5 Hot Swimming Topics for Elite Swimmers

As a take home message:

  1. Some of the hot topics for elite swimmers are shared in this piece
  2. I will elaborate on what Science tell us on those topics and what we have yet to learn
  3. For further reading, I will share a few papers and interviews with leading researchers

We are on the road to two major international competitions: Kazan 2015 and Rio 2016. Everybody is looking forward for both competitions. Those that work on the backstage, such as analysts and researchers, hopefully are experienced, as hot topics can diverge training plans, sometimes for the better, sometimes for the worst.

Here you will find five selected hot topics, based on my personal opinion, that several coaches and elite swimmers have been seeking advice. You are most welcome to add more topics on the bottom of this piece. Please, be my guest.

The piece is structured in a not-too-wordy FAQ style:

  1. What do we know so far? I.e., what is the solid scientific knowledge on the topic and the take home message;
  2. What we don’t know yet? I.e., what are the gaps that we still find in the Science, the grey zone, or the limitations reported by the researchers;
  3. Where do I find more details on this? You can have deeper insight on these topics referring to selected research papers or interviews with leading researchers.

And without further ado, the selected topics are……

5 Hot Swimming Topics for Elite Swimmers

  1. High-intensity (interval) training & Ultra-short race-pace training

What do we know so far?

We do know that for low-tier swimmers, any training program is effective. Can be HI(I)T or any other program, including MICE (acronym

High Intensity Swimming Training

for “moderate-intensity continuous exercise”).

HI(I)T is on one end of the spectrum (High-intensity; low-volume) and MICE on the opposite end (Low-intensity; high-volume). USRPT is considered by some people as an extension of HI(I)T although including some extra features. We also find “mixed” programs with different Hi-Lo combinations of volume and intensity.

Mid-tier swimmers show the same performance enhancement regardless of the program being HI(I)T or MICE. Hence, HI(I)T can be considered as more efficient because they get the same outcome with lower physical and psychological stress.

What we don’t know yet?

We find anecdotal reports and claims that a few elite swimmers showed improvements or delivered good performances after a HI(I)T/USRPT program.

We don’t have solid scientific evidence that HI(I)T/USRPT is more or less effective in high-performance swimmers though. I.e., there is not sufficient evidence to endorse or discontinue HI(I)T/USRPT in elite swimmers.

Nevertheless, I am wondering if world-class coaches, at some point of the periodization program, include in their training sessions some of the HI(I)T concepts.

Where do I find more details on this?

Interviews to leading researchers on the topic can be found here and here.

One research paper can be retrieved here.

  1. Altitude

What do we know so far?

An altitude training camp should take roughly 4 weeks. The best times are posted 2-4 weeks after returning to sea level.

On the first week at sea level, performance might even impair. So re-acclimatization is a good moment for tapering before major competitions.

The duration of this recovery seems to be dependent on the event to be raced and individual characteristics of the swimmer.

Altitude training is related to the hypoxia effect, but also the fact of swimmers and coaches are completely focused on the training round the clock, with no need to juggle between different commitments.

Most of the times these camps are held at venues where swimmers can easily approach support staff (e.g., biomechanists, physiologists, Mireia Belmonte VO2 swimming test Altitude Trainingnutritionists, physical therapists, etc.) to be monitored, seeking their advice and thoughts (seems to improve performance at least by 3%).

What we don’t know yet?

There is an individual response to altitude, hence swimmers that are low-responders should be flagged beforehand.

The effect of intermediate- v high-altitude training is still a little bit controversial. I.e., what is the minimum altitude needed?

A lot of research will be done on the different combinations of Hi and Lo regimens.

The nocebo and placebo effects of being part on this kind of training camps is still to be studied.

Where do I find more details on this?

The interview to a leading researcher on the topic can be found here.

One research paper can be retrieved here.

  1. Warm-up

What do we know so far?

Active warm-up has a positive effect on the swimmer’s performance. Bigger effects were found notably for middle- and long-distance (i.e. 200m onwards) than for sprint events.

Pre-race dry-land stretching drills are a common practice as a complement to the in-water warm-up; despite no effects preventing injuries or enhancing the performance. Clarification: I’m talking about stretching before the race and not about a well-designed program over time to enhance flexibility to an optimal range of motion.

The in-water warm-up should last for 15–25 min, including a moderate-intensity set, another of specific drills focusing also on the stroke efficiency, a set with reps at the race pace, starts and turns.

For the time-lag between the in-water warm-up and the race, passive warm-up should be considered.

What we don’t know yet?

The optimal design (e.g., duration, volume, intensity, type of drills and recovery period) according to the event to be raced is not yet fully understood.

Little is known on the effect of different passive warm-up strategies, although none should rise the body temperature above 39 degrees Celsius, otherwise performance might impair.

Where do I find more details on this?

The interview to a leading researcher on the topic: still to come. Stay tuned.

One research paper can be retrieved here.

  1. Strength & conditioning

What do we know so far?

A S&C program concurrent to the in-water training helps to prevent injuries and enhance the performance.

A S&C coach should also monitor anthropometric features and sometimes a preliminary assessment of the body posture and limbs’ alignments. However, physiotherapists can run more comprehensive clinical tests.

The program must be coupled with a proper diet according to the goals to be achieved (i.e. swimmer should refer to a nutritionist).12th FINA World Swimming Championships (25m) - Day Three

S&C can help when the swimmer pushes solid bodies (i.e. block-start; wall-turns) being explosive power a major determinant.

Performance can also be improved while he pulls a fluid body (i.e. water-swim strokes).

Dryland S&C does not have a direct effect on the performance. The earlier one will have an influence on specific in-water parameters and the later on the performance.

As rule of thumb, routines should change every 3-4 weeks (i.e., mesocycle or block) and training loads adjusted to remain effective and avoid injuries.

What we don’t know yet?

The challenge though is the transfer of dry-land strength & power to water and make the best use of it swimming, turning and starting.

More reliable in-water measuring techniques could be developed in the new future. E.g., handgrip testing is not specific enough and tethered swim has some hydrodynamic limitations. Obviously, these tests also have some pros, but I won’t elaborate on that today.

One concern that we cannot rule out is how to build-up power (that is based on maximal strength) avoiding the significant increase of body surface area and weight that affects drag force, buoyancy and underwater torque.

Should the S&C session be before or after the in-water training?

Where do I find more details on this?

The interview to a leading researcher on the topic can be found here.

One research paper can be retrieved here and here.

  1. Starts & turns

What do we know so far?Doha 2014 Dive

Starts plus turns can account up to 50% in a sprint.

Turns can represent up to 30% of the race time in middle- and long-distance events.

Streamline gliding and dolphin kicks are important phases in both race moments.

Over the start, underwater phase (i.e. gliding and dolphin kick) depends upon above-water phases (i.e., take-off horizontal velocity and optimal flight trajectory).

What we don’t know yet?

The body of knowledge on the start seems to be more solid and consistent than for the turns.

The big challenge for the swimmer is to understand when to stop gliding and begin the dolphin kicks, stop the kicking and start or resume the swim stroke.

Where do I find more details on this?

The interview to a leading researcher on the topic can be found here and here.

One research paper can be retrieved here.

By Tiago M. Barbosa PhD degree recipient in Sport Sciences and faculty at the Nanyang Technological University, Singapore

The post 5 Hot Swimming Topics for Elite Swimmers appeared first on Swimming Science.

How to Analyze Breaststroke Swimming

As a take home message:
1. In this piece we did the analysis of three age-group breaststrokers.
2. Modeled data sometimes does not fit completely the individual data of a specific swimmer.
3. After benchmarking the swimmers against data retrieved from the literature we have learned that one of the swimmers is able to reach a high speed (strong point), but with a high speed fluctuation (main concern).
4. Several analyses were carried out to run a full diagnosis, prescribe what to change and predict the outcome of such improvements. He would be able to increase the speed by 0.1 m/s (faster) and decrease the speed fluctuation by 10% (more efficient).

In my latest piece eventually I shared a picture that depicts modeled and real data. At that time, it was explained that most textbooks and even research papers share modeled data because: (i) it will be easier to understand a concept having “smoothed” data and; (ii) the modeled curve aims to represent the main trend across all subjects assessed.

Unfortunately, there is a huge drawback of this. Most of the times the theoretical model does not fit in the data of one particular subject. In academia, this falls under the topic “universal versus individual data analysis” (Barbosa et al., 2010). I.e., data from a pooled sample of swimmers does not represent what is the best for my swimmer. Indeed, the inter-individual variability is a concern for several researchers (Seifert et al., 2011).

A very good example is the assessment of the speed fluctuation. The academic jargon for speed fluctuation is “intra-cyclic variation of the velocity”. Meaning, it is how speed changes over one fig1single stroke cycle. As you are aware the swim speed is the result of the balance between thrust (propulsion) and resistance (drag). So, over one single stroke cycle the speed goes up whenever the thrust is higher than the resistance. The speed goes down if the thrust is lower than the resistance.

Let’s apply these two concepts (universal v. individual analysis; assessment of the speed fluctuation) to breaststroke. Figure 1 (top panel) depicts what would be the typical speed fluctuation at breaststroke reported in a textbook. At the begging of the stroke cycle the speed goes up due to the kicking and eventually reaches a first peak (thrust by the kick is higher than the water resistance). After the kick the swimmer will glide in the streamlined position. Because there is no thrust, only passive drag is acting upon the body, the speed decreases and we can find that “valley”. After the glide it is performed the arms’ stroke and the speed increases once again (second peak). With the legs’ recovery the resistance increases significantly and speed goes south sharply.

Now, that we did the re-cap of the stroke cycle at breaststroke, I must share with you that this curve is the modeled data of three age-group breaststrokers. Figure 1 (bottom panel) depicts the variations in the modelled curve considering the individual differences among the three swimmers. For instance, at the beginning of the stroke cycle (the first upward slope, i.e., kicking) the vertical lines are rather small. That means that the three swimmers are quite similar, little difference can be found among them. But, the vertical lines on the second peak are big. So, it seems that the three are doing thing in a different way at this phase of the stroke cycle.

So far, we did the analysis of the pooled and modeled data of three swimmers (i.e. universal analysis). Moving on to the individual analysis. Figure 2 depicts the individual curves of each subject. One seems to be a top-tier age-group breaststroker (blue line), the other two a mid- and a low-tier swimmers (red and green lines, respectively). Now, you understand why I told you at the beginning that unfortunately the modeled curves most of the times do not fit the individual curves. Figure 1 was computed based on the data of these three swimmers represented in Figure 2. We can see that at the beginning the curves of the three match almost perfectly, but then start to drift away from each other. This is why the variation is low at the beginning of the cycle and high at the end as shared earlier (vertical lines, i.e. standard deviation, in figure 1 – bottom panel).

 

fig2

Now, we are ready to do the quantitative analysis. For the kinematic analysis, I selected the average swimming velocity (v), stroke frequency (SF), stroke length (SL), maximal velocity (v-max) and minimal velocity (v-min) within the stroke cycle. Two other variables were selected as efficiency estimators, and this includes the stroke index (Costill et al., 1985) and the speed fluctuation (e.g., Barbosa et al., 2005).

Based on the average speed over the cycle it is easy to follow that we are assessing swimmers of different competitive levels. The green swimmer has a lower speed, SF, SL, dv and v-max. What makes the difference between the blue and red swimmers? The SF is slightly higher, but the SL shorter for the later breaststroker. The red swimmer has a lower speed fluctuation than the blue counterpart. So, this deserves some further investigation.

table1

First things first, we should benchmark the swimmers against other subjects in our database or data retrieved from the literature. Today I will benchmark the swimmer against the data reported in a research paper (Barbosa et al., 2013). The black dots are the data reported in the paper, the coloured dots are our swimmers. We are benchmarking the relationship between speed fluctuation and swim velocity. Now, we are sure that the green swimmer is an average breaststroker, the red a mid-tier-almost-top-tier and the blue a top-performer. The main concern is that the blue swimmer despite reaching a high speed also shows a big speed fluctuation in comparison with two other counterparts that race at similar paces (1.2-1.3 m/s, black dots). These two reach the same speed with speed fluctuations lower than 40% though. Being the bigger picture, now we should do the analysis of the individual curve of the blue swimmer.

fig3

The top-left panel (figure 4) depicts the kick. The blue swimmer is the one reaching the highest speed (2.01m/s). The rate of speed development is the same for the three, but the kicking action is 0.03s longer for the blue swimmer (the kick took 0.28s). So, one might say that the kick power (or mechanical impulse) is quite nice for the three, the main difference might be in the legs’ insweep. This is the end of the kick, when the swimmer squeezes up the water between the calf and feet, the plantar surface almost touches each other and toes point backwards-inwards.fig4

The top-right panel (figure 4) is related to the glide. This seems to be a major drawback for the blue swimmer. The speed drops 0.99m/s in 0.32s. Probably the glide is a little bit too long and the body position not the best. For instance, the red swimmer does not have such a significant decrease in speed. One should have arms fully extended and horizontal, head in a neutral position between the upper-arms and looking downward-forward, hips high close to the surface, legs fully extended and horizontal with no sinking of the feet.

The bottom-left panel (figure 4) reports the arms’ action. That took 0.26s and he reached a maximal speed of 2.09m/s. The blue swimmer is very balanced because the ratio between the maximal speed reached by kick and arms is 2.01 v. 2.09m/s. Several breaststrokers are more kick-driven and neglect the arms’ stroke. Both the red and green swimmers are not able to reach the same speed over the arms’ stroke they did at the kicking. I.e., the second peak (arms) is smaller than the first (kick). If they improve the arms’ action, the average speed would increase even though at the cost of the efficiency (i.e. probably speed fluctuation would increase). With that, they would reach the performance level of the blue swimmer. After reaching such level, would be time to think about the speed fluctuation (which is what we are doing right now to the blue swimmer).

The bottom-right panel (figure 4) help us to have a deeper understanding of the legs’ recovery, when the knees and hips bend. This should be another concern for the blue swimmer. In 0.34s he loses 1.83m/s reaching the lowest speed (0.25m/s). I.e., for tenths of a second he almost stopped in the water. Avoid dropping the thighs. Less bend by the hip and keep the knees high. The end of the arms’ insweep and legs’ recovery happens at the same time. Head moves as one with the torso (spine completely aligned). Do not bend or extend the neck. This phase is all about tempo and sync between upper and lower limbs.

An analyst must be able to answer a few questions:

  1. What is happening?
  2. What can we do to improve?
  3. How much will be the improvement?

Well, the diagnosis is done. So we can try to help the blue swimmer to be one of the finest breaststrokers.

Time to re-cap what we’ve learned so far: his propulsion is very good. Let’s keep this good work. The resistance after the glide and legs’ recovery are two concerns and deserve special attention.

Good coaches will suggest a set of drills in order to improve the gliding position, the tempo (notably the duration of the glide), the thigh and shank positions over the legs’ recovery and timing between arms and legs. Follow the link for a comprehensive list of drills (WARNING: the original paper is in Portuguese. Sorry for the inconvenience. If you speak a Latin language it is easy to understand. Alternatively I have a nerdy solution for you: 1. Install the “google translate” in your smartphone or tablet; 2. Set the app to translate from Portuguese to English; 3. Below the field to type the word to be translated you will find the camera icon. Press that icon/button. 4. Point the camera to the text and the app will automatically translate the text for you. 5. To clarify: you need a hardcopy of the piece or softcopy being displayed in a second device. E.g., display the piece on a laptop and use the phone for the automatic and real-time translation).

A good analyst will try to predict what happens with the changes advised. He will have to work the math, do some modelling, signal processing, chunk the numbers and provide a result. My prediction for the blue swimmer is as follows. If over the legs’ recovery the speed does not decrease up to 0.25m/s but 0.33m/s, the speed fluctuation improves to 36.03% and the speed to 1.36m/s (i.e. 0.1m/s faster). Figure 5 includes the real glide (blue line) and the “optimal” glide (magenta line). If the swimmer improves his glide, the speed fluctuation reduces to 35.29% and the speed to the same 1.36m/s.

So, if the swimmer and the coach embark in only one of these two solutions, the dv-v will be 35%-1.36m/s. End of the day, shifting the blue dot in the figure 3 to the coordinates (35; 1.36) one can learn that the swimmer not only becomes the fastest but also the most efficient.

fig5

References
1. Barbosa TM, Keskinen KL, Fernandes RJ, Colaço C, Lima AB, Vilas-Boas JP. (2005). Energy cost and intra-cyclic variations of the velocity of the centre of mass in butterfly stroke. Eur J Appl Physiol. 93: 519-523.
2. Barbosa TM, Morouço P, Jesus S, Feitosa W, Costa MJ, Marinho DA, Silva AJ, Garrido ND (2013). Interaction between speed fluctuation and swimming velocity in young competitive swimmers. Int J Sports Med. 34(2): 123-130
3. Costill D, Kovaleski J, Porter D, Fielding R, King D (1985). Energy expenditure during front crawl swimming: predicting success in middle-distance events. Int J Sports Med. 6: 266-270
4. Seifert L, Leblanc H, Herault R, Komar J, Button C, Chollet D. (2011). Inter-individual variability in the upper-lower limb breaststroke coordination (2011). Hum Mov Sci 3:550-65

By Tiago M. Barbosa PhD degree recipient in Sport Sciences and faculty at the Nanyang Technological University, Singapore

The post How to Analyze Breaststroke Swimming appeared first on Swimming Science.

Masters Swimming: 2014 FINA World Top-10

Take Home Message on Masters Swimming Performance:
1. The aim was to compare the performance in some of the most popular events across different master´s age-groups and elite counterparts (50, 100, 200 and 400 LCM freestyle);
2. The average race speed decreases with age in the four selected events;
3. Elite swimmers are more homogeneous than remaining age-groups. The coefficient of variation (an index of how competitive is an event within an age-group) is rather low (i.e. highly competitive) till the 65-69y for the sprints and by 50-54y and 55-59y for long-distances events;
4. The partial difference between elite and master swimmers increases with the distance. Master swimmers are able to keep a difference up to 10% of elites´ performance till their 40-44 years-old. The sharp decreases happen from this age on.

Masters swimming competitions are increasingly popular these days. It is all about racing, competitions and bonding Not your typical masters swimmerfor a lot of middle-aged people (some are former competitive swimmers and others that never were). A little bit more of belly hiding the 6 pack, not as bulky as they used to be, but the same desire to touch the wall in the first place as 2-3 decades ago. The number of competitions in US, Australia, Europe and Asia is increasing at fast-pace. For instance, in Japan (and probably in other countries) almost every weekend is held at least one master competition. Checking the times posted by people in their 40s-50s one will be surprised how fast these guys still are. I will showcase with two swimmers in the 2014 FINA Master World top-10 ranking (LCM): (i) Brent Barnes (SIN, 55-59) ranked 1st in the 50 free with 25.83s; (ii) José Freitas (POR, 50-54) ranked 2nd in the 200 free with 2:07.64s. And yes, the nationalities were not chosen randomly, you are right…

Determinants of Masters Swimming Performance

As far as research concerns, there is a major drawback. Of the papers published on masters swimming, fitness-oriented and recreational subjects are often recruited for research on performance. It is just like assessing a saloon (some countries named it as “sedan”) to learn how to improve a GT car. The GT car resembles a sedan, have similar car body design, but completely different components under the bonnet. Well, that´s my two cents. Others are entitled to their opinion and I respect them. Only a few research papers share evidence on “competitive” masters swimmers, including those that retired as competitive athletes and shift to master swim (e.g. Mejias et al., 2014). There is a lot to learn on masters swimming. Probably this is one of the most interesting topics to carry out research and only now we started to gather some insights.

As happens with elite and young counterparts, master´s performance is related to the biomechanical and energetic profiles (Ferreira et al., 2014; 2015). You can always re-cap some of these factors referring to the pieces published here on the Swimming Science by Allan Phillips #1 #2. Today, though, I will focus on the main outcome: performance. My aim is to compare the performance in some of the most popular events (men´s 50, 100, 200 and 400 LCM freestyle) across different master´s age-groups and elite counterparts. Times were retrieved from the 2014 FINA master world top-10 rankings and 2014 FINA rankings for the top-10 elite swimmers.

Analysis of Masters Swimming Top-10

As expected the average race speed decreases with increasing age in the four events (Fig 1). Comparing elite swimmers with the 25-29 age-group we can see a sharp decrease, even though both are somewhere in their 20s. In an earlier piece I reported the same findings. In sport science, there is a discussion about nature and nurture. Here we have a clue that albeit nature is important, other factors play determinant roles. Age might have a significant effect, but something else is also involved in the performance impairment over time.

The vertical lines represent the data dispersion i.e., how competitive is an event within an age-group. Narrow vertical lines represent low dispersion (hence, times are very close together being a very competitive event). Overall, it seems that as the distance increase, likewise the dispersion also increases (i.e. less competitive). However in a given event, the competitive level is not homogeneous. For example, refer to the 400 free (red line): the 35-39 and 45-49 age-groups are less competitive than the 40-44 and following ones. With that said, the main trend is to the performance dispersion increase with age (e.g. 50 free, 100 free and 200 free). At least in these three events younger master swimmers deliver more consistent performances than the older counterparts. I am confident on that all the way till the 90-94y. From this age onwards we find less than 10 swimmers per event, therefore not so sure.

Figure 1 with legend

To have a deeper insight I will report three basic statistics to quantify the changes (table 1): (i) the mean; (ii) the median – it splits the data into lower and upper half. If I report that the median income in a country is 2,000 dollars it means that at least half of the population earns that much and the other half more than 2k. Hence, if in a group of 10 swimmers the median is 2.00m/s it means that at least 5 swimmer race at that speed or faster; (iii) coefficient of variation – it is a standardized measure of dispersion. It enables us to learn how competitive the swimmers are within an age-group. The parameter ranges between 0 and 100%. If theoretically all the 10 swimmers have exactly the same time this is extremely competitive and the coefficient returns the value of 0%. So, lower the coefficient of variation, more tightly and close together are the performances (0% means very competitive; 100% not so competitive).

Now, I will explain how to interpret the data for the 45-49 age-group in the 400 free event and then you can do it yourself for the remaining events and age-groups (table 1). On average, the 2014 top-10 45-49y swimmers raced at 1.63m/s (mean), half of them at least at 1.52 m/s (median) and there is a data dispersion of 19.83% (coefficient of variation). Obviously elite swimmers are more homogeneous than remaining age-groups. The coefficient of variation is rather low till the 65-69y for the 50 and 100 free, by 50-54y and 55-59y for remaining events.

tabe 1 with legend

Another way to do the analysis is comparing the partial difference (i.e. %) instead of the absolute values (i.e. m/s). So, we must consider that elite swimmers show the best performances (100%). From here I did the calculation of how much does represent the performance at a given age-group in percentage. The top panel are the average values and the bottom is the same data after modelling it. When we read a good textbook most of the times we find nice, smooth and beautiful graphs because it is data modeled. It is easier to understand a concept having the “smoothed” data, there is little variance and random noise in the dataset. Today I am providing both ways to depict the performance change over time.

The partial difference is higher in the 400 free and lower in the 50 free. So, the partial difference increases with the distance. According to the model (Fig2, bottom) master swimmers are able to keep a difference up to 10% till the 40-44y. At 80-84 and 85-89y the swimmers deliver 50% of the elites´ performances. Between mid-20s and late 40s swimmers are able to keep a fairly stable performance (i.e. slight decrease over these 15-20 years). The sharp impairment happens from this age on; despite there is no clear inflection point. Hence, we cannot set a milestone as “this is the age when everything shifts so we must pay extra attention”.

figure 2 with legend
As shared at the beginning, energetics is a major player. For instance in one of our research projects, aerobic metabolism was the major contributor to total energy expenditure in the 200 free in both genders, albeit the partial aerobic contribution was higher in women and the partial anaerobic contribution greater in men (Ferreira et al., 2014). It is not clear if this is completely due to the gender or the performance level. Because men posted were better times than women. So it might be a gender effect, a performance effect or an interaction between gender and performance level. However, in masters swimming it is very challenging to improve the energetics if they are already in shape. To build-up further these parameters one must increase the external training load i.e., train more often or for longer to increase the training volume, intensity and elicit such energetic pathways. This is a big challenge for a masters swimmer that has to juggle work and family commitments. If one manages to train a little bit more and harder, on the flip side of the coin are the overuse injuries due to the increase in the external training load. With aging, the odds of an injury increase significantly. Another strategy might be to preserve the energetics as much as possible and concurrently improve the technique (Ferreira et al., 2015). However, at least “young” masters that were former elite swimmers showed to be able to have the same swimming efficiency (Mejias et al., 2014). In comparison to elite swimmers, these masters clearly impaired the energetics (V4, vVO2max, peakVO2, total energy expenditure), but kept the stroke length and propelling efficiency.

It seems that there are several ways to enhance the performance in masters swimming and one should tailor a solution that best fit his/her specific characteristics, background and goals. Nevertheless, we are still in an early stage of gathering knowledge on masters swimming. Research is eagerly needed so that we are in conditions to design more effective and efficient training programs to these swimmers.

References:
1. Ferreira, M. I., Barbosa, T. M., Neiva, H. P., Vilaça-Alves, J., Costa, M. J., & Marinho, D. A. (2014). Changes of the energetic profile in masters swimmers over a season. The Journal of sports medicine and physical fitness. Online-first.
2. Ferreira, M. I., Barbosa, T. M., Neiva, H. P., Marta, C. C., Costa, M. J., Marinho, D. A. & Bolama, R. M. D. A. (2015). The effect of gender, energetics and biomechanics on swimming masters performance. Journal of strength and conditioning research. Online-first.
3. Mejias, J. E., Bragada, J. A., Costa, M. J., Reis, V. M., Garrido, N. D., & Barbosa, T. M. (2014). “Young” masters vs. elite swimmers: comparison of performance, energetics, kinematics and efficiency: original research article. International SportMed Journal, 15(2), 165-177.

By Tiago M. Barbosa PhD degree recipient in Sport Sciences and faculty at the Nanyang Technological University, Singapore

The post Masters Swimming: 2014 FINA World Top-10 appeared first on Swimming Science.

Swimming Turns and Starts Guide to Glide and Depth

Take Home Message:
1. The aim was to perform the analysis of the final time improvement at different swimming turns push-off intensities and glide depths of a former world-ranked swimmer
2. The velocity would be 1.50, 2.18 and 3.02m/s performing the push-off 0.75m deep at 1.1, 1.5 and 2BW, respectively
3. For this swimmer, the optimal depth would be between 1.25 and 1.50m.
4. He/she would be shaving between 0.029-0.034, 0.014-0.016 and 0.007-0.008s if the push-off would be done at 1.1, 1.5 and 2.0BWs, respectively.


Every now and then I get e-mails by coaches seeking my advice on different matters, ranging from swimming turns to starts to psychology. I have to say, they are quite friendly and generous complimenting my effort (probably not always so well succeed) to explain in a straightforward way the technological innovations that can be implemented in competitive swimming.

I got a few messages bringing my attention to the talks delivered in Doha by world-class coaches at the FINA Swimming Coaches Golden Clinic. You can find the lectures on the FINA’s YouTube® channel. I will share the talk delivered by Fred Vergnoux and from here you can easily find the remaining videos. Be prepared for some hours of great viewing on swimming turns, starts, and much more! I watched all of them back-to-back and a couple did it twice.

Why did I enjoy so much? Because the clinic did not feature a group of academics (I hope not to offend my peers…) that were explaining how innovation, science and technology helps the swimmers to excel. In most of the talks, top-class coaches were able to go straight to the point on how a given device or test can be used to implement a holistic evidence-practice. They not only explain the testing procedures and devices selected, but also showcased how the insight was useful for their daily practice. However, eventually all coaches acknowledged having advisers as very well-known and established swimming researchers.

Swimming Turns and Starts

A concern that crossed over most talks was the swimming turns and starts. How to improve these two moments of the swimming race? Getting back to the e-mails that I got. Some people sought my advice on start & turns, while others suggested me to publish a post on the topic. Previously, I shared a piece on the dolphin kick. But, before the underwater kick there is the push-off and the glide. So, today let’s do the analysis of these two moments.

Swimming Turns Testing Push-Off

We do know that the swimming turns push-off must be as powerful as possible. How to measure this? Imagine that you weight yourself on a weighting scale and it displays 70kg. In your case, one body weight (to be accurate “body mass”) is 70 kg. Now, put the weighting scale on a track. You will jog and one of the strides must hit on the weighting scale. Ask someone to check the weight displayed in that exact moment that the foot strikes. The value was 210kg. Therefore, you stride at 3 times your body weight (210kg/70kg=3.0BW). In biomechanics, we have at our disposal some fancy weighting scales by the name of force plates. Not so different of the wi-fiit® though. If we set one force platform on the head-wall of the swimming pool it is possible to measure the intensity of a push-off (i.e. ground reaction force). There is evidence that good swimmers will perform the push-off between 1.1 and 1.5 body weights (BW) (e.g., Lyttle et al., 1999). In some extreme cases, they may go up to almost 2.0BW.

Swimming Turns Glide Tests

But, then we have another concern: what is the best depth for swimming turns glide? To learn that computer fluid dynamics (CFD) can be used (Marinho et al., 2009). CFD is applied in several settings and notably in motor sports. I went to my database and retrieved some old CFD data of one swimmer that our research group did the hydrodynamic analysis a long, long time ago. The swimmer used to compete on a regular basis at major international competitions (OG, WC) and has the anthropometrical features (i.e., height, weight, arm span, etc.) of a typical 100 & 200 finalist at freestyle and butterfly events. He/she as several swimmers used to perform the glide in the streamlined position at 0.75-1.0m deep.

Ok, now it’s time to advise my swimmer of the ideal swimming turns depth and push-off intensity. Let’s say that the race includes 4 glides (one at the start plus three turns). It can be the 100 SCM event or the 200 LCM (in both he/she must perform 4 glides). The question addressed to me would be: so what is the best depth and push-off? How much can I shave to the final time? I will have as a baseline a glide at 0.75m and be working from there to check what happens if he/she glides: (i) deeper or shallower than that; (ii) after a more or less powerful push-off.

Swimming Turns Push-Off

Intuitively we would say that, higher the intensity of the swimming turns push-off, the better. And the findings confirm that. He/she would have a velocity of 1.50, 2.18 and 3.02m/s performing the push-off 0.75m deep at 1.1, 1.5 and 2BW, respectively. These figures are in accordance to what can be found in the literature (Lyttle et al., 1999; Pereira et al., 2008).

If you do the push-off on an ice ring, your body will displace at a steady speed (i.e. uniform motion) because the ice and air resistance are rather low. In the water though, the drag resistance is a major player, leading to a sharp decay on the speed. That´s why we need to monitor the drag force by CFD or any other testing procedure. The bottom line is that the swimming turns push-off velocity is important, but to have an accurate estimation of the time shaved we must control the drag force and how it will affect the speed decay over the glide.

Swimming Turns Depth

Moving on to the next part of the question: the swimming turns depth. Gliding between the surface and the 0.75m or deeper than 2.5m (yes, you are right no one would glide so deep…) there is no improvement (Fig 1). Actually, the time impairs no matter the push-off intensity in these two bands.

For this swimmer, the optimal depth would be between 1.25 and 1.50m. He/she would be shaving between 0.029-0.034, 0.014-0.016 and 0.007-0.008s if the push-off would be done at 1.1, 1.5 and 2.0BWs, respectively. If the event includes 8 glides (200SCM or 400LCM) the swimmer would improve up to 0.032-0.068s.

Swimming Turns Depth

Swimming Turns Push-off and Glide Improvement

One may argue than an improvement of 0.014-0.068s it’s not exactly impressive, which is partially right. But then again, we are only analyzing the swimming turns glides and neglecting other race moments. If we add these 0.014-0.068s to other improvements, this is something to take into account. Here it is the typical marginal gain “theory” taking place as popularized by Dave Brailsford. Plus, we all are able to recall dramatic races that a swimmer won/lost a gold medal, got a record, did the cut-off to the national squad by 0.014-0.068s.

For those that are not so familiar with swimming, please refer to table 1. You will find the final times in one of the most exciting races in the recent swimming history: Men’s 200m butterfly final at the London 2012 Olympic Games. I am not suggesting that in this particular race the glide was the determinant factor. It is far more complex than that. The point here is to showcase to laymen that there are races decided by as little as 0.1s or even less.

table1A follow-up question would be how long the swimmer should glide. That is a very interesting point, and let me keep this hanging here. We might cover that topic some other time. Allow me to wrap-up saying that the data shared in this piece are only representative of this former swimmer and does not mean necessarily that are the optimal values to others. This kind of analysis must be tailored to the swimmer´s characteristics and race strategy.

Hopefully, I was able to showcase how innovation, science and technology can be useful; despite in a less brilliant way than the presenters at the Coaches Clinic in Doha.

Have fun watching the talks!

References:

  1. Lyttle AD, Blanksby BA, Elliott BC, Lloyd DG (1999). Investigating kinetics in the freestyle flip turn push-off. J Appl Biomech 15: 242-252
  2. Marinho DA, Barbosa TM, Klendlie PL, Vilas-Boas JP, Alves FB, Rouboa AI, SILVA AJ (2009). Swimming Simulation. In: Peter M (ed.). Computational Fluid Dynamics for Sport Simulation. pp. 33-61. Springer-Verlag. Heidelberg.
  3. Pereira S, Vilar S, Gonçalves P, Figueiredo P, Fernandes R, Roesler H, Vilas-Boas JP (2008). A combined biomechanical analysis of the flip turn technique. In: Kwon YH, Shim J, Shim JK , Shin IS (eds). 26 International Conference on Biomechanics in Sports. pp. 699-702. Seoul.

By Tiago M. Barbosa PhD degree recipient in Sport Sciences and faculty at the Nanyang Technological University, Singapore

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Comparison of the Short Course Meters Woman’s 100 Breaststroke World Record

Take Home Message:

  1. The aim was to: (i) compare Ruta Meilutyte (LTU) WR in Moscow (October 2013) and Alia Atkinson (JAM) in Doha (November 2014), both with a time of 1:02.36; (ii) learn the effect of the taper on Alia´s performance (Singapore vs. Doha races, 5 weeks apart).
  2. Water entry and water break was not different comparing Ruta and Alia.
  3. Alia Atkinson showed a shift in the stroke kinematics between the Singapore and Doha events (decrease in the clean speed, stroke length and efficiency but increase in the stroke rate).
  4. Alia’s breakout was around the 8-9m and 9-10m distances in Singapore and Doha, respectively. She not only stayed underwater longer, but the turning speed was also higher (10.6% and 6.9% faster in the first and last turns).

A lot was already said about Alia´s WR and gold medal at the SCM World Championships held last December in Doha. It is great for her, for Jamaica and for the World swimming according to the reasons pointed out in a very comprehensive way in the specialized media. Let´s go back one month, November 2014. Early that month, a few weeks before the Championships, it was held here in Singapore the last leg of the 2014 FINA World Cup Series. Overall, the leg was fairly entertaining considering that: (i) most swimmers were away from home at several weeks to compete at the legs of the Asian cluster; (ii) each leg is a two-days meet packed with a lot of events; (iii) most swimmers race more than two events per day; (iv) there are claims that some of them still have training sessions between the morning and evening races; (v) probably they are looking forward to the World Championships in 4-5 weeks time. However, a couple of athletes posted very promising races, swimming at world record paces.

That time, my comment to a few friends and peers was that if Chad and Alia can race at WR pace 4-5 weeks before Doha, after a good taper, probably they will smash some records in December. So, we must keep an eye on them. Surprisingly, at least for some people, that did happen. So this bring us to today´s post: (i) compare Ruta Meilutyte (LTU) WR in Moscow (October 2013) and Alia Atkinson (JAM) in Doha (November 2014), both with a time of 1:02.36; (ii) learn the effect of the taper on Alia´s performance (Singapore vs. Doha, 5 weeks apart).

Race analysis was done as reported in my previous posts on Ruta Meilutyte’s 100 SCM World Record Race Analysis. The Doha race can be found on YouTube® and the one in Singapore I recorded on the stands.

Ruta is well known to be very quick on the blocks (i.e. reaction time). However the water entry and water break is not so different comparing RM and AA (table 1). Between Singapore and Doha, Alia covered one more meter fully immersed but only spent an extra 0.13s. Hence, one might consider that she improved the first and second glides in the start (RM: 2.43m/s; AA: 2.30m/s and 2.44m/s; an improvement of 5.8% in 5 weeks).

table 1

AA was slightly faster in the first split than RM (AA: 29.46s; RM: 29.56s) but that paid-off even though she was slower by 0.1s in the following one (Table 2). In Singapore, AA did the first split at the WR pace (29.58s). I am not sure if she was only testing paces, really wanted to break the World record but was too tired, saving energy for the remaining events of the session because she raced back-to-back two finals: the W100Br (at 06:24pm) and the W200IM (at 06:53pm). Only she and her coach have the right answer to that.

table 2

Surprisingly the Atkinson´s stroke kinematics were slightly lower than the one performed by RM (table 3). Clean speed, stroke length and efficiency (i.e. stroke index) are lower, but the stroke rate higher. Interestingly, the same trend can be verified comparing the Singapore leg with Doha´s final. In Singapore, 81.8% of the speed was related to the stroke length, while in Doha only 35.34%. So, it seems that she had a strategy based on the stroke rate in Doha, a nice and “smoother” technique in Singapore.

So far, we learned that Alia Atkinson start was quite good, and there was a shift in the stroke kinematics. This lead us to the question on how did she performed during the turns and the finish.
table 3

Over the three turns, AA increased the distance to the water break (table 4). She was doing the water break around the 8-9m and 9-10m distances in Singapore and Doha, respectively. Not only she stayed longer fully immersed but the turning speed was also higher (10.6% and 6.9% faster in the first and last turns). Regarding the finish, the difference between RM and AA is 0.06s. AA showed a slight improvement by 0.04s (1.2%) between November and December. Therefore, it seems that the turns were determinant for Alias Atkinson World Record.
table 4

table 5

To wrap-up, comparing RM and AA WR at the W100Br by the same time of 1:02.36, it seems that the start and the turns were determinants for the later swimmer´s performance. Over that race, the clean swimming relied more on the stroke rate than the stroke length or swimming efficiency. That improvement on the start and turns did happen between the race delivered in Singapore and the final in Doha. Moreover, there was a slight shift in the swimming mechanics (higher SR, lower SL).

Can’t wait for the long course meters woman’s 100 breaststroke world record showdown, any predictions?

By Tiago M. Barbosa PhD degree recipient in Sport Sciences and faculty at the Nanyang Technological University, Singapore

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Summary of Doha 2014 Swimming World Championships

Take Home Message:

  1. It was carried out a descriptive analysis and comparison of the overall performances (FINA points) at Doha 2014 Swimming World Championships (25 m).
  2. The best Women´s performance was delivered by Mireia Belmonte Garcia (ESP) at the 200 butterfly (FINA points = 1029). On the men´s side, the best performance is delivered by Florent Manaudou (FRA) at the 50 backstroke (FINA points = 1053).
  3. On average the women got more FINA points than the men (comparison of the gold medalists, podium, and finalists).
    Considering only the medalists, the men´s butterfly events (FINA points = 966.44, 1 WR in 3 events) and women´s backstroke events (FINA points = 989.67, 3 WR in 3 events) were on average the best.

We reach the end of another amazing World Championship. Even though several top swimmers were absent, 23 World Records were broken (14 individual events, 9 relays) and several other great performances delivered. We do know the competitive value of the absent swimmers albeit that does not make these Championships less attractive for a swim fan. The 2013 Barcelona World Championships reached a cumulative TV audience of almost 4.5 bilion viewers worldwide according to Kantar Media and it’s expected the figures are much higher for Doha 2014.

In table 1 and 2 you can recap the finalists at the individual events. Swimmers that raced more than once are in color cells so that will be easier to spot them. Hopefully there are no typos, because this is a tedious task. In 51 podium slots, only 5 women and 7 men got one single medal. All the others step on the podium and took home two or more medals. Based on the color matrix I would say (by random assignment) that K Hosszu (HUN), M Belmonte Garcia (ESP), S Sjostrom (SWE), E Seebohm (AUS), C le Clos (RSA), F França Silva (BRA), F Manaudou (FRA) are the top-performers. I have to acknowledge this is very subjective so you might have a different opinion.

I am aware that some people have serious concerns on the FINA points. Even though it is not a perfect system, so far it is the best available. I did a basic descriptive analysis only for the individual events (table 3). Women broke 10 world records (10 in 17 events, i.e. 58.82%) and men 4 (23.53%). The best Women´s performance was delivered by Mireia Belmonte Garcia (ESP) at the 200 fly (FINA points = 1029; you can recap the highlights of this race in a couple of posts published earlier: #1, #2). On the men´s side, the best performance is delivered by Florent Manaudou (FRA) at the 50 back (FINA points = 1053). With that being said, several other races were as impressive and exciting as these two. On average the ladies got better performances than the men (gold medalists, podium, and finalists).

In table 4, you have the breakdown of the FINA points by event. The W 100 Fr (SD=3.06) and M 200 Br (SD=10.50) were the events with tightest finish (i.e. smallest time difference between the winner and the other medalists). Considering the 8 swimmers racing, the best final was the W 50 Bk (FINA points = 955.50) and the M 100 IM (FINA points = 954.38). Considering only the medalists, the men´s butterfly events (FINA points = 966.44, 1 WR in 3 events) and women´s backstroke events (FINA points = 989.67, 3 WR in 3 events) were on average the best.

To wrap-up, we had 5 days of exciting races and awesome performances. I am looking forward for Kazan 2015 to see all these swimmers in action once again and what others will be up to. In the next posts, I will try to provide some insight on other races held in Doha. So please stay tuned.

By Tiago M. Barbosa PhD degree recipient in Sport Sciences and faculty at the Nanyang Technological University, Singapore

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Florent Manaudou 50m Power

Take Home Points:

  1. The aim of this post is to analyze the reaction time and the anaerobic alactic power over the Men´s 50m Freestyle final at the Doha 2014 World Championships (25m) that 2014 Doha World Championships Knee Flexion StartFlorent Manaudou (FN, FRA) won (20.26, WR).
  2. Lighter swimmers seem to have a faster reaction time. However, if FM is benchmarked with swimmers that have similar weight, he was better.
  3. Comparing the anaerobic alactic power for the first eight swimmers, on average, the power output was 3.714kW in the semi-finals and increased to 3.739kW in the final.
  4. While FM and Marco Orsi (ITA) increase slightly the power from the semis to the final, two of the main contenders to a medal (Cesar Cielho Filho, BRA; Vladimir Morozov, RUS) decrease it slightly.

Today’s post is on the outstanding race by Florent Manaudou 50m (FM, FRA) at the Men´s 50m Freestyle (20.26, WR). In a sprint like this an analyst must begin with the reaction times. FM reaction time is not completely impressive compared to other swimmers (RT=0.63s in the final; RT=0.62s in the semi-final). But after comparing these starts with others over this and last year, it seems that he is consistent (for more details on the definition of consistency and variability, please have a sneak peak at my previous post).

Nevertheless, we should bear in mind that FM is tall and heavy. This is pure mechanics. Heavier the body, more challenging is to change its motion (Newton´s First Law of motion). I plotted the reactions times against the body mass of the sprinters racing the final and semi-finals (Fig 1). We can see that the weights´ range is similar for finalists and semi-finalists. We have no conditions to state that one group is heavier than the other. However, on average the finalists are quicker on the block. The trend is the same if we are talking about reaction times during the heats, semi-finals or final. Good sprinters have a better reaction time. The effect of the body mass is less determinant for the finalists than semi-finalists (i.e. the slope of the trend line is higher for the semi-finalists than for the finalists). For a deeper insight on the relationship between the reaction time and the performance I invite you to read this paper and the interview delivered to this blog by the leading author.

The two circles represent FM (red is the reaction time during the final, orange during the semis). A couple of other swimmers have a weight similar to him, but poorer reaction times (We didn’t plot the prelim reaction time, as it was the same as his reaction time in the finals, this is also the case for other swimmers and why they aren’t plotted).

Based on this graph, you may think “a sprinter should be slim and light, so they have a quick reaction time”, but reaction time isn’t the only variable…

Another part of the equation of elite sprinting is anaerobic alactic power (AnAl). For a bout that takes 20-25s this is definitely the energetic pathway to be monitored. On top of that, the anaerobic alactic power is associated to lean mass (i.e. muscle power). So, one might be 0.01-0.03s slower on the blocks because is heavier, but all that muscle mass is most useful to produce power in the water.

Please understand that these last posts are prepared in a rush. I have no time to elaborate, add citations and edit the text several times before uploading it. For more details on the procedures to estimate the anaerobic alactic power, kindly refer to an earlier post. To estimate the parameter body mass for each swimmer is needed and unfortunately, I couldn’t find two swimmers body masses. Another limitation is the difference in weight listed online, compared to their actual race weight. We must use what is online, but realize this likely is incorrect.

In the 1990s, the aerobic, anaerobic lactic and anaerobic alactic contribution to total power at the 45.7m sprint (velocity: 1.97+/- 0.07m/s; average weight: 76.9kg) was reported as being 16.8, 58.2 and 24.9%. It remains to be answered if the figures are the same for world-ranked sprinters these days because anthropometrics & training method changed so much in the mean time. A paper published a couple of years ago recruited international level swimmers to perform the 200m Freestyle. They reported for the first split (0-50m) an anaerobic alactic power of 1.09 kW and a partial contribution of 41%. A 50-m freestyle is more complex than you may realize, as it is not 50m, but 2x25m. So, these are two bouts of approximately 8s (neglecting start and turns). We expected the anaerobic alactic power in these elite swimmers in the 50-m to be much higher than previously reported. The anaerobic alactic power that I got is way higher than anything else reported in the literature so far (table 1). Once again, this large difference is from the distance of the event (200m vs. 50m) and the skill level of the athletes (the most elite were the ones we tested).

During the semi-final, on average, the anaerobic alactic power was higher in the swimmers that moved on to the final (finalists: 3.714kW; semi-finalists: 3.515kW). If we compare the semi-final and the final for the first eight swimmers, the anaerobic alactic power also increases (semi-final: 3.714kW; final: 3.739kW). While FM and Marco Orsi (ITA) slightly increased their power from the semis to the final, two of the main contenders to a medal (Cesar Cielho Filho, BRA; Vladimir Morozov, RUS) slightly decreased their power. This decrease in power may explain why Cesar Cielho Filho and Vladimir Morozov had slower and slightly disappointing races.

Overall, this analysis demonstrates the complexity of the 50-meter freestyle. It also shows that reaction time is very dependent on athlete size. Also, it provides some insight, showing that anaerobic alactic power may contribute to overall 50-meter race time.

By Tiago M. Barbosa PhD degree recipient in Sport Sciences and faculty at the Nanyang Technological University, Singapore

 

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Why Katinka Hosszu Went Out so fast at World Championships in the 200 Butterfly

Take Home Points:
  1. The Spaniard Mireia Belmonte Garcia shaved 1.17 second to the Women 200m Butterfly WR, being the first lady swimming bellow 2 minutes (1:59.61). Silver medal was snatched by Katinka Hosszu (HUN) with a final time of 2:01.12
  2. In this post you will find the analysis of the race strategy by these two swimmers during the final and on the way to the World Championships.
  3. Considering all FINA World Cup legs, MBG did on average the first half of the race in 1:00.67 and the second half in 1:04.07; while KH 0:59.90 and 1:05.06. So, the difference between them was an advantage of 0.764s for KH in the first 100m and a disadvantage of 0.997s.

So far, the best race at the Doha 2014 World Championships (25m) was delivered by the Spaniard Mireia Belmonte Garcia (MBG) in the Women 200 butterfly final, breaking the World record by more than one second. In another piece you may find the video and an analysis to her race. Today, we will try to have some insight on the race strategy and the build-up on the way to this final. Both Mireia and Katinka Hosszu (KH, HUN) delivered some of the most entertaining races over the FINA World Cup Series this year. So, why not compare the two of them?

The best World Cup performance was delivered by MBG in the Moscow leg (2:02.99) and by KH in Tokyo (2:03.14). At the 2014 World Championships the Spaniard clocked (1:59.61, WR) and shaved 1.17 second to the record set by Liu Zige (CHI) in 2009. Katinka Hosszu clocked 2:01.12 in the same final. Both swimmers show the same typical profile, being the first half of the race faster than the second half (Fig 1). As usual the first split is the fastest. The 4th split was the slowest for the Spaniard till early October. From October onwards, the 3rd split becomes slower than the 4th.

It is more interesting is to compare both swimmers in each split (fig 2). Over time we can see a trend for a slight improvement in the reaction time for MBG. With no surprise, the split times are better in the World Championships final than over the World Cup Series. If we do not consider the World Championship race, MBG seems to be improving her split times in the second half of the race. From the Beijing leg onwards, the 3rd split (100-150m) became the slowest. I.e., the 4th split is faster than the 3rd between October and December. An excellent article for a scientific journal would need to relate these performances to the external training load (i.e. periodization). Some insight could also be gathered based on some mathematical models as we shared here earlier.  But for that, requires more time and is a post for another day…

Now we need some math to back up the analysis. Based on data in table 1 we can see that the final time between both swimmers is rather similar (i.e. the probability of existing a true difference is quite small). But, if we do the analysis by race splits we start to realize that there are moderate and large differences in the split times and reaction time. Let me share (recap?) a few lines that we hear all the time: “One size does not fit all”, “There is no right or wrong way to do the things. There is your way”, “There are several strategies to reach a given performance”. Table 2 is great to showcase that. Indeed there are different strategies to reach the same outcome.

Variability inversely correlates with consistency. If one is less consistent, than they exhibit higher variability. If variability increases than something is changing a lot over time. The change over time is higher for MBG than for KH. Mireia has been improving more in selected race splits, hence a higher variability. Their race strategy is very different during the start (i.e. reaction time), first and last splits. So, we need to investigate further what these differences are.

To learn about the differences in the split times I will profile the race (fig 3, table 2). For more details on the procedures kindly refer to a piece posted earlier comparing N. Adrian (USA) and J. Magnussen (AUS).  One concern that I should acknowledge is the low number of races available to profile the swimmers (8 races). Therefore, more than predicting the performances I am keen to understand what will be the main trend (i.e. race strategy) and who shows advantage in each split.

There is 95% of confidence to report that MBF is faster on the blocks (reaction time) and the last split. The 3rd split is an even battle between the two rivals. It is challenging to state that clearly one is better than the other. Hosszu takes the lead in the first split and in a less obvious way she keeps it in the second. Based on this, I am wondering if KH tries to take the lead in the first half of the race and get a safe gap between her and the Spaniard because the later one has a powerful finish. If in the first half KH does not obtain a large enough lead, then she may know MBF will catch her.

Considering all FINA World Cup legs, MBG did on average the first half in 1:00.67 and the second half in 1:04.07; while KH 0:59.90 and 1:05.06. So, the difference between them was an advantage of 0.764s for KH in the first 100m and a disadvantage of 0.997s. We can say this in another way, if one wants to win the race, they must have a 1st half at least one second faster than the other competitor. For swimmers, have a body length or more of advantage during the 100m turn (v=1.70m/s, i.e. to travel 1.70m distance in one second, so one body length). If we keep the same reasoning, but doing the calculations only for the races in October and November, because MBG has improved the second half of the race, we get some insight into race strategy and perhaps why Katinka Hosszu went out so fast at World Championships in the 200 Butterfly.

By Tiago M. Barbosa PhD degree recipient in Sport Sciences and faculty at the Nanyang Technological University, Singapore

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