Friday Interview: Miguel Diaz Discusses Salivary Markers and Fatigue

1. Please introduce yourself to the readers (how you started in the

profession, education, credentials, experience, etc.).
I hold a BSc degree in Sports Science (with a strong background in exercise physiology) from the University of Applied and Environmental Sciences in Bogota, Colombia.

In 2009 I completed a Master's Degree in Genetics and Biochemistry at the Institute of Genetics and Biochemistry; Federal University of Uberlandia in Brazil.

At the moment, I am final year PhD student also in Genetics and Biochemistry. I focus my research on the response of salivary proteins and other molecules to the variation in training load, intensity and volume in elite athletes. For the last couple of years I have been working as a consultant for professional swimmers also in this regard.

For both my Masters and Doctorate, I have been working under the supervision of Dr Foued Espindola, who has extensive experience in exercise, biomarkers and translational research.

2. You recently published an article on salivary proteins and fatigue in swimmers. What do we know differs between salivary and blood protein measurements?
The use of biomarkers in blood has been rigorously tested and refined. On the other hand, salivary biomarkers have only recently emerged as an optionfor diagnosis in Sports Medicine. Several of the molecules used in blood for such purpose are found in much lower concentrations in saliva and some others are not found at all. Hence, it becomes necessary to identify surrogates markers and examine whether their variation in response to elite sports training folllows the same pattern of the original target molecules in blood. So far, some work has been conducted on establishing reference values for some of the salivary proteins, which certainly makes the application of these analysis much easier. Nevertheless, substantial work is still needed before salivary markers can be used undisputedly in Sports Medicine. 

3. Why aren't salivary proteins used more frequently?
As mentioned above, research on salivary markers in Sports Medicine just recently emerged. Although the number of publications has been growing especially during the last four or five years, studies involving larger samples and considerably more markers are required before their use can be translated into the field. We and others have been able to demonstrate as a Proof of Concept that salivary markers can be used in Sports Medicine. However, little has been done to extrapolate such results to other sports or populations (age, gender, training experience). To the best of my knowledge, most of the work has been conducted on swimmers and rugby players and to some degree to gymnastics and some fighting modalities. Once we are able to demonstrate that salivary markers show a proportional response to training load in subjects with different physiological characteristics, and that such response can be applied to different training modalities, salivary markers could certainly substitute blood testing in Sports Medicine.

4. What did you study do and what were the main results of your study?
In our most recent study (http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0064043) we demonstrated that salivary proteins such as alpha-amylase and chromogranin A behave in a similar fashion that adrenaline in blood. Interestingly, both salivary and blood markers were inversely correlated to training intensity and load. This means that when the athletes experienced higher workloads in training, the resting concentration of such markers were at their lowest point. This is a known phenomenon in physiology but had never been shown with salivary surrogates of autonomic activity. In addition to this, we were able to reproduce results of yet another study (https://www.thieme-connect.com/DOI/DOI?10.1055/s-0032-1316318) in which we identified salivary nitrite also as a marker of training load. However, different from the salivary proteins mentioned above, salivary nitrite does show a positiveassociation we the training parameters.

5. How can a coach use the results in this study?
There are two main points that coaches can gain from our study. First, the salivary markers we investigated show a proportional response (inverse as in the case of proteins or direct as in the case of nitrite) to training load. This is very important because we now know what the regular dynamics of salivary proteins in response to training are. If someone were to monitor training adaptation by means of salivary markers they know that such response should be equivalent to the training parameters. If the behavior of salivary markers is not corresponding to the training parameters, the latter can be either too low to induce adaptation or too high and hence, might lead to over-training. Secondly, as it is done with traditional markers in blood, we showed that salivary markers can be used during resting conditions. Few studies so far have included this kind of experimental design. The advantage of this is that the athletes can collect the samples themselves during the first hours in the morning and have them sent directly to the lab. Collecting saliva after a training session can be difficult because of mild dehydration and low volume of saliva. Therefore, if monitoring for long-term adaptations sampling for saliva does not interfere with training sessions. 

 

6. What much does frequent salivary sampling cost?
At the moment, there are very few options for salivary testing on-field. Most of the testing needs to be carried out by specialized laboratories.

As part of the translational aspect of our research, we developed the initiative ProBioTec, which aims to provide expert advice and testing for professional athletes.

The analysis of a single sample for the markers mentioned above ranges from 3 to 5 USD.

8. Do you think salivary proteins are a better indicator of sympathetic activity than heart rate variability?
As mentioned in our study, autonomic regulation is a tissue-specific and intricate process. Exercise-induced bradycardia, for instance, is a consequence of increases in vagal tone and a reduction in intrinsic HR. Since salivary proteins can be used as surrogates of blood catecholamines, I think they should be used as part, but not as a substitute of other physiological markers of adaptation. A better understanding of the physiological and biochemical adaptations that athletes experience in response to training will always be more complete when considered as a whole.
 

9. What research or projects are you currently working on or should we look from you in the future?
We have conducted a couple of studies on salivary nitrite as well as nitrite supplementation on recreational athletes that should be published shortly.

As a follow-up of our previous reports on salivary markers in sports medicine, we just completed a study in which we assessed the best conditions for storage and preservation of samples of saliva. This might offer some guidelines to other researches on how to collect and store samples depending on how long (hours, days or months) such samples need to be kept for.

Lastly, we are trying to exploit all of the potential in diagnostics offered by saliva by investigating possible surrogates of genetic changes induced by exercise.

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Inspiratory Muscle Fatigue Impairs Latissimus Dorsi Strength

Take Home Points on the Inspiratory Muscle Fatigue Impairs Latissimus Dorsi Strength

Inspiratory muscle fatigue impairs latissimus dorsi activation, likely reducing swimming motor control and propulsion.

Breathing is a frequent topic of discussion at Swimming Science. Before we get started, first brush up on:

• Inspiratory Muscle Fatigue
• Brief Swimming Review Volume 1 Edition 1
• Breathing and Swimmers' Posture
• Breathing During Sprinting
• Friday Interview: Jernej Kapus Discusses Breathing
• Friday Interview: Dr. Mitch Lomax
• All You Need to Know About Inspiratory Muscles Part I
• All You Need to Know About Inspiratory Muscles Part II
• All You Need to Know About Inspiratory Muscles Part III

Lomax (2003) first demonstrated that a 200-m race results in inspiratory muscle fatigue. Him and his team of researchers then noted inspiratory muscle fatigue before a 200-m race impaired performance (Lomax 2010). Inspiratory muscle fatigue also occurs for other competitive sports (Lomax 2012). However, the specifics of inspiratory muscle fatigue and performance are not well understood. 

Lomax (2014) had eight collegiate swimmers (M=6, F=2; ~22.0 years; mean 200 m freestyle 139 seconds) were recruited to perform two maximal 20 s arms only front crawl sprints in a swimming flume. Both sprints were performed on the same day and inspiratory muscle fatigue was induced 30 minutes after the first sprint. They measured maximal inspiratory and expiratory mouth pressures pre and post each sprint. The median frequency (MDF) of the electromyographic signal burst was recorded from the latissimus dorsi and pectoralis major during the 20 s sprint, along with stroke rate and breathing frequency.

After inspiratory muscle fatigue, stroke rate increased from 56 to 59 cycles/min. Latissimus dorsi MDF decreased from 67 to 61 Hz. No change was observed in the MDF of the latissimus dorsi during the control sprint. The MDF of the pectoralis major shifted to lower frequencies during both sprints, but was unaffected by inspiratory muscle fatigue.

It seems inspiratory muscle fatigue only negatively influences the latissimus dorsi muscles in arms only sprint swimming. This likely decreases propulsion in freestyle and may be a main cause for impaired performance. Another interesting finding is that the pectoralis major fatigues during a 20-second sprint. Now, keep in mind breathing more frequently reduces inspiratory muscle fatigue...(Jakovljevic 2009). 

References

1. Lomax M, Tasker L, Bostanci O. Inspiratory muscle fatigue affects latissimus dorsi but not pectoralis major activity during arms only front crawl sprinting. J Strength Cond Res. 2014 Jan 7. [Epub ahead of print]
2. Lomax ME, McConnell AK. Inspiratory muscle fatigue in swimmers after a single 200 m swim. J Sports Sci. 2003 Aug;21(8):659-64.
3. Lomax M, Iggleden C, Tourell A, Castle S, Honey J. Inspiratory muscle fatigue after race-paced swimming is not restricted to the front crawl stroke. J Strength Cond Res. 2012 Oct;26(10):2729-33.
4. Lomax M, Castle S. Inspiratory muscle fatigue significantly affects breathing frequency, stroke rate, and stroke length during 200-m front-crawl swimming. J Strength Cond Res. 2011 Oct;25(10):2691-5. doi: 10.1519/JSC.0b013e318207ead8.
5. Jakovljevic DG, McConnell AK. Influence of different breathing frequencies on the severity of inspiratory muscle fatigue induced by high-intensity front crawl swimming. J Strength Cond Res. 2009 Jul;23(4):1169-74. doi: 10.1519/JSC.0b013e318199d707.

Written by G. John Mullen who received his Doctorate in Physical at University of Southern California (USC) and is a certified strength and conditioning specialist (CSCS). At USC, he was a clinical research assistant performing research on adolescent diabetes, lung adaptations to swimming, and swimming biomechanics. G. John has been featured in Swimming World Magazine, Swimmer Magazine, and the International Society of Swim Coaches Journal. He is currently the owner of COR, providing Physical Therapy, Personal Training, and Swim Lessons to swimmers and athletes of all skills and ages. He is also the creator of the Swimmer's Shoulder System, Swimming Science, Swimming Science Research Review, Mobility System and the Swimming Troubleshooting System.

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Guide to LTAD in Swimmers

Take Home Points on the Guide to LTAD in Swimmers

Performance of age-group swimmers depends from the interaction of several domains Anthropometrics & biological maturation, Genetics, Biomechanics & Motor control and Psychology are the main determinant factors There are available several straightforward and quick testing procedures for a coach monitor these determinant factors.

Lately, we've posted articles on age-group swimmers breaking national age-group worldwide [Are Youth Swimmers Getting Faster...Any Why? Part I, Are Youth Swimmers Getting Faster...And Why? Part II, Are Youth Swimmers Getting Faster...And Why? Part III]. So what are the main performance determinants in such early ages? How is it possible for a coach with a low budget and short of time to monitor performance and its determinant factors at such early ages? We know that swimming performance is a multifactorial phenomenon. Performance of age-group swimmers depends from the interaction of several domains (Figure 1). The most determinants are the anthropometrics, biological maturation, genetics, biomechanics, motor control and psychology.

Figure 1. Deterministic model of the performance for age-group swimmers (adapted from Marinho et al., 2013)

1. Anthropometrics & biological maturation

For a start, performance enhancement of age-group swimmers is due to growth and biological maturation. After a summer break swimmers that were not engaged in swimming activities improved technique and performance (Moreira et al., 2014). After controlling with a mathematical procedure the growth (let´s say that in a way we are keen to see what would happen if the swimmers did not grow during the summer break) performance and technique would be the same. So, growth is a major player of age-group swimmers and probably the most influential.

Interestingly, knowing the parents heights we can predict the swimmer´s adult height. This is called as “The Khamis-Roche Method” and you can play with it here. Please bear in mind that “estimation” by definition is something that has some sort of associated error. So, this is not completely accurate.

Another key-feature is the ratio between height and arm span. The ape-index as is known should be higher than 1.0 (i.e. the arm span should be higher than the height). There is no evidence, but some researchers and coaches consider good if the ratio is around 1.05-1.10. These figures are quite arbitrary or random as there is no evidence on this (as much as I am aware of). I invite you to play with the ape-index from this link and compare yourself with Michael Phelps (allegedly his Ape Index is 1.04).

A sensitive issue, especially for girls, is the fat mass. A swimmer is supposed to have a higher percentage of fat mass than other sportsmen. It helps with buoyancy, a good body position and therefore less resistance. A straightforward way to estimate the fat mass is the US Navy Circumference Method. This method can be expanded to include other parameters, such as the level of physical activity (link). Another procedure is to estimate the fat mass after measuring a few skin folds with a caliper (caliper methods). It seems that these methods are validated for adults, so care should be exercise using if you are assessing very young children.

2. Genetics

When we talk about sports genetics most of the times people think in science fiction and not in sport sciences. Sorry for any disappointment but we are not a crime scene investigator that with a tinny hair completely damage is able to identify a criminal in a blink of an eye (pick up hair à run the genetic test à search on the database à identify the guy´s ID; all these in 30s as we watch on TV). Unfortunately in the real world we are not able to run genetic tests and say if definitely one should be a sprinter or distance-swimmer, a freestyler or breaststroker, will be a good or poor swimmer.

There are genetic polymorphisms that can be help the swimmer and the coach though. A few genetic markers and/or polymorphism were related to swimming performance, such as the Angiotensin Converting Enzime (ACE), Vascular Endothelial Growth Factor Receptor 2 (VEGFR2) or the Alpha-Actinin-3 (ACTN3) genes (Costa et al., 2013). Some polymorphisms are related to endurance and others to power.

So how useful is the genetic profiling? To learn if a swimmer is a high or a low responder. A high responder is someone that adapts very well to a given training program; while a low responder will be struggling to improve. Imagine that we have two swimmers that are engaged in the same training program for several weeks. Both put the same effort in the program but one improves much more than other. The reason might be that one is a high and the other a low responder. Have a sneak peek at this nice video about the topic.

3. Biomechanics & motor control

Recently our research group came up with a way to classify age-group swimmers (Barbosa et al., 2013). First question: why do we need to classify them? Classification is useful so that: (i) coaches and sports analysts no longer need to produce detailed explanations of the performance and its determinant factors but rather classify more broadly the swimmer as being one of a few types; (ii) enables the design of training programs according to each category; (iii) make communication between coaches and sports analysts quicker and easier. These classifications are used on regular basis in other fields, such as Medicine & Rehab.

Second question: What do we need to classify the swimmer? For this model we needed to measure the trunk transverse surface area (S), drag coefficient (C_Da), speed fluctuation (dv) and average swimming speed (v). I am aware that some of these tests might be too challenging to be done in a swimming club. Hopefully most swimming associations, sports institutes and swimming federations have the expertise and equipment to collect the data.

Third question: How do I classify the swimmer? All that is needed is to collect the data and then calculate the following equations:

Cluster #1_kinematics= 44.198·S - 2.852·C_Da + 4.604·dv/v - 41.280                             (1)

Cluster #2_{anthropometrics}= 49.082·S - 0.305·C_Da + 2.752·dv/v - 28.175               (2)

Cluster #3_{hydrodynamics}= 37.788·S + 17.963·C_Da + 2.195·dv/v - 24.175              (3)

From the three equations, the one with the highest score refers to the cluster the swimmer should be classified as (i.e. “labeled.”). Cluster #1 is related to high speed fluctuations (i.e. less smooth swimming), Cluster #2 to high body dimensions (i.e. taller and larger) and Cluster #3 to high drag coefficient (i.e. high resistance).

Fourth question: So what? How useful these details might be? For instance, after running the tests and calculate the three equations, a swimmer is classified as being in the cluster #3 (labeled “hydrodynamics”). This means that his profile is mainly determined by a high drag coefficient. So, coaches could design a training program for him focused on technique drills, feedback with specific visual and kinesthetic cues to reduce the resistance.

4. Energetics

It is possible to enhance the performance designing two main types of training programs: improving the technique (cf 3. “biomechanics & motor control” section) or building up the energetics. Some other time I will dedicate one post exclusively to the pros and cons of each model. Anyway, for the best and for the worth, energetics is a major player. The challenge is that most accurate tests to gather insight about energetic profile are expensive, time-consuming and sometimes invasive.

There are some procedures to estimate energetic parameters and to learn, or at least have a clue, about aerobic pathways (e.g., critical speed, T30, etc.). However, most age-group swimmers race short distances that depend a lot from anaerobic sources. For these, Science was not able yet to provide us completely reliable testing procedures. I.e. tests that can be carry out during a training session in a straightforward and quick way by a coach. Once more, we should exercise some care interpreting the data from a few tests reported in the literature. I address that issue in a post published earlier.

5. Psychology

Psychology goes beyond my field of expertise (if I have any…). But something that we all talk about is that after an OG or WC edition seems that the young swimmers have a motivational boost. I am not sure if there is any research on this. But at least there are anecdotal reports of an extra motivation. Watch on TV the best of the best competing against each other’s, Championships and World records being broken makes the young swimmers to put a little bit more of effort during competitions and training sessions.

Moreover, after an OG there seems to be a generational change. Several stars announce they retirement after the OG (ones for good, others it´s more like a very long break and later on they resume the career). This generational swap has a domino effect all the way down till age-groups.

References

1.    Barbosa TM, Morais JE, Costa MJ, Goncalves J, Marinho DA, Silva AJ (2013). Young Swimmers' Classification Based on Kinematics, Hydrodynamics, and Anthropometrics. J Appl Biomech, ahead-of-print

2.    Costa AM, Breitenfeld L, Silva AJ, Pereira A, Izquierdo M, Marques MC (2012). Genetic Inheritance Effects on Endurance and Muscle Strength. Sports Med, 42(6): 449-458

3.    Marinho DA, Barbosa TM, Neiva HP, Costa MJ, Garrido ND, Silva AJ (2013) Applied Sports Performance Analysis: running, swimming, cycling and triathlon. In: McGarry T, O’Donoghue P, Sampaio J (Eds). Routledge Handbook of Sports Performance Analysis. pp. 436-463. Routledge, Taylor & Francis Group. Oxon.

4.    Moreira MF, Morais JE, Marinho D A, Silva AJ, Barbosa TM, Costa MJ (2014). Growth influences biomechanical profile of talented swimmers during the summer break. Sports Biomech: ahead-of-print

Written by Tiago M. Barbosa that earned a PhD degree in Sport Sciences and holds a faculty position at the Nanyang Technological University, Singapore

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Dryland Mistake: Dips

Take Home Points on Dips

Dips increase the risk of impingement in swimmers who already have a high risk. The dip doesn't activate the triceps in a position similar the sports demands.

For each exercise, consideration of the risks and benefits is essential. The combination of the risk benefit analysis for a swimmer's needs analysis helps determine the appropriateness of an exercise for an individual. Many perform dips with the goal of improving triceps strength, a vital muscle for arm force production in swimming. However, the dip is far from swimming specific and increases the anterior stress of the shoulder.

The joint capsule has the role of stabilizing the joint and preventing excessive motion. The capsule is a sheet of ligamentous tissue that connects the shoulder socket of the scapula to the humerus (upper arm), with several regions identified by variations in capsule thickness. Little is known about the capsule and pathologies, other than that it is responsible for the common injury adhesive capsulitis (“frozen shoulder”).

Of all the shoulder joints, the glenohumeral joint capsule is most commonly discussed due to its large size. It provides passive stability around the joint, preventing subluxations when active structures are inefficient. A subluxation occurs when the active and passive structures cannot hold the head of the humerus in the correct position. As a result, the humerus migrates out of the glenoid. The majority of subluxations occur anteriorly (Mullen 2011).

Swimming already promotes instability in the shoulder from the amount of overhead shoulder rotations. Do you think doing bench dips is worth the risk of adding anterior instability? 

Swimming training results in greater shoulder range of motion for shoulder internal

rotation, as shoulder imbalances occur at the age of 14 in competitive swimmers (Batalha 2010; Batalha 2013). These imbalances in range of motion increase the likelihood to develop glenohumeral instability, range of motion deficits, impaired scapular retraction strength, proprioception, neuromuscular control, dynamic stability, muscular endurance and poor muscular timing, or dyskinesis (Burkhart 2003; Jobe 1993; Jobe 1994; Kibler 2003; Priest 1976; Wilk 2002). These defects result in further tissue breakdown and injury at the glenohumeral capsule, glenoid labrum, rotator cuff musculature, and tendon (Sein 2008; Jobe 1994; Burkhart 2003). 

When using the bench or bleacher, the humerus internally rotates. This internal rotation wraps the infraspinatus up and impairs the strength of the shoulder. In fact, the head of the humerus slides forward in front of the clavicle and encourages shoulder impingement. Now, this is bad enough when adults with enough strength perform this motion, but think of all the little age-group swimmers you've seen do this improper form? This damaging effect begins before kids have muscular control for the movement resulting in flopping up and down in this compromising position.

Now, bench dips are effective in targeting the lateral head of the triceps, but this does not outweigh the risk. Even perfect form diminishes the space for the rotator cuff under the acromion. If you are a believer of "functional exercise" then how would a bench dip simulate swimming? Perhaps it is like the recovery, but swimmers (anecdotal alert) don't have problems recovering their arm, it is typically the catch and press where the triceps fail. 

If you are seeking a replacement exercise, look no further than band extension. This simple exercise targets the tricpes and can encourage scapular retraction (another commonly weak area) in swimmers. Ensure scapular retraction, as anterior shoulder stress still occurs in this motion, so scapular stability is mandatory. Luckily, this stress occurs without the shoulder elevated. 

COR Swimmer's Shoulder System

Want more information on swimmer's shoulder? Consider the COR Swimmer's Shoulder System.

References

1. Burkhart SS, Morgan CD, Kibler WB. The disabled throwing shoulder: spectrum of pathology Part I: pathoanatomy and biomechanics. Arthroscopy. 2003; 19(4):404Y20. 
2. Jobe FW, Pink M. Classification and treatment of shoulder dysfunction in the overhead athlete. J. Orthop. Sports Phys. Ther. 1993; 18(2): 427Y32. 
3. Jobe FW, Pink M. The athlete’s shoulder. J. Hand Ther. 1994; 7(2): 107Y10. 
4. Kibler WB, McMullen J. Scapular dyskinesis and its relation to shoulder pain. J. Am. Acad. Orthop. Surg. 2003; 11(2):142Y51. 
5. Priest JD, Nagel DA. Tennis shoulder. Am. J. Sports Med. 1976; 4(1):28Y42. 
6. Wilk KE, Meister K, Andrews JR. Current concepts in the rehabilitation of the overhead throwing athlete. Am. J. Sports Med. 2002; 30(1): 136Y51. 
7. Sein ML, Walton J, Linklater J, et al. Shoulder Pain in Elite Swimmers: Primarily Due to Swim-volume-induced Supraspinatus Tendinopathy. Br. J. Sports Med. 2008. (in press) 
8. Batalha NM, Raimundo AM, Tomas-Carus P, Barbosa TM, Silva AJ. Shoulder rotator cuff balance, strength, and endurance in young swimmers during a competitive season. J Strength Cond Res. 2013 Sep;27(9):2562-8. doi: 10.1519/JSC.0b013e31827fd849. 
9. Batalha, N., Tomás-Carús, P., Fernandes, O., Marinho, D. A., & Silva, A. J. (2010). Water training effects shoulder rotator strength in young swimmers. A paper presented at the XIth International Symposium for Biomechanics and Medicine in Swimming, Oslo, June 16–19, 2010.
10. Mullen, GJ. Swimmer's Shoulder System (Second Edition). San Jose, CA: Center of Optimal Restoration, 2013. 

Written by G. John Mullen who received his Doctorate in Physical at University of Southern California (USC) and is a certified strength and conditioning specialist (CSCS). At USC, he was a clinical research assistant performing research on adolescent diabetes, lung adaptations to swimming, and swimming biomechanics. G. John has been featured in Swimming World Magazine, Swimmer Magazine, and the International Society of Swim Coaches Journal. He is currently the owner of COR, providing Physical Therapy, Personal Training, and Swim Lessons to swimmers and athletes of all skills and ages. He is also the creator of the Swimmer's Shoulder System, Swimming Science, Swimming Science Research Review, Mobility System and the Swimming Troubleshooting System.

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Open Water Swimming Performance Trends

Take Home Points on Open Water Swimming Performance Trends

Open water performance peaks in the mid to early 20s for both men and women. Overall performances have generally slowed. Slowing overall times may reflect the importance of tactical surging throughout the race.

Open water swimming has been around for many years, but has grown in stature with its

inclusion in the Olympic schedule. With Olympic hardware at stake, the sport attracts even higher level competition with stalwarts like Ous Meloulli and Grant Hackett having competed in the open water. Naturally, the sport has different demands than the pool, but shares common variables.

There’s plenty of research on open water safety and tactics for channel crossings and marathon swims, along with other research on triathlon swim performance (1500m to 2.4 miles in Olympic and Ironman events). However, our focus here will be on performance characteristics in the main swimming open water events: 5k, 10k, and 25k.

Most recently, Zinng (2014) studied over a decade of World Cup performances from 2000-2012. Key findings included the following:

1. Female swimming speed in the top 10 performances decreased in both the 5k and 25k events significantly, but significantly increased in the 10k. 
2. Male swimming speed in the top 10 decreased in the 5k, but remained unchanged in the other two events 
3. Females peaked at age 22.5 in the 5k, 23.4 in the 10k, 23.8 in the 25k. This average remained consistent through the study period. 
4. Males peaked at age 24.8 and 27.2 in the 5k and 25k respectively. During the study period, the peak age in the 10k increased significantly from 23.7 to 28.0. 

Vogt (2013) studied similar data, but in a shorter time period covering World Cup races from 2008 through 2012. This research team found that “performances remained stable for the fastest elite open water swimmers [both genders] at 10 km FINA competitions between 2008 and 2012, while performances of the top ten men tended to decrease.” They also completed a gender comparison, finding that in this sample (A total of 2,591 swimmers (i.e. 1,120 women and 1,471 men)), women were approximately 7% slower than male times. 

Though 7% was shown to be a smaller gender differential compared to other ultra-endurance sports, it is an even greater difference compared to pool times. As a reference, the difference between the 1500m male and female world records is approximately 3% (Sun Yang’s 14:31 vs. Katie Ledecky’s 15:36). It could also be true that because surging plays such a key role in open water events to stay with a pack (or break those trying to keep contact), the anaerobic demands may be underappreciated. Yet in a sample of elite open water swimmers, VanHeest (2004) found that “lactate threshold (LT) occurred at a pace equal to 88.75% of peak pace for males and 93.75% for females.” 

Practical Implications on Open Water Swimming Trends

Based on the current data, it’s hard to make training conclusions beyond those pertaining to each individual athlete. The data mostly serve a descriptive purpose and perhaps highlight the role of tactics and conditions in the open water. Though most would subjectively agree that more top level swimmers are testing the open water, times have not improved significantly, and in some cases have gotten slower. Regardless of time, it is abundantly clear that open water remains an outlet where post collegiate swimmers may continue competing at a high level without the competition from precocious age groupers!

References

1. Zingg MA, Rüst CA, Rosemann T, Lepers R, Knechtle B1. Analysis of swimming performance in FINA World Cup long-distance open water races. Extrem Physiol Med. 2014 Jan 2;3(1):2. doi: 10.1186/2046-7648-3-2.
2. Vogt P1, Rüst CA, Rosemann T, Lepers R, Knechtle B. Analysis of 10 km swimming performance of elite male and female open-water swimmers. Springerplus. 2013 Nov 12;2:603. doi: 10.1186/2193-1801-2-603. eCollection 2013.
3. VanHeest JL1, Mahoney CE, Herr L. J Strength Cond Res. 2004 May;18(2):302-5. Characteristics of elite open-water swimmers.

Written by Allan Phillips is a certified strength and conditioning specialist (CSCS) and owner of Pike Athletics. He is also an ASCA Level II coach and USA Triathlon coach. Allan is a co-author of the Troubleshooting System and was selected by Dr. Mullen as an assistant editor of the Swimming Science Research Review. He is currently pursuing a Doctorate in Physical Therapy at US Army-Baylor University.

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Weekly Round-up

Each week we aggregate recent swimming journals and blog posts relating to swimming biomechanics, physiology, nutrition, psychology, etc. If you wish to add, please add an article in the comments section.

Research Review

1. PLYOMETRIC LONG JUMP TRAINING WITH PROGRESSIVE LOADING IMPROVES KINETIC AND KINEMATIC SWIMMING START PARAMETERS.
2. Influence of Training Frequency on Serum Concentrations of Some Essential Trace Elements and Electrolytes in Male Swimmers.
3. Response inhibition impairs subsequent self-paced endurance performance.
4. Dynamic Compression Enhances Pressure-to-Pain Threshold in Elite Athlete Recovery: Exploratory Study.
5. The Relationship Between Propulsive Force in Tethered-Swimming and 200m-Front Crawl Performance.
6. Eight weeks of dynamic stretching during warm-ups improves jump power but not repeated or single sprint performance.
7. Effect of instructions on selected jump squat variables.

Blog Review

1. Double Your Gains With Plain Creatine Monohydrate: Up to 2.6x Greater Strength Gains on the Bench With 5g of Plain Creatine Monohydrate per Day in Trained Rookies
2. Hip Strengthening Better than Quads for Patellofemoral Pain
3. Is your vitamin D supplement helping or hurting you? – Precision Nutrition
4. Training For Gains: High Intensity, Low Volume Strength Gains Stick. Low Intensity, High Volume Gains Don't, But They Come With Significant Improvements in Body Comp
5. Protein Power - Study Suggests: 40%+ is Where True Magic Happens. Plus: If Protein is King, Whey is the Emperor
6. Four Tips to be Fast at the End of a Fly Race
7. Carb Controversy: Why Low-Carb Diets Have It All Wrong

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Friday Interview: Beat Knechtle Discusses Long Course Training

1. Please introduce yourself to the readers (how you started in the profession, education, credentials, experience, etc.).

Beat Knechtle started as a swimmer in youth, changed to triathlon and won several ultra-triathlons of the Double, Triple, Quintuple and Deca Iron ultra-triathlon distance. He works as primary care physician and is affiliated with the Institute of General Practice and for Health Services Research, University of Zurich, Zurich, Switzerland.

2. You recently published an article on differences between short course meters (SCM) and long course meters (LCM). Has this ever been looked at before?

No, interestingly the faster swimming speed over SCM (short course pools) compared to LCM (long course pools) is widely appreciated in swimming sport but this phenomenon was never scientifically addressed before.

We looked at this difference using extensive results for elite male and female swimmers over the full range of official race distances in freestyle swimming at national and international level.

3. Do you think the lack of literature is from people assuming they know and understand the differences between these distances?

From our perspective it is very important to clarify 1st whether there is a real difference between SCM and LCM and 2nd if yes what are the underlying mechanisms. With our current study we addressed the first point.

4. What exactly did you study do?

We analysed freestyle swimming performance over 50m, 100m, 200m, 400m, 800m and 1,500m by comparing SCM (25m-pool length) and LCM (50m-pool length) for 92,196 national swimmers (from Switzerland) and 1,104 international swimmers (finalists FINA World Championships) over a period of 13 years (2000 to 2012).

Furthermore, we looked also at the performance trend for the respective race distance over the study period.

5. What were the main results from your study?

The bottom line was that elite swimmers were on average 2.0% faster on SCM than on LCM. This was true for both genders at national and international level.

Furthermore, looking at the performance trend over the study period revealed that swimming speed of international men and women increased significantly in short and long course, whereas only men at national level were able to improve on short and long course events, but not women.

Interestingly, the sex-related differences in swimming speed increased over time for national swimmers but did not change significantly for international swimmers at any course length and distance.

6. Is SCM getting closer to LCM as swimmers utilize underwater kicking more?

As we first tried to identify whether there is a real difference between SCM and LCM we can only speculate about underlying mechanisms for this phenomenon.

Important reasons for a faster swimming speed in short course pools are most likely that swimmers spend about twice as long turning and gliding in 25m pools than in 50m pools. That leads to more recovery time over SCM resulting in a decrease in lactate production and an increase in lactate clearance in the upper body and arm muscles which are used for a regular stroke. Therefore, swimmers with a good turning performance have a particularly large advantage in SCM.

7. In the USA, we use a lot of short course yards training. Are the results likely similar for SCY?

Yes, swim speed results over SCY are most likely faster than on LCY. Although we can only extrapolate this from our study as this has also never been scientifically investigated on a larger scale.

8. What can a coach take away from this research?

Firstly, that there is a real difference between SCM and LCM. Swimmers are approximately 2% faster on SCM than on LCM. This difference is most probably caused by a different pattern of technique over these two pool lengths. Further research, especially including effects of anthropometric, biomechanical, and physiological factors, is required to fully understand the effects of course length on freestyle swimming performance. Nevertheless, vigorous and optimized training programs, focused on muscular force production in combination with efficient swimming skills are crucial points especially in SCM.

9. What research or projects are you currently working on or should we look from you in the future?

Regarding the topic of SCM and LCM we are about to determine whether course length has similar effects on other swim styles (i.e. backstroke, individual medley, breaststroke and butterfly).

Furthermore our research group covers topics like the age of peak swimming performance for all strokes and distances at national and international level.

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Swimmer’s Ear

Swimmer’s ear, or otitis externa, occurs when water becomes trapped in the ear canal,

creating a moist environment for bacterial growth, causing an infection. The condition accounts for almost $500m in U.S. health-care costs each year alone².

The condition can be particularly debilitating for frequent swimmers, particularly in chronic circumstances, so it’s important to be aware of some of the facts before getting in the water:

What causes swimmer’s ear?

The existence of moisture and water-loving bacteria like pseudomonas in the ear is a common cause of swimmer’s ear⁴_, while swimming in polluted water can increase the risk of infection too, caused by germs found in pools, lakes and seas_².

The condition is often associated with high humidity and warmer temperatures - research has shown that 44 percent of reported cases arise in June, July or August² making summer holidays the most likely catalyst.

Another cause of swimmer’s ear in children is the excessive use of cotton swabs while cleaning wax from the ears, or the use of pressure equalization tubes before swimming_3, which makes the skin inside the ear vulnerable to cracking or breaking, leading to a higher risk of infection.

Who gets swimmer’s ear?

The acute form of the condition annually affects four in 1,000 people, with the chronic form, showing signs or symptoms lasting three months or longer, affecting three to five percent of the population¹.

Children between five and 14 years old have the highest rates of infection, as a result of longer periods spent in the water, while adults 21 and older account for more than half of doctor visits¹. 

Divers and regular swimmers are also more likely to suffer from the condition due to frequent exposure to water and a higher likelihood of infection.

Symptoms

Symptoms of swimmer’s ear will onset over a few days to a week, characterized by a small amount of odorless liquid or puss, mild discomfort, redness and itching¹.If the condition worsens it leads to stronger symptoms, especially higher levels of pain and an obstruction within the lumen of the canal, making hearing difficult:

“Unfortunately, I’ve experienced far too many bouts with swimmer’s ear,” says U.S. freestyle sprint champion swimmer, Jason Lezak. “It is painful and uncomfortable and can literally keep you out of the water for a few days.”

Treatment

The most effective treatment of swimmer’s ear is by antibiotic drops containing a corticosteroid, which should reduce itching and redness, killing off bacteria, although doctors will prescribe oral antibiotics if the condition doesn’t quickly clear. 

"Topical antibiotics are effective at treating simple acute otitis externa although in up to 40 percent of cases, oral antibiotics are also prescribed," said Vivek Kaushik, a consultant otolaryngologist at Stepping Hill Hospital in Stockport, England. 

"The findings from our review confirm that topical treatment alone is highly effective and that additional antibiotics are not required."

Immediate treatment can also include a teaspoon of water and vinegar poured into each ear, which will help to clear the ear and reduce pressure before a doctor’s appointment.

Prevention

Swimmer’s ear can be prevented through the use of alcohol drops at the time of busy swimming periods like holidays or galas, while using an ear dryer on a low setting can also aid fluid clearance¹. 

Swimmers should also avoid using cotton swabs to clean the ears as ear wax helps to clean and lubricate the ear¹_, while avoiding areas of dirty water, ensuring that pools are chemically treated and clean. 

Earplugs like Alpine SwimSafe Earplugs also provide a safe and convenient solution, providing an effective seal against water while allowing you to hear ambient noises necessary for safe swimming. 

You don’t want to let swimmer’s ear ruin your busy practice schedule, after all. 

References:

1. Otitis Externa: Review and Clinical Update, Medical University of South Carolina (2006)
2. Morbidity and Mortality Weekly Report, U.S. Centres for Disease Control and Prevention (2011)
3. Cotton-tip applicators as a leading cause of otitis externa, Nussinovitch M, Rimon A, Volovitz B, Raveh E, Prais D, Amir J. Int J Pediatr Otorhinolaryngol (2004). 
4. Use of ototopical antibiotics in treating 3 common ear diseases, Hannley MT, Denneny JC III, Holzer SS, Otolaryngol Head Neck Surg. (2000);122:934–40.

Rob Doole is managing director at Allearplugs.com, check out his latest updates on Google+.

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