Similarities and Differences Between Children and Adults in the Physiological Responses to Exercise

For the last few years, schools, community park and recreation districts, agency and independent fitness centers have been trying to implement the recommendations from both the 1996 report of the U.S. Surgeon General and the 1997 Guidelines for School and Community Programs to Promote Lifelong Physical Activity among young people. Amongst these suggestions is the recommendation that schools, community programs and the fitness industry cooperate to provide safe environments, role models, competent leadership and developmentally appropriate activities for children and adolescents. In addition, parents are encouraged to plan and participate in physical activities with their children. However, if you were playing with your child, would you be concerned if you noticed that your child seemed to be breathing harder and had a higher heart rate but wasn’t sweating as much as you were?Respiratory SystemThe primary role of the respiratory system is to provide oxygen and to eliminate carbon dioxide from the muscle cells. The amount of air exchanged per minute is called minute ventilation and is the product of the number of breaths (frequency) times the volume of each breath (tidal volume). Children and adolescents exhibit a higher frequency and lower tidal volume than adults at all intensities. (1,2) Because rapid breathing is readily noticed, it can be upsetting to a well-intentioned adult. The higher frequency and lower tidal volume is normal and no call for alarm. Actually, if you were to make adjustments for the body weight, children and adolescents breathe more air per minute per kilogram than adults do at the same sub-maximal intensity. These differences are offset by a smaller dead space. Dead space is the volume of air trapped in the conduction portion of the lungs that is not available for exchange at the alveoli. The alveoli provide the vital surface for gas exchange between lungs and the blood.. Alveolar tissue has the largest blood supply of any organ in the body.(3) This is similar to the portion of water in the pipes of your house. The smaller dead space results in a greater portion of the air inhaled by a child actually getting to the alveoli.(4)A comparison is often made between the amount of air that is processed (minute ventilation) and the amount of oxygen used (VO2) to produce energy aerobically. This comparison is called ventilatory equivalent. Children and adolescents have higher ventilatory equivalents than adults do and the difference if inversely related to the age of the child. (1,2) Therefore, the younger the child, the more air they must breathe in. Because of the higher ventilatory equivalent seen in children and adolescent’s generally considered to be insufficient the youngster must expend additional energy to support respiration during exercise. (2) However, neither this insufficiency nor any of the other differences previously described for the respiratory system contraindicates physical activity for children or adolescents.Cardiovascular SystemThe cardiovascular system is primarily a transport system composed of the heart, blood and blood vessels. Its job is to transport oxygen, nutrients in the form of carbohydrate, fat, protein and hormones such as insulin and epinephrine to reach the muscle cells. Carbon dioxide , heat and other by-products of energy metabolism are removed from the cellular level by the cardiovascular system. (5) The delivery of oxygen depends on the amount of blood pumped each minute from the heart which is called cardiac output (Cardiac output = stroke volume: the amount of blood pumped per ventricular contraction x heart beats per minute) and the amount of oxygen unloaded from the red blood cells, the arteriovenous oxygen difference. Children and adolescents exhibit a lower stoke volume and higher heart rate than adults do at all intensities of exercise. Because stroke volume is linked to ventricular size, the higher heart rate is probably an attempt to compensate for the smaller ventricular size of children and adolescents.It’s normal for a child to have a higher heart rate than a parent if they performing the same exercises together. Maximal heart rate is higher in children and adolescents than adults, but does not significantly change during the growing years of 7 to 15. This makes estimation of maximal heart rate by set equations such as 220-age inaccurate for children and adolescents until the late teenage years. It also means unless there are signs of stress or duress, there is no cause for concern for heart rate values greater than 200 bpm. Healthy individuals should be able to exercise for several minutes at maximal heart rates. In fact, because VO2 max (the greatest amount of oxygen that can be inhaled during aerobic exercise) is relative to the individual’s body weight, VO2 max values are as high or higher than most adults. Heart rate will return to resting values quicker in children and adolescents than adults.(2) Temperature control of the cardiovascular system is critical for the exercising participant and is more of a challenge for children and adolescents. Their surface area-to-mass ratio is larger than adults which allows for a greater heat exchange by convection and radiation.Convection is related to conduction which is the ability to gain or lose heat by the exchange of a solid, liquid or gas from one molecule. Because our bodies are usually warmer than the environment, the net exchange of radiant heat energy is through the air to solid, cooler objects in the environment. This does not require molecular contact with the warmer object. Radiation is how the sun warms the earth or in other words a person can remain warm by absorbing radiant heat from the sun or indirect sunlight reflected from snow, sand or water. Children do not sweat as much during exercise as adults. The number of sweat glands is the same but the activation of the sweat glands happens at a higher temperature; less sweat is produced from each gland and the sweat rate per unit of surface area is lower. Children and adolescents also have a smaller plasma volume than adults from which to draw fluids for sweating.(6) In neutral climates the temperature-regulating capacity of children and adolescents is equal to that of adults. However, children and adolescents have a shorter tolerance time for exercise in extreme temperatures. (6) They can acclimate to the heat, but it takes them longer than adults. The tendency is to try to do too much too soon. It is recommended to postpone or recommend strenuous activity when heat and humidity are high and making sure plenty of fluids are ingested before, during and after exercise. Thirst is not an accurate guide for fluid need.Well, now you know the answer to the question in paragraph one. It’s perfectly normal for a child or adolescent to breath harder and have a higher heart rate than an adult, however, if the heat or humidity is excessive it may be prudent to postpone the exercise are lower the intensify. Don’t forget to hydrate before during and after. Good luck!1. Bar-Or. Pediatric Sports Medicine for the Practitioner: From Physiological Principles to Clinical Applications. New York: Springer-Verlag, 1983; pp 1-652. Rowland, T. W Development Exercise Physiology. Champaign, IL: Human Kinetics, 19963. McArdle, William D., Katch, Frank, I., Katch, Victor, L., Exercise Physiology, 2nd edition, pg. 192.4. Bar-Or. Pediatric Sports Medicine for the Practitioner: From Physiological Principles to Clinical Applications. New York: Springer-Verlag, 1983; pp 1-655. Plowman, S.A. and D. L. Smith. Exercise Physiology for Health , fitness and Performance, Boston: Allyn6. Bar-Or, O. children and physical performance in warm and cold environments In Advances in Pediatric Sport Sciences. Vol I: Biological Issues. R.A. Boileau (Editor), Champaign, Il: Human Kinetics Publishers, 1984; pp. 117-0130

4 Things That Cause Acne in Adults

Acne is a problem that is common to people in the U.S. One thing that is surprising is that acne not only is in teenagers but very much in adults. The American Academy Of Dermatology reported that nearly 80% of people between the ages of 20-30 have some mild to moderate types of acne. Another fact is that over half of women of all ages suffer from a form of acne. Many people wonder what causes adult acne so here are 4 things that do.1. Hormonal Factors- Even when we are adults hormones still cause our acne to flare up. The hormones that cause this are androgens that are released from the adrenal glands, ovaries, or testes. These stimulate the sebaceous glands, which lead to an increase in the production of oils and more prone to breakouts. Most adults with acne are women because of hormone fluctuations during ovulation, menstruation, pregnancy, perimenopause, menopause, and through the use of some birth control medications. For acne in adults that are men usually starts when they are teenagers and stays with them when they are adults. The reason men have longer and more severe acne than women is because they have higher levels of testosterone in their bodies. It is not uncommon to see acne in a man for 10 years or more if it is left untreated.2. Cosmetics- Some of the major things that cause acne in adults are cosmetics, moisturizers, hair care products, and makeup. Many products that especially have oil-bases can block pores and lead to acne. Some advice is to use products that are not oily and are marked as noncomedogenic (means not intending to clog pores).3. Conditions and Medications- Medical conditions is one the reasons that cause acne in adults. An example of this is polycystic ovary disease. Medications like steroids, some birth control treatments, and hormone therapies can also cause acne in adults. If you think your medication is worsening your acne then you should speak to your doctor.4. Heredity- For many people who have acne has it run in their family. If a parent had acne before in their life then your risk of having adult acne is higher. Parents who have oily skin tone which cause acne have a chance of passing it on to their kids.Adult acne can be a very frustrating and annoying thing but there are many ways to treat it out there. With the right treatment anyone who has acne as an adult can control it.

Violin Lessons – The Adult Beginner

I have been surprised and impressed by the number of adults who will begin the challenge to learn to play the violin. In preparing for this article I requested email input from the adult beginners that I have had contact with and will be using their suggestions as well as giving you my own thoughts.I have come to believe there is one great myth out there regarding the adult who takes up a new instrument: “It is harder for an adult than it is for a child.” There are many versions of this: “Children are more flexible;” “You can’t teach an old dog new tricks!” Well I don’t believe this is true at all. I believe the reason this myth persists is due to different expectations between adults and children.Children want to play because they heard a violin somewhere; or a parent or grandparent plays and they want to be like them, or for many other reasons. But children are used to being on the beginning end of things, and are used to people teaching them and telling them how to do things. They go to their lesson every week, Mom or Dad helps them practice every day, and before they know it they’ve been at it for a couple of years and are sounding pretty good!The adult on the other hand is by now very proficient at their chosen profession and in many cases is the teacher and not the student in their field. It is uncomfortable therefore, to be a beginning violinist and to play at a beginner level in front of someone who is proficient (his or her teacher). They look constantly for progress and measure themselves against a standard that they have chosen — often an unrealistic standard.I had one student who said he’d always wanted to play violin. His wife gave him a violin and a month of lessons for his birthday, and he was very excited and very nervous. At work he was used to being in front of a boardroom full of executives and this is where he was most comfortable. When he came to lessons he was sweating and nervous and nothing I could do really calmed him down. I’m really not that intimidating! It was just too hard for him to be the beginner again. He lasted about a month and then was too busy with work to continue with violin.The adult students who stick with it have no pre-set expectations other than to play as well as they can. I asked adult beginners what their expectations were when they began lessons. Heather, who began viola lessons in her 40’s said she expected it to be difficult and expected to take as long as two years before she’d want to play for anyone. Bill, who began in his 60’s said he had no real expectations, he just wanted to do as well as he could. Melody, who began lessons in her 30’s, said she just wanted to be able to share music with her son and husband. All of these students have been playing for more than a year now and are seeing great improvements in their tone and in their overall playing.Staying motivated is particularly challenging for the adult student. I advise all my students to continue to play passed-off songs in their practice sessions. When you’ve finished a song and moved on to the next one, play the old songs in your practice sessions often. They can be good warm-up, and they are great encouragement. They get gradually easier and easier which lets you realize that this song that was once so hard is now easy! You have visible progress!Bill stays motivated by listening to good players. He says it’s all difficult, but also fun “when sometimes I make real music.” A big help for Heather has been keeping a violin journal. “About once a month I write in it,” she says. “It helps me sort out motivation hurdles. I try to make a record of it any time I have an A-ha moment. It helps me keep the bigger picture in mind.” Listening to really lovely music also motivates her. Having a goal she wants to meet by a specific time and preparing to play for others is a great motivator. “Because it is so difficult, the sense of accomplishment on mastering a new skill is absolutely thrilling,” says Heather.Melody says, “Having the common interest [with my husband and son who both play violin] bonds us together in a very sweet way. This gives me lots of motivation to keep learning even though I improve very slowly. And as a role model, I want to show [my son] that I won’t quit even though it is not easy.”I asked the adult students if they had advice for someone considering violin lessons as an adult. Bill said, “Go for it!” Heather advises, “Be very honest with yourself about your reasons for wanting to begin playing, and about the time and energy you will have available to invest. Having said that, I would still encourage almost anyone to at least give it a try. Learning something new, especially something as challenging as violin, has been shown in scientific studies to be one of the best protectors against dementia in older age!”Now a few words for the teachers. Teachers need to be aware of the different motivations and teaching approaches for adults versus children. Heather mentioned that it is important not to demand performance in recitals from adult students. I agree with this and always encourage my adult students to play, but let them have the final say. If they choose not to play in the recital, then they can come listen and support the other students. “Also,” says Heather, “Practice rules will be different. Stickers might make an adult feel kind of silly. Instead tell students about new skills presented in each song. Validate their sense of accomplishment by mentioning each thing they learned when they pass off each piece.”Teachers can help [their adult students] best by tuning in to each student personally. Maybe even keep some notes on file, review them right before the lesson or once a month, especially if you have a large studio or an otherwise hectic schedule. Keep reminding us of the benefits of learning violin, tell us how courageous we are, (we are courageous, you know!) and help us to be reasonable in our expectations.”Here are some further suggestions for other adult beginners:Bill: “I have new questions every week and we deal with them. There is no substitute for a real live teacher.”Heather: “A news story on TV talked about recent research showing that our brains record almost exclusively the last frame of mind or emotion associated with any experience. Here’s how this works: you could spend 30 minutes at the dentist getting your teeth drilled without anesthesia, and if you won a million dollars on the way out the door, you would look forward to returning to the dentist!”Ok maybe that’s a bit exaggerated, but I decided to try it. For about a week, I ignored the timer and made sure to stop playing on a ‘high’. It worked, creating almost uncontrollable urges to play! Thoughts bordering on insanity would enter my mind that went something like this: ‘If I get up 20 minutes early tomorrow, I can play for 15 minutes before work.'”I also remember clearly periods of time when I was working specifically on extending my stamina, and would be thoroughly worn out every day when I put down the violin. Soon I would begin thinking of a time to practice and think: ‘I am too tired to practice!’ And I really felt tired too. So with all the other things we have to think of and remember while practicing, we need to figure out how to end on a high note almost all of the time. For myself, playing violin is a treat and a pleasure. In my heart of hearts, I feel it is a sacred privilege.”Teachers who are on their toes can help students feel this way too and send students out the door with a million dollars every week.”Geanellen: “I have found out that my dear very old fashion tape recorder, (probably the 1st kind ever made way back when in my much ‘younger’ years) 🙂 [is very useful]. I take that to class with me and I tape what the teacher says, and have her play the pieces she wants me to work on. If the piece is a fast Irish jig, she’ll play it the way it is suppose to sound up to tempo, but then she’ll slow it down. Sometimes she breaks it down into measures. Then all week at home during my practice sessions I turn on the tape recorder and play along with it. It also has helped me to learn where to place my fingers, so I’ll stay in tune with the music.”I feel that this out of any suggestions is probably the best one for me. As a very active senior citizen, I have a gazillion things going on in my head, including helping my 90-year-old mother who is legally blind and still lives at home on a 10-acre farm with cattle. By the time I get home from a lesson, I don’t always, (well, OK hardly ever) remember whether the teacher said, ‘bow up’ or ‘bow down’ etc., so by having the tape recorder, she talks to me every time I practice, and we practice together. :-)”All these adult students have mentioned that playing the violin is quite a challenge. It reminds me of the movie “A League of Their Own.” Dotty tells her coach Jimmy that she’s quitting baseball because it just got too hard. He very wisely replies, “It’s supposed to be hard. If it wasn’t hard everyone would do it. It’s the hard that makes it great!” All these adult students have tackled the challenge of the violin and are practicing right through the hard times. You inspire me!