MILITARY MEDICINE, 177. 11:1417, 2012

Possible New Modalities for the Navy Physical Readiness Test Paul N. Whitehead, MS*; Brian K. Schilling, PhD*; LCDR David D. Peterson, MSC USNf; Lawrence W. Weiss, EdD* ABSTRACT Tbe current U.S. Navy Pbysical Readiness Test (PRT) measures aerobic fitness and muscular endurance via a 1V-L mile run and curl-up/push-up tests, respectively. Nine new modalities were recommended to eitber replace or supplement tbe current PRT. Personnel and civilians (A' = 179) were recruited from a local Navy base and participated in all modalities (duplicate if possible) over 4 weeks following familiarization sessions. Subjects performed single-leg plcuik, single-leg wall squat, cadence pusb-ups, leg/bip dynamometer, standing long jump, and pro-agility test. Cardiovascular modalities were also perfomied via tbe 300-yard shuttle, 2-km row, and 5-km bike. Performance in tbe modalities was correlated to tbe subjects' existing PRT scores as well as within tbe new modalities. Altbougb most modalities could not be concretely recommended, tbe plank and wall squat were eliminated from consideration because of poor reliability scores. The strongest correlation existed between the standing long jump and pro-agility test for tbe entire sample. Correlation scores were also analyzed by gender. Tbe cardiovascular modalities did not have strong enough scores to elicit a recommendation to replace the 1V2 mile run, but future considerations for similar testing would be to collect scores for the existing modalities in addition to the proposed modalities.

INTRODUCTION The U.S. Navy Physical Fitness Assessment includes the Body Composition Assessment and the Physical Readiness Test (PRT). The Physical Fitness Assessment is designed to biannually assess the minimum level of fitness required for Naval service. The Physical Fitness Assessment is also done, in part, to promote a culture of physical fitness in the Navy.' Stemming from directives and Department of Defense Instructions (DoDI), the PRT was designed to apply physical fitness programs with age-adjusted standards for all personnel.^ Although stamina and cardiorespiratory endurance were originally designated to receive the major emphasis, the DoD has also included a recommendation for strength testing as part of its evolving "Physical Fitness and Weight Control Program."^ Obesity and lack of fitness are major issues plaguing the American population including recruits entering the U.S. Armed Forces."* The current PRT is an assessment of the aerobic fitness and muscular endurance of Sailors, but the relative ease of the individual assessment criteria and the cyclical nature of testing have failed to reinforce good lifestyle choices among some Sailors.''^"'' Multiple amendments have been made to the original PRT since its inception, including numerous alterations on the tested modalities, risks involved, and contingencies for failing the test. There are numerous difficulties in developing the PRT, not limited to a lack of "gold standard" tests for the physical attributes of interest, particularly tests that can be carried out with large numbers of subjects in a field setting with minimal, portable equipment.

*The University of Memphis, 171 Elma Roane Fieldhouse, Memphis, TN 38152. tNavy Personnel Command, Attn: OPNAV N135F, Physical Readiness Program, 5720 Integrity Drive, Millington, TN 38053. Information from this article was used in Paul Whitehead's master's thesis defense. doi; 10.7205/MILMED-D-12-00127

MILITARY MEDICINE, Vol. 177, November 2012

Currently, the PRT battery consists of curl-ups (maximum in 2 minutes), push-ups (maximum in 2 minutes), and a l'/4 mile run. As optional alternatives to the run, the PRT utilizes a 12-minute elliptical, a 12-minute bike test, or a 500-yard/ 450-m swim. By testing new modalities to either replace or supplement the existing components, it is likely that an improved PRT may be developed that encourages consistent training, promotes a healthy lifestyle, and more accurately assesses the physical readiness of Sailors. This investigation was designed to examine the feasibility of new testing modalities that may help the U.S. Navy enhance its goal of establishing a culture of fitness among Sailors and meet the requirements of DODI 1308.3.^ We examined aspects of fitness that are not currently tested in the PRT, such as anaerobic power, anaerobic capacity, and agility. If the current PRT has not fostered optimal exercise habits, we believe that perhaps new tests that utilize multiple energy systems and various components of fitness would promote the incorporation of more appropriate lifestyle exercise practices. METHODS Both active duty military and civilian, male and female volunteers aged 18 and older, were recruited from a local base to participate in testing. Participants were recruited via e-mail, word-of-mouth, and coordination with local command fitness leaders. An attempt was made to have representation in each gender and age category listed in the Chief of Naval Operations Instructions (OPNAVINST) 6011.1 J, and no compensation was given for participation. Even though there were only a small number of civilian participants, they had similar fitness levels to the active duty personnel. The first session preceded any actual testing and included explanation of the testing procedures, completion of both written informed consent and the standard five-question

1417

Possible New Modalities for the Navy Physical Readiness Test

prephysical activity questionnaire, and test-item practice supervised by the official testing staff. Our university's Committee for Human Subject Research approved the study. The study also received approval from the Navy Institutional Review Board. During the preliminary session, all potential participants had the opportunity to ask and have answered any questions concerning the nature of subsequent testing. Subjects participated in a total of six sessions over 4 weeks, performing each proposed modality in duplicate, if possible, including a 10-day interval between repeat testing bouts. All sessions were administered in similar order/fashion as the current PRT (warm-up, strength/speed events, muscular endurance events, cardiovascular event, and cool-down) as dictated by OPNAVINST 6110.1J. After performing the standardized PRT wami-up, individuals had 5 minutes to perform an individual warm-up and stretching as needed. Once participants were adequately warmed up, the day's testing commenced. Description of the tests is as follows.

Single-Leg Plank Test for Time The single-leg plank test for time (PLANK) was proposed to assess the muscular endurance of the abdominal and surrounding musculature.^ It was proposed as a potential replacement for the existing curl-up test as curl-ups and sit-ups have been reported to be possible causes for lowerback injuries.^'** The position of the plank exercise (Fig. 1) has been shown to alleviate the pressure on the low back, while also providing an active position for the musculature of the abdomen area.''^° Subject maintained the PLANK with the foot of the dominant leg on the deck until failure while the nondominant leg rested on top of the dominant leg, with one verbal warning on form (deviation from a straight body) before the test was terminated. Dominant leg was determined by asking the participant which leg they would use to kick a ball.

Single-Leg Wall Squat The single-leg wall squat test (SQUAT) was proposed to quantify unilateral lower-body muscular endurance."'^ As can be seen in Figure 2, the subject folded arms across chest while the hip and dominant knee were each held at approximately 90 degrees. The contralateral leg was lifted approximately 5 cm from the floor, and this position was held for maximum time. The test was terminated when the subject broke form, either with the 90-degree positions or lowered the contralateral leg back to the deck.

U.S. Coast Guard Academy Push-Up Test (Cadence Push-Up) The cadence push-up test (CADENCE) is a 2-minute test of muscular endurance where participants altemate between up and down positions (Fig. 3) of the push-up on each 1 -second count (maximum of 60 push-ups).'"^''^ The subject was instructed to tnaintain a straight line position from the head to the hips to the legs during the "up" position, and they were instructed to reach a depth of chin-to-deck during the "down" position. This modality provides a more strict testing procedure than the cun'ently used push-up test. Although the U.S. Coast Guard testing criteria is the same for both genders (i.e., front leaning rest position), we opted to allow female patticipants to perform the push-ups on their knees in expectation of having the performance values for genders be more similar.

Leg/Hip Dynamometer The leg/hip dynamometer modality (DYNO) was proposed as a measure of muscular strength.'"^"^•' No strength test currently exists in the PRT, an omission running counter to the DoDI for fitness components to be analyzed in the PRT.^ Because it has been reported that many jobs in the Navy require high levels of strength during lifting and pulling motions, this test may be a valuable assessment and training tool for Sailors.^''^^ With the handle of the Baseline BackLeg-Chest Dynamometer positioned at mid-thigh. Sailors were instructed to perform a steady pull to maximal effort (Fig. 4). Mid-thigh was determined by having the tester spread their fingers and place the fingertip of the fifth digit of their right and left hands on participant's right patella and anterior superior iliac spine, respectively. The point where the tester's thumbs intersected was considered as the participant's mid-thigh position. Three trials were given for each testing session and the maximal force recorded.

Standing Long Jump

FIGURE 1.

1418

Single-leg plank for time.

The standing long jump test (SLJ) was proposed as a means of testing time-limited force production in S ai I ors. ^""^^ There is no similar test in the current PRT,^^° but the SLJ has been used in the testing of members in different branches of the military both domestically and internationally.^'*'"* The U.S. Army is currently evaluating the standing long jump for

MILITARY MEDICINE, Vol. 177, November 2012

Possible New Modalities for the Navy Physical Readiness Test

FIGURE 2.

Single-leg wall squat.

FIGURE 3.

Cadence push-up.

their biannual physical fitness test. Three trials were given for each testing session with the maximum distance recorded.

Pro-Agility Test The pro-agility test (AGILITY, Fig. 5) was proposed since no agility component currently exists in the Navy's testing, and it may have operational .specificity to fast movements in limited spaces, such as on a ship.^^'^~ Strong performance in the AGILITY has also been found to have a significant positive correlation to body composition.^^^ A desire to perform well in this modality, if included in the PRT, could potentially allow Sailors to improve their body composition as a result of training.

300-Yard Shuttle Run The 300-yard shuttle run test (SHUTTLE) was proposed as a test of anaerobic capacity.'''^'^'''''"''^ This test can be conducted in a space slightly larger than 25 yards.^^ Also,

MILITARY MEDICINE, Vol. 177, November 2012

this modality may be an asset in the promotion of a culture of fitness desired by the Navy as the training effects may aid aerobic performance while also assisting with body compositton management.

2,000-m Row The 2,000-m row test (ROW) was proposed as a possible altemative for the VA mile run.^^^"*^ Because of its lowimpact nature, ROW is proposed as an alternative for the current bike, elliptical, and swim tests, wbicb serve as optional current alternatives to the run. This modality would be easy for a Sailor to self-administer during training as an electronic display screen allows the participant to be aware of distance, pace, and time. This test is basic in nature, in that Sailors would attempt to row 2,000 m as quickly as possible. This test requires a small footprint in comparison to that needed for a 1V2 mile run, and the Concept 2 Model E Indoor rower equipment is less costly than the current bike and elliptical options.

1419

Possible New Modalities for the Navy Physical Readiness Test

FIGURE 4.

Leg-hip dynamometer. 2"** cone

1 " cone

START

5 yards

5 yards FIGURE 5.

Pro-agility test.

5,000-m Bike The 5,000-m bike test (BIKE) was also proposed as a possible replacement for the VA mile run.'*"'*' Although a stationary bike test currently exists in the PRT as a medical alternative for the run, this proposed modality was a modification of the Buono Test.""' This testing protocol sets the resistance based on the subject's weight at 0.5 kg for every 20 kg of body weight. Rather than simply looking at calorie expenditure during a timed ride, such as with the current cycle test, this modality assessed Sailors' performance over a fixed distance utilizing a Monark Ergomedic 874E cycle ergometer. The ability to calibrate the ergometer is an important inclusion, as both the American College of Sports Medicine Guidelines for Exercise Testing and the U.S. Army Field Manual both state that devices that cannot be calibrated should not be used for official exercise testing. Subjects were encouraged to perform maximally on all tests at both test sessions. Volunteers collected data from each test onto data sheets. The compiled data also included most-recent previous PRT results from the Physical Readiness Infonnation Management System (PRIMS) database. After the data from

1420

each Sailor's various trials—a maximum of two trials for each modality, totaling 18 performance variables—had been collected and successfully input, we used the subjects' scores to create preliminary gender-specific norms for each age group. The age groups as they currently exist in the PRT are 17 to 19, 20 to 24,25 to 29,30 to 34,35 to 39,40 to 44,45 to 49,50 to 54, 55 to 59,60 to 64, and 65-I-. Pearson correlation analyses were performed to examine relationships within the modalities in addition to existing test scores. A priori p-value was <0.05. The existing run times and predicted run times, as reported by PRIMS, were correlated to the SHUTTLE, ROW, and BIKE. Predicted run times were a result of their performance in medical alternatives to the 1Y2 mile run. Reliability of each test was assessed via the intraclass correlation coefficient (ICC) and coefficient of variation (%), with acceptable minimum levels of >0.7 and <15%, respectively.'*'^ Data were analyzed with SPSS 20. Participants in the study were also asked to volunteer to take a 10-question postparticipation survey regarding the testing procedures, modalities, and practice involving the current PRT and the proposed tests. The survey was created

MILITARY MEDICINE, Vol. 177, November 2012

Possible New Modalities for the Navy Physical Readiness Test

on SurveyMonkey, and it was intended to gauge the opinions of the Sailors on the existing PRT and the possible inclusion of the tested modalities in an updated PRT. Subjects signed in and answered anonymously as many questions they felt comfortably answering. No incentive was provided to participate in the survey.

Correlation

Utilizing the best-collected score for each modality, various sample sizes were gathered for each test ranging from a minimum in the wall squat (;i = 130) to a maximum for the SLJ (n = 170). Individual modalities can be seen in Table III, with the exception of the wall squat and plank because of their poor precision. The strongest correlations existed between the scores of RESULTS SLJ when compared with the AGILITY test and the DYNO test. Although the Navy requested data to be reported for all Participants Sailors, further correlation analysis was done among gender Participant information is shown in Table L groups by the researchers to assess the validity of the reported scores for the tested modalities. In the combined scores, a significant correlation existed between the SLJ and the DYNO. Reliability Duplicate tests were analyzed for reliability and precision However, when the scores were looked at by gender, the (Table II). All ICC were statistically significant (p < 0.05) correlation formales (;= 0.399,/?< 0.01,«= 114) and females and all exceeded minimum suggestions of 0.60.^*^ The (/• = 0.250, n = 34) were both considerably lower than the SQUAT and PLANK did not meet proposed suggestions for combined score with the latter showing no significance. The very large*"*^ correlation between the SLJ and the AGILITY precision of 15%.43 was reflected in both males {r = 0.750, p < 0.01, « = 117) and females (r = 0.624, p < 0.01, n = 38). The large"^ negative correlation for the PRIMS push-ups and AGILITY was only TABLE 1. Participant Information (Mean + SD) somewhat reflected in the same analysis for males (/• = 0.389, p < 0.01, n = 109), but for females (r = 0.010, n = 27), the n-Size Age (Years) Height (cm) Weight (kg) correlation was not significant. 137 38.2 ±7.3 178.1 ±7.1" 87.7 ± 12.3'' Male Female Combined

42 179

37.5 + 8.4 37.7 ± 7.6

68.1 ± 10.7'' 82.4 ± 14.8''

167.7 ± 7.6" 175.3 ±8.9"

"Height was not reported for 6 male and 3 female subjects.''Weight not reported for 24 male subjects and 1 female subject.

TABLE II.

The correlation analysis for male scores showed a significant correlation between the PRIMS push-ups and PRIMS sit-ups (r = 0.607, p < 0.01, n = 82). This relationship was reflected slightly in the combined analysis (r = 0.506,p < 0.01,

Te.st-Retest Reliability

Exercise

N

Test 1 (Mean ± SD)

Test 2 (Mean + SD)

ICC (90% Confidence Interval)

Coefficient of Variation (%)

Cadence Push-Up Plank (s) Leg-Hip Dynamometer (lbs) SLJ (Inches) Pro-Agility (s) Wall Squat (s) 300 Shuttle Ave.(s) 5-km Cycle Ergometer (s) 2-km Rowing Ergometer (s)

83 90

27.5 ±8.7 188.9 ±90.3 417.9 ± 146.1 196.3 ± 37.0 5.6 ± 0.5 28.0 ± 18.8 73.9 ±9.1 545.1 ±96.7 546.8 ± 70.0

29.1 ±8.6 193.0 ± 100.2 454.6 ± 189.2 198.9 ±37.4 5.5 ±0.5 29.4 ± 19.9 72.8 ± 9.1 533.6 ± 102.7 528.5 ± 57.8

0.87(0.82-0.91) 0.86(0.81-0.9) 0.89 (0.66-0.97) 0.97 (0.96-0.98) 0.90 (0.86-0.93) 0.85 (0.80-0.90) 0.97 (0.95-0.98) 0.91 (0.88-0.94) 0.90 (0.86-0.93)

13.4 21.3 7.8 3.1 3.1 46.6 2.2

9 90 87 83 81 81 81

TABLE III.

CADENCE DYNO

SLJ AGILITY PRIMS PU" PRIMS CU'' Height Weight

Correlation Between Noncardiovascular Modalities

CADENCE

DYNO

SLJ

AGILITY

1 — — — — — — —

0.251'

0.351' 0.625'

-0.329'' -0.593'' -0.837''

1 — — — — — —

5,2 3.7

1 — — — — —

1 — — .—

—

PRIMS PU" 0.541^ 0.433"^

o.ssó"^ -0.616'' 1 — — —

PRIMS cu''

Height

Weight

0.506' 0.172'' 0.308'' -0.346' 0.572' 1 — —

-0.126 0.480' 0.413' -0.352'' 0.249'' 0.058 1 —

-0.203'' 0.403' 0.233' -0.181'' 0.222'' -0.065 0.682' 1

"PRIMS PU. existing upper body endurance score.''PRIMS CU. existing muscular endurance score.'Correlation is significant at a value of p < 0.01 (2-tailed).''Correlation is significant at a value of p < 0.05 (2-tailed).

MILITARY MEDICINE, Vol. 177, November 2012

1421

Possible New Modalities for the Navy Physical Readiness Test TABLE IV

SHUTTLE ROW BIKE PRIMS" Height Weight

Correlation Between Cardiovascular Modalities

SHUTTLE

ROW

BIKE

PRIMS"

Height

Weight

1 — — — — —

0.582'' 1 — — — —

0.736* 0.514'' 1 .— — —

0.530'' 0.436'' 0.550'' 1

-0.350'' -0.500'' -0.244'' -0.248'' 1 —

-0.064 -0.469'' -0.001 -0.041 0.683'' 1

—

"PRIMS, existing run times and predicted run times based on altemative test performance.''Correlation is significant at a value oíp < 0.01 (2-tailed).

n = 109); however, the scores for the females (r = 0.156, n = 27) were not significant. A separate group of correlation analyses (Table IV) were run for the cardiovascular events tested as well as existing times (« = 145) from the PRIMS data. Similar to the other tests, the SHUTTLE (/; = 147), ROW (n = 139), and BIKE (n = 152) were analyzed first for all best scores collected before being analyzed by gender as well. For the correlation between the SHUTTLE and BIKE (;• = 0.736, p < 0.01, n = 130), a significant large correlation was also found in the separate male (/• = 0.660, p < O.OI, n = 95) and female (r = 0.623, p < 0.01, n = 35) analyses. SurveyMonkey.com provided results of the postparticipation survey, which 92 of the participants responded to. Charts and percentages were produced based on the responses provided by the subjects who voluntarily answered the survey questions. Nearly a third (31.5%) of the participants felt the current PRT is not an adequate test, and 42.2% felt the PRT needs to test more than the current battery. The cadence push-up received the most votes (70.8%) for inclusion in the PRT. Most respondents (58.0% and 36.4%, respectively) reported they participate in cardiovascular training and regular strength training three or four times per week. Not all participants answered each question, with only 95.7% (« = 88) completing the questionnaire in its entirety.

DISCUSSION The main findings of this study center on the lack of precision for the SQUAT and the PLANK. This may stem from the inherent subjectivity in the tests as well as the relative novelty of the modalities, but in either case these tests seem unsuitable as tested herein. Additionally, the significant correlation between the SLJ and DYNO was expected, and the strong negative relationship between the SLJ and the AGILITY reflected that with better jumping ability came lower agility times, similar to other studies."*^ However, the lack of strong positive correlations within the noncardiovascular modalities was somewhat surprising. The significant positive correlations between the cardiovascular events indicated that they all might be equally viable choices for the aerobic portion of the PRT. Comparing these tests with newly collected V/i mile run times, however, would strengthen this finding. Although the SHUTTLE'S strong relationship with the BIKE

1422

indicates potential redundancy, the relatively low correlation between the SHUTTLE and the existing PRIMS run times suggests replacing the VA mile run with the SHUTTLE is not warranted by our data. SHUTTLE performance compared to only actual recorded 1 l^mile run times had a slightly higher correlation (/• = 0.551, /; < 0.01, n = 85) than PRIMS. When broken down by gender, males showed a slightly larger^'* correlation between SHUTTLE and PRIMS (/• = 0.601, p < 0.01, « = 97) than the combined group (;• = 0.530, /; < 0.01, « = 123). There was no correlation (;• = 0.137, p < 0.05, n = 26) between these tests in female subjects. It was surprising to not see a stronger'*''^ correlation between the DYNO and participant weight (r = 0.403, p < 0.01, n = 133). It was expected that heavier Sailors would elicit greater force in the pulls, but the correlation was not strong enough to make that conclusion. Perhaps the novelty of the test, even with familiarization sessions made available, contributed to the low correlation. However, although we are unable to confiiTn because of our lack of data, it is possible that the heavier participants in this study had higher body fat vs. greater lean mass; thus, the higher values for weight reflected more fat mass instead of muscle mass, resulting in a correlation value that was lower than expected. Data related to fat-free mass would be desirable to further examine this relationship. The gender disparity for the SLJ and the DYNO correlations could be the result of males, as a group, having higher scores than the females but neither gender having a linear relationship with other scores within their respective gender because of greater variance. However, the correlation for combined genders proved to be significant. In contrast, the strong correlation between the SLJ and AGILITY in males and females, as well as the combined group, shows that gender does not affect a Sailor's tendency to have a better (i.e., lower) time in the AGILITY if they have good performance expressed in their jumping ability. Since the SLJ is easier to administer, it would seem to be the better choice of these two modalities. In testing the modalities, participants were instructed to achieve the best performance possible and had knowledge of their previous scores if performing the modality a second time. During the normal PRT, many Sailors may be simply trying for a minimum score as the test is designed to

MILITARY MEDICINE, Vol. 177, November 2012

Possible New Modalities for the Navy Physical Readiness Test

assess a personnel member's ability to display the minimum level of fitness required for service. It may be a limitation that our analysis utilized previous PRT scores via PRIMS. Had we collected new data for the existing PRT modalities with a similar approach to motivation, a Sailor attempting to achieve a top time in the lYi mile run, for example, might have yielded a higher correlation with other cardiovascular modalities. Since the SHUTTLE times were only somewhat correlated to run times based on the current data, as were the BIKE and ROW, it would not be unreasonable to suggest the SHUTTLE as a possible alternative for the 1 'A mile run if space limitations existed in the conduction of the PRT. With a fresh collection of run times, perhaps a stronger correlation could be seen, allowing us to suggest the SHUTTLE as a replacement to the run. Despite the lack of correlation for females between SHUTTLE and PRIMS, a very large'*'* correlation was seen between SHUTTLE and BIKE (/• = 0.736, /? < 0.01, H = 130), further indicating the possibility that collecting new run and predicted run times with a similar approach to this round of data collection might yield stronger correlations. When asked if the current PRT was an adequate assessment of physical readiness in Sailors in the postparticipation survey (n = 92), nearly half of the respondents either disagreed or strongly disagreed (31.5 % and 16.3%, respectively). It appears that not only are Navy administrators curious about new modalities, but personnel whose livelihoods can quite possibly rely on their performance in the PRT feel the test has some shortcomings. In another question (n = 90), a majority (72.2%) answered in favor of adding new components of fitness to the assessment of physical readiness. Again, this further emphasizes the benefit to our research in that new modalities would provide for a more well-rounded PRT, and Sailors seem cognizant and in agreement with that. Participants (« = 89) also had a chance to vote for their choices of additional tests for the PRT. The CADENCE (70.8%), ROW (66.3%), and PLANK (53.9%) received the most votes. Similarly, Sailors (n = 86) had a chance to voice their opinion on which tests should not be added, and the SQUAT (61.6%), DYNO (59.3%), and SLJ (53.5%) were the top three vote getters. Testing of the modalities was not without its complications. One notable example came with the assessment of lower-body strength via DYNO. Several of the first set of device platforms broke before the first round of testing was completed for all of the Sailors. Concemed for the safety of the participants, we did not collect data from a majority of the participants on the second round of testing. New devices were purchased from a different manufacturer (Takei Scientific Instruments "Back-A" model) for the final week of data collection, but the results from those assessments were not utilized in the reliability analysis because of the diffetent equipment and thus the small sample size (« = 9) for DYNO reliability. The logistic issues with the dynamometers seemed

MILITARY MEDICINE, Vol. 177, Novetnber 2012

to be resolved with the new devices, but the cost of the dynamometer (approximately $600 USD) may be a limitation to its widespread use for the Navy. Another potential limitation existed in the collection of data in the different styles of instruction and monitoring from the data collection team. Although each volunteer had considerable training in terms of detailing the modality and collection methods, there was likely still some variation in subject-instruction implementation and data recording. Although the PLANK and the SQUAT were more subjective tests to begin with, the variation in tester could have contributed to the low precision scores found for those modalities. It should be noted that widespread use of these modalities in the Navy would also be subject to intertester variability. SUMMARY Given the infonnation noted, it is difficult to suggest a "new" PRT, but it is possible to eliminate certain options in their current state from consideration because of a lack of repeatability and potential redundancy. In particular, the single-leg squat and plank seem unsuitable for inclusion in the PRT as tested herein. Although no strength test exists in the PRT, despite recommendations from the DoD, the DYNO is a questionable modality because of the use of equipment that is relatively costly compared to the current modalities and the fact that the original board proved easily breakable should eliminate that particular model from consideration. Adding a strength component to the PRT, however, could assist with the goal of promoting a culture of fitness, considering some (21.6% of 88 respondents) reported that they seldom-to-never participate in regular strength training. Perhaps, future testing could utilize the .second proposed device that would prove more beneficial and allow for a larger sample of reliability measures to be collected. It is unclear if the unexpected low correlations between the DYNO and SLJ were attributable to the faulty equipment; so, it is yet unclear if the SLJ is a good surrogate test for lower-body strength. Because none of the tests had strong correlations to existing marks, it is suggested that similar future research make it a point to collect new data for the existing PRT modahties as well. Although a modality's ability to be recommended for the PRT is not solely dependent upon correlation to existing marks, proposing an entirely new test may not be acceptable. Based on responses from participants in this study, there is a desire from the personnel for a change in the PRT. Some tests included herein such as the SHUTTLE and the SLJ, which had relatively high precisions scores, have the potential to add new exercise components to the PRT. ACKNOWLEDGMENTS The authors acknowledge the assistance of test administrators Lisa Domengeaux. Richard Easter. Tyler Famey. Kelley Hammond. AFCM Dean H. Harris (Ret.). ENC Darren A. Maydek Sr., Charles Mitchell. FTC Angel Rivera, HMCS Raymond K. Townsel, STGCS Steven K. Wise, as well as the

1423

Possible New Modalities for the Navy Physical Readiness Test support staff YNl Barbara Bauman and Shauntel Johnson. Funding for this project was provided in part by the National Strength and Conditioning Association, The University of Memphis, and the U.S. Navy.

REFERENCES 1. Department of the Navy: OPNAV Instruction 6110.1H, pp 1-167. Washington, DC. Department of Defense, 2005. Available at http://doni .daps.dla.mil/directives/06000%20medical%20and%20dental%20services/ 06-100%20general%20physical%20fitness/6110.1h.pdf; accessed March 15,2012. 2. Department of Defense: DoD Issuances: The Official Department of Defense Web Site for DoD Issuances, 2011. Available at http://www .dtic.mil/whs/directives/; accessed March 15, 2012. 3. Bohnker BK, Sack DM, Wedierhold L, Malakooti M: Navy physical readiness test scores and body mass index (Spring 2002 cycle). Mil Med 2005; 170(10): 851-4. 4. McNulty P: Prevalence and contributing factors of eating disorder behaviors in active duty service women in the Army, Navy. Air Force, and Marines. Mil Med 2001; 166: 53-8. 5. McNulty P: Prevalence and contributing factors of eating disorder behaviors in active duty Navy men. Mil Med 1997; 162: 753-8. 6. Fitness-And-Bodybuilding-Workouts.com: Plank Exercises: The Single Leg Plank Hold. 2011. Available at http://www.fitness-and-bodybuilding -workouts.com/plank-exercises.html; accessed March 15, 2012. 7. McGill S, Belore M, Crosby I, Russell C: Clinical tools to quantify torso flexion endurace: normative data from student and firefighter populations. Occup Ergon 2010; 9: 55-61. Available at http://iospress.metapress .com/conlent/t4vvl26656678878/; accessed March 15, 2012. 8. McGill SM. McDemiott A. Fenwick CM; Comparison of different strongman events: trunk muscle activation and lumbar spine motion, load, and stiffness. J Strength Cond Res 2009; 23(4); 1148-61. 9. Freeman S, Karpowicz A, Gray J, McGill S; Ouantifying muscle pattems and spine load during various forms of the push-up. Med Sei Sports Exerc 2006; 38(3); 570-7. 10. McGill SM, Childs A, Liebenson C; Endurance times for low back stabilization exercises; clinical targets for testing and training from a normal database. Arch Phys Med Rehabil 1999; 80(8); 941-4. 11. Asher Anne, About.com Guide; How to Do a Wall Squat. 2008. Available at http;//backandneck.about.com/od/deskexercises/ht/wallsquat.htm; accessed March 15,2012. 12. Brian Mac Sports Coach; Wall Squat Test. 2011. Available at http;// www.brianmac.co.uk/wallsquat.htm; accessed March 15, 2012. 13. Gouvali MK, Boudolos K; Dynamic and electromyographical analysis in variants of push-up exercise. J Strength Cond Res 2005; 19(1); 146-51. 14. U.S. Coast Guard; Cadence Push-Up Test. 2011. Available at http;// www.cga.edu/athletics2.aspx?id=395; accessed March 15, 2012. 15. Best Priced Products; Ba.seline back, leg, chest dynamometer, adult, 6601b. max force. 2011. Available at http;//www.bpp2.com/physical_ therapy_products/l 134.html; accessed March 15, 2012. 16. Costill DL, Hoffman WM, Kehoe F, Miller SJ, Myers WC: Maximum anaerobic power among college football players. J Sports Med Phys Fitness 1968; 8(2); 103-6. 17. Demura S, Miyaguchi K, Shin S, Uchida Y; Effectiveness of the IRM estimation method based on isometric squat using a back-dynamometer. J Strength Cond Res 2010; 24(10); 2742-8. 18. Duncan MJ, Woodtield L, al-Nakeeb Y; Anthropométrie and physiological characteristics of junior elite volleyball players. Br J Sports Med 2006; 40(7); 649-51; discussion 651. 19. Fabrication Enterprises Incorporated: Baseline Back-Leg-Chest Dynamometer. 2011. Available at http://www.fabricationenterprises.com/ mm5/merchant.mvc?Screen=CTGY&Store_Code=FAB&Category_Code= 2008-02-Measurement-065; accessed March 15,2012. 20. Ozcan A, Donat H, Gelecek N, Ozdirenc M, Karadibak D; The relationship between risk factors for falling and the quality of life in older adults. BMC Public Health 2005; 5; 90.

1424

21. Robertson DW. Trent TT; Documentation of Muscularly Demanding Job Task and Validation of an Occupational Strength Test Battery (STB). MPTL TN 86-1. San Diego, CA. Navy Personnel Research and Development, 1985. Available at http;//oai.dtic.mil/oai/oai?verb=getRecord& metadataPrefix=html&identifier=ADAl 62781; accessed March 15,2012. 22. Topend Sports Network; Isometric Leg Strength Test. 2010. Available at; http;//www.topendsports.com/testmg/tests/isometric-strength.htm; accessed March 15,2012. 23. Vanderburgh PM; Occupational relevance and body mass bias in military physical fitness tests. Med Sei Sports Exerc 2008; 40(8); 1538-45. 24. Harman EA, Gutekunst DJ. Frykman PN, et al; Prediction of simulated battlefield physical performance from field-expedient tests. Mil Med 2008; 173(1): 36-41. 25. Hoffman J: Norms for Fitness, Performance, and Health. Champaign, IL, Human Kinetics, 2006. Available at http://www.humankinetics.com/ product.s/all-products/norms-for-fitness-performancend-health; accessed March 15.2012. 26. Panichkul S, Hatthachote P, Napradit P, Khunphasee A, Nathalang O; Systematic review of physical fitness testing to evaluate the physical combat readiness of Royal Thai Armed Forces. Mil Med 2007; 172(12); 1234-8. 27. Peterson MD, Alvar BA, Rhea MR; The contribution of maximal force production to explosive movement among young collegiate athletes. J Strength Cond Res 2006; 20(4); 867-73. 28. Sports Books Publisher; The Standing Long Jump Test. 2012. Available at http;//www.sportbookspub.com/book focus.php?book=The+Standing+ Long+Jump+Te.st&cat=Standing+Long+Jump&minitab=power§ion= Explosive+Power+Tests; accessed March 15,2012. 29. Taanila H, Suni J, Pihiajamaki H. et al; Aetiology and risk factors of musculoskeletal disorders in physically active conscripts; a follow-up study in the Finnish Defence Forces. BMC Musculoskelet Disord 2010; 11 ; 146. 30. Department of the Navy; OPNAV Instruction 6110.1J, pp 1-34. Washington. DC, Department of Defense, 2011. Available at http;// doni.daps.dla.mil/Directives/06000%20Medical%20and%20Dental %20Services/06-100%20General%20Physical%20Fitness/6110.1 J.pdf; accessed March 15,2012. 31. Schloesser K; TRADOC revises Army Physical Fitness Test. 201 1. Available at http;//www.army.mil/article/52548/; accessed March 15,2012. 32. Cahill S, Jones MT; Measurement of body composition and athletic performance during NCAA-Division I women's volleyball and Softball seasons. J Strength Cond Res 2010; 24(1); 1. Available at http;//joumals .lww.com/nsca-jscr/Abstract/2010/01001/Measurement_Of_Body_ Composition_ And Athletic. 12.aspx; accessed March 15, 2012. 33. Gillam GM. Marks M; 300 yard shuttle run. Strength Cond J 1983; 5(5); 46. Available at http;//joumals.lww.com/nsca-scj/Citation/1983/10000/ 3OO_yard_shuttle_run.lO.a.spx; accessed March 15, 2012. 34. Tabata I, Nishimura K, Kouzaki M, et al; Effects of moderate-intensity endurance and high-intensity intermittent training on anaerobic capacity and V02max. Med Sei Sports Exerc 1996; 28(10); 1327-30. 35. Tremblay A, Simoneau JA, Bouchard C; Impact of exercise intensity on body fatness and skeletal muscle metabolism. Metabolism 1994; 43(7); 814-8. 36. Walklate BM. O'Brien BJ. Paton CD, Young W; Supplementing regular training with short-duration sprint-agility training leads to a substantial increase in repeated sprint-agility performance with national level badminton players. J Strength Cond Res 2009; 23(5); 1477-81. 37. Concept2 Rowing; Model E Indoor Rower. 2011. Available at http;//www .concept2.com/us/indoorrower.s/e_home.asp; accessed March 15, 2012. 38. Kendall KL, Smith AE, Fukuda DH, Dwyer TR, Stout JR; Critical velocity; a predictor of 2000-m rowing ergometer performance in NCAA DI female collegiate rowers. J Sports Sei 2011; 29(9); 945-50. 39. Knapik J; The Army Physical Fitness Test (APFT); a review of the literature. Mil Med 1989; 154(6); 326-9. 40. Buono MJ. Borin TL, Sjoholm NT. Hodgdon JA: Validity and reliability of a timed 5 km cycle ergometer ride to predict maximum oxygen uptake. Physiol Meas 1996; 17(4); 313-7.

MILITARY MEDICINE, Vol. 177, November 2012

Possible New Modalities for the Navy Physical Readiness Test 41. Monark Exercise AB: Ergomedic 874B. 2011. Available at http://www .monarkexercise.se/default.asp?PageID=675; accessed March 15,2012. 42. Weir JP: Quantifying test-retest reliability using the intraclass correlation coefficient and the SEM. J Strength Cond Res 2005; 19(1): 231-40. 43. Stokes M: Reliability and repeatability of methods for measuring muscle in physiotherapy. Physiother Pract J 1985; (1): 71-6. Available at http://

MILITARY MEDICINE, Vol. 177, November 2012

infomiahealthcare.com/doi/abs/10.3109/09593988509163853; accessed March 15,2012. 44. Hopkins WG: A New View of Statistics. 2011. Available at sportsci.org/ resource/stats/; accessed April 3, 2012. 45. Bames JL, Schilling BK, Falvo MJ, Weiss LW, Creasy AK, Fry AC: Relationship of jumping and agility performance in female volleyball athletes. J Strength Cond Res 2007; 21(4): 1192-6.

1425

Copyright of Military Medicine is the property of Association of Military Surgeons of the United States and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.