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RER Value Guide

Slow (0.7)
A1 band - warm-up, recovery, cool-down sets
Moderate (0.85)
A2 band - aerobic capacity sets
Intense (1.00)
A3 band - aerobic power, VO2max sets

Data Source: Zamparo P, Bonifazi M (2013). Bioenergetics of cycling sports activities in water.

Coded for Swimming Science by Cameron Yick

Freestyle data

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Race Analysis: Cesar Cielo 21.39 50 LCM Freestyle

First and foremost, this analysis was based off a streaming video, since the race is not downloaded yet [as far as I know], so some hand times were used [which  has inherent errors]. 

For new comers to the website, we have done numerous race and world record analyses, which are purely meant for enjoyment and discussion. Below is the video of Cesar Cielo's 21.39. Check out our past 50 free WR Comparison.

Cesar Cielo 21.39 50 LCM Freestyle


Compared to his world record swim, Cielo spends more time underwater, bringing him close to the 15-m mark. This dropped his stroke count from 4 (during his world record) to 2 strokes. This propelled him to a 15-m time of 4.89-seconds, nearly two tenths faster than his world record swim. This adjustment in his start gives one of the fastest times to the 15-m mark, comparable to Brad Tandy and George Bovell (other members of the >3.0 m/s club).

15 - 25 Meters

Cesar continued this speed as he reached the halfway mark, taking 8 strokes from 15 - 25 meters, the same as his world record swim. His velocity was nearly identical as his world record swim during this portion of the race (~2.7 m/s).

25 - 35 Meters

During the next leg, Cesar took one less stroke than his world record swim. However, this was likely continued from his longer start and finishing his either stroke during the last portion directly at the end of the 25-m mark. This part had similar time and velocity as his world record swim.

35 - 50 Meters

Into the wall, Cielo took one more stroke than his world record swim (equaling his stroke count in the world record race after removing the first 15 - m). However, this portion was nearly ~.50 seconds slower than his world record swim. 

Swimmer Advice

Maintain current start and underwater duration, as it provided significant time improvement. Work on maintaining stroke rate (seconds/stroke) at 0.18, instead of 0.16. Consider performing maximal efforts with tempo trainer with this set tempo. 

Written by G. John Mullen 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 SystemSwimming ScienceSwimming Science Research Review, and the Swimming Troubleshooting System.

Best Warm-up for Sprint Swimming Performance

Take Home Points on the Best Warm-up for Sprint Swimming Performance

  1. Regular warm-up is the best warm-up for sprint swimming performance, for most.
  2. No warm-up or a short warm-up may best the best warm-up for some swimmers.
  3. Individual warm-up protocols are necessary for sprint swimming performance.

Warm-up (WU) is performed by nearly all swimmers with the goal of increasing heart rate (HR), blood flow, body temperature, and preparing the body for competition/practice. However, many swimmers use an extremely long WU compared to their race distance, potentially causing fatigue. A highly pertinent study looked at what was the best warm-up for sprint swimming performance.

What was done

Sixteen NCAA Division 1 swimmers (M=8, F=8; ~19.9 years; mean male time ~21.96 s, mean female time ~24.35 s) used three WUs before performing a 50-yard freestyle time trial. The three warm-ups were

  1. No WU
  2. Short WU (50-yard at 40% of max and 50-yard at 90% max)
  3. Regular WU (~1300 m)


The mean 50-yard time was significantly faster after the regular WU when compared to the short WU. However, individual data indicated 19% of the participants performed their best 50-yard after a short WU, 37% after no WU, and 44% after regular WU.

HR was significantly higher after regular WU, compared to no WU. No differences were noted in reaction time, rating of perceived exertion post 50-yard, dive distance, or stroke count across the different trials.


Regular WU increases HR more than no WU and causes significantly better times than a short WU. However, the principle of individuality is key, as some athletes performed best times with short or no WU [very surprising, as these were not the swimmers typical WU approach and novelty typically hinders performance].

Practical Implication

The average regular WU is more likely to be the ideal WU for NCAA Division 1 swimmers. However, no WU or a short WU may benefit up to 50% of these swimmers. A variety of WU variations is necessary to determine which WU is ideal for 50-yard performance, as one would expect the fastest time with their accustomed WU, no matter the distance. These findings are extremlely interesting, as many coaches wonder about an ideal WU protocol if no WU pool is available. For some swimmers, no WU pool may maximize performance. 

In the future, out of water dynamic stretching protocols should be compared, as it seems 5 - 10 minutes of dynamic stretching improves running performance, swimming studies are needed (Turki 2011).
  1. Balilionis G, Nepocatych S, Ellis CM, Richardson MT, Neggers YH, Bishop PA. Effects of different types of warm-up on swimming performance, reaction time, and dive distance. J Strength Cond Res. 2012 Dec;26(12):3297-303. doi: 10.1519/JSC.0b013e318248ad40.
  2. Turki O, Chaouachi A, Drinkwater EJ, Chtara M, Chamari K, Amri M, Behm DG.Ten minutes of dynamic stretching is sufficient to potentiate vertical jump performance characteristics. J Strength Cond Res. 2011 Sep;25(9):2453-63. doi: 10.1519/JSC.0b013e31822a5a79. 
By Dr. G. John Mullen received his Doctorate in Physical Therapy from the University of Southern California and a Bachelor of Science of Health from Purdue University where he swam collegiately. He is the founder of Mullen Physical Therapy, owner of COR PT, Strength Coach Consultant, Creator of the Swimmer's Shoulder System, and chief editor of the Swimming Science Research Review.

High Stroke Rate for Elite Sprinting?

"Some people don't have the guts for distance racing. The polite term for them is sprinters."
"The East Germans first used biomechanics. This meant that rather than guessing about technique and form, they could apply changes to athletic performance based on science."
-Bill Toomey

In swimming, proper biomechanics are essential for success. Yet, the biomechanical factors that affect success are numerous and vary between people. An individual stroke is influenced by: anthropometry; range of motion; aquatic signature (level of buoyancy and balance); level of anxiety when first introduced to the sport (survival instinct); natural strength and developmental environment (Skinner 2012). A few studies have tried to find objective factors associated with success, but the only association was age (Saavedra 2010; Variables Predicting Performance in Young Swimmers).

In a more recent study, handgrip strength was related with 100-meter freestyle success in female swimmers.

Another variable influencing stroke biomechanics is race distance. On Swimming Science, we've discussed potential differences in sprint swimming biomechanics, specifically regarding head position.

In track, running speed depends on stride length x stride frequency. In swimming, stroke length x stroke frequency is also associated with success, but unlike track, the items which compose these factors are much more complex. In sprint track, Usain Bolt is a dominant and unique athlete. He is on average 4 - 5 inches taller than other sprinters, which allows him to run his 100-meter sprint much differently than other Olympic 100-meter runner, as Usain uses a higher force production and stride length, but a lower stiffness and stride rate.

Despite the huge differences between running and swimming, I feel some comparison is possible, especially the correlation between force production, stroke length, and stroke rate.

Dr. Havriluk, President of Swimming Technology Research, has studied total force production in elite swimmers using the Aquanex ,a pure measure of force production, not specifically horizontal force. This difference is important as overall in-water force production is highly dependent on the direction of force.

SUBJECTSVPF leftPF rightSR cycles/secSL m/cycleHT inWT lbs

It is well accepted sprinters have a higher stroke rate, but what is the difference between elite sprint swimmers? If the applications of running are similar, than height would be correlated with Olympic success likely has a higher force production, greater stroke length, lower stroke frequency and a lower muscle stiffness, increasing the ability to store and release energy production.

Sprinters often have a higher capacity to produce power. In swimming, propulsion is generated mainly through the arms. Swimmers generate propulsion by orienting their propelling surface (hands, forearm, upperarm) as perpendicular to the water as possible. However, many associate stroke rate and frequency with sprint success, but Usain Bolt, the fastest man alive, has a higher ground reaction time, greater force production, and lower stride rates. Do taller elite swimming sprinters have a longer catch time, which generates higher force production, but a slower stroke rate?

Below are the number of strokes for the last 15 meters compared to athletes height in meters in the Men's 50 free from London. As you see the dots are not linear, but scattered. This appears, height and stroke frequency are not associated in the last 15 meters in elite sprinters. However, this does not answer the main question since height and stroke length aren't always correlated. Moreover, time and stroke rate don't always correlate either.

As you see, the overall time (wish I had actual 15-meter times) and stroke amount also shows a very weak correlation. This data is not very helpful in finding answers about the relationship between stroking parameters in sprint events, as horizontal force production, arm length, stroke rate, and speed are other variables that need further individual analysis. However, is too much to speculate sprint swimming has a Usain Bolt around the corner? Or did we already have a Usain Bolt (Popov's historic technique)?

Too often, sprinters are taught and instinctively perform a high stroke rate. This may result in sprinters rushing their catch and producing inadequate force. Individual information is essential for these elite sprinters, because an outlier like Usain may exist, but they might be rushing their stroke, poorly catching water, taking excess strokes, and fatiguing early. This individualized stroke biomechanics essential, as a swimmers strengths must be maximized. Unfortunately, many coaches are unable to visually quantify force production. This requires more specific testing and research on the subject, where objective measures dictate stroke modifications. Make sure you're making the correct adjustments, with objective, not subjective information.


  1. Taylor MJ, Beneke R.Spring mass characteristics of the fastest men on Earth.  Int J Sports Med. 2012 Aug;33(8):667-70. Epub 2012 Apr 17.

By G. John Mullen founder of the Center of Optimal Restoration, head strength coach at Santa Clara Swim Club, creator of the Swimmer's Shoulder System, and chief editor of the Swimming Science Research Review.

Black Sprint Swimmers

While watching the Olympics in the 100 m dash, anyone could tell black sprinters dominate the sport; this is especially noted in the 100-m distance.

This difference is evident and has been present for a while. However, controversy has surrounded this topic once again as Olympic Gold Medalist Michael Johnson releases his new book. In this book, Johnson discusses the benefits of slavery for athletes. The 44-year-old Texas native tells the Daily Mail "slavery has benefited descendants like me” and "I believe there is a superior athletic gene in us."

He goes on to refer to current research exploring "how much of a factor being descended from slaves contributes to athletic ability."

This is one athlete’s opinion, but he isn’t the only one with this idea. However, the thought of benefits don’t rectify the horrors of slavery.

As many know, this is a controversial subject. In the past, Jimmy the Greek, a sports commentator, was dismantled from his position due to comments on the African American athlete. This article strives to bring only research into the equation, specifically analyzing genes. Everyone has genetic advantages and disadvantages. If you believe in evolution, this is due to the slight genetic variations which occur constantly, Lamarckism. However, evolution does suggest we all came from the same being, making everyone related and the idea of racism and differences irrelevant. But, is the swimming community on the brink of the dominance of black sprint swimmers?

Gene Expression

Specific environments are believed to alter gene expression.

The geneticist, Rachael Irving, was quoted:

"There was not much oxygen on slave ships so they had to use whatever they had to survive."

It was survival of the fittest. A quick search of Dr. Irving returns an article from TrackLife, a Caribbean athletics magazine featuring her. Geneticist and exercise physiologist Claude Bouchard at Laval University in Quebec City has run numerous experiments comparing two populations, French-Canadian and West African students. Using long needles inserted into the thighs of test subjects, Bouchard's team extracted tiny sections of fibers, which look to the naked eye like pieces of raw meat. They were chemically treated to reveal metabolic differences, put on a glass slide, and slipped under a high-power microscope, where they appeared as a collage of tiny red and white crocodile scales. The West Africans, by a ratio of approximately two to one, had more of the larger fast-twitch fibers. The researchers concluded that the force generating capacity of type-II muscle fibers at high velocity, the speed and tempo of movements, and the capacity of an individual to adapt to exercise training are all genetically influenced. This is widely different from the great distance runners of East Africa (Kenya and Ethiopia), but could provide a benefit for black sprint swimmers.


The basic findings of that research showed 6 major physical differences: less body fat, short torsos, thinner hips, longer legs, thick thigh muscles, thinner calf muscles. The main physiological difference is a higher percentage of fast twitch fibers.

As Jimson points out, there are physiological differences, most notably the muscle fiber composition. Again, I feel this is a slight oversimplification, not on Jimson's part, but because I don't believe the science has really uncovered the secret of speed yet. But we're trying! In swimming, it is believed a long torso is beneficial, suggesting their anthropometrics may not be perfect for swimming, however it is difficult to argue the benefits the other characteristics. Moreover, these differences are not seen in every black person, therefore a combination of a long torso with longer legs is not unfathomable.

Different Genes

The finding of statistically similar mtDNA haplogroup distributions in Jamaican athletes and Jamaican controls suggests that elite Jamaican sprinters are derived from the same source population and there is neither population stratification nor isolation for sprint performance. The significant difference between African-American sprinters and African-American controls suggests that the maternal admixture may play a role in sprint performance (Deason 2012).

Given that ACTN3 XX genotype is negatively associated with elite sprint athlete status, the underlying low frequency in these populations eliminates the possibility of replicating this association in Jamaican and US African American sprinters. The finding of no excess in ACE DD or GG genotypes in elite sprint athletes relative to controls suggests that ACE genotype is not a determinant of elite sprint athlete status (Scott 2010).


In the sport of swimming, large efforts have been made to increase diversity. This is most notably the Make a Splash and Swim American campaigns. This result has increased diversity in this majority white sport.

With diversity slowly improving, we should expect to have African Americans begin to perform better at National and International competitions, most notably in sprint events. In my opinion, the biggest barrier to the minority population is availability. Luckily, the aforementioned campaigns suggest this as their site for improvement.

In swimming, the 50 free is the most powerful event and is likely where any athletic advantage would be found. However, will the increase in numbers result in more black sprint swimmers? Or, what are the largest contributors for success?

This history is already being written, as this past weekend 3 swimmers with African American (Cullen Jones, Anthony Ervin, Lia Neal) heritage competed at the Olympics.


Remember genes are not the only variable in the equation, but some feel sprinters are never created nor destroyed, suggesting the large role of genes. In swimming, motor control might be more important than other sports, suggesting genes might not contribute as much for black sprint swimmers, yet the sprint events might allow one to overcome the motor control component [personal belief]. The three main variables appear to be genes, training, and availability.


  1. Deason M, Scott R, Irwin L, Macaulay V, Fuku N, Tanaka M, Irving R, Charlton V, Morrison E, Austin K, Pitsiladis YP.Importance of mitochondrial haplotypes and maternal lineage in sprint performance among individuals of West African ancestry. Scand J Med Sci Sports. 2012 Apr;22(2):217-23. doi: 10.1111/j.1600-0838.2010.01289.x. Epub 2011 Mar 16.
  2. Scott RA, Irving R, Irwin L, Morrison E, Charlton V, Austin K, Tladi D, Deason ACTN3 and ACE genotypes in elite Jamaican and US sprinters. M, Headley SA, Kolkhorst FW, Yang N, North K, Pitsiladis YP. Med Sci Sports Exerc. 2010 Jan;42(1):107-12.
By G. John Mullen founder of the Center of Optimal Restoration, Swimming World Magazine Columnist, creator of the Swimmer's Shoulder System, and chief editor of the Swimming Science Research Review.