Jennifer J. Wages

Comparisons of Age-Predicted Maximum Heart Rate Equations in College-Aged Subjects

Cleary, MA, Hetzler, RK, Wages, JJ, Lentz, MA, Stickley, CD, and Kimura, IF. Comparisons of age-predicted maximum heart rate equations in college-aged subjects. J Strength Cond Res 25(9): 2591-2597, 2011—This study investigated the accuracy of age-predicted equations to predict heart rate maximum (HRmax) in a college-age sample and establish efficacy of short-duration anaerobic capacity tests to determine the actual HRmax. A criterion HRmax (CHRmax) was obtained from 96 (52 men and 44 women, age = 22.0 ± 2.8 years, height = 163.9 ± 9.5 cm, 70.6 ± 14.7 kg, resting HR = 68.9 ± 11.2 b·min−1) healthy volunteers during 2 200-m sprint trials on a standard track. Maximal effort was confirmed via plasma lactate ≥7 mmol·L−1 and rating of perceived exertion ≥17 points. The CHRmax was compared to 7 age-predicted HRmax equations: Fox et al., 3 equations from Gellish et al., Tanaka et al., and gender-specific equations from Fairbarn et al., and Hossack et al. Descriptive statistics and standard errors of estimate (SEEs) were calculated. One-way analysis of variance was used to assess differences between the criterion HRmax and the age-predicted HRmax from the 7 equations. The predicted HRmax from the Fox equation and those of Gellish3, Tanaka, and Hossack were all significantly higher (p ≤ 0.05) than the CHRmax. The Fox equation resulted in overpredicting HRmax in 88.5% of the cases compared to the CHRmax. Compared to the CHRmax, the age-predicted HRmax equations resulted in the following percentages of the CHRmax: Fox = 104.8%, SEE = 12.7; Gellish1 = 95.2%, SEE = 12.2; Gellish2 = 99.6%, SEE = 8.3; Gellish3 = 101.8%, SEE = 9.1; Tanaka = 102.0%, SEE = 9.3; Fairbarn = 100.1%, SEE = 8.5; and Hossack = 105.2%, SEE = 13.9 of CHRmax. It was concluded that the Gellish2 and Fairbarn equations were the most accurate of the age-predicted HRmax equations in a college-age population. In practical application, 2 200-m sprint trials provide a reasonable estimate of HRmax compared to a graded exercise test.

Hydration Behaviors Before and After an Educational and Prescribed Hydration Intervention in Adolescent Athletes

CONTEXT The effectiveness of education in modifying hydration behaviors in adolescent athletes is unclear. OBJECTIVE To assess the hydration status and behaviors of female athletes before and after a 1-time educational intervention and prescribed hydration intervention in a warm, humid, tropical environment. DESIGN Cohort study. SETTING Non-air-conditioned gymnasium in a tropical environment (indoor wet bulb globe temperature = 24.0 ± 0.2°C). Patient or Other Participants: Thirty-six female adolescent elite volleyball players (age = 14.8 ± 0.8 years, height = 168.2 ± 8.2 cm, mass = 60.8 ± 9.0 kg, body mass index = 21.7 ± 2.7, body surface area = 1.65 ± 0.14 m(2), body surface area to mass ratio = 2.71 ± 0.18 m(2)·kg(-1)·10(-2)) participated. INTERVENTION(S) Four observational periods consisting of 3 practices per observational period separated by 48 hours. The 4 periods included a control period, educational intervention, prescribed hydration intervention (PHI), and observational follow-up (OF-U). After the control period, an educational intervention consisting of a slide presentation was provided to the participants, followed by a week of observation. In the PHI, a precalculated volume of water based on individual sweat rate was consumed every 20 minutes during each 2-hour practice. During all other periods, participants consumed their fluid of choice ad libitum. The order of the treatment periods was not randomized and was the same for all participants. MAIN OUTCOME MEASURE(S) Prepractice to postpractice changes in body mass (ΔBM), percentage of body mass lost (%BML), urine specific gravity, urine color, urine osmolality, sweat rate, and volume of fluid consumed (F(vol)). RESULTS The PHI was the only period during which participants maintained body mass (ΔBM = 0.05 ± 1.3%); F(vol) consumed was greatest during this time (F(vol) = 1.3 ± 0.4 L; F(1,3) = 34.869, P ≤ .001). TheΔBM was less for the PHI (ΔBM = 0.05 ± 0.9 kg, %BML = 0.04 ± 1.3%) than the OF-U period (ΔBM = -0.7 ± 1.1 kg, %BML = -1.2 ± 1.9%; F(1,3) = 6.220, P = .01). The F(vol) (1.3 ± 0.4 L) and percentage of fluid consumed (143.7 ± 110.8%) to restore sweat loss for the PHI period were higher than for any other period (F(1,3) = 34.869, P ≤ .001). None of the participants experienced serious dehydration in any of the conditions. CONCLUSIONS A 1-time education session alone was not successful in changing hydration behaviors. However, prescribing individualized hydration protocols improved hydration for adolescents exercising in a warm, humid environment.

Component Alignment After Minimally Invasive Total Knee Arthroplasty: Results of the First 100 Cases Performed

It has been suggested that minimally invasive total knee arthroplasties increase the risk of component malalignment. Results during the period of initial learning curve on component malalignment are relatively unknown but should be addressed. This study reports the component alignment data of the first 100 minimally invasive total knee arthroplasties performed by a single surgeon from the very start of a community-based practice immediately after fellowship training. The results indicate that the initial learning curve produces results comparable to reported results of standard total knee arthroplasties.

Allometric Scaling of Wingate Anaerobic Power Test Scores in Men

Abstract Stickley, CD, Hetzler, RK, Wages, JJ, Freemyer, BG, and Kimura, IF. Allometric scaling of Wingate anaerobic power test scores in men. J Strength Cond Res 27(9): 2603–2611, 2013—This study examined the appropriate magnitude of allometric scaling of the Wingate anaerobic test (WAnT) power data for body mass (BM) and established normative data for the WAnT for adult men. Eighty-three men completed a standard WAnT using 0.1 kg·kg−1 BM resistance. Allometric exponents and percentile ranks for 1-second peak power (PP), 5-second PP, and mean power (MP) were established. The Predicted Residual Sum of Squares (PRESS) procedure was used to assess external validity while avoiding data splitting. The mean 1-second PP, 5-second PP, and MP were 1,049.1 ± 168.8 W, 1,013.4 ± 158.6 W, and 777.9 ± 105.0 W, respectively. Allometric exponents for 1-second PP, 5-second PP, and MP scaled for BM were b = 0.89, 0.88, and 0.86, respectively. Correlations between allometrically scaled 1-second PP, 5-second PP, and MP, and BM were r = −0.03, −0.03, and −0.02, respectively, suggesting that the allometric exponents derived were effective in partialling out the effect of BM on WAnT values. The PRESS procedure values resulted in small decreases in R2 (0.03, 0.04, and 0.02 for 1-second PP, 5-second PP, and MP, respectively) suggesting acceptable levels of external validity when applied to independent samples. The allometric exponents and normative values provide a useful tool for comparing WAnT scores in college-aged females without the confounding effect of BM. It is suggested that exponents of b = 0.89 (1-second PP), b = 0.88 (5-second PP), and b = 0.86 (MP) be used for allometrically scaling WAnT power values in healthy adult men and that the confidence limits for these allometric exponents be considered as 0.66–1.0 for PP and 0.69–1.0 for MP. The use of these exponents in allometric scaling of male WAnT power values provide coaches and practitioners with valid means for comparing power production between individuals without the confounding influence of BM.

Standard Radiographs Are Not Sufficient for Assessing Knee Mechanical Axis in Patients With Advanced Osteoarthritis

BACKGROUND The use of standard radiographs, and measured tibiofemoral angle (TFA), to assess lower extremity alignment is commonly practiced despite limited knowledge of its relationship to the mechanical axis (MA), as measured on hip-to-ankle (HTA) radiographs. This study assessed the predictive accuracy of previously developed equations, developed gender-specific regression equations using predictors from standard radiographs, and the clinical effectiveness of these equations in a large sample of cases using HTA radiographs as a gold standard. METHODS The MA was measured on HTA radiographs, whereas TFA and femoral angle were measured on standard radiographs in 788 cases diagnosed with knee osteoarthritis. RESULTS Multiple regression analyses indicated that TFA, femoral angle, and height were the strongest factors associated with the predicting MA, accounting for 83% of the variance for men and 86% for women, but were able to predict only the actual MA within ±3° in 66% of men and 69% of women. When applied to previously reported regression equations with similar results, the best predicative accuracy obtained within ±3° was 61% and 63% of men and women, respectively. CONCLUSION Standard radiographs are not sufficient for determining MA, and HTA radiographs should be used while making surgical decisions aimed at correcting alignment to within ±3° or for assessing alignment post-total knee arthroplasty. In addition, surgical alignment outcomes reported in previous research using standard radiographs should be viewed with caution.

Validity and reliability of the Hawaii anaerobic run test.

Abstract Kimura, IF, Stickley, CD, Lentz, MA, Wages, JJ, Yanagi, K, and Hetzler, RK. Validity and reliability of the Hawaii anaerobic run test. J Strength Cond Res 28(5): 1386–1393, 2014—This study examined the reliability and validity of the Hawaii anaerobic run test (HART) by comparing anaerobic capacity measures obtained to those during the Wingate Anaerobic Test (WAnT). Ninety-six healthy physically active volunteers (age, 22.0 ± 2.8 years; height, 163.9 ± 9.5 cm; body mass, 70.6 ± 14.7 kg; body fat %, 19.29 ± 5.39%) participated in this study. Each participant performed 2 anaerobic capacity tests: the WAnT and the HART by random assignment on separate days. The reliability of the HART was calculated from 2 separate trials of the test and then determined through intraclass correlation coefficients (ICCs). Blood samples were collected, and lactate was analyzed both pretest and posttest for each of the 2 exercise modes. Heart rate and rate of perceived exertion were also measured pre- and post-exercise. Hawaii anaerobic run test peak and mean momentum were calculated as body mass times highest or average split velocity, respectively. Intraclass correlation coefficients between trials of the HART for peak and mean momentum were 0.98 and 0.99, respectively (SEM = 18.8 and 25.7, respectively). Validity of the HART was established through comparison of momentum on the HART with power on the WAnT. High correlations were found between peak power and peak momentum (r = 0.88), as well as mean power and mean momentum (r = 0.94). The HART was considered to be a reliable test of anaerobic power. The HART was also determined to be a valid test of anaerobic power when compared with the WAnT. When testing healthy college-aged individuals, the HART offers an easy and inexpensive alternative maximal effort anaerobic power test to other established tests.

Validation of a nonexercise prediction equation of anaerobic power.

Abstract Stickley, CD, Wages, JJ, Kimura, IF, and Hetzler, RK. Validation of a nonexercise prediction equation of anaerobic power. J Strength Cond Res 26(11): 3067–3074, 2012—This study examined the validity of estimating anaerobic power in college-aged students using anthropometric data and a paper and pencil test. Peak power (PP) and mean power (MP) were determined for 157 subjects (92 men and 65 women) using a standard Wingate anaerobic test (WAnT) at a resistance of 0.075 and 0.10 kg·body mass−1 for women and men, respectively. Subjects completed previously established paper and pencil tests for assessing aerobic capacity and rated their ability to perform tasks related to anaerobic power, such as their vertical jump height relative to peers. Descriptive statistics were generated, and multiple regression was performed using SAS v9.1 to assess the ability of paper and pencil tests to predict PP and MP from the WAnT. Mean (±SD) age, height, body mass, body mass index, PP, and MP for subjects were 22.1 ± 2.5 years, 175.6 ± 7.5 cm, 78.5 ± 11.4 kg, 25.4 ± 3.0 kg·m−2, 1015.2 ± 169.7 W, and 784.5 ± 122.1 W and 22.0 ± 3.0 years, 163.6 ± 7.4 cm, 61.1 ± 10.4 kg, 22.8 ± 3.4 kg·m−2, 593.0 ± 102.4 W, and 478.8 ± 72.8 W, respectively. Mean estimated jump height (EJHt) rating values were 5.8 ± 1.5 and 4.7 ± 1.5 (on a 1–9 Likert-type scale) for men and women, respectively. The following multiple regression models were developed: PP = −34.5 + 249.6 (gender; female = 0, male = 1) + 8.1 (BMkg) + 27.8 (EJHt) (R2 = 0.82, SEE = 106.6 W); MP = −37.7 + 163.7 (gender) + 6.7 (BMkg) + 22.8 (EJHt) (R2 = 0.87, SEE = 65.5 W). It was concluded that valid estimates for PP and MP could be obtained from anthropometric data and a single question paper and pencil test asking subjects to estimate relative jumping ability, without the need for performing the Wingate anaerobic cycle test.