of 72 to 96 hours (3 to 4 days) to complete a muscle SRA curve. That means waiting for 120 to 144 hours (5 to 6 days) between Glute workouts wouldn’t make sense if you want them to grow as fast as possible!
But how long should you wait? 1 day? 2 days? 3.36 days? Well, it depends. According to science, the following factors are important:
- Type of Glute Exercise
- Glute Training Experience
Now let’s talk about the first of those factors: Type of Glute Exercise. In a later article, I will cover Glute Training Experience.
Type of Exercise and muscle SRA: 4 aspects
Particularly for the Glutes, you can choose from an impressive collection of exercises: external rotations, hip thrusts, hip abductions, squats, lunges, step-ups, deadlifts, and all of their variations; each of them stimulate the Glutes.
However, some exercises have longer muscle SRA curves than others. Imagine this: You’re doing 4 sets of Band Side Walks on Tuesday, and 4 sets of heavy Bulgarian Split Squats on Friday. Do the Glutes take equal time to Recover and Adapt from these 2 training sessions? Heck no! Muscle recovery and adaptation from the heavy Bulgarian Split Squats takes much longer.
But.. Why? There are 4 well-documented aspects of an exercise that influence the length of the muscle SRA curve.
1. Muscle activity
Muscle activity during an exercise is closely linked to producing muscle tension (Alkner et al., 2000; Miller, 2014). Muscle tension is important in Stimulating a muscle to grow (Schoenfeld, 2010). If you don’t believe me, try growing your Glutes by doing biceps curls (which show close to zero Glute activity).
As we know, a muscle grows by recovering and adapting to a stimulus. Low muscle activation equals low muscle tension, which leads to a small stimulus that has a short recovery time. High muscle activation equals high muscle tension, which leads to a bigger stimulus that has a longer recovery and adaptation time. The following image illustrates a study that’s demonstrated this (Soares et al., 2015). Bret has studied the activity of the biceps during both of these exercises in the past.
2. Range of motion
When an exercise brings a muscle through a bigger Range of Motion (ROM), the muscle does more work (muscular work = muscle force/tension x excursion/distance). This muscular work is often incorrectly called ‘training volume’ (read my article on calculating training volume to see why).
As we would expect, studies show that the more heavy work (training volume) a muscle performs, the longer recovery takes (Lieber & Fridén, 1993; Nosaka et al., 2002; Nosaka et al., 2003). This indicates that exercises with a bigger ROM take the muscle longer to recover (and adapt) from, probably because there’s more muscle breakdown due to increased heavy muscle work.
An example of a Glute exercise with a big ROM would be a Lunge or Bulgarian Split Squat. A Band Side Walk, however, has a small ROM, and takes shorter time to recover and adapt from.
3. Emphasis on eccentrics
As expected, the participants from these studies also took much longer to recover to their old performance levels after the eccentrics. However, they took only 1 day to recover from the concentric movements. The following image illustrates this in terms of muscle SRA.
An example of a Glute exercise with an emphasis on eccentrics would be the Full Squat. You really have to control the weight while going down, while tension on the Glutes gets greater and greater. On the other hand, Band Hip Thrusts are only heavy at the top, and increasingly lighter when going to the bottom (because the elastic resistance decreases). It’s clear that Full Squats emphasize the eccentric part of the movement, and Band Hip Thrusts don’t. Because of this, Squats probably take longer to recover and adapt from.
4. Muscle length at peak tension
More recent studies also show that firing muscles hard when they’re lengthened causes more muscle breakdown compared to when they’re shortened. As expected, these exercises also took longer to recover and adapt from (McHugh & Pasiakos, 2004; Nosaka et al., 2005; Soares et al., 2015).
The image below shows two versions of the partial Biceps Curl. If you only do the bottom portion of the exercise (top of image), there is peak tension in the biceps when it’s lengthened. This results in more muscle breakdown, and a longer SRA curve. If you do only do the top portion (bottom of image) there is peak tension when it’s shortened, resulting in less muscle breakdown, and a shorter SRA curve.
To further clarify how this works for Glute exercises, consider the Parallel Squat and the Barbell Hip Thrust. For the Squat, peak tension happens at the bottom, when the Glutes are lengthened. For the Barbell Hip Thrust, peak tension happens at the top, when the Glutes are maximally shortened. The image below illustrates this.
So where have we reached so far?
Thus far in this article, we have covered the different factors which influence the training frequency for muscles, in particular the glutes. The second part of this article will go on to speak about specific exercises, and how the above 4 aspects of Muscle activity, Range of Motion, Emphasis on Eccentrics, and Muscle length at peak tension can be applied to some of the common glute exercises in order to periodize glute training in the most optimal way. In Part II, we will look at different Glute exercises and how they impact the muscle SRA curve and how to periodize glute workouts for maximum benefits.
Article Credits – Stijn van Willigen