The unexplored advantages of respiratory muscle training

The flexible periodization method defines itself as a holistic method of periodization. In some instances, the associations to the word "holistic" are almost antagonistic to hardcore strength and conditioning and lifting, the preferred style of most elitefts™ readers. However, for me, the word holistic is associated with “maximizing the chances of the best possible result of the training program.” Let me explain.

In relation to the flexible periodization method, holistic means:

• Taking into account all aspects of the human being in the creation of the training program (body, mind, spirit)
• Doing everything that can be done at any point in time
• Seeking maximum synergy and integration between all components of training

“Doing everything that can be done at any point in time” is similar to “surrounding the dragon,” a concept that supposedly has origins in Chinese medicine. The idea of doing everything that can be done at any point in time is also related to the idea that “the devil is in the detail,’ an idea that hints to the fact that a neglect or a mistake on the smallest aspect of training and performance can limit an athlete’s performance. The positive side of “the devil is in the detail’ is that if there is a minute detail about the athlete’s training that hasn't been explored yet, exploring this detail and improving performance in relation to this detail can lead to a new personal record.

I would like to give credit to Charles Staley for first presenting me with the idea of asking the question, “Which aspects that could improve performance have received the least amount of systematic training?” Identify the aspect of an athlete’s training that could improve performance but has received little or no systematic training and you have “a winner.”

Here is an example. A few years ago, I started working with a female road cyclist. She was an elite recreational cyclist and had cycled many hours per week for years but had never performed any strength training. We developed a strength training program following the principles of the flexible periodization method specific to her and her needs in cycling. The following spring she rode the same hills three gears higher and cut forty minutes off her previous best in her main event for the year (reducing her time from nine hours to eight hours and two minutes in a long distance race in France).

Note: The flexible periodization method makes a clear distinction between sport-specific programs and individualized programs. With a sport-specific program, an athlete’s program is based on the needs analysis of the sport (1). The simple example is that a volleyball player would do (a lot of) jump training because jumping is a critical part of volleyball performance. With individualized training programs, we go a step further and ask the question, does this particular player need to improve his jump height? When I lived in Denmark, I used to work with both the male and female national volleyball teams. Some of the males didn't need to jump any higher. In fact, their limiting factor was to avoid jumper’s knees, not to jump higher. In their case, the focus was on strengthening the patella tendon (with deep heavy squats) and ensuring muscle balance around the knee. The only jump training they did was during volleyball practice.

I haven't forgotten “How to Mix 'Oil' and 'Water' Into a Synergistic Cocktail, Part III,” but in this installment, I'll share with you an older strategy that with the development of new and user friendly devices is more appealing to a larger group of athletes. This strategy is termed respiratory muscle training.

Strongmen demonstrate the strength of their respiratory muscles by breaking chains around their ribcage

Respiratory muscle training (RMT), or strength training for the respiratory muscles, is an example of such a detail that might not have received a lot of systematic training in the programs that you create. I first learned about RMT a couple years ago through MMA fighter Shawn Sherk. As anyone involved with elite sports, I'm always on the lookout for an unexplored training method that I can use to help the athletes I work with achieve new personal bests. The concept immediately made sense to me, but it wasn’t until recently that I took a look at some of the science behind RMT.

The following are highlights from “Effects of Respiratory Muscle Training on Performance in Athletes: A Systematic Review with Meta Analysis” (2). After a look at the science, we'll take a look at how to integrate RMT into the training of your athletes.

What is the definition of RMT?

The definition of RMT is training where both the inspiration and the expiration are loaded. On the other hand, inspiratory muscle training (IMT) involves training where only the inspiration is loaded. Key ”players” during inspiration (or inhalation) are the diaphragm and the external intercostals. During faster and deeper inspiration, the sternocleidomastoideus and the scaleni are also engaged (3).

Expiration (or exhalation) during rest is generally passive. Elastic forces in lung tissue, and the thorax (ribcage) and abdominal wall bring the ribcage back to the resting position. During faster and deeper expiration, the movement of the ribcage back to the resting position is supported by the inner intercostals and the muscles of the abdominal wall.

Additional accessory muscles of respiration include (4):

• Serratus anterior: Assists forced inspiration if the scapula is fixed in adduction by the rhomboids
• Pectoralis major: Assists expansion of the ribcage if the arms are fixed, for example, by placing the hands on the floor
• Pectoralis minor: Assists lifting the ribs if the scapula is fixed
• Upper trapezius: Assists lifting the clavical bones (clavicular breathing)
• Latissimus dorsi: Anterior fibers assist in expiration, and posterior fibers assist in inspiration
• Erector spinae (thoracic section): Assists inspiration by raising the ribcage

Develop flexibility before strength. If an athlete can’t breathe deep at all due to tight expiratory muscles, these muscles must be stretched first.

How is RMT performed?

Different resistive devices were used with different characteristics, including a threshold type of device that requires a certain inspiratory and/or expiratory pressure for the valve to open. The devices that allowed for “targeted resistive training” (using a valve) yielded greater improvements in respiratory muscle strength compared with training with devices without this feature. Without the valve that opens only at a certain velocity of airflow, the participants could theoretically have been breathing slowly, which would have rendered the overload on the respiratory muscles negligible. In all studies, intensity was gradually increased throughout the tests.

Different types of protocols were used including one to two sets of thirty to forty respirations or continuous ventilation for fifteen to thirty minutes. Training frequency was from three to four times per week to twice daily. Duration of the studies ranged from three to twelve weeks with six weeks being the most frequent duration. Good effects were documented with four to eleven weeks of training. Even though improvements in maximal inspiratory pressure were seen with one to two sets of thirty to forty repetitions, the authors discussed that the volume was too low to match the needs for high level endurance sports. In the discussion, the authors recommended intervals of several minutes in duration.

What are the results of RMT?

The participants in the studies included in the meta analysis were 80 percent men aged fifteen to forty years and spanned the range from recreational to international level athletes. Overall, the RMT showed significant positive effect on sport performance in the form of:

• Outcome of time trials
• Exercise endurance time (greater effect on intermittent sprint sports and swimming than endurance track sports)
• Repetitions on yo-yo test

The authors discussed that the results might be the greatest when the training meets the demands of the sport in terms of flow rates (velocity of respiratory contraction) and volume changes (range of motion of respiratory muscle contraction). Further, an aggressive progression on intensity is necessary to achieve the necessary overload on the respiratory muscles. It is worth noting that so far scientific studies don't support the claim made by some companies that RMT can improve VO2 max.

Some authorities believe that diaphragmatic breathing is critical in breathing for endurance because the diaphragmatic breath pulls the air into the bottom parts of the lungs, which has the greatest perfusion of blood. For that reason, it makes sense to teach the athlete to use the diaphragm before beginning to strengthen it (5).

How does RMT work?

Fatigue of inspiratory muscles, measured as a decreased inspiratory pressure over time, has been documented in various endurance activities. At a certain point, the body redirects blood from the “locomotor muscles” (arms and legs) to the respiratory muscles. This redirection of blood flow is termed the metaboreflex.When this redirection of blood flow takes place, oxygen delivery to the arms and legs decreases and the muscles start to work more anaerobically, thus shortening the time to exhaustion.

RMT has been proven to strengthen respiratory muscle strength and endurance and is believed to work by improving the strength and endurance of the respiratory muscles, thus attenuating or delaying (in time or with respect to intensity) the metaboreflex. The attenuation of the metaboreflex results in an increase in endurance performance. Further, the improvements of performance are related to decreases in “rate of perceived breathlessness” and decreases in rate of perceived exertion. The reduction was explained with a “desensitization to the respiratory loading” and a reduced relative intensity of contraction of the respiratory muscles (because the maximal strength was increased).

Who can benefit from RMT?

The analysis shows that both recreational and elite athletes from cycling, endurance track sports, intermittent sprint type sports, and rowing improved their maximal inspiratory pressure after RMT/IMT while there wasn't any significant change for swimmers, divers, and Special Forces. It was discussed that swimmers might already be at their peak with respect to respiratory muscle strength or that the program used in the studies didn't provide a sufficiently strong training stimulus.

Conclusion

The review provides a good framework for understanding and performing RMT. However, the review also leaves certain questions unanswered, including where RMT fits into a periodized training program. RMT is relatively new to me. In the next column, I'll discuss the thought process I use and the questions I ask in order to integrate RMT into the flexible periodization method. While this column has included some of the basic RMT exercises, the next column will show more advanced RMT exercises, including exercises with a particular resistive device.

References

1. Jensen K. Beyond Functional Training (workshop). At: #.
2. HajGhanbari B, Yamabayashi C, Buna TR, Coelho JD, Freedman KD, Morton TA, Palmer SA, Toy MA, Walsh C, Sheel AW, Reid WD (2013) Effects of Respiratory Muscle Training on Performance in Athletes: A Systematic Review with Meta Analysis. J Strength Cond Res 27(6):1643–63.
3. Åstrand P-O, Rodahl K (1986) Respiration: Textbook of Work Physiology. McGraw-Hill, pgs. 220–1.
4. Kendall FP, McCreary EK, Provance PG (1993) Facial, Eye and Neck Muscles: Muscles of Deglutition and Respiratory Muscles. In: Muscle Testing and Function, 4th Ed. Williams & Wilkins, pgs. 329–30.
5. Douillard J (1994) Body, Mind, Sport: The Mind-Body Guide to Lifelong Fitness and Your Personal Best. Crown Trade Paperbacks.