The Science (and occasional beauty) of Synchronized Swimming

Plastered smiles, eyes caked with make-up, pointed toes, silly bathing suits, shiny hair, and limbs flailing about. This is what most people envision when they hear “synchronized swimming”.

What most people visualize when they hear “synchronized swimming” (Austin Powers)

But this is what I think of.

Since the age of 11, when I was first able to don a nose plug and flip upside down at a swim practice instead of swimming laps, my chosen sport of synchronized swimming has always turned heads and sparked a lot of raised eyebrows and questions from those who have never seen the real side of synchro before. The FINA World Championship is currently underway in Budapest, Hungary, which means that my Instagram, Facebook, and Youtube are filled with incredible images and videos of the best synchro swimmers in the world. I tend to forget that not everyone is as immersed in the world of synchro as I am (it is quite literally the only sport I follow, with the exception of the Olympics), so I thought I would take this highly relevant time to talk about the science of synchronized swimming.

After almost 20 years of synchronized swimming I have discovered that people have a lot of questions. Here are a few of my responses to the most frequently asked questions and some facts that seem to surprise people:

  • We do not touch the bottom of the pool. Ever. It’s a penalty.
  • Since we cannot touch the bottom of the pool we either (1) tread water to stay up, or (2) scull
  • Yes sculling really does keep our legs above the water
  • We have music on underwater (people are always surprised about this) – we use an underwater speaker and without it we would have a really hard time staying synchronized
  • Most of us wear nose plugs (there are a select few who don’t need them – lucky bastards)
  • Yes it is still synchronized swimming if they are performing a solo – they are synchronized to the music
  • We wear goggles during practice but during a competition we open our eyes underwater
  • Also during competitions we put our hair in buns and use knox gelatin (basically unflavoured jello) to keep everything in place
  • If you want to learn more, and see a first hand account of what elite synchronized swimming is about, watch this CBC documentary, Perfect, about the Canadian team’s attempt to quality for the 2016 Summer Olympics in Rio.

But the most frequent question I’m asked? “How long can synchronized swimmers hold their breath”? I am actually never sure how to answer this question, because the answer is not straightforward; synchro swimmers are never simply holding their breath. Instead I have heard swimming a routine compared to running a 400 m sprint, while holding your breath (Watch this Synchro Canada video showing one of the ways they train breath holding). Passive breath holding is not our style. So, in order to learn more, lets delve into the science of breath holding and what makes synchro swimmers so good at it.

“I am a synchronized swimming, yoga-doing, horseback-riding, wall-climbing-type girl. My hand-eye coordination is zero.” – Mia, The Princess Diaries (2001)

First, probably not unsurprisingly, science has shown that synchronized swimmers are better at holding their breath than the average person. Research by Alentejano et al. 2008 found that during a national competition, soloists were underwater an average of 18 times for an average of ~7 seconds each, with the longest breath hold period lasting ~39 seconds. Another study by Alentejano et al. in 2010 found that during a passive breath holding study, synchronized swimmers exhibited an enhanced ability to breath hold (109.8 ± 39.3 vs. 78.3 ± 25.0s) compared with a control group; these swimmers also experienced a lower heart rate during recovery, suggesting a better adaptation to breath holding. Studies by Rodriguez-Zamora et al. in 2012 & 2014 show that swimmers undergo periods of bradycardia (or low heart rate) while holding their breath (in apnea) and performing intense movements, in comparison to a spiked, very high, heart rate (tachycardia) while breathing above the water.

Heart rate profile of an Olympic and World medalist while swimming a duet routine (Rodriguez-Zamora et al. 2012)

These studies were novel as they tracked heart rate and blood lactate changes in practice and during competition, instead of passive breath holding, as a number of previous studies have done. One additional factor both studies examined was the “rate of perceived exhaustion”, or how difficult a swimmer believes a routine to be. Rodriguez-Zamora et al. (2014) suggest that using a swimmer’s rate of exhaustion, instead of more invasive heart rate or blood lactate monitors, can be a sufficient way to tailor training and practices. This study also found that the best way to prepare a swimmer for competition is to do more full swim throughs (when you perform the entire routine). While this was a really interesting study, reading this as a swimmer makes me terrified because full swim throughs are the worst.

Unfortunately holding your breath can also have unintended consequences; that is, if you do it for too long you’re going to pass out. In my research, I found a case report of a practice in which multiple swimmers lost consciousness while doing an underwater set (Quan et al., 2010), that is multiple laps where you swim from one end to the other underwater, without coming up to breathe. In this study, four swimmers fully lost consciousness, experiencing shallow water blackout, while additional swimmers also complained that they were experiencing mild hypoxic symptoms (disorientation, loss of muscle control, and memory loss). Unfortunately this is not uncommon, and many swimmers I know have undergone these extreme hypoxic events, losing consciousness underwater. While synchro swimmers obviously train to hold their breath, the goal is not to pass out. Davies et al., 1995 examined if there was a correlation between breath holding and the score received, which may suggest that judges favoured a potentially dangerous practice.

synchro_Screen Shot 2017-07-16 at 8.02.38 PM
Davies et al. 1995 correlating the length of time spent underwater during a figure to how well a swimmer performed in competition. 

As you can see, he took the time a swimmer held their breath during a figure (these are required elements that are typically performed slowly and make up 50% of your score) and correlated it with the position the swimmer placed in the competition. With the exception of barracuda, which is a known to be a quick figure, there was a slight correlation between time spent underwater and score. However, as a swimmer and a judge this becomes a slippery slope; it is not the time underwater that makes a swimmer perform better, but rather when a swimmer is stronger they typically have trained more and can stay underwater for longer than a weaker swimmer. So while training methods that encourage extreme hypoxia and blackouts are obviously potentially dangerous, tailoring a practice towards a high “rate of perceived exhaustion” for your swimmer is probably a better way to slowly increase their synchro skills.

“The greater degree of hypoxia seen in the synchronized swimmers is an indication of the considerable muscular work involved in this activity, where an elegant limb held motionless above the surface gives no indication of the dynamic effort required below to maintain this posture.” – Davies et al., 1995

Finally, in addition to performing more inter-comparable studies on synchronized swimmers, a recent review paper also pointed out the need to begin studying the physiological effects of breath-holding and synchro related stress on men (Ponciano et al. 2017). While men were never banned from joining synchronized swimming, the inability for men to compete internationally has created a very gendered sport (I’m sure many people didn’t even know that there were men in synchro). However, as of 2015, mixed duets (one man & one woman) were officially introduced as an event at the FINA World Championships and this category may be added to the Olympics (To see the future of synchro: Bill May and Kanako Spendlove at 2017 Worlds). Synchro is still a relatively new sport that is constantly changing; 20 years ago teams focussed on strength, stability, and synchronization, while nowadays the best teams are sharp, quick, and high (both in the water and in the air – some of the throws are incredible). Although I am incredibly biased, this sport is cool. Do yourself a favour, watch some of the videos below, and if you ever have any synchro questions – I’m always happy to answer them.

Some of my favourite routines:

Synchro Canada’s Queen Combo 

Russia’s Michael Jackson Duet

And to compare and contrast how synchro has changed over the last 15 years:

Synchro Canada’s 2000 Team – Olympics in Sydney (Bronze Medal winning routine)

Synchro Canada’s 2015 Team  – Olympic Qualification Event



Alentejano TC, Marshall D, Bell GJ. A timemotion analysis of elite solo synchronized swimming. Int J Sports Physiol Perform (2008); 3: 31–40.

Alentejano, T. C., Marshall, D., & Bell, G. J. (2010). Breath holding with water immersion in synchronized swimmers and untrained women. Research in Sports Medicine, 18(2), 97-114.

Davies, B. N., Donaldson, G. C., & Joels, N. (1995). Do the competition rules of synchronized swimming encourage undesirable levels of hypoxia?. British journal of sports medicine, 29(1), 16-19.

Ponciano, K., Miranda, M. L. D. J., Homma, M., Miranda, J. M. Q., Figueira JĂșnior, A. J., JĂșnior, M., … & Bocalini, D. S. (2017). Physiological responses during the practice of synchronized swimming: a systematic review. Clinical Physiology and Functional Imaging.

RodrĂ­guez-Zamora, L., Iglesias, X., Barrero, A., Chaverri, D., Erola, P., & RodrĂ­guez, F. A. (2012). Physiological responses in relation to performance during competition in elite synchronized swimmers. PLoS One, 7(11), e49098.

RodrĂ­guez-Zamora, L., Iglesias, X., Barrero, A., Torres, L., Chaverri, D., & RodrĂ­guez, F. A. (2014). Monitoring internal load parameters during competitive synchronized swimming duet routines in elite athletes. The Journal of Strength & Conditioning Research, 28(3), 742-751.


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