University of Alabama Repository :: Browsing by Author "Esco, Michael R."

Browsing by Author "Esco, Michael R."

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Accuracy of a Mobile 2D Imaging System for Body Volume and Subsequent Composition Estimates in a Three-Compartment Model
(Lippincott Williams & Wilkins, 2021) Fedewa, Michael V.; Sullivan, Katherine; Hornikel, Bjoern; Holmes, Clifton J.; Metoyer, Casey J.; Esco, Michael R.; University of Alabama Tuscaloosa
Purpose The purpose of the study was to compare a single two-dimensional image processing system (IMAGE) to underwater weighing (UWW) for measuring body volume (BV) and subsequently estimating body fat percentage (%Fat), fat mass (FM), and fat-free mass (FFM) via a 3-compartment (3C) model. Methods A sample of participants age 18-39 yr was recruited for this study (n = 67, 47.8% female). BV was measured with UWW and predicted via the IMAGE software. The BV estimates from UWW (3C(UWW)) and IMAGE (3C(IMAGE)) were separately combined with constant total body water and body mass values for 3C model calculation of %Fat, FM, and FFM. Results BV obtained from the IMAGE was 67.76 +/- 12.19 and 67.72 +/- 12.04 L from UWW, which was not significantly different (P = 0.578) and very largely correlated (r = 0.99, P < 0.001). When converted to %Fat (3C(UWW) = 21.01% +/- 7.30%, 3C(IMAGE) = 21.08% +/- 7.04%, P = 0.775), FM (3C(UWW) = 14.68 +/- 5.15 kg, 3C(IMAGE) = 14.78 +/- 5.08 kg, P = 0.578), and FFM (3C(UWW) = 57.00 +/- 13.20 kg, 3C(IMAGE) = 56.90 +/- 12.84 kg, P = 0.578) with the 3C model, no significant mean differences and very large correlations (r values ranged from 0.96 to 0.99) were observed. In addition, the standard error of estimate, total error, and 95% limits of agreement for all three metrics were small and considered acceptable. Conclusions An IMAGE system provides valid estimates of BV that accurately estimates body composition in a 3C model.
Acute effects of exercise between sets on upper-body power
(University of Alabama Libraries, 2016) Fava, Anthony William; Bishop, Phillip A.; University of Alabama Tuscaloosa
Performing exercise between sets allows for increased workload in a given training session. Prior use of exercises can contribute to muscle activation or mobility which can aid in the performance of the following set. The purpose of this study was to determine the acute effects on upper-body (UB) power when performing different exercise types between sets. Resistance-trained (men: N = 7, age = 24 ± 2.4 years, Ht. = 176 ± 6.1 cm, Wt. = 92.5 ± 18.4 Kg, Body Comp = 18 ± 6.3 % fat; women N = 3, age = 21± 1.2 years, Ht. = 170 ± 5.1 cm, Wt. = 66.5 ± 7.16 Kg, Body Comp = 29 ± 6.0 % fat) volunteers participated in this study. All subjects underwent seven experimental trials and one familiarization trial. Each trial incorporated an exercise that was repeated between four sets of an UB-power test. The effects of six different exercises were tested. A pre-power measurement (PreP) was the first set prior to the start of the exercise and used as a comparison measurement. Exercise performed between sets included: resistance exercise to agonist muscle groups using suspension training (RA), mild stretching exercises to agonist muscle groups (SA), resistance exercise to antagonist muscle groups using suspension training (RAnt), mild stretching exercises to antagonist muscle groups (SAnt), plyometric to agonist muscle groups (PlyoA) and rest as control (C). Treatments were counterbalanced and randomly assigned to participants. There was no significant effect on UB power among treatments performed (p = .080), independent of sets. There was no significant effect on UB power across sets (p = .449), independent of treatment. There was a significant interaction between treatment and sets (p = .038). UB power responded significantly different among treatments and across sets. Mean UB power (MUBP) increased from the first set to the second set for all treatments except control. MUBP for RA and SAnt then decreased on the third set before increasing on the fourth, showing fluctuation in UB power across sets. Over time PlyoA and SA increased until the third set before decreasing on the fourth set demonstrating a ceiling effect, yet effective for early sets. MUBP for RAnt continued to increase across all sets. MUBP remained above C for all treatments for sets two, three and four except RA and the fourth set of SA.
Adequacy of the Ultra-Short-Term HRV to Assess Adaptive Processes in Youth Female Basketball Players
(Sciendo, 2017) Nakamura, Fabio Y.; Pereira, Lucas A.; Abad, Cesar C. Cal; Cruz, Igor F.; Flatt, Andrew A.; Esco, Michael R.; Loturco, Irineu; Universidade Estadual de Londrina; University of Alabama Tuscaloosa
Heart rate variability has been widely used to monitor athletes' cardiac autonomic control changes induced by training and competition, and recently shorter recording times have been sought to improve its practicality. The aim of this study was to test the agreement between the (ultra-short-term) natural log of the root-mean-square difference of successive normal RR intervals (lnRMSSD - measured in only 1 min post-1 min stabilization) and the criterion lnRMSSD (measured in the last 5 min out of 10 min of recording) in young female basketball players. Furthermore, the correlation between training induced delta change in the ultra-short-term lnRMSSD and the criterion lnRMSSD was calculated. Seventeen players were assessed at rest pre-and post-eight weeks of training. Trivial effect sizes (-0.03 in the pre-and 0.10 in the post-treatment) were found in the comparison between the ultra-short-term lnRMSSD (3.29 +/- 0.45 and 3.49 +/- 0.35 ms, in the pre-and post-, respectively) and the criterion lnRMSSD (3.30 +/- 0.40 and 3.45 +/- 0.41 ms, in the pre-and post-, respectively) (intraclass correlation coefficient = 0.95 and 0.93). In both cases, the response to training was significant, with Pearson's correlation of 0.82 between the delta changes of the ultra-short-term lnRMSSD and the criterion lnRMSSD. In conclusion, the lnRMSSD can be calculated within only 2 min of data acquisition (the 1(st) min discarded) in young female basketball players, with the ultra-short-term measure presenting similar sensitivity to training effects as the standard criterion measure.
Agreement Between A 2-Dimensional Digital Image-Based 3-Compartment Body Composition Model and Dual Energy X-Ray Absorptiometry for The Estimation of Relative Adiposity
(Elsevier, 2022) Sullivan, Katherine; Metoyer, Casey J.; Hornikel, Bjoern; Holmes, Clifton J.; Nickerson, Brett S.; Esco, Michael R.; Fedewa, Michael, V; University of Alabama Tuscaloosa; Washington University (WUSTL); Texas A&M International University
The purpose of this study was to compare relative adiposity (%Fat) derived from a 2-dimensional image-based 3-component (3C) model (%Fat(3C-IMAGE)) and dual-energy X-ray absorptiometry (DXA) (%Fat(DXA)) against a 5-component (5C) laboratory criterion (%Fat(5C)). 57 participants were included (63.2% male, 84.2% White/Caucasian, 22.5 +/- 4.7 yrs., 23.9 +/- 2.8 kg/m(2)). For each participant, body mass and standing height were measured to the nearest 0.1 kg and 0.1 cm, respectively. A digital image of each participant was taken using a 9.7 inch, 16g iPad Air 2 and analyzed using a commercially available application (version 1.1.2, made Health and Fitness, USA) for the estimation of body volume (BV) and inclusion in %Fat(3C-IMAGE). %Fat(3C-IMAGE) and %Fat(5C) included measures of total body water derived from bioimpedance spectroscopy. The criterion %Fat(5C) included BV estimates derived from underwater weighing and bone mineral content measures via DXA. %Fat(DXA) estimates were calculated from a whole-body DXA scan. A standardized mean effect size (ES) assessed the magnitude of differences between models with values of 0.2, 0.5, and 0.8 for small, moderate, and large differences, respectively. Data are presented as mean +/- standard deviation. A strong correlation (r = 0.94, p <.001) and small mean difference (ES = 0.24, p <.001) was observed between %Fat(3C-IMAGE) (19.20 +/- 5.80) and %Fat(5C) (17.69 +/- 6.20) whereas a strong correlation (r = 0.87, p <.001) and moderate-large mean difference (ES = 0.70, p <.001) was observed between %Fat DXA (22.01 +/- 6.81) and %Fat(5C). Furthermore, %Fat(3C-IMAGE )(SEE = 2.20 %Fat, TE= 2.6) exhibited smaller SEE and TE than %Fat(DXA) (SEE = 3.14 %Fat, TE = 5.5). The 3C image-based model performed slightly better in our sample of young adults than the DXA 3C model. Thus, the 2D image analysis program provides an accurate and non-invasive estimate of %Fat within a 3C model in young adults. Compared to DXA, the 3C image-based model allows for a more cost-effective and portable method of body composition assessment, potentially increasing accessibility to multi-component methods.
Association among aerobic performance, resting heart rate and heart rate variability in physically active college-aged adults
(University of Alabama Libraries, 2018) Martin, Darrell; Esco, Michael R.; University of Alabama Tuscaloosa
The purpose of this study was to determine the relationship between smartphone-derived heart rate measures (resting heart rate [RHR] and heart rate variability [HRV]) and performance on an aerobic performance test. Seventeen male college students performed 55-second HR measures in the seated position every morning for 5 days. The root mean square of successive normal-to-normal interval differences (RMSSD) was used as the HRV metric. The weekly mean and coefficient of variation of RHR (RHRM and RHRCV, respectively) and RMSSD (RMSSDM and RMSSDCV, respectively) were determined. Participants completed the 2 mile run (2MR) on the last day of the week. Intra-class correlations (ICC) were used to determine the stability in the heart rate measures across the 5-day period. Pearson correlations were performed to determine the relationship between 2MR and RHRCV, HRM, RMSSDM and RMSSDCV. RHR (ICC = 0.87 [0.74 to 0.95], p < 0.05) displayed better stability over the 5-day period relative to the RMSSD (ICC = 0.66 [0.32 to 0.86], p < 0.05). RHRM was very strongly correlated with 2MR (r = 0.63), as was RMSSDCV (r = 0.55). Conversely, neither RHRCV nor RMSSDM correlated significantly to the 2MR. Therefore, both RHRM and RMSSDCV may be useful objective heart rate indicators to reflect aerobic performance.
Association between Subjective Indicators of Recovery Status and Heart Rate Variability among Divison-1 Sprint-Swimmers
(MDPI, 2018) Flatt, Andrew A.; Esco, Michael R.; Nakamura, Fabio Y.; University of Alabama Tuscaloosa; G d'Annunzio University of Chieti-Pescara; James Cook University
Heart rate variability (HRV) is a physiological marker of training adaptation among athletes. However, HRV interpretation is challenging when assessed in isolation due to its sensitivity to various training and non-training-related factors. The purpose of this study was to determine the association between athlete-self report measures of recovery (ASRM) and HRV throughout a preparatory training period. Ultra-short natural logarithm of the root mean square of successive differences (LnRMSSD) and subjective ratings of sleep quality, fatigue, muscle soreness, stress and mood were acquired daily for 4 weeks among Division-1 sprint-swimmers (n = 17 males). ASRM were converted to z-scores and classified as average (z-score -0.5-0.5), better than average (z-score > 0.5) or worse than average (z-score < -0.5). Linear mixed models were used to evaluate differences in LnRMSSD based on ASRM classifications. LnRMSSD was higher (p < 0.05) when perceived sleep quality, fatigue, stress and mood were better than average versus worse than average. Within-subject correlations revealed that 15 of 17 subjects demonstrated at least one relationship (p < 0.05) between LnRMSSD and ASRM variables. Changes in HRV may be the result of non-training related factors and thus practitioners are encouraged to include subjective measures to facilitate targeted interventions to support training adaptations.
Balance, Basic Anthropometrics and Performance in Young Alpine Skiers; Longitudinal Analysis of the Associations During Two Competitive Seasons
(Sciendo, 2017) Lesnik, Blaz; Sekulic, Damir; Supej, Matej; Esco, Michael R.; Zvan, Milan; University of Ljubljana; University of Split; University of Alabama Tuscaloosa
Balance is hypothesized to be important in alpine skiing, while it is known that balance depends on anthropometric indices. The aim of this investigation was to explore the association between balance, anthropometrics and skiing-results over two competitive seasons among youth alpine-skiers. Eighty-one skiers (40 females) participated in this study. The participants were tested twice over two competitive seasons: when they were 12-13 years old (U14) and when they were 14-15 years old (U16). The variables consisted of anthropometrics (body height and body mass) and three balance indexes (medio-lateral-, anterio-posterior- and overall-stability-index). Additionally, skiing results in U14 and U16 were evaluated. The balance status did not change significantly over the observed period of time regardless of the significant changes in body mass and height. The relationships between balance and skiing results were higher in the U14 (Pearson's r = 0.45-0.54) than in the U16 (Pearson's r = 0.05-0.28). The relationships between anthropometrics and competitive results were generally stronger in girls (Pearson's r = 0.39-0.88) than in boys (Pearson's r = 0.26-0.58). After clustering athletes into three achievement groups on a basis of their competitive performance, discriminant canonical analysis showed that relationships between balance and skiing results decreased, while the relationships between anthropometrics and skiing results increased over the two observed seasons. This study highlighted the importance of balance in youth alpine skiing in the age range of 11-14 years.
Blood lactate and electromyograpy during aerobic exercise
(University of Alabama Libraries, 2017) Snarr, Ronald Lee; Bishop, Phillip A.; Esco, Michael R.; University of Alabama Tuscaloosa
The assessment of lactate threshold (LT) is an important measurement to prescribe training intensities and monitor chronic adaptations in athletes. A non-invasive method, electromyography (EMG), has been suggested as an alternative approach to LT testing. Three experiments determined the ability of EMG incorporated into compression shorts to estimate LT, effect of exercise on LT and EMG threshold (EMGT), and determined the most appropriate filtering method of the EMG signal to estimate LT. In the first investigation, participants performed an incremental exercise test while blood lactate and EMG were measured. EMG displayed no differences from blood lactate in the ability to predict LT (p = 0.08). EMGT and LT showed a moderate correlation (r = 0.68, p = 0.01) between the determination of work rates. The EMGT occurred at the same stage of the incremental test as LT in 11 out of the 13 participants (85%). No differences were seen between percentage of maximal oxygen consumption or percentage of maximal heart rate between LT and EMGT. In the second study, the effect of exercise on LT and EMGT measurement was evaluated. Participants completed two maximal exercise tests separated by 30-minutes of exercise. Individual agreement demonstrated that pre- and post-exercise LT occurred at the same work rate in 5 of 10 participants; while pre- and post- EMGT occurred at the same work rate in 6 of 10 participants. Results indicated no significant difference between the work rates of the pre-exercise LT and EMGT (0.43), although post-trial LT was significantly lower than post-trial EMGT (p = 0.007). No difference in test stage were seen between the pre- and post-exercise EMGT; however, post-trial LT occurred at a lower work rate as compared to pre-trial LT (p = 0.03). In the final study, four popular methods of EMG signal transformation were examined in order to determine their effectiveness in estimating LT. The methods used were root mean square (10- and 60-second epochs), 60- second Smoothing, and 60-secons peak-amplitude averaging. Results indicated no differences in the ability of any signal processing variations to predict LT or in relation to %VO2peak at each threshold level. In conclusion, EMG has been demonstrated to be a viable tool to estimate LT and may provide a reliable low-cost, non-invasive method of prescribing training intensities based upon EMGT testing.
Body composition assessment in adults with down syndrome
(University of Alabama Libraries, 2017-12) Russell, Angela R.; Esco, Michael R.; University of Alabama Tuscaloosa
Individuals with Down syndrome (DS) have a high prevalence of obesity and low bone mineral density (BMD), but body composition assessment needs additional study in DS. Three studies examined the agreement between body fat percentage (BF%) from air displacement plethysmography (ADP) and dual-energy x-ray absorptiometry (DXA), BF% from a four-compartment (4C) model and skinfolds (SF) and bioelectrical impedance analysis (BIA), and bone mineral content (BMC) from DXA and BIA. Sixty-six adults participated (33 DS, 33 control). In the first study, DXA provided higher BF% than ADP in both DS (t = 5.252, df = 32, p < .000) and controls (t = 7.714, df = 32, p < .000). In the second study, BF% from four BIA equations was not significantly different from 4CBF% in DS (p > .01), but these had a standard error of estimate (SEE) from 4.8 to 6.0 and wide limits of agreement (± 9.5% to ± 11.6%). Two BIA equations were not significantly different than 4CBF% in controls (p < .01), but these had SEE’s of 7.2 and 7.8 and wide limits of agreement (± 24.6% and ± 22.9%). Two SF equations were not significantly different from 4CBF% in DS (p < .007). Two of the SF equations were significantly different from 4CBF% in controls (p < .008). In the third study, BMC from DXA was significantly lower than BIA in DS (t = -5.237, df = 20, p < .000). DXA was significantly higher in controls (t = 3.110, df = 20, p = .006). There was no significant difference in DS males (t = -1.116, df = 7, p = .301) or control females (t = -7.978, df = 12, p = .000). DXA was significantly higher in control males (t = 5.641, df = 7, p = .001) and significantly lower in females with DS (t = -7.978, df = 12, p = .000). In conclusion, many methods of BF% assessment may be acceptable for adults with DS, but only appropriate equations should be selected. BIA should not currently be used to assess BMC in DS.
Body fat percentage via dual energy X-ray absorptiometry following multiple different approaches compared to a laboratory-based 3-compartment model
(University of Alabama Libraries, 2019) Welborn, Bailey Arthur; Esco, Michael R.; University of Alabama Tuscaloosa
The purpose of this study was to examine the accuracy of using dual energy X-ray absorptiometry (DXA) derived body volume (BV) equations in a multi-compartment model for estimates of body fat percentage (BF%) in comparison to traditional under water weighing (UWW) measures of BV. BF% was estimated using three-compartment (3C), two-compartment (2C) models, and the DXA. The 3C-Siri equation with UWW for BV and deuterium oxide (D2O) for total body water (TBW) was used as the criterion. One hundred twenty-nine adults (55 men and 74 women) volunteered to participate (age = 30 ± 13 years). DXA-derived BV was determined with the recent equations from Smith-Ryan et al. and Wilson et al. and then incorporated into multi-compartment models (i.e., 3CSiri-SR and 3CSiri-W). The 3CSiri-SR and 3CSiri-W DXA-derived BV values were highly correlated with UWW measured BV (74.24L, 74.30L, and 71.97L, respectively, and r=.999 for both). However, the mean BF% was overestimated in all multi-compartment models regardless of which DXA-derived BV equation was used. These results were consistent for the total sample and when stratified by sex, with the observed error ranging from 4.92% to 17.75% (effect size [ES] = .61 to 1.96, all p<.001). The correlation between the DXA-derived BV and 3C-criterion BF% was strongest for both Smith-Ryan et al. and Wilson et al. when utilized in the Siri model (i.e., 3CSiri-SR and 3CSiri-W) in the total sample, (r= .979 and .964, respectively) for men, (r= .974 and .971, respectively) and for women (r= .981 and .973, respectively). The 3CSiri-SR yielded the best accuracy in the total sample, as well as when stratified by men, and women as indicated by the smallest SEE of all methods (1.91%, 1.83%, and 1.76% respectively), although it overestimated BF% by 6% in both sex-specific subgroups. These data indicate that both DXA-derived BV equations are strongly correlated with UWW, however do not provide an accurate measure when incorporated in a 3-compartment model for estimation of BF%. This is likely due to the higher BV values produced by the DXA-derived equations (roughly 2 liters), which overestimated BF% by roughly 5%.
Comparison of weekly HRV measures collected from two different recording times and their relation to performance in collegiate female rowers
(University of Alabama Libraries, 2018) Sherman, Sara Rae; Esco, Michael R.; Fedewa, Michael V.; University of Alabama Tuscaloosa
INTRODUCTION: Root-mean-square difference of successive RR intervals (RMSSD) is a common heart rate variability (HRV) metric used in the realm of athletic monitoring. Time constraints in a collegiate sport environment and irregular practice hours are challenges that make obtaining the mean value (RMSSDM) and coefficient of variation (RMSSDCV) of daily RMSSD assessment difficult. It is unclear whether the time of day (i.e., measured immediately upon waking versus immediately prior to morning practice) influences these metrics and their relationships to performance. PURPOSE: To compare HRV values when recorded immediately upon waking to values recorded later in the morning prior to practice, and to determine the associations of HRV measures with performance outcomes in competitive female rowers. METHODS: Thirty-one NCAA Division I rowers were monitored for six consecutive days. Two seated RMSSD measurements were obtained on at least three mornings using a photoplethysmography application. Each 1-minute RMSSD measure was recorded following a 1-minute stabilization period. The first (T1) measurement occurred at the athlete’s home following waking, the second (T2) upon arrival at the team’s boathouse immediately before practice. From the daily measures, RMSSD mean and CV were calculated. Rank was determined by the coaches based on performance for that week. Two objective performance assessments were conducted on an indoor rowing ergometer on separate days: timed 2000m and distance covered in 30 minutes. Paired samples t-test was used to assess the potential differences between T1 and T2. Bivariate correlations were assessed using an intraclass correlation coefficient (ICC). Statistical significance assessed using α-level, p<0.05. RESULTS: No differences in RMSSDM and RMSSDCV were observed between T1 and T2 (p=0.73, p=0.66, respectively). RMSSDM at T1 and T2 were strongly correlated (ICC=0.82, 95% CI=0.63 to 0.92), as well as RMSSDCV at both times (ICC=0.75, 95% CI=0.48 to 0.88) (both p<0.01). RMSSDM at T1 and T2 was moderately associated with athlete rank (r=-0.55, r=-0.46, respectively), 30-min distance (r=0.40, r=0.41, respectively), and 2,000m at T1 (r=-0.37). No significant correlations were observed for RMSSDCV. CONCLUSIONS: Ultra-short RMSSD can be measured immediately upon waking or prior to practice, however assessing HRV immediately upon waking yielded stronger correlations with performance.
Daily Heart Rate Variability before and after Concussion in an American College Football Player
(MDPI, 2019) Flatt, Andrew A.; Wilkerson, Gary B.; Allen, Jeff R.; Keith, Clay M.; Esco, Michael R.; University of Alabama Tuscaloosa; University of Tennessee at Chattanooga
This case report demonstrates the effects of sport-related concussion (SRC) on heart rate variability (HRV) in an American college football player. Daily measures of resting, ultra-short natural logarithm of the root mean square of successive differences (LnRMSSD), subjective wellbeing, and Player Load were obtained each training day throughout a 4-week spring camp and 4 weeks of preseason training. SRC occurred within the first 2 weeks of the preseason. During spring camp and preseason pre-SRC, the athlete demonstrated minimal day-to-day fluctuations in LnRMSSD, which increased post-SRC (LnRMSSD coefficient of variation pre-SRC 3.1%, post-SRC = 5.8%). Moderate decrements in daily-averaged LnRMSSD were observed post-SRC relative to pre-SRC (Effect Size +/- 90% Confidence Interval = -1.12 +/- 0.80), and the 7-day rolling average fell below the smallest worthwhile change for the remainder of the preseason. LnRMSSD responses to SRC appeared similar to trends associated with stress and training fatigue. Therefore, performance and sports medicine staff should maintain regular communication regarding player injury and fatigue status so that HRV can be interpreted in the appropriate context. Detection and monitoring of autonomic dysregulation post-SRC may require near-daily assessment, as LnRMSSD showed greater daily fluctuations rather than chronic suppression following the head injury.
Effects of Acute Blood Flow Restriction Exercise on Metabolic Function in Untrained Individuals
(University of Alabama Libraries, 2024) Adams, Tiffany Leeann; Winchester, Lee J.
RE decreases the symptoms of metabolic disorders due to its ability to increase glucose disposal and uptake by myofibrils, thus, RT resulting in hypertrophy is beneficial for disease management. BFR can be a beneficial addition to an exercise protocol as it can induce hypertrophic gains with lower exercise loads and chronically can improve glucose uptake. An acute bout of RE with BFR in untrained individuals may have the ability to improve insulinogenic and glycemic regulation. PURPOSE: The purpose of this study is to determine the systemic effects of blood flow restriction exercise in untrained individuals on glucose uptake and utility, and insulinogenic response compared to a non-BFR session. METHODS: 11 non-resistance trained individuals participated in three laboratory visits in a randomized, crossover, repeated measures experimental design. After the first familiarization session, the proceeding exercise sessions included 4x15 body-weight air squats with control and BFR conditions. BFR was inflated to 60% LOP during exercise. Blood lactate (mmol/L), glucose (mg/L), and insulin (mU/L) concentrations were taken before and after exercise. RPE and perceived pain were collected at the end of each set. Data analysis was done in SPSS with a significance level of 0.05. RESULTS: There was a significant effect of time for blood lactate (p < 0.001), but no significant effect of condition. There was an effect of condition on the change in lactate (p < 0.05). There was no significance for any other variable. There was a significant effect of time (p < 0.001) and condition (p = 0.049) for RPE, but no significant interaction of time x condition. There was a significant effect for time (p < 0.001), condition (p = 0.002), and time x condition (p = 0.017) for pain. CONCLUSION: Lactate significantly increased in both conditions between resting levels and immediately post-exercise, and decreased post-exercise. Glucose and insulin had no significant changes over time or differences between conditions. These results indicate that a light-intensity RE with BFR, while fasted, produces similar metabolic outcomes as a session without BFR and does not produce any extreme glycemic or insulinemic changes while fasted in a healthy untrained population.
The effects of expectancy and autonomy on neural measures of motivation
(University of Alabama Libraries, 2019) Wilhelm, Ricardo; Gable, Philip A.; University of Alabama Tuscaloosa
Motivation drives humans to attain desired goals or objects by enhancing our attention, facilitating faster physical movement, and reinforcing behaviors that lead to goal acquisition. Behavioral and physiological studies find evidence for this effect by manipulating extrinsic motivation using pre-goal states and implementing rewards. Further research on motivation suggests intrinsic motivation also has similar behavioral effects to extrinsic motivation. The current studies examined whether performance expectancy and autonomy enhance motivation using behavioral and electroencephalography (EEG) measures. Study 1 manipulated performance expectations that a flanker task would be difficult or easy based on a social comparison. Study 2 manipulated autonomy by giving participants a choice of task and self-controlled feedback. Study 1 results revealed greater neural motor-action preparation and feedback processing to difficult (vs. easy) expectancy trials. Difficult expectancy also narrowed attention but did not reveal performance differences with RT. Participants also self-reported marginally greater high-approach motivation during difficult (vs. easy) expectancy. Study 2 results revealed no difference in neural motor-action preparation and feedback processing to autonomy (vs. no autonomy). Autonomy also broadened (rather than narrowed) attention. Autonomy also increased response times to a flanker task. Participants self-reported marginally more low-approach motivation during autonomy (vs. no autonomy). Taken together, results suggest not all forms of intrinsic motivation influence motivation in similar ways. Based on neural and behavioral measures, it seems performance expectancy enhances high motivational intensity, while autonomy enhances low motivational intensity.
The effects of interval walking on caloric expenditure
(University of Alabama Libraries, 2015) Mitchell, Jermaine B.; Bishop, Phillip A.; University of Alabama Tuscaloosa
Purpose: As obesity rates continue to rise in physically inactive individuals, modified training methods should be explored to address exercise adherence. The purposes of the proposed studies were to evaluate the effectiveness of interval walking, intermittent interval walking, and self-paced intermittent interval walking on oxygen uptake (⩒O_2) and excess post- exercise oxygen consumption (EPOC). Methods: In Study I and Study II participants completed a 30-min continuous walking protocol at a low-moderate intensity. Each protocol in these studies incorporated the same volume [90 metabolic equivalent-minutes (MET-min)] of exercise. Study I consisted of two interval walking protocols of cycled high-moderate and low-moderate intensities of 30-s work bouts and active recovery bouts of 60 and 120 s and total durations of 24-min-24-s (protocol 1) and 26-min-20-s (protocol 2). Study II consisted of three 10-min intermittent walking bouts of low-moderate intensities, three 8-min-40-s interval walking bouts of 30-s work bouts and active recovery bouts of 120 s, and three 8-min interval walking protocols of 30-s work bouts and active recovery bouts of 60 s. Study III assessed oxygen uptake before, during, and after continuous, intermittent, and intermittent interval walking of a self-regulated moderate RPE range (RPE 12-13), each totaling 30 min. Intermittent walking consisted of three 10-min bouts of walking and intermittent interval walking consisted of cycled 30-s high-moderate:120-s low-moderate intensity walking. Results: Study I: ⩒O_2 during interval walking was higher (p < 0.05) than during continuous walking; however, EPOC differed only between continuous walking and interval walking protocol 1 (p < 0.05). Study II: Compared to continuous walking, intermittent walking and both intermittent interval walking protocols elicited higher (p < 0.05) cumulative ⩒O_2 during exercise, and cumulative total 20-min EPOC values were higher as well (p < 0.05). Study III: Compared to continuous walking, both self-paced intermittent and intermittent interval walking protocols elicited higher cumulative ⩒O_2 during exercise periods and higher cumulative total 20-min EPOC values (all p < 0.05). Conclusion: These results indicate that moderate-intensity interval and intermittent interval walking protocols elicited higher exercise ⩒O_2 and EPOC compared with continuous walking of the same volume (90 MET-min) or duration (30 min).
The efficacy of subjective and objective indices of recovery during and following exhaustive resistance exercise
(University of Alabama Libraries, 2019) Tolusso, Danilo V.; Esco, Michael R.; University of Alabama Tuscaloosa
Monitoring recovery status within and between exercise sessions can optimize training adaptations. As such, it is critical that the tools we use to monitor recovery status are both valid and reliable. One such tool, perceptual recovery status (PRS), has been developed to assess recovery status between days of repeated sprinting exercise. Yet, few studies have investigated the validity of PRS as a marker of recovery between sets or days of resistance exercise, or how fatigue influences the stability of performance indices. We conducted three studies to address these gaps. Study 1 investigated the utility of PRS as a marker of daily recovery following a bout of resistance exercise. Performance tests and PRS were recorded as baseline, 24, 48, and 72 h following a fatiguing high-volume back squatting protocol. Strong correlations were revealed between PRS and countermovement jump, bar velocity, isokinetic knee extension, and isometric mid-thigh pull (r = .61 to .86; p < .001). Study 2 evaluated the validity of PRS as a marker of inter-set recovery using bar velocity metrics during a high-volume back squatting protocol. Peak and mean bar velocity, as well as their decrements within a set were calculated across 4 sets of back squat. Main effects for time were observed for PRS and mean bar velocity metrics (p < .05) where all metrics tended to decrease throughout the bout. Strong correlations were observed between PRS all bar velocity metrics (r = .55-.65; p ≤ .001). Study 3 investigated the influence of fatigue on the stability of performance indices following a single bout of resistance exercise. Daily recovery scores––calculated from performance tests recorded at baseline and again at 24, 48, and 72 h post-fatiguing protocol––were used to represent four different fatigue states (FS). Reliability analyses for each performance test revealed that intraclass-correlation coefficients (ICC) remained high (ICC > .79) and standard error of the measurement values were comparable regardless of an individual’s FS. Therefore, PRS can be used as a subjective metric of recovery between sets and days of exercise and FS does not affect the stability of objective performance metrics.
Electromyographical Comparison of a Traditional, Suspension Device, and Towel Pull-Up
(De Gruyter, 2017) Snarr, Ronald L.; Hallmark, Ashleigh V.; Casey, Jason C.; Esco, Michael R.; Georgia Southern University; University of Alabama Tuscaloosa
Strengthening muscles of the back may have various implications for improving functions of daily living, aiding in the transfer of power in throwing, and assist in injury prevention of the shoulder complex. While several versions of the pull-up exist, there is currently no literature comparing their differences. The purpose of this investigation was to compare the electromyographical activity of the latissimus dorsi, posterior deltoid, middle trapezius, and biceps brachii while performing three variations of the pull-up. Resistance-trained men and women (n = 15, age = 24.87 +/- 6.52 years) participated in this study by performing traditional pull-ups, suspension device pull-ups, and towel pull-ups in a randomized fashion. Each pull-up was performed for three repetitions with a 1.5 biacromial grip-width for each participant. Normalized (%MVC) electromyographical values were recorded for each muscle group during each pull-up variation. No significant differences existed within the latissimus dorsi, biceps brachii or posterior deltoid between any of the exercises. For the middle trapezius, towel pull-ups provided significantly lower muscle activity than the traditional pull-up, while no differences between suspension pull-ups and the other variations occurred. In conclusion, only one muscular difference existed between the exercise variations and all versions examined provided electromyographical values, determined by current literature, to invoke a sufficient stimulus to promote increases in muscle strength and hypertrophy. Although further research is needed, practitioners can be confident when programming any of the movement variations examined when attempting to elicit adaptations of muscular strength and hypertrophy.
Evaluation of HRV as a predictor of response to a modified physical training program in ROTC cadets
(University of Alabama Libraries, 2016) Allen, Kimberly Elizabeth; Bishop, Phillip A.; University of Alabama Tuscaloosa
Continually enhancing military personnel training is essential in order to prepare soldiers to perform optimally. The soldier’s ability to perform may be closely associated with baseline autonomic nervous system activity, indicated by heart rate variability (HRV). Variability in heart rate may be related to results on the Army Physical Fitness Test (APFT). PURPOSE: The purpose of this study was to determine if ROTC cadets’ APFT scores would improve following a novel 8-week training program, if performance on the APFT was related to baseline HRV, and if training adaptations in APFT performance were related to changes in HRV. METHODS: Twenty ROTC cadets (age 20 ± 1 yr) were evaluated on APFT at baseline, 4 and 8-weeks. A subset of 13 cadets completed HRV recordings using a validated smartphone application immediately upon awakening. The initial 3-days of HRV recordings served as baseline HRV. A subset of 8 cadets recorded HRV after the 4th week APFT through the end of the 8th week. An average of 3 readings at the beginning and end determined ΔHRV, and week 4 and 8 scores were subtracted to get ΔAPFT. RESULTS: APFT scores significantly improved in all fitness measures over the 8-week training program. Baseline HRV was moderately correlated with performance in each event, except for push-ups. Change in HRV and change in APFT scores from week 4 to week 8 was not significantly correlated. CONCLUSION: A periodized, progressive overload program significantly improved APFT scores. A trend towards moderate to strong correlations were found between performance tests and HRV, though they were not all significant in this sample size.
Evaluation of Methods for Determining Various Components of Body Composition
(University of Alabama Libraries, 2020) Cicone, Zackary; Esco, Michael R.; Fedewa, Michael V.; University of Alabama Tuscaloosa
Doubly indirect methods of assessing body composition are commonly used in laboratory and practical settings. The purpose of this dissertation was to expand upon the methodological discrepancies associated with various techniques, and to provide improved equations to overcome these limitations. A series of three studies was conducted to 1) improve the estimation of underwater residual lung volume (RLV), 2) systematically review and quantify the error associated with single-frequency bioimpedance analysis (SFBIA) for the determination of total body water (TBW), and 3) develop a novel equation for predicting percent body fat (%BF) from skinfolds using a criterion multi-compartment model. The first study developed an equation for the prediction of underwater RLV in healthy adults using age and height as predictor variables. The new equation produced superior validity statistics upon cross-validation compared to four existing equations, indicating that it may be used by practitioners to accurately estimate underwater RLV during hydrostatic weighing. The second study systematically reviewed and meta-analyzed 264 effects from 51 original studies designed to compare SFBIA to criterion dilution methods for TBW estimation. Although a non-significant overall effect was identified, there was significant variability associated with SFBIA methodology (i.e., frequency and resistivity index) and sample sex (% female). Moderator analyses indicated that SFBIA procedures utilizing Ht2/R at 100 kHz produced the most accurate estimate of TBW when compared to isotope dilution techniques. The third study developed a skinfold-based equation for the prediction of five-compartment model %BF in a sample of healthy adults. The new equation outperformed selected existing equations when cross-validated, indicating its potential utility for practitioners concerned with obtaining accurate estimates of %BF in the general population.
Evaluation of selected field and laboratory measures of body composition
(University of Alabama Libraries, 2016) Nickerson, Brett Stephen; Esco, Michael R.; Bishop, Phillip A.; University of Alabama Tuscaloosa
The four-compartment (4C) model is a laboratory method that is a valid method for the assessment of body composition. Three experiments were performed to 1) determine the validity of selected bioimpedance equations with the 4C model, 2) determine the impact of predicted vs. simultaneous residual lung volume (RLV) during underwater weighing (UWW) on the 4C model, and 3) develop a new body fat prediction equation. In the first study, subjects had body fat percentage (BF%) and fat-free mass (FFM) predicted from four bioelectrical impedance equations and compared to the 4C model. Three equations produced a significant mean difference, while another was non-significant. However, all four equations had a small standard error of the estimate (SEE) and fairly narrow limits of agreement. In a second study, RLV was measured simultaneously and predicted when determining UWW and 4C model BF%. The mean differences for UWW BF% was significant when comparing predicted vs. simultaneous RLV, but non-significant when the body density values derived via UWW were incorporated in the 4C model. The error was lower when using RLV prediction equations for determining BF% via the 4C model than UWW. In a third study the variables sex, body mass index (BMI), sum of combined handgrip strength, and vigorous physical activity was utilized in a regression equation to predict 4C model BF%. The new BF% equation, previous BMI-based BF% equations and skinfolds were compared to the 4C model. The new equation and BMI-based equations had significantly different BF% values and provided large 95% limits of agreement. Similarly, skinfolds had a significant mean difference, but the SEE was 3.7%, leading to the recommendation of skinfolds over the new equation and BMI-based equations. In conclusion, BIA equations can be used in the field, but practitioners should consider the tendency of the equations to over-predict BF% and under-predict FFM. Furthermore, the prediction of RLV can be used for the UWW procedure when determining 4C model BF%, but should not be used for UWW BF% alone. Lastly, the new BF% equation and BMI-based equations did not compare favorably with 4C model and the use of skinfolds is recommended.

Browsing by Author "Esco, Michael R."

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