CAN THE AIR FORCE PHYSICAL FITNESS ASSESSMENT PREDICT AEROBIC AND ANAEROBIC CAPACITY?

Cameron S. Mackey1, Tyler W.D. Muddle1, & Jason M. DeFreitas1 1 Applied Neuromuscular Physiology Laboratory, Oklahoma State University, Stillwater, OK PURPOSE: To determine if the components of the Air Force physical fitness assessment (PFA) can predict laboratory/clinical based performance capabilities. METHODS: 30 male Air Force Reserve Officers’ Training Corps (ROTC) cadets (mean ± SD age = 20.3 ± 2.1 yr) participated in this investigation. Each performed an incremental treadmill test to exhaustion to determine peak oxygen uptake (VO2peak; ml/kg/min) and a 30-sec. Wingate Anaerobic Test (WAnT). A commercially-designed bioelectrical impedance spectroscopy (BIS) device was utilized to determine body fat percentage (BF%). The 1.5 mile run times, 1-minute pushups, 1-minute sit-ups, and waist circumference were collected during participants’ ROTC PFA. Relationships among the dependent variables were analyzed with Pearson correlation coefficients. Stepwise, multiple regression was used to determine the relative contributions of the PFA components to the VO2peak and WAnT measurements. RESULTS: The means ± SDs for each variable, as well as the results of the correlations are shown in Table 1. The multiple regression analysis indicated that 1.5 mile run time and waist circumference contributed significantly to the prediction of VO2peak (p = 0.002 and p = 0.036, respectively). The 1.5 mile run time contributed significantly to the prediction of the WAnT anaerobic capacity (p = 0.005), and waist measurement contributed significantly to the prediction of BF% (p = 0.022). CONCLUSION: There were significant relationships among run time, VO2peak, WAnT fatigue index and anaerobic capacity. In addition, the PFA composite score had a significant relationship to WAnT anaerobic capacity, and the waist circumference was significantly related to BF%. However, these data suggest that while the pushup and sit-up components of the PFA may not be able to predict aerobic and anaerobic capacities, the 1.5 mile run time and waist circumference showed significant contributions to VO2peak, WAnT anaerobic capacity, and BF%

COMPARISON OF BODY COMPOSITION ACROSS CLASS RANKS IN RESERVE OFFICERS’ TRAINING CORPS (ROTC) CADETS

Quincy Johnson1, Cameron S. Mackey1, Tyler W.D. Muddle1, Doug B. Smith1, & Jason M. DeFreitas1 1Oklahoma State University, Stillwater, OK Body composition (BC) measurements are used to determine qualification for enlistment and to ensure active members are meeting standards. Although there is extensive research on BC in active-duty military, very few have examined ROTC cadets. We hypothesized that longer exposure to ROTC training programs could significantly improve BC with each year in the program. PURPOSE: To compare differences in BC of freshmen, sophomore, junior, and senior ROTC cadets utilizing bioelectrical impedance spectroscopy (BIS) measurements of fat mass (FM; kg), fat mass percentage (FM%), fat free mass (FFM; kg), and fat free mass percentage (FFM%). METHODS: 36 ROTC cadets (14 freshmen, 7 sophomores, 4 juniors, and 11 seniors) volunteered for this study (descriptives in Table 1). Prior to assessment, participants were placed in a supine position for ~10 minutes with their arms abducted and legs separated. Height, weight, and gender were programmed into the BIS device. Two single-tab electrodes were placed on the right side of the body 5cm apart on the wrist and the ankle. Impedance was measured using 256 frequencies between 4kHz and 1000kHz to estimate total body water, extracellular fluid and intracellular fluid based on Cole modelling with Hanai mixture theory, which the BIS device used to estimate the BC variables. Separate 1-way ANOVAs were run for each dependent variable. When appropriate, Bonferroni post hoc analyses were performed. RESULTS: No interaction was observed for FFM between class ranks (P=0.253). However, freshmen had significantly less FFM (P=0.008) and more FM% (P=0.008) than the seniors. Additionally, freshman and sophomores had a significantly greater FM compared with seniors (P=0.002-0.004). CONCLUSIONS: This study observed significant differences in BC across class ranks in ROTC cadets. This suggests that an increased exposure to ROTC training is beneficial for FFM% and FM%

TEST-RESTEST RELIABILITY OF BIOIMPEDANCE SPECTROSCOPY FOR THE ANALYSIS OF BODY COMPOSITION IN PHYSICALLY ACTIVE MALES

Tyler W.D. Muddle1,2, Patrick M. Tomko1,2, Ryan J. Colquhoun1,2, Mitchel A. Magrini1, Nile F. Banks1,2, Nathaniel D.M. Jenkins1,2 1Applied Neuromuscular Physiology Laboratory 2Laboratory for Applied Nutrition and Exercise Science Oklahoma State University, Stillwater OK No previous studies, to our knowledge, have examined the reliability of bioimpedance spectroscopy (BIS) for the evaluation of body composition. PURPOSE: To evaluate the test-retest reliability of BIS for the assessment of total body water (TBW), extracellular water (ECW), and intracellular water (ICW) content, as well as fat mass (FM), fat-free mass (FFM), and body fat percentage (BF%) in physically active males. METHODS: Sixteen males (Mean ± SD, 25 ± 3 y, 90 ± 11 kg, 176 ± 6 cm) were assessed at two visits, separated by 2 – 7 days. During each visit, participants rested quietly for 3 – 5 min in a supine position with their arms abducted ≥ 30° away from their torso and legs separated prior to their assessment. Two single-tab electrodes were placed on the right side of the body 5 cm apart on both the dorsal surface of the wrist and dorsal surface of the ankle, respectively. The BIS device was used to estimate TBW, ECW, and ICW (liters; L) based on Cole modelling with Hanai mixture theory, which were then used to calculate FM (kg), FFM (kg), and BF%. Reliability was examined by calculating the intraclass correlation coefficient (ICC; model 2,1) and standard error of measurement (SEM). The coefficient of variation (CV) was calculated by expressing the SEM relative to the grand mean (%). The 95% confidence interval (CI) for each ICCwas calculated and used to test the null hypothesis that each ICC was equal to zero. Systematic variability was assessed for each variable via a paired t-test. RESULTS: Reliability statistics are displayed in Table 1. None of the dependent variables displayed systematic variability (p \u3e 0.05). ‘Excellent’ relative and absolute reliability was observed among all body water (ICC = 0.91 – 0.99; CVs = 1.08 – 3.50%) and body mass (ICC = 0.95 – 0.99; CVs = 1.10 – 6.99%) measurements. CONCLUSION: These results indicate that the BIS device used in this study allows for the reliable assessment of TBW, ECW, ICW, FM, FFM, and BF% in physically active men

SIMILAR ADAPTATIONS FOLLOWING TWO HIGH INTENSITY INTERVAL TRAINING CONFIGURATIONS: 10s:5s VERSUS 20s:10s WORK-TO REST RATIO

Masoud Moghaddam1, Carlos A. Estrada1, Tyler W.D. Muddle1, Mitchel A. Magrini1, Nathaniel D.M. Jenkins1, Bert H. Jacobson1, FACSM 1Oklahoma State University, Stillwater, OK High intensity interval training (HIIT) refers to a group of short bouts separated by rest periods. Intensity and duration of exercise and rest periods are the most significant factors in optimizing HIIT adaptations. Since a 2:1 work-to-rest ratio causes a higher oxygen deficit, a 10s:5s work-to-rest ratio was incorporated to establish a shorter yet potentially effective interval duration. PURPOSE: This study compared the effects of ultrashort (UH) versus short (SH) functional HIIT on body composition, vastus lateralis cross sectional area (VL CSA), anaerobic, and aerobic performance. METHODS: Thirty-four recreationally active participants were randomly assigned to SH (8 males and 9 females) and UH (8 males and 9 females) groups and completed 6 cycles of 6 exercises at ~90% of maximal heart rate (i.e. kettlebell snatches; step-up jumps; jumping jacks; front squat; burpees; high knees) 3 d/wk for 4 weeks. SH was performed with 20s:10s work-to-rest ratio, and a 2-minute recovery between cycles, while UH was completed with 10s:5s work-to-rest ratio, and 1-minute recovery. Fat mass (FM), fat free mass (FFM), VL CSA, Wingate anaerobic capacity (i.e. peak power [PP] and anaerobic power [AP]), and aerobic fitness (i.e. VO2max) were measured before and after the intervention and analyzed with 2-way mixed factorial ANOVAs. RESULTS: FM did not significantly (p\u3e0.05) change, however, both groups significantly (p\u3c0.05) improved FFM (UH: 60.8 ± 15.0 to 61.5 ± 15.2 kg, SH: 54.3 ± 11.5 to 55.5 ± 11.0 kg), as well as VL CSA (UH = 24.8 ± 6.2 to 27.1 ± 6.3 cm, SH = 25.6 ± 5.1 to 27.9 ± 5.5 cm). Additionally, anaerobic (UH: PP = 913 ± 305 to 1033 ± 300 W; AP = 11.5 ± 1.1 to 12.6 ± 1.1 W/kg, SH: PP = 839 ± 162 to 887 ± 181 W; AP = 11.8 ± 1.1 to 12.5 ± 1.2 W/kg) and aerobic capacity (UH: VO2max = 35.8 ± 6.9 to 38.9 ± 6.1 ml/kg/min, SH: VO2max = 39.7 ± 9.3 to 42.6 ± 9.1 ml/kg/min) significantly (p\u3c0.05) increased in both groups. There were no significant (p\u3e0.05) differences between groups. CONCLUSION: These results suggest that HIIT at a 10s:5s work-to-rest ratio can improve physical fitness with a shorter time commitment. Future studies are needed to examine a differential effect of these protocols for men versus women. Since the participants would be best categorized as low-fitness, caution is warranted when extrapolating these results to others with higher-fitness levels

EFFECTS OF DIFFERENT RELATIVE LOADS ON POWER PERFORMANCE DURING THE BALLISTIC PUSH-UP

The purpose of this investigation was to examine the effect of load on force and power performance during a ballistic push-up. Sixty (24.5 +/- 4.3 years, 1.75 +/- 0.07 m, and 80.8 +/- 13.5 kg) recreationally active men who participated in this investigation completed all testing and were included in the data analysis. All participants were required to perform a 1 repetition maximum bench press, and ballistic push-ups without external load (T1), with 10% (T2) and 20% (T3) of their body mass. Ballistic push-ups during T2 and T3 were performed using a weight loaded vest. Peak and mean force, power, as well as net impulse and flight time were determined for each ballistic push-up. Peak and mean force were both significantly greater (p > 0.01) during T3 (1,062 +/- 202 and 901 +/- 154 N, respectively), than both T2 (1,017 +/- 202 and 842 +/- 151 N, respectively) and T1 (960 +/- 188 and 792 +/- 140 N, respectively). Peak and mean power were significantly greater (p < 0.01) during T1 (950 +/- 257 and 521 +/- 148 W, respectively), than both T2 (872 +/- 246 and 485 +/- 143 W, respectively) and T3 (814 +/- 275 and 485 +/- 162 W, respectively). Peak and mean power were greatest during T1, regardless of participants' strength levels. Significant (p > 0.01) greater net impulse and smaller peak velocity and flight time were also noted from T1 to T3. Results of this investigation indicated that maximal power outputs were achieved without the use of an external load when performing the ballistic push-up, regardless of the participants' level of strength

Response-Methodological issues associated with the use of force plates when assessing push-ups power.

We read with interest the article by Wang et al. (5). The authors calculated the peak power and mean power of ballistic push-ups as the highest and average power output using similar methods as for lower-body jump squats assessment (i.e., force-plate technique). We believe that the evaluation of power in Wang et al.'s (5) study is based on a misinterpretation of the articles cited in their study. Specifically, Hogarth et al.'s (4) study performed measures which indicate the performance of the exercises but did not actually evaluate power. However, Cormie et al.'s (1) study compared different methods of estimating peak power output. There are sufficient and necessary conditions that have to be respected in order to be able to correctly estimate the power on lower-limb dynamic exercises. We believe that Wang et al. (5) have in appropriately applied this method to the upper-limbs, for the following reasons: Cormie et al. (1) demonstrated that the force-plate technique underestimates the velocity and power output. In addition, this approach assumes linear kinetics, whereas the push-up movement involves rotation of the body about the toes. Moreover, in the push-ups, contrary to the vertical jump where the hands are \u201cfree,\u201d both the hands and feet are in contact with the ground so all ground reaction forces should be measured. Nevertheless, only one part of the external forces were measured (hand-related forces) in the experimental protocol in the study of Wang et al. (5). The power provided in lower-limb vertical jump articles (1,3) is linear as the body moves upward in a linear motion. However, the trajectory of the center of mass of the body in the longitudinal plane when performing jump/ballistic push-ups is a circular arc around the toes (fixed point). A kinematic analysis is therefore needed to verify the path of the push-up and quantify the errors in power estimated when it is assumed that the push-up jump movement is perfectly vertical. We believe that this \u201ctransposed\u201d technique used with the lower-limb to the upper-limbs is inappropriate. This takes on assumptions and can cause large measurement errors. We therefore suggest either (a) using some indices that are related to components of power without actual measurement of power (2), such as rate of force development, impulse, and flight-time, or (b) using 2 synchronized force-plates, which allow supporting the whole body in push-up position. We hope our concern be taken as constructive