Category Archives: Diversity

The Olympics, sex, and gender in the physiology classroom

Are there sex based difference in athletic performance before puberty?

In the past few years most state legislatures have considered laws stating that only members of the female sex can participate in girl’s and women’s sports (37 states in 2021 alone), and as of April 20, 2022 fifteen states have adopted such legislation (1). There have also been several well publicized instances of transwomen competing for championships in women’s sports (for example see 2, 3, 4). The International Olympic Committee, the NCAA, and other sports governing bodies have also recently revised their policies regarding the inclusion of transwomen in women’s sports (5, 6).  All of this has resulted in students in my exercise physiology classes commonly asking questions about sex-based differences in sports performance and the inclusion of transwomen in women’s sports.

In a previous PECOP Blog (7) I briefly summarized the sex-based advantages men have in athletic performance in adults, and the research evaluating the effects of testosterone suppression and cross sex hormone use on factors that influence athletic performance. In this PECOP Blog, I will briefly summarize the sex based prepubertal differences in athletic performance and touch on puberty blockers.

A 2012 report from the CDC indicated there were no differences between 6–11-year-old boys and girls in performance on physical fitness tests (8).  Many sports leagues for pre-pubertal children are not separated by sex since the focus is developing basic sports skills rather than competition (9). Furthermore, some scholars have stated that there are no differences in athletic performance between boys and girls prior to the onset of puberty, and that it is only the increased testosterone secretion during puberty that causes males to outperform females in athletic competition (10, 11).

On the other hand, evaluations of fitness testing in children as young as 3 years old shows that boys perform better than girls of the same age on tests of muscular strength, muscular endurance, and aerobic fitness (12-17).  For example, Tomkinson et al. (17) observed that at age 9 boys are running an average of 3.2% faster than girls of the same age during the last stage of a 20 m shuttle run (Figure 1).  In a separate evaluation Tomkinson et al. (16) reported that at age 9 boys have a bent arm hang time that is an average of 48.1% longer than girls of the same age (Figure 2).

Furthermore, youth records from USA Track & Field (18) in the 8-and-under age group and in the 9-10-years-old age group (who can reasonably be assumed to be pre-pubertal) show that boys outperform girls in all events (Table 1).  The smallest difference in track and field records between boys and girls is 0.94% in the 8-and-under 100 m run, with the largest difference being 38.42% in the 8-and-under javelin throw.  We recently analyzed top 10 data for national performance from Athletic.net in 100 m, 200 m, 400 m, 800 m, 1500 m, and 1600 m running events for children in the 7-8 and 9–10 year-old age groups for the years 2019-2021 and found that across all events 7-8-year-old boys were 4.4 ± 1.9% faster than girls, and 9-10-year-old boys were 5.4 ± 1.8% faster than girls (figure 3; not yet published data).  Youth records from USA swimming also show that in 19 out of 23 events the national records for 10 and under boys are faster than girls by an average of 1.72% (19).  It is important to note that in competition the difference between first and second place often comes down to as little as 0.02% difference in speed (Data to be presented at the 2022 ACSM Annual Meeting).

There is no question that the differences in running performance between prepubertal boys and girls is less than the 10-13% difference in running performance observed between post-pubertal boys and girls, and between adult men and women (10, 11, 20).  And there is no question that the large increases in circulating testosterone experienced by boys during puberty is responsible for most of the differences in athletic performance between post-pubertal boys and girls, and between adult men and women (21).  But the existence of differences in athletic performance between prepubertal boys and girls is well demonstrated (12-19).  Juxtaposing the statements of no pre-pubertal athletic differences between boys and girls (8, 10, 11) and the evidence demonstrating that there are pre-pubertal athletic differences between boys and girls (12-19) can facilitate an interesting discussion about data collection, sample size, data analysis, and other factors that may contribute to these contradictory findings.

When explaining the biological causes of the prepubertal athletic advantages in boys, a good starting point is to discuss the differences in growth and development between boys and girls and to explain the processes of sex determination and sex differentiation (22).  Sex determination occurs at conception with the conferral of sex chromosomes.  Six weeks later, sex differentiation begins to become apparent and during the remainder of development the gonads and genitalia acquire male or female characteristics.  During sexual differentiation, the presence of the SRY gene on the Y chromosome along with androgen exposure and anti-Müllerian hormone cause the internal and external genitalia to follow the male developmental pathway. In the absence of the SRY gene on the Y chromosome, lack of androgen exposure, and lack of anti-Müllerian hormone the female developmental pathway occurs. Of course these few brief sentences fail to cover the myriad of complex interactions of genes, primordial stem cells, and hormones that regulate sex development, and the possible differences and disorders that can occur. But it is remarkable that with all of the possible missteps that can happen during sexual differentiation and development, sex can be accurately and easily identified at birth 99.83% of the time (23).

Further substantiating the important role of sex in growth and development are the World Health Organization fetal growth charts (24), which indicate small but meaningful sex-based differences with male fetuses being consistently larger than female fetuses.  Similarly, substantiating the important role of sex in growth and development, the Centers for Disease Control and Prevention have different growth charts for boys and girls from birth through adolescence with boys having consistently higher values for body mass and body height (25).

With an eye towards physical fitness and athletic performance, starting at birth and continuing throughout youth girls have more body fat and less fat-free mass than boys. For example, Davis et al. (26) in an evaluation of 602 infants reported that at birth and age 5 months, infant boys have larger total body mass, body length, and fat-free mass while having lower percent body fat than infant girls. In an evaluation of 20 boys and 20 girls ages 3-8 years old, matched for age, height, and body weight Taylor et al. (27) reported that the boys had less body fat, lower percent body fat, and a higher bone free lean body mass than the girls, such that the girls’ fat mass was 52% higher than the boys, while the bone-free lean tissue mass was 9% lower. In an evaluation of 376 prepubertal [Tanner Stage 1] boys and girls, Taylor et al. (28) observed that the boys had ~22% more lean mass, and ~13% less body fat (when expressed as percent of total body mass) than did the girls. In a review of 22 peer reviewed publications on the topic, Staiano and Katzmarzyk (29) concluded that girls have more total body fat than boys throughout childhood and adolescence.  It is a tenet of exercise science that having more lean body mass provides athletic advantages, so it is reasonable to conclude that having more lean body mass contributes to the prepubertal sex-based male athletic advantages.

It is worth noting that serum testosterone concentrations in boys are higher for the first 5 months after birth than in girls (30). Testosterone concentrations are then similar between boys and girls until the onset of puberty, when testosterone concentrations increase 10-20-fold in boys.  Given the well know anabolic and androgenic effects of testosterone, the higher testosterone levels in newborn boys likely contributes to the sex related differences in body size and composition in newborns.  It is unknown how much the lingering sex-linked differences in body size, body composition, physical fitness, and athletic performance are due lasting effects of the higher testosterone levels in newborns, and how much the differences are due to Y chromosome or other sex-linked effects.

Strongly suggesting that sex linked differences in physical fitness and athletic performance in children before puberty are due to biological factors, Eiberg et al. (13) measured body composition, VO2max, and physical activity in 366 Danish boys and 332 Danish girls between the ages of 6 and 7 years old.  Their observations indicated that absolute VO2max was 11% higher in boys than girls, while relative to body mass the boys’ VO2max was still 8% higher than the girls.  Accelerometry based measurements of physical activity indicated that when boys and girls regularly participated in the same amount and intensity of physical activity, the boys had higher measured physical fitness than the girls.  When the findings of Eiberg (13) are taken collectively with the findings of large scale school based physical fitness testing in children that also shows pre-pubertal boys outperforming girls in measurements of aerobic fitness, muscular strength, and muscular endurance (12, 14-17), the youth records from USA Track & Field (18) showing that pre-pubertal boys outperform girls in all events, and the 10 and under records from USA Swimming showing that boys outperform girls in 19 out of 23 events (19), there exists strong evidence that there are differences in physical fitness and athletic performance between boys and girls before puberty.

And finally, this discussion arising from laws stating that only members of the female sex can participate in girl’s and women’s sports can lead to questions about the effects of puberty blockers on physical fitness and athletic performance in prepubertal children.  Puberty blockers are correctly known as gonadotropin-releasing hormone agonists (GnRHa), which disrupt the normal pattern of secretion of as gonadotropin-releasing hormone causing the pituitary gland to stop producing follicle-stimulating hormone and luteinizing hormone. Unfortunately, there is minimal research on the effects of puberty blockers on factors that influence physical fitness and athletic performance.

To the best of my knowledge, there is no research on the effects of puberty blockers on muscle strength, running speed, or other measures of athletic performance.  Indeed, Klaver et al. (31) is the only published research that I am aware of that has evaluated the use of puberty blockers on any athletic performance related factor, and this is only on body composition. Klaver et al. (31) demonstrated that the use of puberty blockers in Tanner stage 2-3 teenagers increased body fat and decreased lean body mass in transgirls, but the use of puberty blockers did not eliminate the differences in body composition between transgirls and comparable female teenagers. Roberts and Carswell (32), concluded that there is no published research that sufficiently characterizes the impact of puberty blockers on growth or final adult height.  Thus, the effect of prescribing puberty blockers to a male child before the onset of puberty on the physical components of athletic performance is almost entirely unknown. This becomes a great point in a discussion to remind students of the ever-evolving nature of science.  Any further discussion on this topic becomes speculation or can be removed from the realm of physiology and into metaphysical discussions of what is or is not fair.  Such metaphysical discussions can be fascinating, and also heated, so caution is advisable when proceeding outside of the realm of physiology in a physiology classroom.

In summary, there is strong evidence that even before puberty there are sex-based differences in physical fitness and athletic performance with boys running faster, jumping farther and higher, and demonstrating greater muscle strength than girls of the same age.  These pre-pubertal sex based differences are smaller than the differences in post pubertal teens and adults, but the differences are likely meaningful in terms of competition.  There is currently insufficient evidence to determine what effects puberty blockers have on physical fitness and athletic performance in children.

References

  1. Lavietes M. (April 13, 2022) Kentucky Legislature overrides governor’s veto of transgender sports ban [online]. NBCNews.com  https://www.nbcnews.com/nbc-out/out-politics-and-policy/kentucky-legislature-overrides-governors-veto-transgender-sports-ban-rcna24303 [Accessed April 20, 2022]
  2. Barnes K.  (March 17, 2022)  Amid protests, Penn swimmer Lia Thomas becomes first known transgender athlete to win Division I national championship. [online]. espnW.com. https://www.espn.com/college-sports/story/_/id/33529775/amid-protests-pennsylvania-swimmer-lia-thomas-becomes-first-known-transgender-athlete-win-division-national-championship [Accessed April 20, 2022]
  3. Ellingworth J, Ho S.  (August 2, 2021) Transgender weightlifter Hubbard makes history at Olympics. [online]. APNews.com https://apnews.com/article/2020-tokyo-olympics-sports-weightlifting-laurel-hubbard-e721827cdaf7299f47a9115a09c2a162 [Accessed April 20, 2022]
  4. Morton V.  (June 3, 2019)  CeCe Telfer, Franklin Pierce transgender hurdler, wins NCAA women’s national championship [online]. Washingtontimes.com  https://www.washingtontimes.com/news/2019/jun/3/cece-telfer-franklin-pierce-transgender-hurdler-wi/ [Accessed April 20, 2022]
  5. Yurcaba C.  (January 22, 2022) NCAA’s new trans athlete guidelines sow confusion amid Lia Thomas debate [online]. NBCnews.com https://www.nbcnews.com/nbc-out/out-news/ncaas-new-trans-athlete-guidelines-sow-confusion-lia-thomas-debate-rcna13073 [Accessed April 20, 2022]
  6. Nair A, Nair R, Davis T.  (April 8, 2022) Transgender women unable to compete in British Cycling events as policy suspended [online]. Reuters.com https://www.reuters.com/lifestyle/sports/british-cycling-suspend-transgender-participation-policy-2022-04-08/[Accessed April 20, 2022]
  7. Brown G. (August 18, 2021). The Olympics, sex, and gender in the physiology classroom [online].  PECOP Blog. https://blog.lifescitrc.org/pecop/2021/08/18/the-olympics-sex-and-gender-in-the-physiology-classroom/ [Accessed April 20, 2022]
  8. Ervin RB,  Wang CY, Fryar CD, Miller IM, and Ogden CL. [online] Measures of Muscular Strength in U.S. Children and Adolescents, 2012.  NCHS Data Brief No. 139, December 2013. (https://www.cdc.gov/nchs/products/databriefs/db139.htm; accessed April 6, 2022)
  9. Wells MS, Arthur-Banning SG.  The Logic of Youth Development: Constructing a Logic Model of Youth Development through Sport. J Pakr & Rec Admin.  26: 189-202, 2008
  10. Handelsman DJ. Sex differences in athletic performance emerge coinciding with the onset of male puberty. Clin Endocrinol (Oxf). 87:68-72, 2017
  11. Handelsman DJ, Hirschberg AL, Bermon S. Circulating Testosterone as the Hormonal Basis of Sex Differences in Athletic Performance. Endocr Rev. 39:803-829, 2018
  12. Catley MJ, and Tomkinson GR. Normative health-related fitness values for children: analysis of 85347 test results on 9-17-year-old Australians since 1985. Br J Sports Med 47: 98-108, 2013.
  13. Eiberg S, Hasselstrom H, Gronfeldt V, Froberg K, Svensson J, and Andersen LB. Maximum oxygen uptake and objectively measured physical activity in Danish children 6-7 years of age: the Copenhagen school child intervention study. Br J Sports Med 39: 725-730, 2005.
  14. Latorre Roman PA, Moreno Del Castillo R, Lucena Zurita M, Salas Sanchez J, Garcia-Pinillos F, and Mora Lopez D. Physical fitness in preschool children: association with sex, age and weight status. Child Care Health Dev 43: 267-273, 2017.
  15. Tambalis KD, Panagiotakos DB, Psarra G, Daskalakis S, Kavouras SA, Geladas N, Tokmakidis S, and Sidossis LS. Physical fitness normative values for 6-18-year-old Greek boys and girls, using the empirical distribution and the lambda, mu, and sigma statistical method. Eur J Sport Sci 16: 736-746, 2016.
  16. Tomkinson GR, Carver KD, Atkinson F, Daniell ND, Lewis LK, Fitzgerald JS, Lang JJ, and Ortega FB. European normative values for physical fitness in children and adolescents aged 9-17 years: results from 2 779 165 Eurofit performances representing 30 countries. Br J Sports Med 52: 1445-14563, 2018.
  17. Tomkinson GR, Lang JJ, Tremblay MS, Dale M, LeBlanc AG, Belanger K, Ortega FB, and Leger L. International normative 20 m shuttle run values from 1 142 026 children and youth representing 50 countries. Br J Sports Med 51: 1545-1554, 2017.
  18. (December 19, 2018)  American Youth Outdoor Track & Field Records.  [online] USATF http://legacy.usatf.org/statistics/records/view.asp?division=american&location=outdoor%20track%20%26%20field&age=youth&sport=TF  (accessed April 20, 2022)
  19. (2022) National Age Group Records [online]. USA Swimming. https://www.usaswimming.org/times/popular-resources/national-age-group-records (accessed April 20, 2022)
  20. Millard-Stafford M, Swanson AE, Wittbrodt MT. Nature Versus Nurture: Have Performance Gaps Between Men and Women Reached an Asymptote? Int J Sports Physiol Perform. 13:530-535, 2018
  21. Levine BD, Joyner MJ, Keith NR,  Bagish AL, Pedersen BK, Schmidt W, Stachenfeld N, Girard O, Nagatomi R, Foster C, Okazaki K, Stellingwerf T, Jiexiu Z, Robson SJ, Bailey DM, Bosch A, Murphy RM, Qiu J, Lollgen H, Mitchell J, Kearney J, Scott JM, Lundby C, Steinacker J, Trappe S, La Gerche A, Masuki S, Roach R, Schneider S, Millet G, Kohrt WM, Roberts WO, Kraus WE, Benjamin HJ, Koning JJ, Gatterer H, Wehrlin JP, Charkoudian N, Lawley JS, Hopman MTE, Hawley J. The role of testosterone in athletic performance. [online] https://web.law.duke.edu/sites/default/files/centers/sportslaw/Experts_T_Statement_2019.pdf (accessed April 6, 2022).
  22. Rey R, Josso N, Racine C. Sexual Differentiation. 2020 May 27. In: Feingold KR, Anawalt B, Boyce A, Chrousos G, de Herder WW, Dhatariya K, Dungan K, Hershman JM, Hofland J, Kalra S, Kaltsas G, Koch C, Kopp P, Korbonits M, Kovacs CS, Kuohung W, Laferrère B, Levy M, McGee EA, McLachlan R, Morley JE, New M, Purnell J, Sahay R, Singer F, Sperling MA, Stratakis CA, Trence DL, Wilson DP, editors. Endotext [Online]. South Dartmouth (MA): MDText.com, Inc.; 2000–. PMID: 25905232. (Accessed April 6, 2022)
  23. Sax L. How common is intersex? a response to Anne Fausto-Sterling. J Sex Res. 39:174-8, 2002
  24. Kiserud T, Piaggio G, Carroli G, Widmer M, Carvalho J, Neerup Jensen L, Giordano D, Cecatti JG, Abdel Aleem H, Talegawkar SA, Benachi A, Diemert A, Tshefu Kitoto A, Thinkhamrop J, Lumbiganon P, Tabor A, Kriplani A, Gonzalez Perez R, Hecher K, Hanson MA, Gülmezoglu AM, Platt LD. The World Health Organization Fetal Growth Charts: A Multinational Longitudinal Study of Ultrasound Biometric Measurements and Estimated Fetal Weight. PLoS Med. 14:e1002220, 2017
  25. Centers for Disease Control and Prevention.  Clinical Growth Charts  [online] https://www.cdc.gov/growthcharts/clinical_charts.htm; (Accessed April 6, 2022)
  26. Davis SM, Kaar JL, Ringham BM, Hockett CW, Glueck DH, and Dabelea D. Sex differences in infant body composition emerge in the first 5 months of life. J Pediatr Endocrinol Metab 32: 1235-1239, 2019.
  27. Taylor RW, Gold E, Manning P, and Goulding A. Gender differences in body fat content are present well before puberty. Int J Obes Relat Metab Disord 21: 1082-1084, 1997.
  28. Taylor RW, Grant AM, Williams SM, and Goulding A. Sex differences in regional body fat distribution from pre- to postpuberty. Obesity (Silver Spring) 18: 1410-1416, 2010.
  29. Staiano AE, Katzmarzyk PT. Ethnic and sex differences in body fat and visceral and subcutaneous adiposity in children and adolescents. Int J Obes (Lond). 36:1261-9. (2012).
  30. Senefeld JW, Lambelet Coleman D, Johnson PW, Carter RE, Clayburn AJ, Joyner MJ. Divergence in Timing and Magnitude of Testosterone Levels Between Male and Female Youths. JAMA. 324:99-101, 2020
  31. Klaver M, de Mutsert R, Wiepjes CM, Twisk JWR, den Heijer M, Rotteveel J, Klink DT. Early Hormonal Treatment Affects Body Composition and Body Shape in Young Transgender Adolescents. J Sex Med 15: 251-260, 2018.
  32. Roberts SA, Carswell JM. Growth, growth potential, and influences on adult height in the transgender and gender-diverse population. Andrology. 9:1679-1688, 2021.
Dr. Greg Brown is a Professor of Exercise Science in the Department of Kinesiology and Sport Sciences at the University of Nebraska at Kearney where he has been a faculty member since 2004. He is also the Director of the General Studies program at the University of Nebraska at Kearney. He earned a Bachelor of Science in Physical Education (pre-Physical Therapy emphasis) from Utah State University in 1997, a Master of Science in Exercise and Sport Science (Exercise Physiology Emphasis) from Iowa State University in 1999, and a Doctorate of Philosophy in Health and Human Performance (Biological Basis of Health & Human Performance emphasis) from Iowa State University in 2002. He is a Fellow of the American College of Sports Medicine and an American College of Sports Medicine Certified Exercise Physiologist.
Cultivating Belonging through Asynchronous Discussion Assignments and “State Your Perspective”

Advancing diversity, equity, and inclusion (DEI) within college classrooms, whether virtual or in-person, has perhaps never been as high a priority as now. One outcome of pandemic teaching has been critical evaluation of historic teaching practices, placing the onus on instructors to provide inclusive learning environments that are responsive and adaptive to a wide range of individualized circumstances. At the same time, some students have expressed feeling isolated and disconnected from peers, reducing motivation and academic persistence. Cultivating a sense of community and belonging in educational spaces, for all learners, is a current hot topic in higher education. In fact, two recent PECOP blogs have centered around the related idea of incorporating team-building practices to enrich learning in physiology education (From a Group to a Team: Medical Education Orientation Curriculum for Building Effective Teams and Developing a Community of Practice in an A&P Course)

Belonging, or the belief that one’s individual abilities and attributes are valued, respected, and on par with others’ abilities, is a strong driving force for persistence in STEM fields (1, 2, see also the Iowa State University Center for Excellence in Learning and Teaching webpage: Foster a Sense of Belonging and the Indiana School of Education Building a Sense of Community for All resources). I am not an expert on this, yet I care about supporting the community of learners within the courses that I teach.  This led me to ask: What can I do to build students’ understanding of physiology while also deepening their belief that they belong here, in my classroom, which in turn may foster resilience, persistence, and improved satisfaction within college-level coursework?

Collaborative work is included in all courses I teach. These collaborations take different forms based on the learning goals for the course, learner characteristics (first year versus fourth year students, for example), and topic complexity. Summarized below is one course activity I have used which aims to: (1) help students master challenging physiology concepts through peer-to-peer interactions, (2) develop communication skills related to expressing ideas about human function (a highly-valued professional skill),  and (3) build community and a sense of belonging.

Asynchronous Discussion Assignments and “State Your Perspective”. One course I teach is an in-person, large lecture-style Human Physiology service course for second, third, and fourth year undergraduate students (as well as a handful of graduate students) from biomedical sciences, biomedical engineering, pharmacy interest, public health, and other STEM programs. Many students express trouble “learning how to learn” human physiology, which can be quite different compared with the academic work typical for their varied primary programs of study. They also report feeling isolated in a large classroom and that they have trouble finding study groups, which they value while preparing for exams.

Traditionally, exams in this Human Physiology course were comprised predominantly of multiple choice questions and a few short answer questions (e.g., 3-4 sentences in length). I recently found myself asking: WHAT IF students moved from providing short written explanations on exams that lacked detail due to time constraints to having sufficient time to carefully think through how to explain a physiological process? And, WHAT IF this activity could be designed in such a way to help students recognize what they understand (and what they don’t understand) in advance of an exam, giving them the opportunity to review course materials and try again? And, WHAT IF groups of students were working through this together, leveraging peer-to-peer learning?

These questions, along with experiences from the online and blended instruction I have been doing for many years, gave rise to incorporating asynchronous, online discussion assignments that students would complete in small groups (6-8 students per group). The goal was to give students an opportunity to practice using appropriate anatomical and physiological terminology to precisely describe how the human body functions in a relatively low-stakes setting that supported peer interactions. Students were given a discussion prompt (see below for examples) to which they posted an initial response in the LMS-based virtual discussion forum. Next, all group members were responsible for reviewing their peers’ initial posts and providing two follow-up responses, adding to and building upon the initial physiological descriptions. There were a total of four sets of discussion assignments, one per unit, across the semester. While the discussion assignment structure remained similar from unit to unit, the expectation to communicate increasingly complex ideas was inherent within the discussion prompts.

Specifically to address DEI and belonging, students were to begin their initial responses with a “State Your Perspective” statement. “State Your Perspective” entailed providing a 1-2 sentence summary statement to describe the context by which the topic at hand was viewed. In Human Physiology, this might be knowledge based on prior coursework, the focus of the lab in which they worked, practical clinical experiences for those who work in health care settings, and such. While ice-breaker introductions are frequently incorporated into group work, the use of bolder “State Your Perspective” language is intentional. It helps to move from a generic introduction that generally alludes to differing background experiences to an explicit and purposeful statement intended to summarize the specific context for the way a particular physiological function is understood.

Here are excerpts of the discussion prompts and how “State Your Perspective” is modeled for students.

UNIT 1 Discussion Prompt: One theme for UNIT 1 has been to develop connections between new information and previously-known concepts in order to understand how the human body works:  What have you learned in prior courses that apply to human physiology? Specify (1) the prior knowledge/what you knew before this course, and (2) the new ideas presented UNIT 1 that expands upon your background knowledge and therefore your understanding of human function.

  • “State Your Perspective”: Include a 1-sentence introduction at the beginning of your initial post that includes your major and anything else important for your group members to know that provides context for your perspective. For example “I am a third year biomedical sciences student and I work in a research lab that studies RNA, therefore I have learned ….”.
  • As you will see, some of your group members may have academic backgrounds that are different from yours, and they might present concepts in a different way. This is great! We hope the discussions become more interesting from sharing multiple ways to view the same physiological concept.

UNIT 2 Discussion Prompt: Prepare an answer to one of the Exam 2 Study Guide prompts to share with your group members. Include at least one type of conceptual model within your response: how one “Core Concept of Physiology” can be used to remember this process [see Reference 3 for information about the Core Concepts of Physiology], an originally-created concept map, an analogy, an annotated figure, or another self-generated study tool.

  • Begin your response with a 1-sentence “State Your Perspective” that provides context for your response. For example “I am a pharmacy interest student, and it is important for me to learn about neurotransmitters and receptors because ….”

UNIT 3 Discussion Prompt: Summarize one physiology concept presented in UNIT 3 for your group members, in your own words and including the appropriate anatomy and physiology terminology. Suggested length:  4-6 sentences. NEXT: Create four different 1-sentence statements about your topic, including two statements that are TRUE and two statements that are FALSE (but don’t identify which is which, see below).

  • Begin with a 1-sentence introduction, similar to previous discussion forums so that your new group members understand something about your perspective. Example: “I am an interdisciplinary studies student interested in healthcare; therefore, I found the lecture on hypertension really interesting ….”
  • For your responses to classmates: Carefully review each statement. Select one that you think is false and provide a physiological rationale to support your reasoning. Next, make the appropriate corrections to turn it into a TRUE statement.

Teaching Hint #1: This is manageable in a large lecture course of 150-250 students because I have teaching assistants who understand their primary responsibility is to regularly engage directly with students in the small-group discussions and provide feedback for correct and incorrect descriptions (this is a high priority for students. Practically speaking, this equates to each TA managing 6-10 groups of ~8 students each.

Teaching Hint #2: Once the grading is completed, I ask the TAs to summarize what they learned about how students learn physiology. This has been a good way to mentor TAs and prompt thoughts about their own teaching philosophies. I sometimes ask them what they would change (nothing like grading 50+ discussion assignments based on a poorly-worded prompt…). In fact, this is how the UNIT 3 true/false statements came to be; a graduate student proposed it as a way to incorporate greater critical thought and reasoning within discussion assignments.

So what did students think about this type of discussion assignment? Here are examples of comments provided on the end-of-class evaluation forms, paraphrased and in aggregate form (i.e., these are not actual student comments but represent themes in responses):

  • The discussion assignments were a good way for me to think critically about one idea then communicate my understanding of human function to my peers.
  • Discussions were a great way to see what my classmates were doing to learn human physiology that I could apply to my own learning—my group members proposed study strategies and ways of thinking about the human body that I hadn’t thought of before.
  • I enjoyed learning from my peers, who might know something more than me based on their experiences outside of class.
  • Even though this was a large lecture course with quite a bit of content presented online, I enjoyed interacting with my peers, the professor, and TAs in the discussions. I felt like everyone was there to support my learning.

Despite initial skepticism, very few students conveyed negative comments about the discussion assignments or described them as “busy-work”.

Beyond student feedback, here are a few subjective comments conveying my personal observations about classroom dynamics that arose from this course activity.

  • By design, one aim of “State Your Perspective” statement was to help students recognize that they hold certain views on a topic based on their background experiences. For some 20-something year-olds, it might not be intuitive that they, in fact, have certain perspectives and attitudes that they bring into group work. “State Your Perspective” has the potential to be affirming—when articulating prior experiences it can become more explicit, to ourselves and others, that we all have something unique to contribute to group work.
  • Sharing perspectives, along with the underlying narrative (but briefly, in 1-2 sentences), seemed to normalize the idea that we all have different backgrounds and experiences so OF COURSE we may hold different perspectives, or ways of viewing things.
  • Because the context for why discussion prompts were answered with a particular focus was evident, it seemed to reduce the pressure that every student should know “everything”. Instead, over time and through several rounds of discussions, students became more comfortable talking about what they understood and what they didn’t understand. Clarifications could be made and misperceptions could be corrected by peers, who almost always demonstrated remarkable diplomacy and kindness toward their classmates.
  • In some cases, the online and asynchronous nature of these discussions seemed to reduce barriers with regard to asking for help. It seemed to move students from a mindset of “I should know this but I don’t/everyone knows this but me” to the non-threatening “This is a topic maybe I need to ask about.” Students seemed less self-conscious when asking questions.

In summary, collaboration during small group, asynchronous discussion assignments seemed to promote a sense of community and belonging among students in a Human Physiology for non-majors course. As the instructor, it was rewarding to see improvement in students’ abilities to explain physiological processes across the semester. It was also extremely rewarding to see the great care exhibited by students to be inclusive and supportive of their peers.

 

References:

  1. Herman J, Hilton M. Supporting Students’ College Success The Role of Assessment of Intrapersonal and Interpersonal Competencies (Consensus Study Report of the National Academies of Sciences, Engineering, and Medicine). Washington, DC: The National Academies Press, 2017.
  2. Wilton M, Gonzalez-Nino E, McPartlan P, Terner Z, Christoffersen RE, Rothman JH. Improving academic performance, belonging, and retention through increasing structure of an introductory biology course. CBE Life Sci Educ, 18:1-13, 2019.
  3. Michael J, Cliff W, McFarland J, Modell H, Wright A. The Core Concepts of Physiology A New Paradigm for Teaching Physiology. New York: Springer, 2017.
My Perspective: I am an Associate Professor of Instruction in the Department of Health and Human Physiology at the University of Iowa. I am the Program Director for the B.S. Human Physiology program, which serves approximately 625 majors. I am also an active participant in several undergraduate student success initiatives at the collegiate level.  The most rewarding part of my job is learning about how students learn physiology, in their own words. I solicit student feedback for their academic experiences regularly.

Jennifer Rogers, PhD

Associate Professor of Instruction

Department of Health and Human Physiology

University of Iowa

 

Expanding “normal” in physiology

We are not formal authorities, rather informal allies who have enacted a few small classroom and content related changes related to diversity and inclusivity in our medical school. We hope that our experience will help you in your pursuits in the education of all students.

It took someone in power (a Departmental Leader and Course Director) to act. Author KSC recognized that key person group diversity content was missing and that societal and student sentiment had shifted. This was in the early fall following the 2020 “Black Lives Matter” demonstrations.  Knowing that even with firm institutional commitment, change would take time, author KSC inserted intentional diversity and inclusivity curricular time into the Cardiovascular Systems course (USA medical year 2, 5-week Fall course) in 2020. The social determinants of healthcare and related topics received some curricular coverage but were less present in foundational coursework. Three required elements were added to the course that would both have learning objectives and corresponding assessment items, as assessment often indicates importance in coverage and content to students.

Having passion and insight does not mean that this person must deliver the content. Author TEW was the person selected to deliver the material since the topic of “normal” had been informing his teaching for several years, especially in developing physiology content for Pediatrics and Gerontology medical blocks and an understanding that 50% of people could be excluded if sex as a biological variable is not included.  In 2017, author TEW also led a teaching workshop at the International Union of Physiological Sciences in Brazil with the goal of challenging physiology educators from across physiology societies to include sex and lifespan material in physiology education and to teach these differences not as special topics but as “normal” physiology.

The three elements covered included: sex, lifespan (older and younger), and USA person groups with historic health disparities. One lecture (“Normal” physiology and how it changes across the lifespan and between sexes – covering respiratory, renal, and cardiovascular systems) and 6 podcasts (Selected sex-specific issues in BP control & hypertension, Selected race & ethnicity issues in BP control & hypertension, An innovative approach to hypertension care in African American males, Sex-specific physiology: CV signs and symptoms, Sex-specific physiology: Heart disease, and CV epidemiology delineated by race and ethnicity) were incorporated and spaced within an integrative organ-based content.  We attempted to have material that was race/culture-informed but not race/culture based, which allows some separation of social constructs, the individual vs. person group, and a determinant vs. prevalence. In other Year 2 medical courses, Department physiologists added information on historical bias in normative prediction equations (pulmonary function testing and glomerular filtration rate) as well as environmental justice and air quality.  These other additions were in the form of one to a few formally presented slides, part of a case presentation, or as a brief class discussion topic.

Were the additions easy? No. It took curricular time, administrative support, and a great deal of learning on our part. Documents such as APS Medical Physiology Learning Objectives do not directly address diversity and inclusivity to guide the field in what is important to include.  Perhaps as a Society this is a change we can implement.  Some take-homes for physiology educators: 1) no matter your background, you can contribute (very few people have formal training in this area), 2) collaborate with other faculty, 3) obtain feedback from all person groups and from students, as perception and intent can be quite different, 4) be intentional and precise with wording, and 5) implement small changes. We encourage you to expand “normal” physiology in one or two ways this upcoming semester, but do not be surprised if students are quite interested and request more.

 

 

 

 

 

Ken Campbell is a Professor and Director of Graduate Studies in the Department of Physiology. He also in the Co-course Director of the Cardiovascular Course in the Year 2 medical curriculum University of Kentucky College of Medicine.

 

 

Thad Wilson is a Professor and Director of the Graduate Certificate in Physiology Teaching in the Department of Physiology. He also is the Co-course Director of the Respiratory Course in the Year 2 medical curriculum and teaches physiology in several of the other medical courses at University of Kentucky College of Medicine.

 

 

The Olympics, sex, and gender in the physiology classroom
The recent Tokyo Olympic Games present an opportunity for a number of intriguing discussions in a physiology classroom.  Typical discussion topics around the Olympic Games involve muscle strength, muscle power, aerobic fitness, bioenergetics, and a number of other physiological factors that determine athletic performance.  Coronavirus, immunity, disease transmission, and similar topics may be unique areas of discussion related to the Tokyo Olympic Games.  Another topic that has been prevalent in the news for the Tokyo Olympic Games is the role of sex and gender in athletic competition.

Before and during the Tokyo Olympic Games several athletes were featured in news headlines due to either gender identity or differences of sexual development (DSD, also sometimes called disorders of sexual development).  Male-to-female transgender athletes competing in women’s sports in the Tokyo Olympic Games include weightlifter Laurel Hubbard, archer Stephanie Barrett, cyclist Chelsea Wolfe, soccer player Quinn, and volleyball player Tifanny Abreu, (1, 2).  There have also been news stories about Caster Semenya, Christine Mboma, and Beatrice Masilingi being ineligible to participate in the Olympics due to their DSD causing their serum testosterone concentrations to be above the allowed limits for female athletes (3, 4).  In addition to physiology sex and gender are interwoven with culture, religion, and politics, so how to discuss sex and gender in the physiology classroom needs to be carefully considered by each instructor depending on the campus climate, policies, and individual comfort level with walking into these potential minefields.  However, sex and gender in sports are very appropriate topics to discuss from a physiological perspective.

Although sex and gender have been used interchangeably in common conversation and in the scientific literature, the American Psychological Association defines sex as “physical and biological traits that distinguish between males and females” (5) whereas gender “implies the psychological, behavioral, social, and cultural aspects of being male or female (i.e., masculinity or femininity)” (6).  Using these definitions can be helpful to draw a clear distinction between gender (and/or gender identity) as a social construct and sex as a biological variable, which can help focus the discussion on physiology.

As reviewed by Mazure and Jones (7) since 1993 the NIH puts a priority on funding research that includes women as well as men in clinical studies and includes an analysis of the results by sex or gender.  Mazure and Jones (7) also summarized a comprehensive 2001 Institute of Medicine sponsored evaluation that concluded that every cell has a sex.  A 2021 Endocrine Society scientific statement provides considerable information on the biological basis of human sexual dimorphism, disorders of sexual development, and lack of a known biological underpinning for gender identity (8).  On August 12, 2021 a PubMed search using the term “Sex Matters” (in quotation marks) returned 179 results, with many of the linked papers demonstrating the importance of sex for health, disease, and overall biological function (without quotation marks there were 10,979 results).  Given that there have been various discussions in the news media and across social media blurring the distinction between sex and gender, it is very important that students in physiology understand that sex in humans is an important biologically dimorphic trait of male or female.

Relevant to a discussion of the Olympic Games, the differences in performance between male and female running has been analyzed for world’s best and world’s 100th best (9), annual world’s best performance (10), world record performance (11-13), Olympic and elite performance (13-16), High School performance in CA, FL, MN, NY, and WA (17), and 100 all-time best Norwegian youth performance (18).  Hilton and Lundberg (19) also provided an excellent review of the large differences in athletic performance between men and women in numerous sports.  Overall, by mid-puberty males outperform comparably aged and trained females by 10-60%, depending on the sport (see figure 1 of Hilton and Lundberg, reproduced here with no changes under the Creative Commons license https://creativecommons.org/licenses/by/4.0/).

 

Hilton and Lundberg (19) also reviewed the present state of research regarding the effects of male-to-female hormone treatment on muscle strength and body composition and concluded that men typically have 45% more muscle mass than women, and male-to-female hormone treatment reduces muscle mass by ~5%.  These authors also concluded that men typically have 30-60% higher muscle strength than women, and male-to-female hormone treatment reduces muscle strength by 0-9%.  Overall, Hilton and Lundberg (19) conclude that transwomen retain considerable advantages over cisgender women even after 1-3 years of male-to-female hormone treatment.  Harper at al. (20) also reviewed the research regarding the effects of male-to-female hormone treatment on muscle strength and body composition and came to the same conclusions as Hilton and Lundberg.  Harper et al. (20) further concluded that male-to-female hormone treatment eliminates the difference in hemoglobin concentrations between cisgender men and women.  In a single research project, Roberts et al. (21) observed that before transition male-to-female members in the US Air Force completed a 1.5 mile running fitness test 21% faster than comparably aged cisgender women.  After 2.5 years of male-to-female hormone treatment the transwomen completed the 1.5 mile running fitness test 12% faster than comparably aged cisgender women. (Figure 1 Hilton and Lundberg)

All of the previously mentioned information is important to consider when asking if transwomen can be fairly and safely included in women’s sports.  It is also important to note that the effects of male-to-female hormone treatment on important determinants of athletic performance remain largely unknown.  Measurements of VO2max in transwomen using direct or indirect calorimetry are not available.  Measurements of muscle strength in standard lifts (e.g. bench press, leg press, squat, deadlift, etc.) in transwomen are not available.  Nor have there been evaluations of the effects of male-to-female hormone therapy on agility, flexibility, or reaction time.  There has been no controlled research evaluating how male-to-female hormone treatment influences the adaptations to aerobic or resistance training.  And there are only anecdotal reports of the competitive athletic performance of transwomen before and after using male-to-female hormone treatment.

The safe and fair inclusion of transgender athletes and athletes with DSD in women’s sports is a topic being debated in many states and countries, and by many sporting organizations including the International Olympic Committee.  In the end, whether it is safe and fair to include transgender athletes and athletes with DSD in women’s sports comes down a few facts that can be extrapolated, lots of opinions, and an interesting but complicated discussion.  This is a worthwhile discussion in a physiology classroom because it allows a good review of the biologically dimorphic nature of human sex.  However, the safe and fair inclusion of transgender athletes and athletes with DSD in women’s sports is also a discussion that should be approached with caution due to the many opinions this topic entails that reside outside of physiology.

 

 

1.    The Economist explains: Why are transgender Olympians proving so controversial? The Economist. https://www.economist.com/the-economist-explains/2021/07/16/why-are-transgender-olympians-proving-so-controversial. [Accessed: August 12, 2021, 2021].

2.    Pruitt-Young S. Live Updates: The Tokyo Olympics Canadian Soccer Player Quinn Becomes The First Out Trans And Nonbinary Gold Medalist NPR. https://www.npr.org/2021/08/06/1025442511/canadian-soccer-player-quinn-becomes-first-trans-and-nonbinary-olympic-gold-meda. [Accessed: August 12, 2021, 2021].

3.    The Clock Ticks on Caster Semenya’s Olympic Career https://www.nytimes.com/2021/06/28/sports/olympics/caster-semenya-olympics-gender.html. [Accessed: August 12, 2021, 2021].

4.    Tokyo 2020: Two Namibian Olympic medal contenders ruled ineligible for women’s 400m due to naturally high testosterone levels CNN. https://www.cbs58.com/news/tokyo-2020-two-namibian-olympic-medal-contenders-ruled-ineligible-for-womens-400m-due-to-naturally-high-testosterone-levels. [Accessed: August 21, 2021, 2021].

5.    APA Dictionary of Psychology: sex. American Psychological Association. https://dictionary.apa.org/sex. [Accessed: August 12, 2021, 2021].

6.    APA Dictionary of Psychology: gender. American Psychological Association. https://dictionary.apa.org/sex. [Accessed: August 12, 2021, 2021].

7.    Mazure CM, and Jones DP. Twenty years and still counting: including women as participants and studying sex and gender in biomedical research. BMC Womens Health 15: 94, 2015.

8.    Bhargava A, Arnold AP, Bangasser DA, Denton KM, Gupta A, Hilliard Krause LM, Mayer EA, McCarthy M, Miller WL, Raznahan A, and Verma R. Considering Sex as a Biological Variable in Basic and Clinical Studies: An Endocrine Society Scientific Statement. Endocr Rev 2021.

9.    Sparling PB, O’Donnell EM, and Snow TK. The gender difference in distance running performance has plateaued: an analysis of world rankings from 1980 to 1996. Med Sci Sports Exerc 30: 1725-1729, 1998.

10.  Tang L, Ding W, and Liu C. Scaling Invariance of Sports Sex Gap. Front Physiol 11: 606769, 2020.

11.  Cheuvront SN, Carter R, Deruisseau KC, and Moffatt RJ. Running performance differences between men and women:an update. Sports Med 35: 1017-1024, 2005.

12.  Thibault V, Guillaume M, Berthelot G, Helou NE, Schaal K, Quinquis L, Nassif H, Tafflet M, Escolano S, Hermine O, and Toussaint JF. Women and Men in Sport Performance: The Gender Gap has not Evolved since 1983. J Sports Sci Med 9: 214-223, 2010.

13.  Sandbakk O, Solli GS, and Holmberg HC. Sex Differences in World-Record Performance: The Influence of Sport Discipline and Competition Duration. Int J Sports Physiol Perform 13: 2-8, 2018.

14.  Millard-Stafford M, Swanson AE, and Wittbrodt MT. Nature Versus Nurture: Have Performance Gaps Between Men and Women Reached an Asymptote? Int J Sports Physiol Perform 13: 530-535, 2018.

15.  Seiler S, De Koning JJ, and Foster C. The fall and rise of the gender difference in elite anaerobic performance 1952-2006. Med Sci Sports Exerc 39: 534-540, 2007.

16.  Nuell S, Illera-Dominguez V, Carmona G, Alomar X, Padulles JM, Lloret M, and Cadefau JA. Sex differences in thigh muscle volumes, sprint performance and mechanical properties in national-level sprinters. PLoS One 14: e0224862, 2019.

17.  Higerd GA. Assessing the Potential Transgender Impact on Girl Champions in American High School Track and Field. In: Sports Management. PQDT Open: United States Sports Academy, 2020, p. 168.

18.  Tonnessen E, Svendsen IS, Olsen IC, Guttormsen A, and Haugen T. Performance development in adolescent track and field athletes according to age, sex and sport discipline. PLoS One 10: e0129014, 2015.

19.  Hilton EN, and Lundberg TR. Transgender Women in the Female Category of Sport: Perspectives on Testosterone Suppression and Performance Advantage. Sports Med 2020.

20.  Harper J, O’Donnell E, Sorouri Khorashad B, McDermott H, and Witcomb GL. How does hormone transition in transgender women change body composition, muscle strength and haemoglobin? Systematic review with a focus on the implications for sport participation. Br J Sports Med 2021.

21.  Roberts TA, Smalley J, and Ahrendt D. Effect of gender affirming hormones on athletic performance in transwomen and transmen: implications for sporting organisations and legislators. Br J Sports Med 2020.

Dr. Greg Brown is a Professor of Exercise Science in the Department of Kinesiology and Sport Sciences at the University of Nebraska at Kearney where he has been a faculty member since 2004. He is also the Director of the General Studies program at the University of Nebraska at Kearney. He earned a Bachelor of Science in Physical Education (pre-Physical Therapy emphasis) from Utah State University in 1997, a Master of Science in Exercise and Sport Science (Exercise Physiology Emphasis) from Iowa State University in 1999, and a Doctorate of Philosophy in Health and Human Performance (Biological Basis of Health & Human Performance emphasis) from Iowa State University in 2002. He is a Fellow of the American College of Sports Medicine and an American College of Sports Medicine Certified Exercise Physiologist.