You can obtain more information about breathing training at www.breathestrong.com, where you can also find out about my comprehensive guide to breathing and exercise “Breathe Strong, Perform Better” (published by Human Kinetics Inc.). Scroll to the bottom of this page to visit the ‘Breathe Strong’ Amazon store.
On Friday September 30th, I’m presenting a 30-minute seminar at the Cycle Show Expo at the NEC (www.cycleshow.co.uk, Cycle Arena, 12.30pm). The title of my talk is "Breathing Strong in the Saddle: Improve Your Riding the Easy Way". In this Blog, I’m going to give you a sneak preview of what I’ll have to say at the Cycle Show next week.
I’m going to approach the seminar by considering two sides of the same coin - the limitations that breathing muscles impose upon cycle performance, and vice versa. Why vice versa? Because the body position in cycling presents a number of problems that aren’t present in other sports, especially for time trialists and triathletes who are using aerobars. We all know that minimizing frontal area minimises aerodynamic drag, but this benefit has a cost (see www.bikeradar.com/racing/article/aero-position-isnt-everything-31165 for a very interesting article on this), and much of that cost is borne, by the breathing muscles.
Aerobars – A double-edged sword
Research suggests that cyclists who are inexperienced in the use of aerobars exhibit detrimental effects on their breathing and mechanical efficiency compared to cycling in the upright position (www.ncbi.nlm.nih.gov/pubmed/14514538). For example, compared with upright cycling, aerobars resulted in a lower maximal oxygen uptake and lower maximal ventilation. In addition, breathing appeared to be constrained, such that breath volume was lower and breathing frequency was higher. This is a very inefficient breathing pattern; indeed, the study found that mechanical efficiency was lower when using aerobars, i.e. the same amount of cycling work required more energy.
The explanation for these findings resides in the influence of a crouched body position on inspiratory muscle mechanics during cycling. First, there is an effect on diaphragm movement caused by the large organs of the abdominal compartment (stomach, liver, and gut). These organs lie immediately below the main inspiratory muscle, the diaphragm, and they are effectively a noncompressible mass (visceral mass) that must be pushed out of the way by the descending diaphragm. When a cyclist is crouching forward, the abdominal organs press against the diaphragm, impeding its movement; the volume of the abdomen is also reduced, which means there is less space to accommodate movement of the visceral mass during breathing (see figure below - from "Breathe Strong, Perform Better", Human Kinetics).
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| Impediments to diaphragm movement during cycling. From "Breathe Strong, Perform Better", Human Kinetics |
The abdominal wall, which normally bulges forward during inhalation, is also stiffer because it contributes to core stabilization, increasing diaphragm work still further. In addition, the extreme hip flexion brings the thighs closer to the abdominal wall, where they can also impede its outward movement during inhalation. These effects conspire to impede the free movement of the diaphragm and rib cage muscles, increasing inspiratory muscle work. Second, if cyclists are forced to adopt a higher breathing frequency (because breathing deeply is too uncomfortable in the crouched position), inspiratory flow rate must be higher. This forces the inspiratory muscles to work in a region of their force–velocity relationship where fatigue and effort perception are greater (find out about the force-velocity relationship and other properties of muscles here - http://muscle.ucsd.edu/musintro/props.shtml). Because studies appear to show that the aerobar position has fewer detrimental effects in cyclists who have used aerobars for a prolonged period, it appears likely that the inspiratory muscles adapt to the increased demands imposed by aerobars. A shortcut to this adaptation is to train the inspiratory muscles so that they are able to cope with the mechanical changes induced by the aerobar posture (visit www.breathestrong.com for information on how train the inspiratory muscles).
Now it’s time to consider the other side of the breathing/cycling coin, i.e., the limitation that breathing muscles impose upon cycling performance. There are two components to this; first, we need to consider the performance implications of the fact that breathing muscles are an integral part of the core stabilisation system; second, we need to consider the metabolic repercussions of breathing muscle work during cycling.
The core – The seat of your power
In most sports, including cycling, the core provides the foundation from which force is generated. The stabilising action of the core is very important for the production of cycling power. This is illustrated by the fact that external stabilisation of the trunk (i.e., relieving the core muscles of the need to stabilise the trunk) significantly reduces the metabolic cost of cycling (www.ncbi.nlm.nih.gov/pubmed/16258182). The effect is greatest at pedaling speeds that induce the highest pedal forces. In other words, cyclists expend a lot of energy stabilizing their trunk in order to optimise power production.
If the core provides the foundation from which force is generated during the pedal stroke, and if the stability of the core is influenced by breathing, a question then arises regarding the best time to breathe during the pedal cycle. Because a complete respiratory cycle (breathing in and out) occurs only once every two or three pedal revolutions, it is inevitable that force will not always be exerted on the pedals during, for example, an exhalation. To date, no studies have examined the potential benefits of breathing during particular phases of the pedal stroke, and this is probably because it’s unlikely to have a large impact on performance. However, more than just performance should be considered. Exerting force on the pedals during the pedal downstroke requires the coordination of more than just the leg muscles. The stability of the upper body also needs to be maintained in order to ensure that it provides a stable foundation and that spinal movements are controlled. If a vital part of this stabilizing system is otherwise engaged (in breathing), the potential exists for impaired function of the core.
At high pedal rates (greater than 70 rpm), the forces transmitted to the pedals are relatively small compared to the maximum force-generating capacity of the muscles involved; therefore, the competition between the postural role of the trunk muscles and their role in breathing is not as problematic as it is in sports such as rowing. However, during steep hill climbing, pedal rates drop, and pedal forces increase. During climbing, cyclists may find it advantageous to synchronise breathing and pedal cadence; indeed, this tends to occur intuitively, especially on very steep climbs. Notwithstanding this, evidence from elite cyclists suggests that the most important aspect of breathing and pedal synchrony is keeping a steady rhythm for each and maintaining a 1:3 ratio (1 breath for every 3 pedal revolutions). This ratio will optimise the efficiency and comfort of breathing, but a cyclist needs to work at maintaining the ratio; the reason that cyclists slip into a 1:2 ratio is because their inspiratory muscles are not sufficiently strong and fatigue resistant to maintain breath volume. This is where specific breathing muscle training can help (see "Heavy breathing" improves performance, below).
My book, “Breathe Strong, Perform Better” includes specific guidance on how to optimise breathing training for cycling, as well as how to undertake breathing muscle training using functional training principles in order to optimiase the contribution of breathing muscles to cycling mechanics.
“Heavy breathing” improves performance
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| Changes in 40km time trial performance after six weeks inspiratory muscle training (IMT) using POWERbreathe |
In considering the metabolic repercussions of breathing muscle work during cycling, we can again turn to the scientific literature. Perhaps the most striking demonstration of these repercussions is considering what happens to cycling performance if we train the breathing muscles (specifically, the inspiratory muscles), using a bit of “heavy breathing” (see www.breathestrong for details). In other words, let’s look at what happens when we minimise any limitations that the breathing muscles impose. We published a research paper on this in 2002 (www.ncbi.nlm.nih.gov/pubmed/12166881), and it remains the most comprehensive and compelling study of inspiratory muscle training (IMT) to date. In a nutshell, we found that six weeks of IMT improved 20km laboratory time trial performance by 3.8% (66 sec) and 40km time trial performance by 4.6% (115sec) (see figure above).
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| Improvements in breathing and whole body effort sensation after six weeks inspiratory muscle training (IMT) using POWERbreathe |
The cyclists also felt that their breathing and whole body perceived exertion were lower (see figure opposite). In other words, they felt that the same cycling power output was easier. In addition, the exercise-induced fatigue of their inspiratory muscles was abolished after IMT. These changes were made possible by the improvements in strength, power and endurance of the breathing muscles; for example, the peak power output of the cyclists' inspiratory muscles increased by 39%. Find out why performance improved by reading my previous Blog.
So there you have it, a sneak preview of my seminar for the Cycle Show (www.cycleshow.co.uk).
If you found my Blog interesting, please come back for further articles and news, as well as my musings on all things breathing and sport related. Also, don’t forget that you can obtain more information about breathing training at www.breathestrong.com, where you can also find out about my comprehensive guide to breathing and exercise “Breathe Strong, Perform Better” (published by Human Kinetics Inc.). Scroll to the bottom of this page to visit the ‘Breathe Strong’ Amazon store.
