Physiological Responses of Female Motor sport Athletes to the Environment of the Cockpit:

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1 Science Physiological Responses of Female Motor sport Athletes to the Environment of the Cockpit: A Case Study In a groundbreaking new study, Dr Edward Potkanowicz examines the physiological responses of female drivers to the unique conditions competitors endure in the cockpit. Corresponding Author: Edward S. Potkanowicz, Ph.D. Susie Wolff is the most recent female driver to take part in an F1 Grand Prix weekend Introduction Driver science is the scientific examination of a racing driver s response to the cockpit, and this term applies to both genders. After an exhaustive review of the literature for investigations involving female drivers, none were found. This case study is therefore offered to quantify the core body temperature, heart rate, and physiological strain of female drivers in real-time and also as an attempt to gather and include female driver data in the growing body of driver science work. For the study, two female drivers were observed during a 40-minute session on a 2.75-mile, 21-turn, clockwise course and their core body temperature and heart rate data were collected simultaneously and physiological strain values were derived from this data

2 By examining the minute-by-minute data, it can be seen that female drivers are challenged to the same degree as their male counterparts. However, recommendations for how female drivers can prepare for the rigors of the cockpit are not as obvious, or available. Given that the genders differ in their response to uncompensable heat stress, one must consider gender in decisions around and involving driver training and preparation. Although there is overlap, gender specific recommendations also need to be made. Gender is one of many issues that need to be addressed in order for driver safety to become more comprehensive. Introduction The term driver science, which was first coined by Potkanowicz and Mendel (1), is defined as the objective and scientific examination of a driver s physiological response to the cockpit from which databased recommendations can be made to improve driver safety, tolerance and performance. Although this term applies to both male and female drivers, an exhaustive review of the literature for investigations on the physiological response of the female driver to the environment of the cockpit yields nothing within the published literature. But when examining the motor sport driver community, women are found in just about every kind of racing and at just about every level. While there isn t an exact figure to attest to an increase in the number of female drivers, anecdotally, the number is growing. This dearth of published work supports the contention that while we have learned Pippa Mann at the 2016 Indy 500 Motor sport should STRive to evaluate the RESponses of all drivers, male and female, to the cockpit environment some about the male race car driver, we have learned nothing about the female race car driver (2,3,4,5,6,7,8). For example, where authors such as Brearly and Finn (2), Carlson, Ferguson, and Kenefick (3), and Potkanowicz (7) have confirmed the significant increase in core body temperature of male drivers, no such work exists for women. Where Jacobs, Olvey, Johnson, and Cohn (6) have demonstrated the metabolic demand of competitive driving, no such work exists for women. Ebben and Suchomel (5) offer training recommendations for the driver athlete, but, again, no such recommendations exist for the female driver athlete. If the motor sport community is truly interested in promoting safety, then the community should strive to examine, quantify, and evaluate the responses of all drivers to the environment of the cockpit, male and female. To that end, this case study is offered for the following two reasons: to quantify the core body temperature, heart rate, and physiological strain values of female drivers in real-time on a minute-by-minute basis, and, secondly, as an attempt to gather and include female driver data in the growing body of work relating to driver science. Methods Participants Four female amateur Sports Car Club of America (SCCA) licensed drivers were recruited to participate in the study. As part of the SCCA licensing process, drivers are required to undergo a regular physical examination. As such, each of the four drivers was in good apparent health and of adequate fitness, with no reported conditions that would compromise their performance or thermoregulation. Each of the drivers volunteered and each were provided with, and signed, an informed consent in accordance with the human participant practices of the principal investigator s institutional review board. There was an equipment failure during the study and as a result only two driver data sets were used. The demographics and characteristics for those two drivers are provided in Table 1. Table 1 Participant Demographics/Characteristics Characteristic Driver #1 Driver #2 Age (yrs.) Height (cm) Weight (kg) Body Surface Area (m2)

3 values were substituted for rectal probe temperature values. A CorTemp recorder was placed on each driver s right hip Apparatus The HQ CorTemp ingestible core temperature probe was used to assess driver core body temperature. Four hours prior to driving, each participant consumed the probe according to the manufacturer s instructions. Using the HQ CorTemp Data Recorder, set in auto-run mode, body temperature was monitored in real-time. In the auto-run mode, a data point is logged every 60 seconds. The recorders were affixed to the belt of each of the driver s fire suits and positioned above 48 the driver s hips. In this position the recorder did not interfere with the driver s safety harness or driving (see Figure #1). A Polar T-31 un-coded heart rate monitor was used to assess driver heart rate. The T-31 pairs with the HQ Data Recorder and allows for the simultaneous and synchronous collection of core temperature and heart rate. During the evaluation, the driver s heart rates were measured every 60 seconds. To ensure the highest accuracy, a sampling rate of three heartbeats was chosen. At this sample rate the recorder samples the number of beats chosen for the interval and extrapolates a heart-rate-per-minute value based on the time it took to sample the programmed number of beats. The Physiological Strain Index (PSI) was calculated using the equation of Moran, Shitzer, and Pandolf (9). The original equation, applicable to both men and women, was modified to account for the use of the ingestible temperature probe (10). Therefore, ingestible temperature probe Procedures The four female drivers were observed during a forty-minute driving session at the private motorsports facility in July Prior to the driving session, each driver sat quietly for thirty minutes in an air conditioned room with an ambient air temperature of 22 C and a relative humidity of 42 per cent. These values were determined using an Omega OMEL-USB-2-LCD-Plus temperature, humidity, and dew point data logger centrally positioned in the room and left to record the environmental conditions for the 12 hours preceding the baseline data collection period. At the end of the thirty-minute baseline period, resting data (i.e. heart rate, core temperature, and PSI) was collected. The drivers then made their way to their cars. Once all safety measures were confirmed, the group of four drivers were released from the paddock to begin the forty-minute driving session, which took place between 14:00 and 15:00. Each driver drove either a race-spec closed cockpit Porsche 944 or Porsche 924. No driver used an external cooling device. Ambient air temperature during the driving session was C and relative humidity was 22 per cent, as determined by the R6012 Series sling psychrometer. The track temperature immediately before the driving session was 52.5 C, and was measured using a Raytek Mini Temp MT6 Noncontact infrared handheld thermometer. The average cockpit temperature during the forty-minute session was 41 C, and it was measured using the Omega temperature, humidity, and dew point data logger, centrally positioned in the cockpit and left to record the environmental conditions for the entirety of the driving session. 49

4 Table 2 Table 3 Minute-by-minute core temperature, heart rate, and PSI data for driver 1. Minute-by-minute core temperature, heart rate, and PSI data for driver 2. Simona de Silvestro at the 2016 Paris eprix Results Statistical Analysis As a case study, the statistical analysis was limited to descriptive statistics. And because of an equipment failure, only two data sets are reported here. Core Temperature Pre-race core temperature (Tgi) data for drivers one and two was and C, respectively. Drivers one and two s post-race Tgi was and C, respectively. The Tgi difference (pre vs. post) for drivers one and two was 1.13 and 1.19 C, respectively. The real-time, minute-byminute, Tgi data is presented in Table 2 and Table 3. Heart Rate Pre-race heart rate for drivers one and two was 80.6 and 85.7 beats per minute (bpm), respectively. Drivers one and two had postrace heart rates of 152 and bpm, respectively. The heart rate difference (pre vs. post) for drivers one and two was 71.4 and 27.7 bpm, respectively. Real-time, minute-by-minute, heart rate data for each driver is presented in Table 2 and Table 3. Physiological Strain Index Prior to leaving the paddock, PSI for drivers one and two was 2.03 and 2.57, respectively (minimal to low on the 0-10 scale). The PSI value at the end of the fortyminute session for drivers one and two was Minute Core Temp ( C) Heart Rate (beats/min) PSI 00: : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : Baseline Minute Core Temp ( C) Heart Rate (beats/min) PSI 00: : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : :

5 6.00 and 3.86, respectively (moderate and low on the 0-10 scale). The PSI difference was for drivers one and two was 3.97 and 1.29, respectively. Real-time, minute-by-minute, PSI data for each driver is presented in Table 2 and Table 3, respectively. Discussion While similar studies have been completed, none, that the author was able to find, have reported using real-time data from female drivers. Examining the current case study s data, it is clear that female drivers are thermally challenged, in the same way as their male counterparts. Further, the increases in female driver core temperature, heart rate, and PSI are similar to those recorded by others reporting on male drivers. These findings suggest that, like their male counterparts, female drivers are at similar risk for the development of uncompensable heat stress and potentially dangerous performance deficits. However, while the responses of the female drivers are similar to those of male drivers, what is less well known is what recommendations would best prepare the female driver for the rigors of the cockpit. Current general recommendations for managing uncompensable heat stress include adequate hydration, a higher level of fitness, and reduced body fat (11).However, given the cited differences between men and women with respect to uncompensable heat stress, one must consider gender differences in the approach to driver training and preparation (11,12,13,14,15). For example, differences relating to a woman s larger body surface to mass ratio, increased subcutaneous fat content, and lower exercise capacity are cited as reasons for a woman s reduced capacity to tolerate heat loading (both exogenously and endogenously). Furthermore, even when controlled experimentally, these differences result in a reduced sweat response when compared to the male counterpart (15). The literature also suggests that women who choose not to use oral contraceptives are at a thermoregulatory disadvantage during the luteal phase of the menstrual cycle (11,16). For the sake of clarity, the luteal phase (from approximately day seven to 22 of the normal menstrual cycle) represents a period of time during a woman s normal menstrual cycle when the normal biphasic rhythm of a woman s thermoregulation is approximately 0.4 C higher than during the follicular phase. As such, starting from a somewhat already elevated core body temperature, a female athlete may be predisposed to heat stress. Similarly, the literature suggests an increase in basal body temperature during the luteal phase and fluid regulation changes throughout the menstrual cycle have the potential to negatively effect prolonged exercise performance (14). This is particularly important when one considers the length of a typical race event. While this case study was successful in achieving its objectives (i.e. quantifying heart rate, core temperature, and physiological strain responses), it also contributed to making an even stronger case for continued and more comprehensive work in the area of driver science. Additionally, the current investigation stands alone in that not only did it involve female drivers, but also, it represents the longest continuous monitoring of any driver athlete. While Brearly and Finn (2) CHM Photography Each driver in the study drove either a race-spec closed cockpit Porsche 944 or Porsche

6 monitored drivers in longer races, their data was limited to pre and post-race data. Similarly, Carlson, Ferguson, and Kenefick (3) had an average monitoring time of 17 minutes, with longest period being 19 minutes. Likewise, Potkanowicz (7) only managed 25 minutes of continual monitoring. Conversely, while this case study was successful in achieving its objectives, it also has a number of limitations beyond the limited number of participants. As one example, consideration must be given to the well-established impact of age on one s capacity to thermoregulate (there was a 20-year difference between the two reported drivers). Sweat production shows an age-related decrease, so older adults cannot take full advantage of evaporative cooling, the primary mechanism for heat loss during exercise (17). As a result, compared to their younger counterparts the aging adult demonstrates an increase in heat storage. Similarly, genderrelated issues such as the influence of body composition, hormonal status, and fitness levels each represent areas for future investigation. Nonetheless, from a practical and applied perspective, the value of the current case study is that it represents the beginning, and necessary first step, of a new discussion and a starting point for more inclusive work in the area of driver science. Take Away Points Driver science is the scientific examination of the driver athlete s response to the cockpit. Female driver athletes are becoming increasingly more present in motor sport. There is a dearth of published scientific work examining the female driver athlete. There are no recommendations directing the training of female driver athletes. Based on the findings of the current case study, female driver athletes exhibit similar core body temperature, heart rate, and physiological strain responses as their male counterparts. Specific gender-related influences and differences have yet to be, and need to be, examined (for example, body composition and hormonal status). A larger and more comprehensive examination of the female driver athlete needs to be undertaken and supported, both scientifically and financially, by the motor sport community. Acknowledgements The author would like to thank each of the participants who volunteered for this case study. Your willingness to participate was obviously integral to the successful completion of the work. Lastly, the author would like to acknowledge the invaluable assistance and contribution of Mr. Daniel A. Colvin, B.S. Mr. Colvin s contribution was particularly significant in that he gave of his time, his expertise, and his enthusiasm. That contribution is greatly appreciated. Sport Mode is always on! CorTemp monitor and ingestible probe capsules References and resources 1. Potkanowicz ES, Mendel RW. The case for driver science in motorsport: A review and recommendations. Sports Med 2013; 43: Brearley MB, Finn JP. Responses of motor-sport athletes to V8 Supercar racing in hot conditions. Int J Sports Physiol Perform 2007; 2: Carlson LA, Ferguson DP, Kenefick RW. Physiological strain of stock car drivers during competitive racing. J Therm Biol 2014; 44: Ebben W. Strength and conditioning for stock car racing. Strength Cond J 2010; 32: Ebben WP, Suchomel TJ. Physical demands, injuries, and conditioning practices of stock car drivers. J Strength Cond Res 2012; 26: Jacobs PL, Olvey SE, Johnson BM, Cohn KA. Physiological responses to highspeed, open-wheel race car driving. Med Sci Sports Exerc 2002; 34: Potkanowicz ES. A real-time case study in driver science: Physiological strain and related variables. Int J Sports Physiol Perform 2015; 10: Watkins ES. The physiology and pathology of Formula One Grand Prix motor racing. Clin Neurosurg 2006; 53: Moran DS, Shitzer A, Pandolf KB. A physiological strain index to evaluate heat stress. Am J Physiol 1998, 44: R129-R Moran DS, Shapiro Y, Laor A, Izraeli S, Pandolf KB. Can gender differences during exercise-heat stress be assessed by the physiological strain index? Am J Physiol 1999; 276:R1798-R Cheung SS, McLellan TM, Tenaglia S. The thermophysiology of uncompensable heat stress: Physiological manipulations and individual characteristics. Sports Med 2000; 29: Anderson GS, Ward R, Mekjavic IB. Gender differences in physiological reactions to thermal stress. Eur J Appl Physiol 1995; 71: Horvath SM, Drinkwater BL. Thermoregulation and the menstrual cycle. Aviat Space Environ Med 1982; 53: Janse de Jonge, XAK. Effects of the menstrual cycle on exercise performance. Sports Med 2003; 33: Kaciuba-Uscilko H, Grucza R. Gender differences in thermoregulation. Curr Opin Clin Nutr Metab Care 2001; 4: Tenaglia SA, McLellan TM, Klentrou PP. Influence of menstrual cycle and oral contraceptives on tolerance to uncompensable heat stress. Eur J Appl Physiol O 1999; 80: Kenney LW, Hodgson JL. Heat Tolerance, Thermoregulation, and Ageing. Sports Med 1987; 4: