Marathon performance was observed to be better in the morning than evening, possibly due to the detrimental effect of a different time of day, as well as increases in Tdb opposing the potential improvement in marathon performance from prior years of training and favorable Twb.
This does a nice job of summarizing the data in a way that is concise and easy to understand.
547 male runners and 63 female runners
I wonder if it would have been more beneficial to have a more even number of participants in regards to male and female? Although, this imbalance might have just been due to random selection, or a lack of female runners.
on the same cohort of runners’ marathon performance across multiple years.
It is interesting that a study wasn't found that followed the same group of runners over a series of years. I have found that most studies collect data from the same group of people for a somewhat extended amount of time to get more accurate data that also shows progression, or lack thereof.
Tdb is the ambient temperature of the air [Citation16Legg R. Chapter 1 - Properties of Humid Air. In: Legg R, editor. Air conditioning system design. Oxford, United Kingdom: Butterworth-Heinemann; 2017. p. 1–28. [Google Scholar]] and is often used as a measure to assess the impacts of environmental heat in both sporting or occupational activities [Citation17James CA, Willmott AGB, and Dhawan A, et al. Increased air temperature decreases high-speed, but not total distance, in international field hockey. Temperature. 2021;1–16. doi:10.1080/23328940.2021.1997535. [Taylor & Francis Online], [Google Scholar],Citation18Jay O, and Brotherhood JR. Occupational heat stress in Australian workplaces. Temperature. 2016;3(3):394–411. doi:10.1080/23328940.2016.1216256. [Taylor & Francis Online], [Google Scholar]]. Twb and Td are similar in the sense that both measurements relate to humidity [Citation19Razak AMY. 14 - Power augmentation. In: Razak AMY, editor. Industrial gas turbines. Sawston, United Kingdom: Woodhead Publishing; 2007. p. 376–408. [Crossref], [Google Scholar],Citation20Camuffo D. Chapter 2A - theoretical grounds for humidity. In: Camuffo D, editor. Microclimate for cultural heritage. 2nd ed. Boston: Elsevier; 2014. p. 49–76. [Crossref], [Google Scholar]], and are viable indicators of marathon performance capability [Citation11Trapasso LM, Cooper JD. Record performances at the Boston marathon: biometeorological factors. Int J Biometeorol. 1989;33(4):233–237. [Crossref], [PubMed], [Web of Science ®], [Google Scholar],Citation21Suping Z, Guanglin M, Yanwen W, et al. Study of the relationships between weather conditions and the marathon race, and of meteorotropic effects on distance runners. Int J Biometeorol. 1992;36(2):63–68. [Crossref], [PubMed], [Web of Science ®], [Google Scholar]]
I like that they gave the definition of each of these terms because I had never heard of them before. This helped to further my understanding of the text drastically.
Furthermore, the physiological challenge of running a marathon is vastly different than running shorter distance races
This is so true because the endurance and stamina required to run long distances, especially when doing a marathon, is much greater than that required for shorter distances. Having to overcome the stamina and endurance aspect of it, on top of the environmental conditions, would make marathons even trickier.
investigated whether performance was poorer during an evening marathon compared with morning marathons.
This is actually a very interesting topic to research! I have always thought that running performance was best at certain times of the day for people as a result of emotions or their mentality, so I am interested in seeing how dry and wet bulb temperature play a role.