Theses and Dissertations - Department of Kinesiology

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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.
Anxiety and affective responses to acute bouts of moderate intensity exercise (walking): effects of varying durations
(University of Alabama Libraries, 2015) Geary, Colleen Louise; Richardson, Mark T.; University of Alabama Tuscaloosa
Anxiety affects approximately 40 million American adults each year (Kessler, Chiu, Demler, and Walters, 2005; National Institute of Mental Health [NIMH], 2009). However, the dose-response research investigating the antianxiety and affective benefits of acute bouts of exercise indicates that multiple dose-response issues remain unresolved. The purpose of this study was to investigate the anxiolytic and affective responses following an acute bout of moderate intensity walking of different durations (30, 10 and 5 minutes) on a moderately fit, non-clinically anxious population. This study also sought to test the duration of effect by assessing post-exercise responses immediately and at 20 and 40 minutes post-exercise. This is the first study to include the analysis of four specific covariates (trait anxiety, fitness level, enjoyment of activity, and sex) when examining psychological responses to walking. One of the main findings of the current investigation was that a main effect of time was observed for the majority of variables. While some measures showed favorable (anxiety, tense arousal, calmness, tension, tranquility, physical exhaustion, affective valence, and revitalization) other measures ultimately showed unfavorable (positive affect, perceived activation, energetic arousal, energy, and positive engagement) responses following the cessation of exercise. Secondly, although several measures were affected by exercise duration (tranquility, physical exhaustion, and affective valence), the majority were not. Finally, of the four covariates, only fitness (positive affect, energetic arousal, and energy) and sex (positive affect, revitalization, energy, and calmness) influenced the exercise-affect relationship.
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.
Beverage choice impact on hydration and performance for the recreational athlete
(University of Alabama Libraries, 2010) O'Neal, Eric Kyle; Bishop, Phillip A.; University of Alabama Tuscaloosa
Three studies examined hydration and performance for recreational exercisers (REC). Three beverages (flavored caloric (CE) and non-caloric (NCE) electrolyte-containing sport drinks and water (W)) were served to male (n = 24) and female (n = 14) REC in a counter-balanced order during 1-h of moderate intensity cycling (mean ± SD heart rate = 146 ± 4 beats/min) in an environment of 25° C wet bulb globe temperature. The volume of beverage served was equal to sweat loss measured (mean ± SE = 834 ± 59 mL) in a familiarization trial with no fluid intake during exercise. No differences (p > .05) among beverages were found in: performance (peak and mean power) during a set of three Wingate Anaerobic Tests completed after cycling, perceived exertion, or mood states among beverages. After exercise in the familiarization trial with no fluid intake, participants drank ad libitum for 30 min with all beverages available. Consumption volume among beverages did not differ (p > .05). Participants reported that replacing 100% of sweat loss was an appropriate volume and did not result in stomach discomfort for the majority of individuals in fluid intake during exercise sessions. Total intake in the familiarization session when fluids were consumed in recovery only (mean ± SD, 971 ± 375 mL) was less (p < .001) than when consumed during both exercise and recovery (W (1,415 ± 560 mL,), NCE (1,244 ± 538 mL, p < .001), and CE (1,196 ± 444 mL), and W was greater than CE (p = .01)). The survey found decreased performance (69%) and heat-illness (45%) believed to be related to dehydration among runners was very common. Almost all (94%) of participants (n = 276) reported drinking during outdoor runs in warm weather. Faster higher volume runners believed that consuming sport beverages would result in improved performance and better hydration than water. For REC exercising for ~1 h, replacing sweat loss during exercise and drinking ad libitum afterwards, should result in a fluid intake level that will return body mass close to pre-exercise level, be tolerable, and result in no decrease in performance when W or CE are used instead of CE.
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.
Cardiovascular and themoregulatory responses to ice slurry ingestion during heat stress
(University of Alabama Libraries, 2015) Ng, Jason; Wingo, Jonathan E.; University of Alabama Tuscaloosa
Fluid ingestion has been reported to influence cardiovascular and thermoregulatory function, thereby affecting exercise performance. It remains unclear whether ice slurry ingestion during exercise results in similar effects. Three experiments examined thermal-, cardiovascular-, and exercise-related responses to ice slurry ingestion. In the first study, participants in firefighter protective clothing walked at ~7 METs in 35 °C while ingesting carbohydrate-electrolyte beverages as a tepid fluid, cold fluid, and ice slurry in a counterbalanced repeated measures study design. When ingested in large quantities and during uncompensable heat stress, ice slurry ingestion mitigated physiological strain by attenuating the rise in heart rate and rectal temperature. In a second study, cardiovascular drift (CV drift) was measured during 45 min of cycling at 60% maximal oxygen uptake (V̇O2max) in 35 °C, immediately followed by measurement of V̇O2max. Participants ingested fluid and ice slurry during two counterbalanced trials of exercise. CV drift was attenuated with ice slurry ingestion but V̇O2max was unaffected. In a third study, participants ingested ice slurry or cold fluid ad libitum while cycling at 50% maximal workload in 35 °C, immediately followed by a 15-min time trial during which participants completed as much work as possible. Compared to the fluid treatment, participants consumed half as much ice slurry, but total work completed during the time trial was not different. In conclusion, ice slurry ingestion blunts physiological strain during conditions in which evaporative heat loss is impaired, such as when wearing occlusive coverings. Furthermore, ice slurry ingestion attenuates the magnitude of CV drift during exercise in the heat, but this does not blunt the decrease in V̇O2max associated with exercise in hot conditions. Lastly, a smaller quantity of ice slurry is voluntarily ingested compared to cold fluid during prolonged submaximal exercise in the heat, but this does not differentially affect exercise performance.
Clothing fabric effects on physiological and comfort responses
(University of Alabama Libraries, 2011) Balilionis, Gytis; Bishop, Phillip A.; University of Alabama Tuscaloosa
During exercise and in hot environments, the main cooling mechanism is through sweat evaporation. However, clothing can disrupt evaporation, which leads to decreased performance and in some cases can lead to heat illness. New fabrics and designs have been introduced with the purpose of improving thermoregulatory properties. One of those innovations is a channeled synthetic fabric. The first of three studies evaluated the effects of a channeled synthetic and synthetic t-shirts under a ballistic vest on physiological and comfort responses during exercise in a hot environment. Eight participants, in counterbalanced order, completed two simulated "industrial" protocols for three hours. The overall (0 - 180 min) change in rectal temperature was significantly (p = 0.04) lower with channeled synthetic shirt compared to a synthetic shirt. Additionally, overall change in thermal comfort (p = 0.05), sweating sensation (p = 0.06), and heart rate (p = 0.07) were, or tended to be more favorable throughout exercise with channeled synthetic compared to synthetic shirt. We also examined the effects of channeled synthetic shirt and synthetic cycling shirt effects on thermoregulation, thermal comfort, and heart rate. Eight participants attempted a 30-km cycling time trial. Results indicated significantly (p = 0.04, n = 8) smaller increase in rectal temperature from baseline to 15th km (first dropout) with the channeled synthetic shirt compared to cycling shirt. Also, the change in thermal comfort was significantly (n = 5, p = 0.03) lower with channeled shirt compared to cycling shirt from baseline to 30th km. A third study examined channeled compression shorts, compression shorts, and cycling shorts effects on thermoregulation, heart rate, and thermal comfort response during 30-km cycling trial in hot a environment. Eight participants completed a 25-km cycling trial. Results revealed no significant main effect for rectal or skin temperatures, heart rate, and thermal comfort between the three different types of shorts (n = 8, p > 0.05). In conclusion, wearing a channeled synthetic shirt provided better thermoregulatory or thermal comfort responses compared to synthetic shirt in two studies. Channeled compression shorts did not improve thermoregulatory or thermal comfort responses compared to cycling and compression shorts.
Effect of different warm-ups and upper-body vibration on performance in Masters Swimmers
(University of Alabama Libraries, 2009) Nepocatych, Svetlana; Bishop, Phillip A.; University of Alabama Tuscaloosa
ABSTRACT The purpose of the study was to evaluate the effects of no, short, or regular warm-up and Upper-Body Vibration (UBV) only or UBV+ short warm-up on swimming performance in Masters Swimmers. Six females and four males, aged 24-50, healthy master swimmers volunteered to participate in the study. Participants completed all assigned warm-ups (no, short, regular, UBV-only, or UBV + short) in counterbalanced order, rested for three minutes and completed a 50-yard (45.7 m) freestyle maximal performance time trial. Rating of perceived exertion (RPE) and heart rate (HR) were measured post warm-up and post 50-yd time trial. No significant difference (p = 0.987) was found among no, short or regular warm-up regarding 50-yd freestyle time (29.0 ± 3.7, 29.0 ± 3.6, and 29.1 ± 3.4 s, respectively). No significant difference (p = 0.563) was found among regular, UBV-only or UBV + short warm-ups regarding 50-yd freestyle time (29.1 ± 3.6, 28.9 ± 3.4, and 29.1 ± 3.6 s, respectively). RPE after no warm up (6 ± 0) was significantly lower compared to after short (13 ± 2, p < 0.001) or regular warm-up (12 ± 2, p < 0.001). RPE after regular warm-up was higher (12 ± 2) compared to UBV-only warm-up (9 ± 2), approaching statistical significance (p = 0.059). RPE post 50-yd for no, short or regular warm-up and after regular, UBV-only or UBV + short were not significantly different (p =0.76, p = 0.216). HR after no, short or regular warm-up before 50-yards was not significantly different (p = 0.062); however, a significantly higher (p = 0.023) HR was observed after regular warm-up (88 ± 15 b/min) compared to UBV + short (75 ± 9 b/min). HR post 50-yd after regular warm-up (148 ± 15 b/min) was significantly higher compared to no (136 ±20 b/min) p = 0.001, UBV-only (139 ± 12 b/min) p = 0.005 and UBV + short ( 138 ± 14 b/min) p = 0.013, but not short (142 ± 17 b/min) warm-up (p = 0.077). In conclusion, Master Swimmers may perform the same or better with no or short and UBV-only or UBV + short, compared to regular warm-up.
Effect of intermittent cooling on baseball pitching and catching
(University of Alabama Libraries, 2012) Bishop, Stacy Howard; Bishop, Phillip A.; University of Alabama Tuscaloosa
Cryotherapy has been shown to be an effective method for reducing edema and inflammation, decreasing pain in acute injury, and is being studied as an aid in recovery. The traditional recovery treatment between innings for pitchers and catchers is to rest in the dugout. In this study, pitchers (n = 8) threw two simulated games separated by 5-7 days for recovery. Participants were given 4 min of intermittent arm and shoulder cooling treatment (AC) or no cooling (NC) in between each of 5-simulated innings. Pitchers that received NC had a significant decrease in velocity over the 5 innings (4%); by contrast, pitchers that received AC maintained pitching velocity (p = 0.04) (all-innings mean velocity 31.2 ± 2.1 m*s−1 versus 30.6 ± 2.2 m*s−1). Average pitch speed in the 4th inning and 5th inning was significantly faster for AC (31.3 ± 2 m*s−1 and 31.3 ± 2 m*s−1) compared to NC (30 ± 2 m*s−1 and 30.4 ± 2 m*s−1, p= 0.04), respectively. Additionally, AC resulted in significantly lower perceived exertion (RPE) (p = 0.01) and improved perceived recovery (PRS) (p = 0.01) compared to NC in a temperate environment. In catchers (n = 6), torso cooling (TC) resulted in a significantly lower RPE (p = 0.01) and improved PRS (p = 0.01) compared to NC. Significantly lower mean recovery HR was seen during the TC treatment compared to NC in the 5th (84 ± 8 vs. 90 ± 9 bpm, p = 0.04), 7th (84 ± 3 vs. 92 ±7 bpm, p = 0.02), and 9th (85 ± 7 vs. 93 ± 5 bpm, p = 0.01) innings. Increase in rectal temperature was smaller in TC compared to NC (0.58 ± 0.20 ºC vs. 0.98 ± 0.20 ºC, p = 0.01). Working HR was significantly lower at the end of the TC when compared to NC (108 ± 16 vs. 120 ± 19 bpm, p = 0.02). Cryotherapy improved recovery during baseball pitching and catching, attenuated a decrease in pitching velocity as well as attenuated core temperature increases in catchers.
Effect of whole-body vibration on acute recovery after fatiguing exercise
(University of Alabama Libraries, 2011) Nepocatych, Svetlana; Bishop, Phillip A.; University of Alabama Tuscaloosa
High-intensity intermittent or resistance activity for a short period of time causes an increased break down of energy stores and accumulation of metabolic by-products. Increased metabolic disturbances may lead to decreased muscle contractile function which eventually will lead to muscle fatigue. Sufficient recovery time is needed for optimal competitive performance and optimizing the ability to tolerate high-intensity, various lengths and duration training loads. There are a number of recovery modalities available that have been used between training sessions, pre- and post- training, and between competitions. In order to evaluate vibration as a recovery aid that contributes to improved performance, three studies were conducted. The first study evaluated the effects of whole-body vibration (WBV) and WBV plus cooling on lower-body peak and mean anaerobic performance, leg volume, perceived recovery, and muscle soreness. The second study evaluated the effects of WBV and upper-body vibration (UBV) on upper-body performance, perceived recovery and muscle soreness, and the third study evaluated the effect of WBV on sprint performance, leg volume and perceived recovery. Healthy and physically active male and female volunteers participated in the studies. In a repeated measures, counterbalanced design, participants completed fatiguing exercise, each recovery treatment and performance test. As indicated by the group mean data, results of the first study suggested possible psychological but not performance enhancing benefits after the use of WBV and WBVC as a recovery method. The findings of the second study suggest no psychological or physiological benefits using WBV and UBV as a recovery modality. The results of the third study suggest no benefits for WBV in enhancing recovery or sprint performance. However, while actual recovery was not enhanced, perceived recovery was better after WBV compared to no vibration. Even though actual recovery or performance was not enhanced by the addition of WBV to the recovery, psychological perception of better recovery may be of some benefit for training or competition. It appears that acute exposure to WBV does not enhance performance under the conditions of this study.
Effects of bunker gear temperature and different work rates on micro-E and heat stress
(University of Alabama Libraries, 2015) Hornsby, Jared Heath; Bishop, Phillip A.; University of Alabama Tuscaloosa
Wearing protective clothing (PC) such as firefighter bunker gear leads to increased heat strain. Bunker gear has multiple layers which creates a heat sink during the first several minutes after donning, potentially providing some amount of cooling of the micro-environment (micro-E) around the skin. Furthermore, predicting heat strain at various work rates while wearing PC is important for determining work tolerance limits. The purpose of these studies was to determine the effect of a COLD (< 0 °C) bunker gear on rectal temperature (T_re ) and micro-E at a steady-state exercise intensity and to begin creating a regression model to predict micro-E temperature and relative humidity under bunker gear based on work rate. Studies I and II utilized a repeated-measures randomized experimental design, which consists of 4 trials (LO, MOD, HI (HOT), and HI (COLD)). Human volunteers wore bunker gear for 30 min while oxygen uptake (V̇O_2), heart rate, perceptive measures (ratings of perceived exertion, thermal sensation, sweating sensation, and clothing comfort), T_re, skin temperature, and micro-E (temperature and relative humidity at the anterior and posterior portion of the jacket and pants) were measured. A repeated measures MANOVA with a Bonferroni post hoc analysis was used to evaluate: the physiological measures; while the Friedman's Test was performed with a Wilcoxon Signed Rank Test on all perceptual measures. The COLD bunker gear did not significantly alleviate heat strain when compared to HOT bunker gear. Additionally we low, moderate and high intensities of work in ~ 29 °C macro-E WBGT did not differentially affect micro-E WBGT under bunker gear, and these data were used to derive models of micro-E from macro-E. Further data is needed to cross-validate the derived micro-E WBGT model predicted from macro-E WBGT and work rate.
Effects of different types of warm-up on swimming performance in collegiate swimmers
(University of Alabama Libraries, 2009) Balilionis, Gytis; Bishop, Phillip A.; University of Alabama Tuscaloosa
The purpose of the present study was to evaluate the effect of three different types of warm-up on swimming performance in NCAA Division I swimmers. Eight male and eight female swimmers utilized three warm-up protocols prior to performing 50-yard (45.72-meter) freestyle swim trials each trial in counterbalanced order and separated by 48 hours. The warm-up protocols consisted of: (1) no warm-up, (2) short warm-up (50-yards at 40% maximal effort and 50-yards at 90%), (3) regular warm-up (swimmers own pre-competition warm-up). Following the warm-up regimen, participants rested for three minutes and completed a 50-yard freestyle swim trial. Heart rate pre- and post- trial, diving distance, reaction time, post warm-up RPE, post 50-yard trial RPE, and stroke count were measured. Times for 50-yard swim were significantly (p = 0.03) different among warm-ups. Mean 50-yard time was significantly (p = 0.01) faster after regular warm-up (24.95 ± 1.53 sec) compared to short warm-up (25.26 ± 1.61 sec) and approached significance between no- and regular- warm-ups (p = 0.06); however, no significant difference was found between no- (25.19 ±1.54 sec) and short warm-ups (p = 0.59) on 50-yard time. Individual data indicated that 19% of participants performed their best 50-yard time after short warm-up, 37% after no-, and 44% after regular warm-up. Heart rate was significantly (p = 0.01) higher after regular warm-up (100 ± 13 b/min) compared to no warm-up (88 ± 18 b/min) and approached significance between short- and regular warm-ups (p = 0.07); however, no significant difference was observed between no- and short warm-ups (92 ± 19 b/min) (p = 0.32). RPE was significantly (p <0.001) lower after no warm-up (6.3 ± 0.5) compared to short warm-up (10.1 ± 1.7) and regular warm-up (12.1 ± 1.0). No significant difference was found in reaction time (p = 0.96), RPE post 50-yard time trial (p = 0.11), dive distance (p = 0.67), and stroke count (p = 0.23) among warm-ups. In conclusion, regular warm-up was better than short warm-ups to achieve the fastest mean 50-yard freestyle time but individuals differed in their response to different warm-ups.
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).
Energy cost and thermal contribution of components of protective firefighter gear
(University of Alabama Libraries, 2009) Casaru, Catalina; Bishop, Phillip A.; University of Alabama Tuscaloosa
Firefighter turn-out gear negatively impacts firefighters' ability to dissipate heat and increases energy expenditure consequently decreasing work tolerance and efficiency. The purpose of this study was to determine the contribution of individual components of firefighter turn-out gear to the energy expenditure and heat retention during work in a hot environment. Male participants (n=8) (Mean ± SD: 24.8 ± 2.6 yr, 73.1 ± 9.8 kg, 181 ± 4 cm, 57.3 ± 8.8 ml*kg⁻¹*min⁻¹ VO₂ max) worked for 40 min (12 min walk followed by 3 min of 10 arm curls) on a treadmill at a speed and grade eliciting 50% of VO₂ max in a heat chamber (WBGT: 33°C, RH: 40-45%) while wearing firefighter turn-out gear and a breathing apparatus (SCBA). Energy expenditure was measured during work to assess the energy costs of five firefighter turn-out gear configurations (full gear, trousers, coat, SCBA alone, and peripherals: helmet, hood and gloves (HHG)). Mean walking and arm-curl VO₂'s were not significantly different (p > 0.05) among any of the gear combinations. Mean delta (T₄₀-T₀) heart rate (ΔHR) was significantly higher (p = 0.01) for full gear (85 ± 25 beats*min⁻¹) compared to trousers (53 ± 16 beats*min⁻¹), SCBA (57 ± 13 beats*min⁻¹), and HHG (58 ± 17 beats*min⁻¹). In addition, mean delta body core temperature (ΔTre) was significantly higher (p < 0.05) for full gear (1.4 ± 0.4°C) compared to coat (0.8 ± 0.3°C), SCBA (0.8 ± 0.4°C), and HHG (0.8 ± 0.2°C). Ratings of Perceived Exertion (RPE) were significantly higher (p < 0.05) for full gear (9 ± 3) compared to trousers (6 ± 2), coat (6 ± 3), and HHG (6 ± 2). Each component of the firefighter turn-out gear similarly increased VO2 and hampered heat dissipation in a hot and humid environment. Although, the SCBA accounted for over half of the total weight of the firefighter gear, it made a similar contribution to the thermoregulatory demands as other pieces of equipment. Availability of lighter and safer protective clothing and SCBA could reduce physiological stress and potentially improve rescue time, but there appear no clear advantages to improving any particular piece of gear.
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 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.
Firefighter thermoregulation: clothingfit, cognition, and menthol
(University of Alabama Libraries, 2014) Casaru, Catalina; Bishop, Phillip A.; University of Alabama Tuscaloosa
The multilayered firefighter turn-out gear is not only restrictive to movement but also contributes to increased body rectal temperature, heart rate, and skin temperature by trapping moisture and heat between the layers of the clothing. Firefighter gear fitting more loosely than needed may result in more clothing "pumping," which might result in a more favorable micro-environment during some phases of firefighting. Because of the potential for impaired cognition of the firefighters under stressful conditions, heat stress, and limited time to save victims, it is imperative to understand when cognition is compromised. Recent menthol studies have found a reduced sweat rate when menthol was applied. Firefighters could benefit from a delay in sweat rate because sweating in the high humidity of the micro-environment may lead to hypohydration without the benefit of cooling. The present study had three purposes: 1) to evaluate firefighter gear fit (loose and regular); 2) to assess cognitive responses to 30-minute exposures in 21 °C and 33 °C and 60% RH; and 3) to assess the effects of menthol skin application on local sweat rate in 33 °C. Ten healthy volunteers participated in three trials of 30 minutes each at 21 °C (control, regular fit, loose fit) and three trials at 33 °C (control, regular fit, loose fit). At the beginning and the end of each trial, participants were tested with three cognitive tests: Reaction Time (RT), MATH (MATH), and Memory (MEM). During the menthol study, ten participants exercised twice (menthol and no-menthol treatments, counterbalanced) for 30 minutes followed by 20 minutes passive recovery and then 30 minutes of exercise in 33 °C while wearing firefighter gear. Loose and regular fit had no significant effect (p > 0.05) on firefighters. Individual positive and negative responders were found for cognitive scores based on LSD. Menthol treatment had no effect (p > 0.05) on thermoregulation or sweat production rate. Additional studies are needed to assess the effects of firefighter gear fit and cognition after multiple exposures to heat. In addition, further investigation is needed to assess the effects of a higher menthol concentration on the skin.
Impact of heat stress and cooling strategies on body temperature and performance in elite tennis players
(University of Alabama Libraries, 2017) Crew, Kermit Ray; Esco, Michael R.; Bishop, Phillip A.; University of Alabama Tuscaloosa
Tennis matches are intense, of long induration, with brief recovery periods, played in hot environments. This subjects elite tennis athlete to heat stress. Whether high core temperature impacts performance, and whether performance decrements are attenuated with cooling, remains unknown. Three studies evaluated heat stress on rectal temperature (Tre), skin temperature (Tsk) and shot accuracy (SA) after performing high intensity exercise at 22 °C and 38 °C and relative humidities of 31% and 38% respectively. Study 1 compared Tre, Tsk, SA in a temperate environment (TE) and a hot environment (HOT). HOT trial Tre (38.5 ± 0.4 °C) and Tsk (35.0 ± 1.6 °C) were higher than TE (37.8 ± 0.7 °C and 32.0 ± 1.3 °C, respectively). SA decreased (p = 0.003) between TE [57.5 ± 17.9 au out of 100] and HOT (33.4 ± 4.0 au), with greatest reduction in players with highest scores. Study 2 examined cooling of abdominal walls and thighs during rest periods and recovery on Tre, SA. Tre increased between start and end of both trials (p < 0.008). Treatments didn’t mitigate increased Tre. Treatment SA increased (p < 0.05). Study 3 evaluated continuous cooling device (vest) plus ice-pack applications on thighs, during rest periods in the high intensity protocol and recovery in hot condition verses control on Tre, SA. A significant time by condition effect for Tre (p < 0.05). Tre at end of high intensity protocol in control was 38.3 ± 0.6 °C. Tre at end recovery in control was 38.4 ± 0.4 ° C. No difference between Tre at start of treatment condition (37.5 ± 0.6 °C) and end of high intensity exercise (38.0 ± 0.7 °C). Tre at the end of recovery (37.0 ± 1.4 °C) was lower than Tre at end of high intensity exercise (p < 0.008). Tre at the end of recovery in control was higher than Tre at end of recovery in treatment. SA increased in treatment condition versus control [(p < 0.05) and large effect size (Cohen’s d = 1.38)]. Combined cooling mitigated the rise of Tre and increased SA in elite tennis athletes.
Implementation and evaluation of a physical activity intervention for rural children using a community based participatory research approach
(University of Alabama Libraries, 2015) Hamilton, Kara Cook; Higginbotham, John C.; Richardson, Mark T.; University of Alabama Tuscaloosa
Background: Physical inactivity is a leading cause of obesity in the United States, largely contributing to the increased risks of disease and premature death in this country. Effective physical activity interventions are needed for children since health behaviors track into adulthood and risk factors for diseases begin early in life. One approach that has been proven effective when devising interventions and research strategies is called Community Based Participatory Research (CBPR). Objective: The objective of this investigation was to determine if a CBPR intervention increased moderate-to-vigorous physical activity (MVPA) and decreased sedentary behavior in 10-11 year old children residing in a rural community in Alabama. Methods: This investigation included: 1) Leading a group of children (n=12) through a Photovoice project; (2) Designing a physical activity video intervention guided by the themes that emerged during the Photovoice project, and that featured members of the community as educators; and (3) Implementing the 4-week video intervention and evaluating psychosocial constructs related to physical activity and determining if this led to concomitant improvements in physical activity behavior (Actigraph, wGT3X-BT, Pensacola, FL) pre-to-post intervention. Results: Follow-up measurements of the psychosocial constructs were significantly higher compared to baseline measures for the intervention group (p<0.05). Participants in the intervention group (n=18) had higher delta scores for skills (t=2.45, p=0.020) and knowledge (t=4.71, p<0.001) with respect to the comparison group (n=19). Follow-up MVPA of the intervention group (30±18.5 min) was significantly higher than the comparison group (18.2±12.1 min) (t=2.17, p=0.037). Baseline MVPA did not differ between groups. There were no significant differences within or between groups for sedentary behavior. A regression model adjusting for known moderators was significant (F=7.91, p<0.001), and indicated that group (intervention vs. comparison) was a significant predictor of MVPA (Beta= 0.405, p=0.019). Conclusion: Following the intervention, the intervention group’s MVPA was 43% higher than the comparison group. MVPA remained relatively stable for the intervention group from pre-to-post, while a decreasing MVPA trend was evident in the comparison group. Physical activity interventions such as the one in this project may be an effective tool, favorably impacting physical activity levels of rural children in Alabama.
The involvement of norepinephrine, neuropeptide Y, and endothelial nitric oxide synthase on cutaneous vascular responses to local skin warming
(University of Alabama Libraries, 2012) Sparks, Paul Agnew; Hodges, Gary J.; University of Alabama Tuscaloosa
We investigated the role of endothelial nitric oxide synthase (eNOS), norepinephrine (NE), and neuropeptide Y (NPY) in cutaneous vasodilation in response to local skin warming. In a two part study, we used four treatment sites on the skin of the forearm for insertion of microdialysis fibers, and placement of local skin heaters and laser-Doppler probes. We allowed an hour and a half for needle trauma resolution. We recorded 10 min of baseline data, begin drug perfusion for 50 min to ensure full receptor antagonism (alpha, beta, Y1) and enzyme inhibition. In both parts of the study, the local warming protocol was such that local skin temperature was increased from 33 to 42 °C at 0.5 °C * 15 s-1. In Part 1 of our study, we used three sites for drug treatment 1) L-NAA (eNOS inhibition), 2) Yohimbine (YOH) and Propranolol (PRO) (alpha- and beta-receptor antagonism), 3) a combination site (L-NAA+YOH+PRO), 4) untreated site for control. Treatments resulted in a reduction of vasodilation (P < 0.05) that did not differ (P > 0.05) from each other. In study 2 the same test procedure was utilized, with four treatment sites: 1) L-NAA, 2) BIBP (antagonize Y1-receptors), 3) L-NAA+BIBP, 4) control site. Treated sites resulted in a reduction (P < 0.05) of the vasodilator response when compared to control sites; again treatments did not differ (P > 0.05) from each other. These data indicate that NE and NPY are working via eNOS in cutaneous vasodilator response to local skin warming.

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