Gabe Dennett (left) and Nate Goodwin (right). Photo credit: Jeremy Gasowski
I am a rising senior at UNH with a double major in Exercise Science and Nutrition. This summer, my colleague, Nate Goodwin, and I are conducting a research study funded by a Summer Undergraduate Research Fellowship (SURF) from the Hamel Center for Undergraduate Research. Our project has two distinct aims. Nate is focusing on the effects of an acute model of circadian misalignment on central blood pressure, heart rate variability, and inflammation. The main purpose of my study is to assess the impact of such a disrupted sleep schedule on substrate utilization and exercise capacity. Specifically, I was interested in assessing if a misaligned circadian pattern would hinder fat oxidation, decrease aerobic capacity, and elevate heart rate during exercise.
As you probably could have guessed by my fields of study, health and fitness are a pillar of my life and a passion I love sharing with others. I enjoy learning about practical changes we can all make to optimize our wellbeing and physical fitness. One such area is sleep! A common stereotypical experience in the college population is a chronic lack of sleep fueled by social commitments, long nights of studying, or spontaneous fun. Recognizing this phenomenon in many of my peers and friends led me to ponder the field of research dedicated to sleep and its importance in health and fitness. Such a phenomena marked by chronic fluctuations in sleep and wake times, despite maintaining adequate amounts of sleep, is circadian misalignment, or social jet lag. Social jet lag refers to the all-too-common discrepancy between sleep and wake times, often between weekdays and weekends. In diving into the sleep and social jet lag literature that Nate and I reviewed to develop our SURF proposal it became apart to me that this can have serious implications for daily function, and long-term health.
Specifically, research done in shift-workers have demonstrated increased rates and risk for a plethora of chronic diseases and cardiometabolic events, including heart attacks, cardiovascular disease, stroke, type II diabetes, and excess adiposity and obesity. Mechanistically, the increased risk of disease is related to our body’s internal “clock,” mediated by external stimuli like light, exercise, and feeding times, that control the physiology on a deep internal level, affecting every layer of biology from the cell to the organism as a whole. This concept, however, remained largely unexplored in a college aged population, who are among the most common to experience such drastic, chronic fluctuations in sleep timing. By conducting this social jet lag study in a college-aged population, I aimed to generate novel insights into circadian misalignment that extend beyond the traditionally studied shift-worker demographic, addressing an important gap in our understanding of this phenomenon.
Nate Goodwin (left), Dr. Michael Brian (middle) and Gabe Dennett (right). Photo credit: Jeremy Gasowski
To research social jet lag, we employ two sleep protocols, a standardized and a misaligned, and collect data on variables such as central blood pressure, heart rate variability, C-Reactive Protein as a marker of systemic inflammation, and exercising substrate utilization and oxygen consumption. By assessing these variables, we look at the effects of misalignment on both daily exercise performance and day-to-day function, as well as a predictive measure of potential long-term degradation of health and increased risk of a cardiometabolic disease later in the lifespan. The standardized protocol is based on preferential sleep and wake times, with an eight-hour sleep window, four days in a row, which Nate outlines in greater detail in his own post.
I’ll walk you through a typical post-sleep intervention visit: Our participants enter the lab in the morning. First, we collect the blood pressure and heart rate variability data. Since these are Nate’s variables of interest, he heads this portion of the study visit. (Please read Nate’s blog post to learn more about this step in the research process.) Then, we invite them to the exercise testing area where I operate the metabolic cart and proctor a graded exercise test. This is a stationary cycling test lasts 30 minutes and increases in difficulty every 5 minutes with added resistance. The cycling protocol is designed to test the participants’ ability to switch between different fuel sources—fats and carbohydrates—at a submaximal exercise intensity. The participants wear a mask to measure gas exchange, specifically the amount of oxygen they are inhaling and carbon dioxide they are exhaling. By measuring this exchange, the metabolic cart can quantify my variables of interest for data collection: substate utilization, fat oxidation, carbohydrate oxidation, aerobic capacity and oxygen consumption.
This SURF granted me an opportunity to submerge myself in a research lab setting and gain an understanding of how exercise science research is conducted from start to finish. Specifically, working with human subjects, proctoring exercise tests, collecting and analyzing blood samples, and running data analyses are important skills that acquiring this early on in my academic career will equip me to enter any lab with ease.
However, the truly invaluable aspect of my experience this summer is the relationships I was able to build with my mentor, colleague, and fellow lab mates. The environment we created this summer reflected the “work hard, play hard” mentality. In between hard work and diligent effort, we always found time to laugh and enjoy each other’s company. Many jokes and fits of laughter emerged from our time working together and the people I began this project with as colleagues became some of my closest friends. One of the most pleasurable parts, was our Journal Club “JC,” where we would read peer-reviewed articles and discuss them in an in-depth manner. This almost always regressed into humorous conversation. Working with such a genuine, hardworking, jovial group of people in Dr. Brian’s cardiometabolic research group taught me just how much a team effort can elevate your success. For me, the relationships built this summer with our team were equally, if not more, important than the knowledge gained on the effects of social jet lag.
My experience this summer has prepared me thoroughly to continue my education and research endeavors at the graduate level. Long-term, my goal is to further my education in a master’s program, then work towards earning a PhD.
