Heart rate, metabolic and hormonal responses to maximal psycho-emotional and physical stress in motor car racing drivers

Heart rate variability, recovery and stress analysis of an elite rally driver and co-driver during a competition period

To ensure both optimal health and performances, monitoring physiological and psychological states is of main importance for athletes. It is well known that monitoring heart rate variability and using validated questionnaires is useful for monitoring both the health and training status of athletes of different sports. Motorsports such as rally require high levels of physical and mental preparation thus information about psychophysiological status of rally athletes is fundamental. The aim of this study was to assess the autonomic regulation, stress, recovery conditions of one driver and one co-driver competing at the Italian National Rally Championship during their competition period. Heart rate variability parameters, acute recovery and stress states were assessed the day before, during the two days of race and the day following the races. Results showed that driver and co-driver had a sharp decrease of mean RR intervals, root mean square of successive differences between normal heartbeats, and standard deviation of the N-N interval during race days, while the stress index showed the inverse trend, and this behaviour was clearly visible in the Poincaré plots and power spectrum density graphs. The acute recovery and stress states questionnaire showed significant differences in recovery and stress scoring for the driver but not for the co-driver, although the trends were similar. This study describes the psychophysiological demands of a rally competition period suggesting that a daily evaluation of heart rate variability, recovery, stress states is useful for monitoring health status in rally athletes and could be implemented to make decision about training and recovery strategies.

Prompted hands-free drinking improves simulated race car driving in a hot environment

Race car drivers are often hypohydrated during a race. The FluidLogic drink system is a hands-free, prompted drinking system that is hypothesized to increase the likeliness of drivers' consuming fluids and thereby mitigating hypohydration. To test the hypothesis, 20 elite professional race car drivers participated in a 2-day cross-over study in which they drove on a race simulator in an environmental chamber that was heated to regulation cockpit temperature (38°C). Drivers used either the FluidLogic drink system or a standard in-car water bottle system (Control) on one of each testing day. The results indicated that there was consistent fluid consumption with the FluidLogic system, while the Control condition elicited fluid consumption in bolus doses. The Control condition was associated with moderate (0.5%) increased core body temperature (P < 0.05) and substantial (3.3%) increased urine-specific gravity (P < 0.001) as compared to the FluidLogic condition. Driving performance metrics indicated that lap times during the Control Condition were 5.1 ± 1.4 (4.1%) seconds slower (P < 0.05) than the FluidLogic Condition, due to driving errors that occurred in the high-speed corners. Based on these results, prompted hands-free drinking can mitigate hypohydration and performance loss in automobile racing drivers.

Application of a Reactive Agility Training Program Using Light-Based Stimuli to Enhance the Physical and Cognitive Performance of Car Racing Drivers: A Randomized Controlled Trial

BACKGROUND

There is a need to develop strategies that could contribute to the physical and mental preparation of motorsport athletes. A common method used by experienced motorsport athlete physical trainers is flashing light devices to train or assess reactive agility, despite limited evidence. Therefore, in the present study, we determined the effects of a 6-week reactive agility training program using light-based stimuli on the physiological and cognitive abilities of car racing drivers.

MATERIALS AND METHODS

The CONSORT guidelines for randomized controlled trial were used. In a single-blinded randomized controlled trial, 24 car racing drivers (EXP, n = 12; CON, n = 12) performed a comprehensive battery of cognitive tests marketed specifically at motorsport athletes from Vienna test system (VTS) at rest or during moderate intensity exercise on a bicycle. Physiological abilities were determined via a maximal incremental cardio-respiratory treadmill test. Baseline and post-intervention tests were performed on three consecutive days. Participants in EXP underwent a 6-week intervention consisting of 60-min training sessions twice a week using the Witty SEM light stimulus.

RESULTS

Participants in EXP but not in CON performed some of the VTS cognitive tasks with higher accuracy and/or shorter reaction time after the intervention at rest and during exercise. Car racing drivers performed the STROOP word-reading condition more accurately when the task was performed during the exercise vs. rest, regardless of group. In addition, the intervention induced beneficial changes in peak heart rate (HR), HR at gas exchange threshold, ventilation, and relative maximal oxygen consumption (rVO₂ max). In contrast, body mass and fat mass increased, while peak HR and rVO₂ max decreased in CON. Finally, participants in EXP improved their reactive agility performance and reaction time throughout the training program.

CONCLUSION

Overall, the reactive agility training program using light-based stimuli appeared to be efficient to induce beneficial effects on some physiological and cognitive performance measures; therefore, it may have the potential to contribute to car racing drivers' physical and mental performance.

Rossitto J, Ray K, A. Dufurrena Q, Blue RS. Blood Glucose Alterations and Continuous Glucose Monitoring in Centrifuge-Simulated Spaceflight

INTRODUCTION: Sympathetic stimulation is known to be associated with transient alterations of blood glucose (BG) concentration; spaceflight acceleration may be similarly associated with alterations of BG, potentially posing a risk to diabetic individuals engaging in future spaceflight activities. Despite prior studies demonstrating diabetic subjects’ tolerance to centrifuge-simulated spaceflight, data are lacking regarding blood glucose response to hypergravity. It remains unclear whether hypergravity or associated physiological response may pose a risk to diabetics. Continuous glucose monitors (CGM) offer a means of noninvasive glucose monitoring and may be useful in spaceflight and analog environments. Here, we describe the results of continuous glucose monitoring during centrifuge-simulated spaceflight.METHODS: Subjects participated in 1–5 centrifuge-simulated spaceflight profiles (maximum +4.0 Gz, +6.0 Gx, 6.1 G resultant). Data collection included heart rate, blood pressure, electrocardiogram, continuous glucose via CGM, intermittent fingerstick BG, and postrun questionnaires regarding symptoms related to hypergravity exposure.RESULTS: CGM data were collected from 26 subjects, including 4 diabetics. While diabetic subjects had significantly higher BG compared to nondiabetics, this was not associated with any difference in symptoms or tolerance. Transient hypergravity-associated CGM glucose alterations did not affect tolerance of the centrifuge experience. CGM data were found to be reliable with occasional exceptions, including four instances of false critical low glucose alarms.DISCUSSION: While further study is necessary to better characterize CGM fidelity during hypergravity and other spaceflight-related stressors, CGM may be a feasible option for spaceflight and analog settings. As in prior studies, individuals with well-controlled diabetes appear able to tolerate the accelerations anticipated for commercial spaceflight.Ong KM, Rossitto JJ, Ray K, Dufurrena QA, Blue RS. Blood glucose alterations and continuous glucose monitoring in centrifuge-simulated spaceflight. Aerosp Med Hum Perform. 2022; 93(9):688–695.

Redox Implications of Extreme Task Performance: The Case in Driver Athletes

Redox homeostasis and redox-mediated signaling mechanisms are fundamental elements of human biology. Physiological levels of reactive oxygen species (ROS) and reactive nitrogen species (RNS) modulate a range of functional processes at the cellular, tissue, and systemic levels in healthy humans. Conversely, excess ROS or RNS activity can disrupt function, impairing the performance of daily activities. This article analyzes the impact of redox mechanisms on extreme task performance. Such activities (a) require complex motor skills, (b) are physically demanding, (c) are performed in an extreme environment, (d) require high-level executive function, and (e) pose an imminent risk of injury or death. The current analysis utilizes race car driving as a representative example. The physiological challenges of this extreme task include physical exertion, g loading, vibration, heat exposure, dehydration, noise, mental demands, and emotional factors. Each of these challenges stimulates ROS signaling, RNS signaling, or both, alters redox homeostasis, and exerts pro-oxidant effects at either the tissue or systemic levels. These redox mechanisms appear to promote physiological stress during race car driving and impair the performance of driver athletes.

Responses of Driver-Athletes to Repeated Driving Stints

PURPOSE

The purpose of this study was to examine and quantify the effect of repeated driving stints on the physiologic, metabolic, and hormonal responses of three professional endurance driver-athletes.

METHODS

Core body temperature, HR, and physiological strain index were recorded during the Rolex 24 Hours of Daytona endurance race using the Equivital Life Monitor system. Blood glucose was monitored continuously during the event using a FreeStyle Libre Pro (Abbott, Alameda, CA). Alpha-amylase and cortisol were sampled immediately before the beginning of a stint and immediately after.

RESULTS

First-stint overall and individual driver-athlete responses were similar to those reported in the literature. Later-stint responses diverged from the literature. Reductions in initial core temperature, absence of increases in HR and physiological strain index, and altered glucose and hormonal responses were each observed in the later stint.

CONCLUSION

The data support previous research showing that motorsports has a measurable physiological, metabolic, and hormonal effect on the driver-athlete. This study also shows that multiple stints elicit responses that deviate from the published literature on single-stint events. This study is also particularly interesting in that it represents one of the first times that longitudinal data have been gathered on endurance racing driver-athletes.

Real-Time Digital Biometric Monitoring during Elite Athletic Competition: System Feasibility with a Wearable Medical-Grade Sensor

Introduction

Real-time digital heart rate (HR) monitoring in sports can provide unique physiological insights into athletic performance. However, most HR monitoring of elite athletes is limited to non-real-time, non-competition settings while utilizing sensors that are cumbersome. The present study was undertaken to test the feasibility of using small, wearable medical-grade sensors, paired with a novel technology system, to capture and process real-time HR data from elite athletes during professional competition.

Methods

We examined the performance of the BioStamp nPoint® sensor compared to the Polar chest strap HR sensor in 15 Professional Squash Association (PSA) tournament matches in 2019-2020. Fourteen male professional squash players volunteered for the study (age = 23.8 ± 4.9 years; height = 177.9 ± 7.1 cm; weight = 71 ± 7.0 kg), which was approved by the PSA in accordance with their Code of General Conduct and Ethics. Algorithms developed by Sports Data Labs (SDL; Detroit, MI, USA) used proprietary data collection, transmission, and signal processing protocols to produce HR values in real-time during matches. We calculated the mean and maximum HR from both sensors and used widely accepted measures of agreement to compare their performance.

Results

The system captured 99.8% of HR data across all matches (range 98.3-100%). The BioStamp's mean HR was 170.4 ± 20.3 bpm, while the Polar's mean HR was 169.4 ± 21.7 bpm. Maximum HR ranged from 182 to 202 bpm (Polar) and 185 to 203 bpm (BioStamp). Spearman's correlation coefficient (r _s) was 0.986 (p < 0.001), indicating a strong correlation between the 2 devices. The mean difference (d) in HR was 1.0 bpm, the mean absolute error was 2.2 bpm, and the percent difference was 0.72%, demonstrating high agreement between device measurements.

Conclusions

It is feasible to accurately measure and monitor real-time HR in elite athletes during competition using BioStamp's and SDL's proprietary system. This system facilitates development and understanding of physiological digital biomarkers of athletic performance and physical and psychosocial demands in elite athletic competition.

Cockpit Temperature as an Indicator of Thermal Strain in Sports Car Competition

PURPOSE

This study aimed to evaluate the relationship between race car cockpit temperature and thermal strain indicators among race car drivers.

METHODS

Four male racing drivers' heart rate (HR), skin temperature (Tskin), and core temperature (Tcore) were measured continuously using the Equivital Life Monitor bio harness, and physiological strain index (PSI) was calculated during a hot (ambient temperature of 34.1°C ± 2.8°C) 6-h endurance race. Only data collected during green flag racing laps were analyzed.

RESULTS

Cross-sectional analyses showed that cockpit temperature did not have a significant relationship with percent of HRmax, Tskin, Tcore, or PSI (P > 0.05) during the race. Cockpit temperature decreased during driving time, whereas percent of HRmax, Tskin, Tcore, and PSI increased (P < 0.05).

CONCLUSION

Cockpit temperature does not correlate with measures of race car driver thermal strain. Therefore, metrics to determine driver thermal strain should include direct monitoring of the race car driver.

A Comparison of the Physiological Responses in Professional and Amateur Sports Car Racing Drivers

Purpose:Automobile racing is physically challenging, but there is no information related to experience level and physiological responses to racing. The aim of this study was to compare physiological responses of professional (PRO) and amateur (AM) sportscar drivers. Methods:Four male racing drivers (PRO n = 2, AM n = 2), completed a physical fitness assessment and had heart rate (HR), breathing rate 10 (BR), skin temperature (T_sk), core temperature (T_core), physiological strain index (PSI) and blood glucose (BG) measured continuously during six races. Rate of perceived exertion (RPE), blood lactate, and fluid loss were measured post-race. Results:AM had higher HR compared to PRO during driver changes (AM: 177 ± 12 beats·min^-1, PRO: 141 ± 16 beats·min^-1, p < .0001), pit stops (AM: 139 ± 14 beats·min^-1, PRO: 122 ± 1 beats·min^-1, p = .0381) and cautions (AM: 144 ± 13 beats·min^-1, PRO: 15 123 ± 11 beats·min^-1, p = .0059). During pit stops, PRO (26 ± 6 respirations·min^-1) displayed a significantly greater BR than AM (AM: 18 ± 7 respirations·min^-1, p = .0004). T_core was greater for PRO (38.4 ± 0.4°C) drivers while in the car during pit stops than AM (36.1 ± 2.5°C, p < .0001). AM displayed elevated PSI during cautions (AM: 5.5 ± 1.8, PRO: 3.2 ± 1.3, p < .0001) and pit stops (AM: 5.6 ± 1.4, PRO: 2.8 ± 1.1, p < .0001). BG was increased for AM versus PRO during pit stops (AM: 20 132.9 ± 20.2 mg·dl^-1, PRO: 106.5 ± 3.5 mg·dl^-1, p = .0015) and during racing (AM: 150.9 ± 34.6 mg·dl^-1, PRO: 124.9 ± 16.0 mg·dl^-1, p = .0018). AM (3.3 ± 1.7 mmol·dl^-1) had a higher blood lactate than PRO (1.7 ± 2.6 mmol·dl^-1, p = .0491) from pre to post-race. AM (1.90 ± 0.54 kg) lost more fluids over the race than PRO (1.36 ± 0.67 kg, p = .0271). Conclusions:Amateur drivers could fatigue faster in the car which results in a decreased driving performance.

Advantage and use of S-patch cardio solution in competitive motor sports

BACKGROUND

Motorsport karting has developed into a professional international competition. Kart racing poses a unique set of physiologic challenges for athletes who compete in this sport. Until today no major study has evaluated the physical and cardiac challenge in professional kart racing.

OBJECTIVE

The aim for this study was to measure and analyze heart rate and cardiac rhythm by a mobile, smartphone based ECG (s-patch) on professional kart-race-drivers during actual karting races through annual seasons to test the hypotheses that high g-force and stress could trigger cardiac arrhythmia.

MATERIAL AND METHODS

ECG-data from kart-drivers were acquired during local races, the ADAC Kart-Masters (KZ2), the German Kart Championship (DSKC) and the European Championship Senior CIK-FIA-Serie and analyzed in this observational study. In total, free practice, qualifying practice and 32 races were assessed during the kart season 2019. Data were interpreted by two independent experienced physicians.

RESULTS

The average heart rate (HR) during a selected German Kart Championship (DSKC) race in Genk (Belgium) was 169 beats min-1. The longest R-R interval was 0.72 sec. The average HR during a selected European Championship CIK-FIA-race in Lonato (Italy) was 160 beats min-1. The longest R-R interval was 0.74 sec. The average HR during a selected ADAC Kart-Masters (KZ2) races in Wackersdorf (Germany) was 147 beats min-1. The longest R-R interval was 0.86 sec. In total 32 races could be recorded successful. No couplets or bigeminy cycles were detected. In one other kart racer a supraventricular extrasystole and a ventricular extrasystole was detected. Interestingly, kart-drivers were found to have sinustachycardia throughout the races most likely triggered by emotional and physiological stress during speeding.

CONCLUSION

Professional kart racing drivers had sinustachycardia with heart rates up to 193 beats min-1 during races. This is most likely attributed to a considerably high emotional and physiological stress affecting the cardiovascular system. Episodes of tachycardia positively correlated with mean speed. In the warm-up lap the heart rate was significantly lower in comparison to the race, suggesting that faster driving speed would induce greater cardiovascular stress to professional drivers during actual races. The experimental results showed that the proposed S-patch system provided a good ECG signal quality with accurate measurements even during the kart race and could detect the ECG features of the race in real time. The cardiac interpretation software performs well and is a useful tool to assist clinicians.

The Physiology of Auto Racing

INTRODUCTION

Auto racing poses a unique set of physiologic challenges for athletes who compete in this sport. These challenges are not widely recognized due to the limited amount of original research in this field and the diffuse nature of this literature. The purpose of this article is to review the major physiologic challenges of auto racing and summarize what is currently known about athletes in this sport.

CONCLUSIONS

The physical stressors of either driving or servicing the race car are overlaid with particular environmental challenges associated with racing (e.g., thermal, noise, carbon monoxide exposure) that increase the physiological stress on motorsport athletes. Physical stress reflects the muscular work required for car control and control of posture during high gravitational (g) loads: factors that predispose athletes to fatigue. The physiologic effects of these stressors include cardiovascular stress as reflected by prolonged elevation of heart rate, cardiac output, and oxygen consumption in both driver and pit athletes during competition. Psychological stress is evident in autonomic and endocrine responses of athletes during competition. The thermal stress of having to compete wearing multilayer fire suits and closed helmets in ambient temperatures of 50°C to 60°C results in the ubiquitous risk of dehydration. Published data show that both drivers and pit crew members are accomplished athletes with distinct challenges and abilities. There are gaps in the literature, especially in regard to female, older adult, and child participants. Additionally, minimal literature is available on appropriate training programs to offset the physiological challenges of auto racing.

Physiological Responses of Male and Female Race Car Drivers during Competition

Automobile racing is one of the largest spectator sports in the world with male and female drivers competing together. Popular media has speculated on the relative capabilities of males and females in automobile racing, yet there are no scientific investigations examining physiological responses to racing among males and females.

PURPOSE

1) To evaluate the physiological responses of male and female drivers in open and closed cockpit race cars, 2) to examine the moderating influence of menstrual cycle phase on physiological responses to racing among female drivers.

METHODS

HR, breathing rate, skin temperature, core temperature, and Physiological Strain Index (PSI) were measured using the Equivital Life Monitor in male (n = 6) and female (n = 6) drivers at three races in open or closed cockpit cars. Among females, menstrual cycle phase for each race was recorded.

RESULTS

During racing conditions there was no difference (P > 0.05) between male and female drivers for HR, skin temperature, core temperature, or PSI. The female drivers had a higher (P < 0.001) breathing rate compared with the male drivers. Compared with the follicular phase, the luteal phase had an increased (P < 0.001) HR, breathing rate, skin temperature, core temperature, and PSI. The closed cockpit cars elicited (P < 0.001) a higher skin temperature, core temperature and PSI as compared with the open cockpit cars.

CONCLUSIONS

There were no differences in the physiological responses to automobile racing between male and female drivers. The luteal phase elicited higher physiological responses than the follicular phase, but was not different from the male drivers. Thereby, practitioners should focus on reducing stresses induced by a closed cockpit race car as opposed to the menstrual cycle.

V˙O2peak, Body Composition, and Neck Strength of Elite Motor Racing Drivers

PURPOSE

Automobile racing is widely known to be physically demanding; however, there is no published information comparing the physical fitness variables of elite-level race car drivers across various competitive championships.

METHODS

We documented the body composition, peak oxygen consumption (V˙O2peak), and isometric neck strength in a sample of elite race car drivers currently competing in Formula 1, IndyCar, NASCAR, and International Motor Sports Association sports car racing (IMSA GTD), to determine current human performance benchmarks and establish goals for drivers wishing to compete in these series.

RESULTS

Percent body fat was significantly (P < 0.001) lower in Formula 1 drivers (8.1% ± 1.7%) as compared with the other series, with IndyCar (17.4% ± 1.7%) and NASCAR (17.3% ± 4.6%) being less than IMSA GTD (24.9% ± 1.8%). Percent lean mass followed the same trend as percent body fat. IMSA GTD had not only the highest percent body fat but also the lowest (P = 0.001) V˙O2peak (45.2 ± 2.1 mL·kg·mL) compared with Formula 1 (62.0 ± 6.0 mL·kg·mL), IndyCar (58.05 ± 6.40 mL·kg·mL), and NASCAR (53.2 ± 4.1 mL·kg·mL). Isometric neck strength was the highest in Formula 1 and IndyCar drivers as compared with IMSA GTD and NASCAR drivers.

CONCLUSION

These results support the hypothesis that the varying physical demands of each competition series require different physical fitness levels of drivers. These benchmarks can be used by exercise professionals to better prepare athletes for competition.

Physical Fitness and Blood Glucose Influence Performance in IndyCar Racing

Ferguson, DP and Myers, ND. Physical fitness and blood glucose influence performance in IndyCar racing. J Strength Cond Res 32(11): 3193-3206, 2018-Charlie Kimball (CK) is an elite-level IndyCar driver who has type 1 diabetes. Since CK became a full-time competitor, there has been exponential growth in the number of racing drivers competing with type 1 diabetes. Therefore, the purpose of this article is to present a case report of data collected on CK over 6 years, to better inform strength and conditioning coaches on how to prepare racing drivers with type 1 diabetes for competition. We hypothesized that the physical requirements to pilot the race car would include an elevated aerobic and glycolytic capacity and that blood glucose would influence key driving parameters (vertical gravitational force [Gz] tolerance and reaction time/response accuracy) related to success (finishing position). Physical fitness was evaluated with a V[Combining Dot Above]O2max test, dual-energy X-ray absorptiometry body composition analysis, Wingate power test, and a lower-body negative pressure test for vertical Gz tolerance. To test the role of fitness and blood glucose on driving performance, heart rate (HR), breath rate (BR), and skin temperature (ST) were evaluated during practice racing sessions using the Equivital Life Monitor. Blood glucose was monitored in 47 races using a continuous glucose monitor. Driving a race car resulted in increased HR, BR, and ST. The driver's body composition, skeletal muscle power output, and aerobic capacity values were in the 10th percentile of the average population. A blood glucose range of 100-168 mg·dl was identified as optimal for driving performance for the case study participant because it improved reaction time/response accuracy and Gz tolerance.

The Racer's Mind-How Core Perceptual-Cognitive Expertise Is Reflected in Deliberate Practice Procedures in Professional Motorsport

The exceptional performance of elite practitioners in domains like sports or chess is not a reflection of just exceptional general cognitive ability or innate sensorimotor superiority. Decades of research on expert performance has consistently shown that experts in all fields go to extraordinary lengths to acquire their perceptual-cognitive and motor abilities. Deliberate Practice (DP) refers to special (sub)tasks that are designed to give immediate and accurate feedback and performed repetitively with the explicit goal of improving performance. DP is generally agreed to be one of the key ingredients in acquisition of expertise (not necessarily the only one). Analyzing in detail the specific aspects of performance targeted by DP procedures may shed light on the underlying cognitive processes that support expert performance. Document analysis of professional coaching literature is one knowledge elicitation method that can be used in the early phases of inquiry to glean domain information about the skills experts in a field are required to develop. In this study this approach is applied to the domain of motor racing - specifically the perceptual-cognitive expertise enabling high-speed curve negotiation. A systematic review procedure is used to establish a corpus of texts covering the entire 60 years of professional motorsport textbooks. Descriptions of specific training procedures (that can be unambiguously interpreted as DP procedures) are extracted, and then analyzed within the hierarchical task analysis framework driver modeling. Hypotheses about the underlying cognitive processes are developed on the basis of this material. In the traditional psychological literature, steering and longitudinal control are typically considered “simple” reactive tracking tasks (model-free feedback control). The present findings suggest that—as in other forms expertise—expert level driving skill is in fact dependent on vast body of knowledge, and driven by top-down information. The knowledge elicitation in this study represents a first step toward a deeper psychological understanding of the complex cognitive underpinnings of expert performance in this domain.

Speed ratio but cabin temperature positively correlated with increased heart rates among professional drivers during car races

OBJECTIVES

The present study measures heart rate (HR) on a number of professional race-car drivers during actual car races through annual seasons to test hypotheses that faster relative speed and higher cabin temperature would induce higher HR.

METHODS

Heart rates in fifteen male drivers (31.2 ± 5.5 years old) were obtained by chest-strap sensors during official-professional 13 races. Average HR was calculated while the driver was racing from the start to the end of each race.

RESULTS

The average HR during races was 164.5 ± 15.1 beats min-1 and the average amount of time each driver spent driving per race was 54.2 ± 13.7 min. Average HR significantly and positively correlated with mean speed ratio (P < 0.001), but not with the average cabin temperatures (P = 0.533, range 25.6-41.8 °C) by the multiple linear regression analysis. Both average HR and mean speed ratio were significantly lower under wet, than dry conditions (151.9 ± 16.5 vs. 168.3 ± 12.5 beats min-1, 86.9 ± 4.4 vs. 93.4 ± 1.5 %).

CONCLUSIONS

The cardiovascular system of drivers is considerably stressed at extremely high HR. This high average HR positively correlated with mean speed ratio, suggesting that faster driving speed would induce greater cardiovascular stress to professional drivers during actual races. However, contrary to our hypothesis, cabin temperature was not significantly correlated with average HR. It is speculated that direct body cooling systems used in this professional race category work well against increases in HR by thermal stress under the temperature range found herein.

Stress Markers During a Rally Car Competition

The aim of the study was to assess the stress responses in drivers during an official rally car race and the influence of fitness and body composition on stress hormones. Fitness and body composition were assessed in 9 rally car drivers with an incremental exercise test for determination of maximum aerobic speed (MAS) and 6-site skinfold method, respectively. Before (pre) and after (post) the first stage of an official rally car race, data were collected for heart rate (HR), blood samples were collected for analysis of hormones (i.e., epinephrine [EPI], norepinephrine [NE], cortisol, and aldosterone) and metabolites (i.e., lactate [LA], glucose, and ammonia). There were significant (p ≤ 0.05) increases in all assessed variables except glucose at postrace. Heart rate increased 93% (p ≤ 0.05) at the end of the race stage, reaching 88.77 ± 4.96% of HRpeak. Also, EPI and NE significantly (p = 0.001) increased by 45 and 65%, respectively, and LA increased by 395% (p < 0.001). Significant correlations between percent body fat (%BF) and postrace EPI (r = 0.95; p < 0.001), and percentage change of EPI (r = 0.83; p = 0.012) were observed. The MAS was not associated to any metabolic or hormonal variable. These results suggest that psycho-physiological stress induced by the race elicited important changes in hormonal and metabolic variables and that %BF could be an important mediator of psycho-physiological stress in rally car drivers. Specific programs, including both strength and aerobic training, and nutritional plans should be implemented for appropriate conditioning of rally car drivers.

The Healthy Heart: Lessons from Nature's Elite Athletes

The incidence of cardiovascular disease in humans is more than three times that of many wild and domestic mammals despite nearly identical heart morphologies and responses to exercise. A survey of mammalian species from 0.002-kg shrews to 43,000-kg whales shows that the human heart is more dog-like than cat-like and that neither body size nor longevity accounts for the relative vulnerability to cardiovascular disease. Rather, a major difference is daily activity patterns, which may underlie the comparatively healthy hearts of wild mammals.

Physiological and selective attention demands during an international rally motor sport event

PURPOSE

To monitor physiological and attention responses of drivers and codrivers during a World Rally Championship (WRC) event.

METHODS

Observational data were collected from ten male drivers/codrivers on heart rate (HR), core body (T core) and skin temperature (T sk), hydration status (urine osmolality), fluid intake (self-report), and visual and auditory selective attention (performance tests). Measures were taken pre-, mid-, and postcompetition day and also during the precompetition reconnaissance.

RESULTS

In ambient temperatures of 20.1°C (in-car peak 33.9°C) mean (SD) peak HR and T core were significantly elevated (P < 0.05) during rally compared to reconnaissance (166 (17) versus 111 (16) beats · min(-1) and 38.5 (0.4) versus 37.6 (0.2)°C, resp.). Values during competitive stages were substantially higher in drivers. High urine osmolality was indicated in some drivers within competition. Attention was maintained during the event but was significantly lower prerally, though with considerable individual variation.

CONCLUSIONS

Environmental and physical demands during rally competition produced significant physiological responses. Challenges to thermoregulation, hydration status, and cognitive function need to be addressed to minimise potentially negative effects on performance and safety.

Optimizing the physical conditioning of the NASCAR sprint cup pit crew athlete

Stock car racing is the largest spectator sport in the United States. As a result, National Association for Stock Car Automobile Racing (NASCAR) Sprint Cup teams have begun to invest in strength and conditioning programs for their pit crew athletes. However, there is limited knowledge regarding the physical characteristics of elite NASCAR pit crew athletes, how the NASCAR Sprint Cup season affects basic physiological parameters such as body composition, and what is the most appropriate physical training program that meets the needs of a pit crew athlete. We conducted 3 experiments involving Sprint Cup motorsport athletes to determine predictors of success at the elite level, seasonal physiological changes, and appropriate physical training programs. Our results showed that hamstring flexibility (p = 0.015) and the score on the 2-tire front run test (p = 0.012) were significant predictors of NASCAR Sprint Cup Pit Crew athlete performance. Additionally, during the off season, pit crew athletes lost lean body mass, which did not return until the middle of the season. Therefore, a strength and conditioning program was developed to optimize pit crew athlete performance throughout the season. Implementation of this strength and conditioning program in 1 NASCAR Sprint Cup team demonstrated that pit crew athletes were able to prevent lean body mass loss and have increased muscle power output from the start of the season to the end of the season.

Bioenergetical and Cardiac Adaptations of Pilots to a 24-Hour Team Kart Race

This study aimed to evaluate energy expenditure (EE) and heart rate (HR) response in kart pilots to successive driving bouts during a 24-hour team race. Eight adult male pilots (22.8 ± 4.1 years) participated to a team 24-hour speedway kart race in Le Mans (France). They alternatively piloted a 390 cm kart. Each relay was 45 minutes long and each pilot performed 4 relays. For each pilot, mean speeds were calculated from lap-to-lap duration recordings using a telemetric infrared timing device. Heart rate values were recorded continuously on 5-second intervals using a portable cardiometric device. Total energy expenditure (EET) and physical activity ratio (PAR) were determined by accelerometry. To pilot a kart during 45 minutes at a mean speed around 62 km·h induces a 300-kcal EET, corresponding to a 5.6-Mets PAR. This effort is responsive for a 73 b·min increase in HR, from 84.1 ± 7.6 to 157.4 ± 11.0 b·min (82% maximal heart rate intensity). However, during this relay period, HR values seemed independent to mean speed performance and bioenergetical values. Thus, in the context of the 24-hour team race, the variability in effort made during each relay and relay succession did not alter bioenergetical adaptation of pilots to kart driving. The high EE and HR values would be better explained by both emotional stress and environmental constraints such as speedway configuration and vibrations. The way how these factors specifically influence bioenergetical demand, and their relative importance, has to be specified to optimize training procedure and recommendations.

Usefulness and metabolic implications of a 60-second repeated jumps test as a predictor of acrobatic jumping performance in gymnasts

Gymnastics floor exercises are composed of a set of four to five successive acrobatic jumps usually called a “series”. The aims of the study were: 1) to relate the acrobatic gymnastics performance of these series with a repeated jumps test of similar duration (R60), 2) to study the relation between R60 and physiological parameters (heart rate and blood lactate), and the performance obtained in different kinds of jumps, 3) to confirm whether R60, executed without a damped jumping technique, can be considered an anaerobic lactic power test. Twenty male and twenty-four female gymnasts performed three repeated jumps tests for 5 s (R5), 10 s (R10) and 60 s (R60) and vertical jumps, such as drop jumps (DJ), squat jumps (SJ) and countermovement jumps (CMJ). We assessed heart rate (HR) and blood lactate during R10 and R60. The average values of the maximal blood lactate concentration (L_max) after R10 (males = 2.5±0.6 mmol · l⁻¹; females = 2.1±0.8 mmol · l⁻¹) confirm that anaerobic glycolysis is not activated to a high level. In R60, the L_max (males = 7.5±1.7 mmol · l⁻¹ females = 5.9±2.1 mmol · l⁻¹) that was recorded does not validate R60 as an anaerobic lactic power test. We confirmed the relation between the average power obtained in R60 (R60Wm) and the acrobatic performance on the floor. The inclusion in the multiple regression equation of the best power in DJ and the best flight-contact ratio (FC) in R5 confirms the influence of other non-metabolic components on the variability in R60 performance, at least in gymnasts.

Physical demands, injuries, and conditioning practices of stock car drivers

The purpose of this study was to assess the physical demands, injuries, and conditioning practices of stock car drivers. Forty stock car drivers from 27 states in the United States participated in the interviews for 43.9 ± 13.9 minutes. The interviews examined background information, the physical demands of racing, injuries associated with racing, and the athletic and fitness background and practices of the subjects. Numerical data were analyzed using Pearson's correlation coefficients. Responses to open-ended questions were analyzed using inductive content analysis. Results revealed significant correlation between track points standings and the length of the resistance training sessions (R = -0.71, p = 0.002) and subject self-assessment of their fitness (R = -0.53, p = 0.045). Results also revealed that "upper-body strength" was identified as the most important physical demand. Extreme fatigue was the most common feeling after a demanding race. Subjects reported that shoulder fatigue was the most common form of muscle soreness experienced after a race. Back and torso injuries were the most common injury, although head injuries most frequently required medical attention. The subjects' biggest fear was fire, followed closely by head and neck injury. The bench press and running were the most commonly performed resistance training and cardiovascular exercises, respectively. Subjects reported that their highest motivation for training was to improve their racing performance. Many subjects had athletic backgrounds with football identified as the sport they had most commonly participated in. This study provides additional detailed information. Results of this study can assist strength and conditioning professionals in the development of strength and conditioning programs for performance enhancement and injury prevention that are specific to the needs of this population of athletes.

The effect of competition on heart rate during kart driving: A field study

Background

Both the act of competing, which can create a kind of mental stress, and participation in motor sports, which induces physical stress from intense g-forces, are known to increase heart rate dramatically. However, little is known about the specific effect of competition on heart rate during motor sports, particularly during four-wheel car driving. The goal of this preliminary study, therefore, was to investigate whether competition increases heart rate under such situations.

Findings

The participants drove an entry-level formula kart during two competitive races and during solo driving against the clock while heart rate and g-forces were measured. Analyses showed that heart rate values during the races (168.8 beats/min) were significantly higher than those during solo driving (140.9 beats/min) and rest (75.1 beats/min).

Conclusions

The results of this preliminary study indicate that competition heightens heart rate during four-wheel car driving. Kart drivers should be concerned about maintaining good health and developing physical strength.

Heart Rate Responses and Fluid Balance of Competitive Cross-Country Hang Gliding Pilots

Purpose:

To evaluate the physiological challenges of competitive cross-country hang gliding.

Methods:

Seventeen experienced male pilots (age = 41 ± 9 y; mean ± SD) were fitted with a monitor that recorded heart rate and altitude at 0.5 Hz throughout a competitive fight. Fluid losses were evaluated by comparing pilot pre- and postfight mass.

Results:

The pilots’ displacement was 88.4 ± 43.7 km in 145.5 ± 49.4 min. Mean fight altitude was 1902 ± 427 m (range = 1363-2601 m) with a maximum altitude of 2925 ± 682 m (1870-3831 m). The mean in-fight heart rate of the pilots was 112 ± 11 bpm (64 ± 6% predicted HRmax). For all except one subject, heart rate was highest while launching (165 ± 12 bpm, 93 ± 7% predicted HRmax), followed by landing (154 ± 13 bpm, 87 ± 7% predicted HRmax). No statistically significant relationship was observed between heart rate during the launch and reported measures of state anxiety. Heart rate was inversely related (P < .01) to altitude for all pilots except one. Fluid loss during the fight was 1.32 ± 0.70 L, which approximated 0.55 L/h, while mean in-fight fluid consumption was 0.39 ± 0.44 L. Six pilots consumed no fluid during the fight.

Conclusions:

Even among experienced pilots, high heart rates are more a function of state anxiety than physical work demand. Fluid losses during fight are surprisingly moderate but pilots may still benefit from attending to fluid balance.

Responses of Motor-Sport Athletes to V8 Supercar Racing in Hot Conditions

Background:

Despite the thermal challenge of demanding workloads performed in high cabin temperatures while wearing heavy heat-retardant clothing, information on physiological responses to racing V8 Supercars in hot conditions is not readily available.

Purpose:

To describe the thermal, cardiovascular, and perceptual strain on V8 Supercar drivers competing in hot conditions.

Methods:

Thermal strain was indicated by body-core temperature using an ingested thermosensitive pill. Cardiovascular strain was assessed from heart rate, hydration status, and sweat rate. Perceptual strain was estimated from self-rated thermal sensation, thermal discomfort (modified Gagge scales), perceived exertion (Borg scale), and perceptual strain index.

Results:

Prerace body-core temperatures were (mean ± SD) 37.7°C ± 0.4°C (range 37.0°C to 38.2°C), rising to 39.0°C ± 0.4°C (range 38.4°C to 39.7°C) postrace. Driver heart rates were >160 and >170 beats/min for 85.3% and 46.7% of racing, respectively. Sweat rates were 1.06 ± 0.12 L/h or 13.4 ± 1.2 mL · kg−1 · h−1, and postrace dehydration was 0.6% ± 0.6% of prerace body mass. Drivers rated thermal sensation as hot (10.3 ± 0.9), thermal discomfort as uncomfortable (3.1 ± 1.0), and perceived exertion as very hard to very, very hard (8.7 ± 1.7) after the races. Overall physiological and perceptual strain were 7.4 ± 1.0 and 7.1 ± 1.2, respectively.

Conclusions:

Despite the use of cooling, V8 Supercar drivers endure thermal, cardiovascular, and perceptual strain during brief driving bouts in hot conditions.

Reactivity, stability, and strength performance capacity in motor sports

BACKGROUND

Racing drivers require multifaceted cognitive and physical abilities in a multitasking situation. A knowledge of their physical capacities may help to improve fitness and performance.

OBJECTIVE

To compare reaction time, stability performance capacity, and strength performance capacity of élite racing drivers with those of age-matched, physically active controls.

METHODS

Eight élite racing drivers and 10 physically active controls matched for age and weight were tested in a reaction and determination test requiring upper and lower extremity responses to visual and audio cues. Further tests comprised evaluation of one-leg postural stability on a two-dimensional moveable platform, measures of maximum strength performance capacity of the extensors of the leg on a leg press, and a test of force capacity of the arms in a sitting position at a steering wheel. An additional arm endurance test consisted of isometric work at the steering wheel at +30 degrees and -30 degrees where an eccentric threshold load of 30 N.m was applied. Subjects had to hold the end positions above this threshold until exhaustion. Univariate one way analysis of variance (alpha = 0.05) including a Bonferroni adjustment was used to detect group differences between the drivers and controls.

RESULTS

The reaction time of the racing drivers was significantly faster than the controls (p = 0.004). The following motor reaction time and reaction times in the multiple determination test did not differ between the groups. No significant differences (p>0.05) were found for postural stability, leg extensor strength, or arm strength and endurance.

CONCLUSIONS

Racing drivers have faster reaction times than age-matched physically active controls. Further development of motor sport-specific test protocols is suggested. According to the requirements of motor racing, strength and sensorimotor performance capacity can potentially be improved.

Plastic Surgeon???s Life: Marvelous for Mind, Exhausting for Body

Surgery is accepted as one of the most demanding professions that create both physical and mental strain on the performers. Therefore, the authors aimed to elucidate the mental burden of surgeons, which is dedicated to operative stress. They also tested the hypotheses that participating in surgery creates mental stress on surgeons that leads to cardiovascular changes, and that this stress is more pronounced for actual operators than for first assistants. The method chosen for this purpose was an analysis of heart rate variability. Twelve surgeons (five plastic surgery staff and seven plastic surgery residents) were monitored by a digital ambulatory Holter recorder on at least two occasions. Half of the recordings were carried out on operating days and the other half on office days. Heart rate variability indices (low frequency, high frequency, high frequency/low frequency ratio, and heart rate) were analyzed from those recordings using computerized research tool software. The heart rate variability indices of the operators showed statistically significant differences between operating days and office hours in favor of an increased sympathetic and decreased parasympathetic activity for the former. For first assistants, three of the parameters, with the exception of heart rate, changed in favor of a sympathetic predominance over parasympathetic activity; these changes were also statistically significant. These results showed a sympathetic hyperactivity for both operators and first assistants during the operations. When the sympathovagal balance of the actual operators was compared with that of assistants, the former group showed a more pronounced sympathetic arousal. This difference is accepted as a proof for the mental stress of the surgery being the main factor responsible for the sympathetic hyperactivity that we detected during the operations. Surgeons continuously face a unique mental strain that other professions rarely bring forth, and these psychological stressors are associated with alterations in cardiac autonomic control that may contribute to the development of cardiac disease. Prolonged sympathetic hyperactivity could anticipate cardiac discomfort in more experienced surgeons with marginal cardiac reserve. Such cardiac diseases would be reconsidered as occupation-related illnesses, which might be reimbursed to the physician. In addition, the legal responsibility of surgeons concerning their unfavorable results might be assessed with more understanding with a realization of their undue working conditions.

Physiological responses to high-speed, open-wheel racecar driving

High-speed auto racing has been demonstrated to produce accelerated heart rate (HR) during competition. However, it has not been determined whether the increase in HR was due to physical work efforts or a result of emotional stress.

PURPOSE

The purpose of this investigation was to examine the physiological responses associated with open-wheel automobile driving at competitive speeds.

METHODS

Oxygen consumption and HR were assessed in seven professional automobile racing drivers during two incrementally paced driving sessions. A portable metabolic analyzer and EKG were directly attached to the subjects as they participated in driving tests on an oval speedway and a roadway course. Maximal physiological responses of the subjects were also determined during a graded treadmill test.

RESULTS

During treadmill testing, maximal oxygen consumption (VO2max) ranged from of 42.0 to 59.7 mL x kg(-1) x min(-1) (mean +/- SD = 47.6+/-8.1). The road course and oval speedway testing at competitive speeds elicited mean VO2 values of 38.5 and 21.9 mL x kg(-1) x min(-1), respectively, which correspond to 79% and 45% of VO2max. Road course driving produced mean HR values of 152 beats x min(-1) with 142 beats x min(-1) recorded when driving at competitive speed on the speedway course.

CONCLUSIONS

Professional open-wheel race drivers possess cardiorespiratory capacity similar to athletes participating in sports such as basketball, football, and baseball. The VO2 and HR responses to road course driving were similar to those previously reported in traditional sports settings. The findings of this study suggest that professional open-wheel racing drivers should be regarded as athletes that encounter significant physiological stresses.(2)

Performance enhancement in rally car drivers via heat acclimation and race simulation

To investigate the combined use of an interactive racecar simulator and heat acclimation on psychomotor (driving) performance, eight rally drivers underwent 4 days of repeated heat (50 degrees C) exposure (1 h x day(-1)) during which they performed a simulated rally drive (3x12-min stages each separated by a 2-min break), after first cycling for 15 min at 125 W to induce some degree of fatigue and heat storage prior to beginning the rally. During the rally stages, a generic set of pace notes were read to the subject by a co-driver. In each simulation, sweat loss, heart rate, core (rectal) and skin temperatures were recorded and driving and psychomotor performance were assessed by recording stage times and time to complete a psychomotor test. Levels of physiological and perceived thermal strain were also recorded. Significant decreases in rally stage times (88 s; P<0.005), psychomotor test time (18 s; P<0.01), final core (0.25 degrees C; P<0.001) and skin (0.44 degrees C; P<0.005) temperatures, heart rate (16 beats x min(-1); P<0.05) and physiological (15 W x m(-2); P<0.005) and perceived thermal (3.7 units; P<0.01) strain were evident by the end of the final simulation, and a significant (P<0.05) increase in sweat sensitivity (+0.33 g x h(-1) x degrees C(-1)) was also recorded. These results suggest that both heat acclimation and race simulation can improve the psychomotor performance of rally drivers, although the relative contribution of each factor was not determined here. However, in a practical setting, these factors would not be used in isolation. After performing the acclimation and simulation protocol prior to an actual rally, drivers subjectively reported improvements in tolerating a high thermal load and in their ability to control the rally vehicle.

The combined effect of heat and carbon monoxide on the performance of motorsport athletes

Two of the major stressors endured by a motorsport athlete (MSA) during a racing event are the effects of heat and carbon monoxide. To date, there has been little research into their combined effect on driving performance. Using an interactive racecar simulator located within an environmental chamber, subjects drove a simulated race (60 min) in environmental conditions similar to those that develop during a NASCAR Winston Cup oval track race (50 degrees C ambient temperature and 10-12% carboxyhaemoglobin levels). Subjects also completed cool (20 degrees C) and heat only (50 degrees C) race simulations. During the simulations, oxygen consumption, heart rate, core and skin temperatures and psychomotor performance were measured. The results demonstrated that exposure to a racecar micro-environment combining both heat and CO produced significantly greater (P<0.05) sweat loss and core temperature change (1.53 kg; 1.06 degrees C) when compared to the heat only (1.14 kg; 0.73 degrees C) and cool conditions (0.35 kg; 0.09 degrees C). Furthermore, a significant decrease (P<0.05) in psychomotor performance was also shown between the heat/CO condition (contact points=38), and both the heat only (25 points) and cool conditions (22 points). It follows that lengthy exposure to these two stressors could produce a substantial decrement in driving performance, thereby endangering the MSA and other race competitors.

Sense of coherence buffers relationships of chronic stress with fasting glucose levels

Sense of coherence (SOC) was examined as a buffer of the relationship of chronic stress with fasting glucose and insulin levels. Spouse caregivers of persons with diagnoses of Alzheimer's disease (AD) (n = 73) were compared to controls [spouses of nondemented persons (n = 69)], group-matched on age/gender. After controlling for anger and coronary heart disease (CHD), interactions of SOC and gender explained variance in glucose (but not insulin) at study entry (T1) and 15-18 months later (T2). However, this occurred only in caregivers. At both times SOC and glucose were negatively related in men caregivers but not in women caregivers or in controls. In caregivers (but not controls), SOC at T1 predicted glucose at T2, independent of gender, anger, and glucose at T1; and hassles at T1 appeared to mediate this relationship. Future research should examine SOC as a buffer of other chronic stressors and metabolic variables.

Insulin and glucose: relationships with hassles, anger, and hostility in nondiabetic older adults

Relationships of psychosocial factors (anger, hostility, hassles, and caregiving) with fasting insulin and glucose levels were examined. Samples included two groups of nondiabetic adults (mean age = 69.4 years): spouse caregivers (CG) of individuals with diagnoses of Alzheimer's disease (AD) (N = 78) and spouses of nondemented controls (CO) (N = 72) matched for age and gender. The groups were assessed twice with a 15-to 18-month hiatus. To obtain more stable assessments, all biopsychosocial measures were averaged over time. Psychosocial factors were associated with insulin and glucose, even after controlling for significant health variables: obesity, lipids, and cardiovascular disease. As hypothesized, CG with high anger-out/hostility (AOHO) had significantly higher glucose levels than all other group combinations. The glucose levels for subjects with high hassles or high AOHO were significantly higher than those for subjects who were low on both of these factors. For insulin, a three-way interaction occurred among AOHO, hassles, and gender-hormone replacement therapy (HRT); in women taking HRT, no relationships occurred between insulin with AOHO and hassles. In women not taking HRT, those with high AOHO and high hassles had significantly higher insulin levels than the other three combinations, whereas in men, those with either high AOHO or high hassles had significantly higher insulin levels than men who were low on both of these factors. Given these results, future research should examine the degree to which interactions between metabolic processes with psychosocial variables, gender, and HRT have long term health consequences in nondiabetics.

Aerobic fitness and sympatho-adrenal response to short-term psycho-emotional stress under field conditions

A possible relationship between aerobic fitness (AF), measured by maximal cycle ergometry (CE) and sympatho-adrenal response to acute, short lasting psycho-emotional stress was investigated by monitoring heart rate (fc) and excretion of catecholamines. The activation of the sympatho-adrenal system was characterised by the noradrenaline: adrenaline ratio. A group of 11 healthy men [22.8 (SD 2.52) years] lived under identical environmental conditions; their mean maximal oxygen uptake (VO2max) was 47.1 (SD 3.9) ml.min-1.kg-1. After the physiological and psychological laboratory tests had been completed the fc of the subjects was monitored continuously during the "guerilla slide" and "parachute jump by night", two emotionally stressful military tasks. Maximal fc (fc, max) attained during these events was 84.5% and 83% of fc, max during CE (fc, max, CE), respectively. A significant relationship (r = -0.92, P < 0.0002) between fc, max reached during the stressful tasks and VO2max was found only for the guerilla slide, which was preceded by physical strain, sleep deprivation and energy deficit. One subject with some prior experience in parachuting showed the lowest fc response and the lowest sympatho-adrenal activation in both events, independent of the degree of AF. In conclusion, AF was found to influence the sympatho-adrenal and fc response to acute, short-lasting emotional stress when the stressful event was aggravated by preceding physical strain, the magnitude of the stress response depending largely on individual experience and effective mechanisms for coping with specific stimuli.

Lipids in psychological research: the last decade

We review the recent literature examining lipid changes during stressful experiences, and the psychological and constitutional differences that influence lipid levels at rest and that may modulate lipid response to stress. Mild forms of chronic or episodic stress are apparently not associated with alterations in lipids and lipoproteins, but severe forms of real or perceived stress do appear to alter lipid levels. Acute laboratory stress is frequently associated with short-term alterations in lipids and lipoproteins, but the significance of these changes is unclear. Several individual characteristics, such as heightened neuroendocrine or autonomic reactivity to stressors, Type A component behavior, and other aspects of personality, appear to be associated with an atherogenic lipid profile. Stress may influence lipid concentrations and metabolism through a variety of physiological and behavioral mechanisms, but none have been clearly elucidated. Future research should concentrate on understanding these mechanisms.

Reactivity to stress and psychological adjustment in adults with pituitary insufficiency

OBJECTIVE

Hypopituitary adults who were affected during childhood have a below-average rate of marriage, a rate of unemployment that exceeds national norms, and often indicate dissatisfaction with their life circumstances. We undertook the present study to determine the effects of short stature versus those of pituitary hormone deficiency.

DESIGN AND PATIENTS

We compared hypopituitary adults (n = 25) with normal short adults (n = 25) who were matched for height, sex, age and socioeconomic status.

MEASUREMENTS

In these two groups of subjects, we compared the physiological responses to a simulated social stressor, a public speaking task, and we measured the psychometric attributes that are indicators of social assertiveness and extraversion.

RESULTS

Before, during and after the stress of public speaking, patients with multiple pituitary hormone deficiencies (n = 20) had lower mean systolic and diastolic blood pressures than controls, while patients with isolated growth hormone deficiency (n = 5) were equivalent to controls. The reactivity to stress, assessed using delta scores based on changes in blood pressure and heart rate, was also decreased in multiple hormone deficient patients. Psychometric test results indicated that patients with multiple hormone deficiencies showed lower openness, lower assertiveness, greater neuroticism and a tendency towards less extraversion than did controls. The responses of patients with isolated GH deficiency on the psychometric tests were not statistically different from controls, but the number of subjects in this group (n = 5) was too small to draw conclusions.

CONCLUSIONS

The impaired cardiovascular responses to stress in patients with multiple hormone deficiencies, compared to short control subjects and to patients with GH deficiency leads us to conclude that factors other than stature and GH are responsible for these observations. The differences might be related to insufficiency of catecholamines or cortisol in the patients with multiple hormone deficiencies. These hormonal deficiencies might also account for the socially inhibited behaviour of these patients. Our results suggest that more attention needs to be directed at preparing hypopituitary patients for the challenges of adulthood. Also, these patients may be helped by more intensive efforts at hormonal replacement in adulthood.