Stock car racing, specifically the National Association for Stock Car Automobile Racing (NASCAR) Sprint Cup Series, is one of the most popular sports in the United States (16). Companies invest 25 to 35 million dollars a year in primary sponsorship for one Sprint Cup race car (16). Because of the high cost associated with competition in the NASCAR Sprint Cup series, there is a demand to identify ways to increase the race car's finishing position on the racetrack.
One method to improve finishing order on the racetrack is to decrease the pit stop time of the race car. Pit stops are necessary in Sprint Cup competition and allow for refueling, tire changing, and adjusting the race car (15). The time in which these tasks are completed is crucial, with elite crews completing a pit stop in 12.5–15.0 seconds (15). It has been estimated that every second a race car is on pit road an opposing race car travels 61 m on the racetrack (11). Depending on the type of track, a loss of 61 m·s−1 could be the difference in finishing the race in 10th place as compared with first.
One of the areas that can lead to minimizing the time of a pit stop is by increasing the physical fitness of the pit crew athletes. Placing emphasis on pit crew athlete physical fitness is a recent development in NASCAR. Before the mid-1990s, pit crew members were the mechanics who built the race car (16). It is not known the amount of physical conditioning these individuals participated in, but if they did participate in a program, it was performed on the individuals' own time because the race team did not provide training (11). In the mid-1990s, NASCAR teams began to incorporate personal trainers, and in the early 2000s, NASCAR teams incorporated fitness facilities into the race shop and hired strength and conditioning coaches and athletic trainers to increase the performance and prevent injuries of the pit crews (11). In the past 5 years, race teams have begun to recruit professional and collegiate athletes to be members of the pit crew team, leading to the current philosophy of NASCAR teams, which is that “you can train an athlete to be a mechanic, but you cannot train a mechanic to be an athlete” (11).
Despite the fact that NASCAR teams are incorporating strength and conditioning into their racing philosophy, there is still very limited literature regarding the physical conditioning requirements of race car drivers and pit crew athletes (15). To date, there are only 17 articles on race car drivers (3,4,6,7,12–14,18,21–24,26,28,30,35,37), and of these articles, only 4 are on stock car drivers (12–14,37). Additionally, there is only 1 article on pit crew athletes (15), and it is the only study to examine motorsport athletes (drivers or pit crews) at the NASCAR Sprint Cup level of competition. Because of the limited literature on the unique physiological demands of NASCAR Sprint Cup competition, there is a gap in understanding what an optimal physical conditioning program would be to increase performance of the NASCAR Sprint Cup pit crews.
The NASCAR Sprint Cup racing schedule poses unique time constraints that can hinder a physical conditioning program and performance gains (36). Specifically, the race season consists of races every weekend from the middle of February to the end of November (16). When combined with the fact that the pit crews normally face extensive interstate travel to these races, there is only 4 days per week available for physical conditioning. Furthermore, the physical conditioning program must accommodate the shop duties of the pit crew members (i.e., building the race car), thus leaving a reduced amount of time available for physical training. We hypothesize that to compete as a NASCAR Sprint Cup Pit Crew athlete, there are several physical characteristics required for optimal performance and that by designing a training program to optimize these characteristics, one could increase the performance of pit crew athletes. Therefore, the purpose of this project was to document the key physical characteristics of the NASCAR Sprint Cup Pit Crew athlete during the race season and implement a conditioning program designed to increase performance across the 9-month race season. The practical implications from this work could benefit strength and conditioning coaches working in racing, as it could aid in the development of training programs that will increase the performance of their pit crew athletes.
Experimental Approach to the Problem
This project consisted of 3 studies, with the first 2 examining the physical characteristics of NASCAR Sprint Cup athletes, and the third evaluating a training regimen designed for NASCAR Sprint Cup Pit Crew athletes. The Institutional Review Boards at the University of North Carolina Charlotte (experiments 1 and 2) and Texas A&M University (experiment 3) approved all studies as conforming to the appropriate guidelines for the protection of human subjects. Experiment 1 used previously collected demographic information obtained by Performance Instruction and Training (PIT; Mooresville, NC, USA), which is a school designed to train individuals to become NASCAR pit crew athletes. As the information was previously collected by PIT, the Institutional Review Board at University of North Carolina Charlotte deemed the PIT data analysis portion of experiment 1 exempt from informed consent. A procedure for the transfer of data from PIT to the investigators was outlined by the Institutional Review Board at University of North Carolina Charlotte and adhered to by the investigators and PIT. Briefly, all identifiable information (name, birthday, address, etc) was removed from the data set. The data were then legally and securely transferred to the investigators with the understanding that the data would be analyzed for program evaluation in an effort to optimize the training program offered at PIT. The data would remain confidential until December 31, 2012, at which point the investigators could publish the data. The experimental design and the associated risks and benefits of participating in the studies were presented in a written document and verbally explained to the subjects, and an informed written consent was obtained for experiments 2 and 3. For the 3 experiments, all subjects were considered active with exercising 1–2 hours a day for 4 days a week, which was reported to us at the beginning of the experiment by verbal communication from the subjects. Before testing, subjects were instructed to attempt to receive 8 hours of sleep the night before, refrain from consuming alcohol, and to drink at least 500 ml of water before testing in attempt to ensure adequate hydration.
Experiment 1: Predictors of Pit Crew Success
There is no information on the physical attributes required to be a successful pit crew athlete. The purpose of this study was to determine the physical characteristics that lead to an individual competing in the highest level of NASCAR competition. To accomplish this purpose, physical fitness measurements were obtained from pit crew athletes who competed at various levels of stock car racing. This included the NASCAR Sprint Cup Series, NASCAR Nationwide series, NASCAR Camping World Truck series, Automobile Racing Club of America (ARCA) series, and United Speed Alliance Racing (USAR) series. The highest level of competition was the NASCAR Sprint Cup series, and the lowest level was USAR. By gathering data from all levels of stock car racing, we were able to use regression modeling to build a prediction equation that would identify the key physical performance measurements that would allow an individual to compete in the NASCAR Sprint Cup series. We hypothesized that with statistical regression of the various demographic and performance variables, we would be able to predict the likelihood of an individual successfully competing at the highest level of NASCAR competition based on their fitness indicators. This statistical model will have practical applications, as it would allow strength and conditioning coaches to more accurately screen individuals based on their physical performance results and determine the likelihood of the individual being successful in the NASCAR Sprint Cup series.
The data used in this study were obtained from PIT. The data consisted of measurements from 500 subjects from 1999 to 2006. The data were collected on these subjects at the end of their training program, and in theory, before starting a job as a pit crew member. Of these 500, only 174 subjects had data points for all measurements, and thus, only this subcohort of 174 European American men, aged 24.2 ± 6.0 years (range, 19–44 years) with a height of 179.6 ± 7.6 cm and a weight of 84.8 ± 18.1 kg, were analyzed.
In this data set, there were 10 measurements, which included 2 physical descriptors of body size, 3-pit crew-related skill tests, and 5 performance evaluation tests. The physical descriptors of body size were body mass index (BMI, mass [kg]·height [m−2]) and arm span (cm). Arm span was obtained by having the subject stand with their arms abducted to their side, and a measurement was taken from the tip of the middle finger on the right hand to the tip of the middle finger on the left hand with a tape measure (MEDLINE Industries Inc., Mundelein, IL, USA). The 3-pit crew-related skill tests were: (a) 2 tire front run, (b) 2 tire rear run, and (c) 4 tire run. Briefly, each of these pit crew skill tests were measured as follows:
- The 2 tire front run was the amount of time (in seconds) it took the subject to sprint the distance (1.892 m) from the left front tire of the race car to the right front tire. The subject started in a squatted position at the left front tire. A stopwatch (Bodytronics, Fayetteville, GA, USA) was started when the subject stood up and began to run to the opposite side of the race car. Time was stopped when the subject squatted at the right front tire. Distance between the left front and right front tire was confirmed with a tape measure (Sears, Charlotte, NC, USA).
- The 2 tire rear run was the amount of time (seconds) it took the subject to sprint the distance (1.994 m) from the left rear tire of the race car to the right rear tire. The subject started in a squatted position at the left rear tire. A stopwatch (Bodytronics) was started when the subject stood up and began to run to the opposite side of the race car. Time was stopped when the subject squatted at the right rear tire. Distance between the left rear and right rear tire was confirmed with a tape measure (Sears).
- The 4 tire run test was the amount of time for the subject to run the wheelbase (2.794 m) of the race car, while squatting at each tire. A stopwatch (Bodytronics) started when the subject stood up from a squatted position at the left front tire and ended when the subject returned and squatted at the left front tire. Distance traveled around the race car was measured with a tape measure (Sears).
The performance evaluation tests included muscular endurance, explosive power, agility, flexibility, and strength. Briefly, these evaluations were measured as follows, with detailed methods of how each of these tests were performed contained in the cited references:
- Muscular endurance was the sum of the number of sit-ups completed in a minute plus the number of push-ups completed in a minute (2). A sit-up was only counted if the subject went through the full range of motion in completing the exercise. Additionally, a push-up was only counted if the subject performed the push-up with little-to-no flexion in the spine or hips and started with full elbow extension and ended with the chest ∼5 cm above the ground. To count the number of sit-ups and push-ups, a mechanical hand counter was used (Zorro Tools, Buffalo Grove, IL, USA).
- Explosive power was measured by jump tests, which was the sum of the scores the subject achieved on the standing long jump and vertical jump tests (8). Each subject was given 3 attempts to achieve their best result. For the standing long jump, the subject stood still, and when instructed, jumped forward. Distance was measured with a tape measure (Sears). Vertical jump was measured using a Vertec vertical jump meter (Vertec, Knoxville, TN, USA). The Vertec was adjusted to the subject's standing height with the right arm raised above the subject's head. Vertical jump height was calculated by the number of vanes moved on the Vertec by the subject's hand; this value was then converted to jump height in centimeters.
- Agility was the sum of the times the subject achieved on the pro shuttle run to the right, pro shuttle run to the left, and 10-yard dash (27). Each subject was given 3 trials to achieve their best score on the run. A stopwatch (Bodytronics) was started when the subject initiated movement of the run and stopped when the subject crossed the finish line. Distance run by the subject was confirmed by tape measure (Sears).
- Flexibility was the subject's score on a sit and reach test (2). The subject completed a moderate warm-up (light jog for 5 minutes) before testing hamstring flexibility. A ruler (Sears) was placed between the subject's feet with 15-cm mark on the ruler located at the subject's toes. Flexibility was measured by how far the subject's hand traveled during spinal flexion. Each subject was given 2 attempts to achieve their best result.
- Strength was the sum of the 1 repetition maximums (rep max) for the bench press, leg press, and bicep curl (Fitness Gear, Binghamton, NY, USA) (2). For each test, the subject had a 10 repetition warm-up followed by progressively adding weights until the subject could only complete 1 repetition while maintaining proper form.
Pit crew athlete position references the part of the race car that the pit crew athlete services during the race. The 3 positions analyzed in this study were tire changer, tire carrier, and jackman. The tire changer uses a pneumatic impact wrench to remove 5 lug nuts that secure the wheel to the race car. The tire carrier transports the new tire from the pit wall to the tire changer. The jackman uses a hydraulic jack to lift the car allowing the tires to be changed (15). Pit crew athlete position was included in the analysis to determine if certain skill sets determined the position at which the pit crew athlete competed. For regression analysis, the pit crew athlete positions were numerically coded wither carrier = 1, changer = 2, and jackman = 3.
These tests were performed over a 2-day period at the end of the PIT instructional program. Day 1 consisted of arm span, BMI, and pit crew-related tests, whereas day 2 was performance evaluation tests. The tests were monitored and timed by strength and conditioning coaches certified by the National Strength and Conditioning Association (NSCA). These coaches were also former pit crew athletes.
The data were analyzed with a stepwise regression (JMP version 7; SAS, Cary, NC, USA) with an alpha value of 0.05 set a priori. Unstandardized and standardized coefficients were generated for each test. For statistical analysis, the series of competition was given an arbitrary value of “1” for the highest level of competition (Sprint Cup) and “5” (USAR) for the lowest. Thus, in the results of the stepwise regression, a negative standardized coefficient would indicate that the higher a subject scored on that test, the more likely the subject could compete in the NASCAR Sprint Cup series.
After analysis of the stepwise regression, a cohort (n = 25) of male European American NASCAR Sprint Cup Pit Crew athletes from an active Sprint Cup team, aged 34.3 ± 7.5 years, were subjected to similar fitness test as the PIT subjects to determine if the physical fitness parameters that were significant in the regression analysis predicted actual NASCAR Sprint Cup Pit Crew member selection.
The performance testing was performed by measuring body composition using a BodPod (Life Measurements Inc., Concord, CA, USA) (9), range of motion during shoulder horizontal abduction through goniometry (Quill Corporation, Palatine, IL, USA) (2), maximum grip strength through a handgrip dynamometer (Camry Electric, Guangdong, China) (2), flexibility through a sit and reach test (2), and oxygen consumption through a
treadmill test (ParvoMedics, Sandy, UT, USA) using the Bruce Protocol (1,2). These tests were chosen because they gave similar results in terms of flexibility, muscular strength, and aerobic capacity as those used by PIT (27) and were performed according to established protocols as defined in the corresponding references (1,2).
Briefly, for body composition analysis, the BodPod software predicted the subject's lung volume, which has been shown to accurately predict actual lung volume (9). Before each testing session, the BodPod was calibrated against a cylinder of known volume (50.227 L). The BodPod was considered to be in accurate calibration if the mean displacement of the cylinder for the 5 calibration tests was within 100 ml of the known cylinder with a SD <75 ml. The subjects were instructed not to eat or drink 2 hours before body composition measurement. On arrival, the subjects had the test procedures explained to them and were instructed to wear compression shorts and a swim cap. The use of this clothing was designed to limit the formation of air pockets, which could hinder the results. Subjects were weighed and then instructed to enter the BodPod. Tests were performed in duplicate to ensure repeatability.
Shoulder horizontal abduction was measured with the subject supine with the hips and knees bent, the shoulder abducted 90°, and the elbow flexed 90°. The superior surface of the acromion served as the goniometer axis. Horizontal abduction was performed with the movement arm parallel to the longitudinal axis of the humerus pointing toward the lateral epicondyle.
Maximal grip strength was obtained by having the subject stand with the handgrip dynamometer in their hand at their side and instructed to generate a maximal effort in gripping the handle of the dynamometer. It was ensured that the elbow was not flexed to avoid confounding the measurement. Each subject was given 2 attempts to achieve a maximal handgrip score.
Flexibility was determined by sit and reach as described above. Aerobic capacity was measured on a treadmill using the Bruce protocol with 3-minute stages (stage 1: 2.7 km·hr−1 at 10% grade; stage 2: 4.0 km·hr−1 at 12% grade; stage 3: 5.4 km·hr−1 at 14% grade; stage 4: 6.7 km·hr−1 at 15% grade; stage 5: 8.0 km·hr−1 at 16% grade; stage 6: 8.8 km·hr−1 at 20% grade). Oxygen consumption, heart rate, heart rhythm, blood pressure, respiratory exchange ratio, and rate of perceived exertion were measured throughout the test. The test was terminated when the subject requested to stop,
plateaued, the subject reach their age-predicted maximal heart rate, respiratory exchange ratio was >1.2, or the subject presented with arrhythmias or blood pressure changes that warrant test termination.
Experiment 2: Changes in Pit Crew Athlete Body Composition Throughout the Season
The NASCAR Sprint Cup season is from February until November. Anecdotal evidence has suggested that later in the season, pit crew members become “weaker” because of the long season. This weakening is further compounded by the fact that during the off season, pit crew members usually cease all physical training. Based on these reports, we hypothesized that the nature of the race season caused alternations in body composition. The purpose of experiment 2 was to evaluate the effect of the long NASCAR Sprint Cup season and 2-month off season on body composition of pit crew athletes. This was performed over 2 consecutive seasons to limit seasonal variance.
The subjects were 10 European American NASCAR Sprint Cup Pit Crew athletes (age: 28.5 ± 3.9 years; height: 184.2 ± 7 cm; mean ± SD) from an active Sprint Cup racing organization with at least 5 years of pit crew experience and 8 years of physical conditioning experience. These subjects represented 3 of the 4 pit crew positions (tire carriers, n = 4; jackmen, n = 2; and tire changers, n = 4).
Body Composition Measurement Procedure
Dates of testing were predetermined to correspond to the beginning (February to April), middle (May to July), end (August to November), and off- (December to January) season portions of the NASCAR Sprint Cup race season. Body composition was measured using the BodPod (procedure described above) during the 2008 and 2009 NASCAR Sprint Cup seasons.
Individual three-way analysis of variance (ANOVA) tests (JMP version 7) were used to compare body composition (percent lean body mass) and body mass (in kilograms) throughout the NASCAR Sprint Cup race season (beginning, middle, end, and off-season). Tukey's HSD post hoc tests were used to evaluate the significance of the main effects or interactions. The alpha level was set a priori to 0.05.
Experiment 3: Pit Crew Training Regimen
Experimental Approach to the Problem/Subjects
As shown in the previous 2 studies (see Results), NASCAR Sprint Cup Pit Crew athletes require unique physical performance attributes (experiment 1) and have a decrease in lean body mass during the off season, which persists until the middle of the season (experiment 2). Thus, it was hypothesized that a pit crew-specific training program would optimize the required physical performance attributes documented in the previous 2 studies. Thus, a strength and conditioning program specific to NASCAR pit crews was designed and implemented during the 2011 NASCAR Sprint Cup season in an active Sprint Cup race team (n = 6 European American males, aged 31 ± 5.7 years, with at least 5 years of pit crew experience and 8 years of physical conditioning experience). This training program included individuals from experiment 2. There were 3 goals outlined for this strength and conditioning program: (a) prevent overtraining and injury throughout the season; (b) have performance peaks at the end of May for the NASCAR Pit Crew Challenge and at the end of August for the beginning of the Chase for the Championship; and (c) be competitive for the first race in February while giving the pit crew athletes ample time off from the end of the racing season (end-November) to the start of the racing season (mid-February). These training requirements had to fit into a 1-hour time schedule on 4 consecutive days of the week, which was the only time available for physical conditioning.
A whole-body resistance training program was prescribed on Tuesday and Thursday consisting of squat, deadlift, bench press, and power cleans. The strength and conditioning coach modified this throughout the season based on an undulating periodization model (33), which consisted of alternating 2-week segments of 3 sets of 10–12 repetitions (reps) at 70% one rep max and 5 sets of 4–6 reps at 88% one rep max. This periodized program consisted of 3 cycles, each consisting of a 12-week training plan followed by a week of recovery. The week of recovery was designed to correspond to time points in the season where peak performance was required. Thus, the first 12-week phase began in the middle of December and ended in the middle of February (start of the NASCAR Sprint Cup race season). The second phase started the second week of February and ended the third week of May, thereby allowing the recovery week to occur the same week as the Pit Crew Challenge (an exhibition style competition where pit crew athletes are awarded monetary prizes for completing pit stops in the fastest amount of time). The third phase began the first week of June and ended the last week of August, allowing the recovery week to be at the start of the 10-week competition for the Sprint Cup Championship. After this phase, a maintenance program was implemented similar to weeks 1–2 of the program to prevent injury and maintain performance during the 10-week Championship Race Series.
On a weekly basis on Wednesdays, a group fitness instructor led the pit crew athletes in yoga style classes that emphasized core strength and hamstring flexibility because the results of the first study showed hamstring flexibility (see Results) was a significant predictor of success. Friday's workouts consisted of cardiovascular or circuit training at a light-to-moderate intensity (55–65% maximum heart rate) because the pit crew athletes would be traveling from Saturday to Monday to compete at a race, and the strength and conditioning coach did not want the pit crew athletes to be sore from training. Examples of the Friday training regimen included such activities as 40 minutes of continuous activity such as treadmill running, swimming, or ultimate Frisbee. To monitor the progression of the new strength and conditioning program, pit crew athletes traveled to the exercise physiology laboratory for performance testing at the beginning and end of the season.
To further evaluate the effectiveness of the training program, “developmental pit crew members” were used as control subjects. These subjects were individuals who were on contract with the race team as potential full-time pit crew members and are considered appropriate controls to evaluate the previously described training program. Specifically, the control subjects practiced pit stops with the trained subjects, traveled to the races, ate at similar locations and times as the trained subjects (often identical meals), and engaged in the training program that was previously used by the subjects before engaging in the modified training regimen outlined in this study. The training program of the control subjects consisted of physical exercise for 1–2 hours a day for 4 days a week emphasized linear periodization and body part–specific exercises (Monday: Chest, Tuesday: Back, Wednesday: Legs, and Thursday: Arms) coupled with cardiovascular activity ranging from 45 to 65% max heart rate (determined by 220-age). Because of the unique nature of NASCAR racing, these individuals were thought to be the most appropriate controls. The control subjects (n = 4, age: 27 ± 4.3 years) visited the laboratory at the same time as the pit crew members involved in the training program. The laboratory visit consisted of a vertical jump test (Vertec), Wingate power test (Lode, the Netherlands), and DEXA body composition measurement (Hologic, Boston, MA, USA). All tests were performed according to NSCA guideline (1,2,8,31).
The DEXA was calibrated using a spinal and step phantom before the subjects' arrival. The subjects were placed supine on the DEXA and were instructed to be still for the 5-minute body composition measurement.
The Wingate power test used a cycle ergometer that mechanically loaded the flywheel. The subjects were positioned on the ergometer and pedaled for 1 minute at a light resistance to warm up. At the completion of the warm-up, the ergometer was loaded at a resistance of 7.5% the subject's body weight. The subjects' were instructed to keep their revolutions per minute above 80 for the 30-second test period. Maximal power and mean power were collected from this procedure.
Wingate and vertical jump tests have been shown to be effective indicators of power output (17). The use of traditional 1 rep max values were not used because they were not shown to be predictive of pit crew success (experiment 1), and the multiple combinations of tests could induce more fatigue in the subjects. Fatigue level of the subjects had to be considered, as they were required to compete at a race 48 hours after testing. Vertical jump power output was determined with the following equation: vertical jump power (in watts) = 2.21 × Weight (in kilograms) × square root of jump height (in meters) × 9.807 (17). All performance tests from the training regimen were analyzed with an ANOVA with the main effects being time (start of season and end of season) and treatment (control and trained) using GraphPad Prism with an a priori alpha level of 0.05.
Experiment 1: Predictors of Pit Crew Success
A significant equation (r = 0.42, r2 = 0.18, p ≤ 0.05) was derived, which would predict the level of competition a pit crew athlete could attain based on their physical characteristics, skill-based testing performance, and performance evaluations scores.
Predicted level of competition = 2.138 + (−0.075 × position) + (0.024 × arm span) + (0.009 × BMI) + (−0.073 × sit and reach) + (−0.006 × muscular endurance) + (0.016 × explosive power) + (−0.019 × agility) + (−0.455 × 2 tire front) + (−0.282 × 2 tire rear) + (0.168 × 4 tire) + (0.001 × strength).
With regard to whether an athlete would have a higher probability of competing on a NASCAR Sprint Cup Pit Crew team, the significant predictive criteria were the 2 tire front run (p = 0.012) and sit and reach tests (p = 0.015, Table 1). The confirmation data from the active Sprint Cup Pit Crew (Table 2) supported the validity of using our derived regression formula as in this cohort of pit crew athletes, and their sit and reach score (33.70 ± 5.65 cm) was categorized as “very good” by the American College of Sports Medicine (2).
Experiment 2: Change in Body Composition Through the Season
There was not a significant change in body mass (Figure 1A) over the course of the NASCAR Sprint Cup seasons (p = 0.189). There was, however, a significant difference in percent lean mass (p = 0.0005) across the seasons (Figure 1B). The athletes at the beginning (75.16 ± 5.51% lean body mass; mean ± SD) and off-season (74.1 ± 5.2% lean body mass) time points had lower percent lean body mass values than at the middle (80.83 ± 6.7% lean body mass) and end-season (79.6 ± 4.62% lean body mass) time points.
Experiment 3: Pit Crew Training Regimen
With the new training regimen, there was no change in body mass (Figure 2A; p = 0.54) between the control and trained subjects across the season. However, there was a significant reduction in percent lean body mass in the control subjects at the end of the season (Figure 2B; p = 0.01). However, the trained subjects had a significant increase in lean body mass (p = 0.03) at the end of the season as compared with the beginning of the season. There was a significant improvement in vertical jump power (Figure 3; p = 0.03) in the trained subjects at the end of the season; however, there was no difference (p = 0.10) in vertical jump power across the season for the control subjects. There was a significant improvement in Wingate peak power (Figure 4A; p = 0.002) in the trained subjects at the end of the season as compared with the beginning of the season. The control subjects had a decrease in peak power (p = 0.01) at the end of the season as compared with the beginning of the season. Thus, the trained subjects had a significantly (p = 0.001) higher Wingate peak power at the end of the season as compared with the control subjects. Mean power (Figure 4B; p = 0.006) also increased in the trained subjects from the start of the season to the end of the season with no change in mean power in the control subjects (p = 0.10).
There is no literature on the physical characteristics of NASCAR Sprint Cup Pit Crew athletes, which is concerning because pit crew athletes are an essential part of NASCAR racing. This project documented the physical characteristics of NASCAR Sprint Cup Pit Crew athletes, developed a prediction equation based on these characteristics to be used to identify probable level of competition that pit crew athletes will succeed to, monitored the change in pit crew athlete body composition over the course of 2 seasons, and designed a training regimen for pit crew athletes. In this study, we observed that hamstring flexibility and pit crew-related skill sets were significantly associated with pit crew athletes who compete at the elite NASCAR Sprint Cup level. Additionally, we noted that pit crew athletes lose lean body mass during the off season and beginning season time points, which were compensated for by a pit crew-specific yearlong training regimen.
The significant predictors of pit crew success at the Sprint Cup level were the sit and reach test and the 2 tire front run test (Table 1). The sit and reach test is a measure of hamstring flexibility (1,2), whereas the 2 tire front run test is a NASCAR-specific skill. It is interesting that the 2 tire rear run test did not present a significant indication of pit crew success. A possible reason this test was not a predictor of success is that during the time these measurements were taken, the NASCAR Sprint Cup Series put a wing on the back of the race car, which caused the car to be wider in the back. Anecdotally, many pit crew athletes said that they struggled with navigating around the wing because the fins of the wings would catch their arm when they ran behind the car. This observation about the 2 tire rear run test highlights the changing nature of racing and emphasizes that when the structure of the car is changed, there may be a need for additional training or differing physical characteristics to maintain performance of pit crew athletes. It is possible that the detriment caused by the wing also influenced the significance of the 4 tire run because the 4 tire run incorporated both the 2 tire front and rear run. As a means of objectively evaluating the anecdotal rational (i.e., wider wing decreased importance of rear tire run), we measured the variance of scores on the 3 separate tire run tests. In fact, we found the variance of the 4 tire and 2 tire rear was 2.1 and 1.7 times higher than the 2 tire front run, respectively, suggesting that the presence of the wing could confound the scores on the 2 tire rear and 4 tire run tests. These observations have been shown in other sports where athletes have decreases in performance when faced with overcoming changes associated with sport-specific skill sets (32).
The sit and reach test, which is a measure of hamstring flexibility (2), was also a significant predictor of success for competing in the NASCAR Sprint Cup Series. Because of the nature of servicing the race car during a NASCAR race, pit crew athletes are often in positions where they are bent over at the waist with locked knees. From this observation, we hypothesized that individuals with poor hamstring flexibility would either be too slow for the NASCAR Sprint Cup competition or would have frequent injuries and be unable to compete. This hypothesis is supported by studies on other forms of competitive sports that show increased hamstring flexibility corresponds to reduced injuries (20,34). Furthermore, we did observe in a cohort of elite Sprint Cup Pit Crew athletes higher sit and reach scores (Table 2), which were considered to be above average for the normal population (2).
To maintain the muscular power to compete in NASCAR Sprint Cup racing, pit crews need to maintain lean body mass throughout the season. Our seasonal monitoring showed that over the course of 2 NASCAR Sprint Cup seasons, body mass did not change (Figure 1A) but that there was a decrease in percent lean body mass during the off season that extended into the beginning of the season (Figure 1B). It is hypothesized that the body composition response observed in the off season and beginning season time points is a result of a loss of lean mass and a gain of fat mass. The loss of lean body mass was of concern because this loss could adversely affect performance (5), especially as some of the biggest races of the year, in terms of publicity and dollar earnings, are at the beginning of the season (e.g., Daytona 500). Furthermore, success at the beginning of the season is crucial for later inclusion in the Sprint Cup Championship. Therefore, the identification that there is a loss of lean body mass during the off season that carries into the beginning of the season supported the need for a pit crew-specific training regimen that would help maintain lean tissue and prevent fat accumulation throughout the year.
We used an undulating periodization training program, which has been shown in a variety of competitive sports to increase performance gains (29). Additionally, the undulating periodization model is particularly suited for long competitive seasons (25), such as NASCAR Sprint Cup racing. Using the modified pit crew training regimen described in this article, we were successful in lean body mass maintenance and prevention of fat accumulation over the course of the season (Figure 2A), as compared with the control subjects who actually saw a decrease in lean body mass at the end of the season.
Besides maintaining lean body mass during the season, it is critical that pit crew athletes maintain or be able to increase power output across the long performance season without increases in injury rate. Our training program prevented decreases in power during the season as shown by the 2 tests that were used to evaluate power: the vertical jump (19) and Wingate power test (10,31). We observed a significant increase (p = 0.03) in vertical jump power output of the trained subjects from the start of the season to the end of the season (Figure 3) and significant increases in Wingate peak power (147% increase; Figure 4A) and mean power (127% increase; Figure 4B) from the start until the end of the season. The increases in Wingate power output were not seen in the control subjects, and in fact, the control subjects had a decrease in peak power at the end of the season.
Ultimately, in racing, as in many sports, the best outcomes are tied directly to success during competition. Although certainly just anecdotal evidence, it is important to note that the team using this training program had a 22% reduction in injuries during the season and some of the fastest pit stop times during the season, with their driver ultimately winning the 2011 NASCAR Sprint Cup Championship.
In summary, our results are the first to predict what physical characteristics are needed of a pit crew athlete at multiple levels of competition. Furthermore, we developed and implemented a physical training program designed to maximize pit crew athlete performance throughout the season. With this training program, we observed maintenance of lean body mass and documented significant improvements in performance throughout the season. These results are beneficial to the strength and conditioning coach working in racing for several reasons: (a) the strength and conditioning coach could use our prediction equation to screen potential pit crew athletes, thus reducing time and money associated with pit crew recruitment; (b) the strength and conditioning coach can incorporate exercises that emphasize hamstring flexibility and pit crew-specific skill sets to optimize performance; (c) implement a strength training program in December before the start of the season that follows an undulating periodization model with an emphasis on large muscle group lifts. By incorporating these parameters into pit crew athlete training, a strength and conditioning coach could reduce the loss of lean muscle mass, increase in fat accumulation, increase muscular power output, reduce injuries, and potentially increase performance during competition.
These studies were completed from 2008 to 2011 with help from many graduate students, faculty, and several NASCAR race teams. The authors wish to thank Emily Schmitt, Analisa Jimenez, Connor Irwin, and Sheril Marek of the Biology of Physical Activity lab at Texas A&M University. In addition, use of the testing facilities of Dr. Stephen Crouse, Dr. Steve Martin, Dr. Brad Lambert, Dr. Richard Kreider, and Chris Rasmussen of Texas A&M University, as well as input from Dr. Robert Bowen at Truett-McConnell College were greatly valued. This project could not have been completed without the generous help of the NASCAR racing community, specifically Jordan Walker (Stewart-Haas Racing), Joe Piette (Stewart-Haas Racing), Breon Klopp (PIT), Greg Morin (Hendrick Motorsports), Kacie Smith (PIT), Adam Merrell (PIT), Kevin Sharpe (Michael Waltrip Racing), Ben Cook (Michael Waltrip Racing), and Lance Munksgaurd (Michael Waltrip Racing). There is no conflict of interest to report nor was there any grant funding received for this project. Additionally, the results of this project do not constitute endorsement by National Strength and Conditioning Association.
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