How Dance Benefits the Circulatory System

"You gotta have heart, all you really need is heart…"                 - Richard Adler

            Anyone who dances can tell you that he or she feels great after dancing, and it is not surprising when one considers all of the physiological benefits that dance provides.  Dance, in any form or style, is healthy for the body in a variety of ways.  This week’s post addresses the benefits to the circulatory system.

            The circulatory system is comprised of the heart and the many blood vessels that run throughout the body.

            As we begin to dance, our hearts start to beat faster, which increases the blood flow to our muscles. As the blood is pumped through our body at a quicker pace, more oxygen is delivered to our muscles. When we do any type of physical activity, it is imperative that our muscle cells have oxygen to efficiently create energy, as was discussed in my post about breathing.  Additionally, rapid blood flow helps remove any metabolic waste from our cells. Metabolic waste is what is left over after our cells create energy. Substances like excess water, and carbon dioxide need to be carried away from the cells and eliminated from the body.

            As muscle use increases, the number of muscle cells increase, and there is a greater need for blood flow. To accommodate this need, the body increases the amount of capillaries found in the muscle fibers. Capillaries are the small blood vessels that branch out from the arteries and veins to ensure that blood can reach every part of the body.

            Since the heart is the organ that actually pumps the blood through the body, it must work harder to increase the blood flow. The heart is a muscle, and like all muscles, the more it is used, the stronger it becomes. The heart is divided into four chambers. The top two chambers are the right atrium and the left atrium, and they receive blood from the body and from the lungs. The bottom two chambers are the right and left ventricles, which pump the blood out. The oxygen-filled blood is sent from the lungs to the left atrium, flows into the left ventricle, and is pumped out by the walls of the left ventricle toward the waiting muscles. In response to physical activity, the left ventricle grows stronger, and the walls of this chamber thicken and contract with greater force to send as much blood to the muscles as possible.

            While these changes occur to enable all the physical activity that dance requires, they also benefit the body when it is at rest, and the physical activity has stopped. Dancers have a resting heart rate that is slower than an average non-exercising person because the heart has grown so efficient. A slower heart rate means the heart does not have to work as hard. It also means there is more time for the blood to fill the chambers. Additional blood enters the heart, and when this larger volume of blood is combined with the strength of the left ventricle, the heart is able to pump more blood throughout the body in less time, using less energy.

            Next week’s post will address the health benefits of dance to the muscular and nervous systems.

            In the meantime, I am still looking for people to share their stories about eating disorders for National Eating Disorders Awareness Week.  Click on this link for more information if you, or someone you know, is struggling or has struggled with an eating disorder.

Time To Share Your Stories

          February is National Eating Disorders Awareness Month, and this blog has always used the month of February to educate the dance community about eating disorders and help create awareness.  This year, I would like to invite any of my readers who have an eating disorder, are recovering from an eating disorder, have survived an eating disorder or have been a parent, friend, teacher or coach of someone with an eating disorder to share their experiences.

         I will accept guest articles from you up until Sunday, February 16, and will celebrate National Eating Disorder Awareness by publishing your stories the last two weeks in February.  Anyone who comments on the shared stories will be entered into a contest to win the 10th Anniversary Edition of Jenni Schaefer's book Life Without Ed.

If you are interested in sharing your story email me, and I will share the guidelines with you!

Reminding Dancers to Breathe

           "He lives most life whoever breathes most air."

                                                  - Elizabeth Barrett Browning

           Last week’s post addressed the importance of breathing when we exercise and how muscles cannot work efficiently without oxygen.  Many dancers, however, often forget to breathe or use their muscles in ways that hinder breathing. 

            When dancers focus on tightening the muscles of the torso or pulling their centers inward, they hold the diaphragm tightly and prevent it from contracting completely.  When the diaphragm cannot contract fully, the lungs cannot fully inflate, and the dancer begins to take shallow breaths and use the muscles of the shoulder area to attempt to make room for the lungs.  Shallow breathing is inefficient and results in a lack of oxygen and a build-up of carbon dioxide in the body. 

            Dancers who do not breathe efficiently will find that they might have difficulty learning and retaining combinations since the brain is not getting an optimal amount of oxygen.  Additionally, dancers may experience muscle cramps due to a build-up of carbon dioxide.  Holding one’s breath can also result in increased blood pressure, which can cause headaches.

            Dancers should focus on lifting their torsos and using the image of lengthening their abdominal muscles rather than contracting them inward.  By doing so, they will be allowing the diaphragm to do its job and be able to breathe more easily. 

           

            Dancers also need to work on remembering to breathe throughout class.  Tension, created when trying to execute steps correctly and remember combinations and corrections, can also hinder breathing or cause shallow breathing. 

            Breathing tends to be more of an issue in ballet class than other classes like modern where teachers often ask to hear audible inhalations and exhalations.  Although it is untraditional, it can be helpful for ballet teachers to also request audible breathing from their students during warm-ups.  Another idea for teachers to employ is asking the dancers to use their voices when moving.  Singing a familiar song during warm-up sautés forces dancers to breathe.

            Additionally, teachers can actually cue breathing during warm-up exercises:  exhaling into a plié and inhaling when coming out of one; inhaling before a cambré forward and exhaling when reaching the floor, inhaling on the way up and exhaling into a cambré back.

            Yoga classes or incorporating yoga into a dance conditioning class will also help dancers to be aware of their breathing and encourage them to use breath to keep themselves dancing efficiently and in a healthy way.

Why Breathing is So Important When We Dance

"He lives most life whoever breathes most air."

                                                  - Elizabeth Barrett Browning

Inhale….

            Exhale…..

                        Inhale…
                                    Exhale….

                                                Oxygen in…..

                                                            Carbon dioxide out…..

Breathing….it’s a functions of the autonomic nervous system that simply happens – until we focus on it -  then it becomes difficult for us to return to our normal breathing patterns….

What happens when we breathe?

            The major muscle involved in breathing, or respiration, is the diaphragm.  The diaphragm is a dome-shaped muscle found right under the lungs that separates the chest cavity from the abdomen.  When the diaphragm flattens, it allows room for the lungs to expand downward.  At the same time, the muscles of the rib cage contract to pull the ribs away from the lungs and allow even more space for them to expand.

            The lungs fill with oxygen, which is then transported throughout the body by the blood.  When oxygen arrives at the muscles, it is either stored in the muscles for future use or combines with glucose to create energy. 

            Glucose is what our bodies use for fuel.  When the body digests food, it breaks it down into glucose.  When glucose combines with oxygen,  it forms something called adenosine triphosphate, or ATP.   ATP is energy and is needed for any type of muscle contraction to occur.  This process of combining glucose with oxygen to create ATP is called aerobic cellular respiration.  In addition to ATP, aerobic cellular respiration also releases heat, water, and carbon dioxide.  The body is able to deal with the additional water and heat, but must rid itself of the carbon dioxide, which it does when we exhale.

            Although the body can create ATP molecules without using oxygen, it is through a process that is very inefficient.  Creating energy without using oxygen is called anaerobic respiration.  Anaerobic respiration only produces 2 molecules of energy at a time as compared to aerobic respiration which can create 36-38 molecules of energy!  

            During exercise it is important to be certain that we are always breathing efficiently so that our bodies can get enough oxygen and efficiently create the energy we need.

            Next week’s post will address why breathing is often a problem for dancers and how they can learn to breathe efficiently and effectively in class, in rehearsals, and in performances.

            

Caring for Muscles During the Performance Season

            "Take care of your body.  It's the only place you have to live." - Jim Rohn

          With the Nutcracker performance season upon us, dancers will be spending extra hours in rehearsals, numerous hours in theaters, and will be expending tons of energy entertaining countless audience members.  While performing is the ultimate goal of dance training, it still takes a toll on the body.  My last post addressed the risk of injuries that result from overused and fatigued muscles.  Over the long term, cross-training and periodic training can help prepare dancers for the stress of performance, but it is also important for dancers to know how to care for their muscles during the performance season.

            It is extremely important for dancers to warm-up before all rehearsals and performances.  Warming-up increases blood flow to the muscles, which ensures the delivery of oxygen and fuel, and raises the internal temperature of the muscles, which leads to the increased flexibility necessary to perform beautiful grand jetés and développés.  Most companies will hold a formal warm-up class before rehearsals and performances, but if there is not one available, it is each dancer’s responsibility to take the time to sufficiently warm-up his or her body to reduce the risk of injury.

            After the warm-up is complete and while the dancers are waiting for their turns on stage, is the perfect time to don all those fashionable sweaters and leg warmers that dancers always carry around in their bags.  Many dancers mistakenly wear these clothes at the beginning of class and peel them off as the body grows warm.  Their intended purpose is to keep already warmed-up muscles from growing cold while waiting.

 

            Drinking water is also a necessity to keep muscles working well.  Hydration is extremely important when trying to avoid muscle cramps.  Muscles are 70% water, which is why the fibers can move freely against each other.  When muscles are dehydrated, the lubrication decreases and movement becomes painful.

            Muscles should definitely be stretched once a performance and/or rehearsal are completed.  Static stretching in the wings before an entrance will not help a performance.  Instead it may hinder it!  My post on different types of stretching will help you understand why static stretching before a performing may actually decrease a muscle’s ability to contract efficiently.  When static stretching follows a performance, however, it is a valuable part of the cool-down that keeps dancers flexible and allows time for the internal temperature of the muscles to gradually decrease.  Stretching and cooling down reduce the chance that muscles will cramp or go into spasm when leaving the studio or theater.  Being sure to wear warm clothes over dance clothes  will also help keep muscles from cramping when dancers leave a warm studio or theater and move out into colder air.   

 

            Finally, a snack that is high in protein will help repair any minor muscle damage that might have occurred while dancing and help ensure that the muscles will be ready for another several hours of rehearsing and/or performing the following day.

            

Dancers, Fatigue & Injuries

           "Fatigue makes fools of us all. It robs you of your skills and your judgment, and it blinds you to creative solutions. It's the best-conditioned athlete, not the most talented, who generally wins when the going gets tough." - Harvey Mackay


Participation in any type of physical activity bears the risk of injury.  Injuries occur in all types of sports programs and across all forms of dance.  With the increased availability of educational information about cross-training and caring for the body, Sports Medicine and Dance Medicine professionals are hoping to decrease the incidence rates, but it is interesting to look at when injuries are more apt to occur and why.

            Studies within the dance community have indicated injury rates as high as 95% in professional ballet dancers and 82% in professional contemporary dancers.  Injury rates in dance are comparable to those in other professional sports.

            Research has shown that 67% of dance injuries occur late in the day and that 75% of all injuries occur during preparation for performances when bodies are tired and/or overworked.   The lack of time and resources for tissue repair, additional hours of rehearsal, and constant repetitive movements when rehearsing specific phrases from dance pieces have all been cited as causes. 

            Dancers are known for diets that are low in nutritional value.  They are constantly going to extremes to avoid foods that may cause them to gain weight or diminish the aimed for aesthetic in the dance community.  Performance and rehearsal schedules allow little time for careful meal planning and food consumption, and it is difficult for dancers to consume enough calories to equal the amount of calories burned during an intensive performance season.

             Additionally, a large percentage of female professional dancers are amenorrheic, or do not have regular menstrual cycles.  The absence of a monthly period results in abnormal estrogen levels which reduce the amount of calcium that the body can absorb and use for repair. 

            Although most athletes’ bodies are able to use protein to recover quickly from minor muscle tears, this is not the case for dancers.  Without a proper diet filled with additional calories for tissue repair, the body is placed under stress during normal situations.  Once the intense performance season begins, the body is unable to care for itself efficiently.

            When this nutrition deficit is combined with a rehearsal/performance schedule that allows little time for rest and recovery, dancers are placed at a high risk for injuries.  While a minor breakdown in body tissue can be sufficiently repaired during an interval of rest, in dancers, who do not have sufficient rest time, the breakdown of tissue becomes greater than the body’s ability to repair, or remodel. 

            When the same muscle groups are used repeatedly during long hours of rehearsal and performance, they grow tired and use up their energy reserves.  When the central nervous system (CNS) receives the message that a muscle is fatiguing and having difficulty holding a contraction, it either tries to get the muscle to work harder, or activates surrounding muscles (synergists) to help.

            Muscular fatigue is only one piece of the puzzle.  Long work hours also stress the central nervous system.  The CNS uses sensory input to determine where the body is in space.  Messages communicated through visual clues and proprioceptive clues help the CNS determine which muscles need to contract and to determine the force that must be used to keep the body moving safely.  Although the body is engineered so that the CNS will protect the tired muscles by directing adjustments in the body, when the CNS is stressed, its ability to direct these adaptations slows down.  The delayed response affects motor control and coordination.  Landings from jumps and the body’s ability to slow down after leaps or turns are affected.  As a result, the way the body normally distributes the stress over the bones and joints is also compromised.

            The change in stress distribution and the lag time in reorganizing the muscular response set the body up for injuries.  All of these factors explain why most dance injuries occur late in the day or during an intense performance season.  Since dancers have a very high pain tolerance, when they get injured, they often do not realize it immediately.  Moreover, injured dancers tend to “dance through” the pain so they do not lose roles or jobs.

            In an ideal world, major rehearsals could be scheduled early in the day before the body is fatigued, and schedules could be designed to accommodate rest periods for dancers to allow for ample recovery time.  Unfortunately, rehearsal space is not always available at ideal times, and dancers need to be able to accommodate the schedules of theater personnel, musicians, and stage, sound, and lighting crews.  Additionally, audiences are only available after the traditional workday ends – in the evening.

            Educating dancers to listen to their bodies, eat properly, cross-train, and using periodization training can be helpful.  Rather than “dancing through” pain, dancers should be encouraged to care for injuries before they become chronic or more serious.  While eating properly has always been a challenge for dancers, a bit of knowledge about healthy foods and the convenience of food today make it easier.  Cross-training will strengthen all of the muscles in the body so that when some muscles fatigue, the synergistic, or helper muscles, will be prepared to start working, and periodization training can help prepare the dancer for performance season and alleviate some of the stress on the body.

            We are given one body to last our entire life.  It is up to us to learn as much as we can about how to dance in a way that preserves its health to the best of our ability.

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       Liederbach, M. Schanfein, L. & Kremenic, I. What is known about the effect of fatigue on injury occurrence among dancers? Journal of Dance Medicine and Science. 2013;17(3):101-8.

       Murgia, C. Overuse, tissue fatigue, and injuries. Journal of Dance Medicine and Science. 2013;17(3):92-100.

      Shah, S., Weiss, D. & Burchette, R.  Injuries in professional modern dancers: incidence, risk factors and management.  Journal of Dance Medicine and Science. 2012;16(1):17-25.

      Tajet-Foxell, B. & Rose, F. D. Pain and pain tolerance in professional ballet dancers.  British Journal of Sports Medicine. 1995:29:31-4.