Assistant Professor Lauro C Vianna, University of Brasília, Brazil, Twitter: @Lauro_Vianna
By using systems-level and integrative approaches to studying human physiology, my research aims to substantially improve our understanding of how sensors located in the neck (baroreflex) and within the skeletal muscle (exercise pressor reflex) are affected by cardiovascular and neurological diseases. This understanding is crucial for creating interventions and treatments that can be implemented to improve cardiovascular health and consequently patients’ quality of life.
In addition to my research duties, I am currently serving as a Senior Editor of Experimental Physiology, and as editorial board member of several other journals. Since 2014, I have held a position as tenured Assistant Professor at the University of Brasilia, where I teach about cardiovascular control and neurophysiology to students.
Throughout my short career as a professor, I have experienced several challenges including the ups and downs of the teaching profession. There will always be challenges in teaching but here is the one that comes to the forefront: physiology can be difficult for students to learn. Over the years, I have come up with a few tips for improving students’ perceptions and learning outcomes in exercise physiology.
Exercise physiology is an essential course in the field of sport, exercise and rehabilitation sciences. Unfortunately, however, physiology is perceived by students as a difficult course, which can potentially increase students’ withdrawal and failures rates.
Several factors are likely contributing to the difficulties in learning physiology, including aspects related to instructions and the perception of students. In general, students are interested in the practical applications and therefore, focusing teaching on these areas could potentially help increase students’ interest and motivation during the learning process.
In fact, the incorporation of active learning activities in conjunction with more traditional approaches to teaching in the classroom have proven to be more effective for student learning and retention compared with lecturing alone.
With this in mind, we decided to tackle students’ perceptions and learning outcomes in exercise physiology by using classical research paper to frame the lessons. The cardiovascular responses to exercise are mediated by several interacting neural mechanisms, including central command, arterial baroreflex, and skeletal muscle mechano- and metaboreflex.
The classic work of Alam and Smirk (1937) employed a simple technique, commonly referred to as postexercise ischemia (PEI), to isolate the metabolic component of exercise pressor reflex (i.e., muscle metaboreflex). During this maneuver, metabolic by-products of muscle contraction, such as lactic acid, potassium, arachidonic acid products, and adenosine, are trapped and stimulate metabolically sensitive afferent fibers. Stimulation of these afferents results in an elevated arterial blood pressure achieved by sympathetically mediated increases in systemic vasoconstriction and cardiac output.
My team and I created a practical laboratory class (Teixeira et al. 2019), using PEI as a simple and useful technique to teach cardiovascular physiology. In an undergraduate exercise physiology class, a traditional four-hour lecture discussed the neural control mechanisms of cardiovascular regulation during exercise. Then, eight students participated in practical laboratory class. Each participant performed 90 seconds of isometric handgrip exercise at 40% of maximal voluntary contraction, followed by three minutes of PEI.
Arterial blood pressure and heart rate were measured by digital monitors at rest and during isometric handgrip, PEI, and recovery. In addition, blood samples were collected from the tip of the exercising finger for blood lactate analyses. After the laboratory class, a survey was given to determine the perceptions of the students.
Overall, the use a classical approach proposed in 1937 by Alam and Smirk to isolate the metabolic component of exercise pressor reflex (i.e., muscle metaboreflex) with PEI has proved to be a valuable pedagogical activity for undergraduate students. More specifically, our laboratory class improved the students’ self-reported understanding of several aspects of cardiovascular regulation during exercise.
The activity also improved the students’ appreciation for the importance of the cardiovascular physiology and students who participated in the present experimental laboratory class tended to have greater scores in the course exam compared with students who had the traditional lecture alone. These encouraging results suggest that this type of active learning should be used more widely in exercise physiology courses.
References
Alam and Smirk (1937). Observations in man upon a blood pressure raising reflex arising from the voluntary muscles. The Journal of Physiology 89(4): 372–383. http://doi.org/10.1113/jphysiol.1937.sp003485
Teixeira, Samora, and Vianna (2019). Muscle metaboreflex activation via post-exercise ischemia as a tool for teaching cardiovascular physiology for undergraduate students. Advances in Physiology Education 43(1): 34–41.
http://doi.org/10.1152/advan.00174.2018