Exercise and Human Performance (EXHP): Student Scholarship

Introduction: Cardiovascular risk factors such as hypertension, abdominal obesity, and high body fat are associated with sedentary behavior and lack of physical activity (PA). Some studies have shown that increasing PA, specifically in the form of increasing number of steps per day, can lower cardiovascular risk factors such as blood pressure (BP) and waist circumference (WC). Methods: This 4-week PA intervention will analyze the effects of increased daily steps on BP, WC, and body fat percentage in 11 healthy adults currently taking fewer than 10,000 steps per day. A baseline week of daily steps will be measured using a pedometer and a daily average will be calculated. Baseline BP, WC (measured in duplicate at the level of the umbilicus), and body fat (measured using InBody 570) will be obtained. Participants will then be asked to increase their average daily steps by 3,000 for 4 weeks while maintaining all usual dietary and activity habits. BP, WC, and body fat will then be reassessed. The data collected will be analyzed using dependent sample t-tests. Hypothesis: We hypothesize that an increase in daily PA will significantly lower BP, WC, and body fat over the course of the intervention. Discussion: Previous research has demonstrated that a modest, short-term increase in PA may lead to improved markers of cardiovascular health in the average sedentary adult. We aim to contribute to this body of knowledge through our intervention examining the effects of increasing PA by 3,000 steps per day.

Proteases aid in the hydrolysis of proteins into smaller peptides and oral protease supplementation may alter the endocrine response to exercise, promoting improved recovery. Purpose: To determine if protease supplementation immediately after an exercise session influences circulating testosterone, cortisol, insulin, insulin-like growth factor-1 (IGF-1), and growth hormone (GH) concentrations. Methods: Ten resistance-trained males (24.1±4.1yr, 69.6±6.8 kg 179±8.6 cm) completed 3 acute lower-body resistance exercise sessions consisting of 4 sets of leg press and leg extension exercises in a randomized, crossover fashion. Each exercise was performed at 75% of each participant’s previously determined one repetition maximum, for 8-10 repetitions, with 90 seconds of rest between sets. Following exercise, participants consumed one of 3 treatments (W: 26g whey; PW: 26g whey + 250mg of a protease enzyme blend; PL: non-caloric control). Blood draws were obtained at baseline (BL), immediatelypost (IP), 1-hour (1H) and 3-hours post-exercise (3H) and analyzed for testosterone, cortisol, insulin, IGF-1, and GH. Data for each hormone were analyzed with a 2-way repeated measures analysis of variance (ANOVA). Results: Significant main effects for time (p<0.05) were observed for all hormones. There was a significant decrease in testosterone at IP (p=0.007), 1H (p<0.001), and 3H (p<0.001). There was a significant decrease in cortisol at all time points (p<0.001) compared to BL. There were significant increases in insulin, IGF-1, and growth hormone at all time points (p<0.001) following exercise. Conclusion: Neither protease nor protein supplementation appear to alter the endocrine response to resistance exercise in trained males compared to a control.

The aim of the current study was to examine the efficacy of whey protein ingestion with or without a digestive enzyme complex on amino acid (AA) availability following acute lower-body resistance exercise. Following an overnight fast, ten resistance trained men performed lower-body acute resistance exercises consisting of four sets each of the leg press and leg extension exercises followed by consumption of one of three drinks of equivalent volume, taste, and appearance which consisted of either: (a) 26g whey protein + 250 mg protease supplement + whey (PW) (b) 26g whey protein (W), or (c) a non-caloric flavored water drink (PL). Results showed significant main effects for time (p<0.001) and time x group interactions (p<0.001) were found for leucine, BCAA, and EAA. WPH drink resulted in significantly greater plasma leucine, BCAA and EAA concentrations at 30 min compared to PL (p<0.001) while not different than W. Leucine was significantly elevated at 30min (p=0.007) and EAAs at 180min (p=0.004) compared to 0min for WPH. The AUC for WPH and W were both significantly elevated groups for leucine, BCAAs and EAAs compared to PL (p<0.001). While no significant differences were found between the W and WPH supplementation groups during the 3-hr period after resistance training; the WPH group produced significantly greater leucine concentrations at 30min and in EAAs at 180min than PL compared to 0m. Results indicate that WPH may provide a more rapid absorption and longer lasting concentration of AAs in the blood after exercise compared with W or PL.

Introduction: Caffeine has been used as a chief substance to enhance exercise performance. Vast evidence exists detailing the effect of caffeine consumption on improving aerobic performance, yet, research is scarce in explaining performance effects on resistance training and anaerobic systems. More work is needed to determine caffeine’s effect on resistance training in recreationally active individuals. Purpose: The purpose of this investigation is to determine the effects of caffeine supplementation on repetitions to fatigue during a leg extension and leg press exercise. This study will provide an overview on the influence that caffeine has on the human body, its ergogenic effect, and specifically, its anaerobic influence. Methods: A blinded, randomized, repeated measures design will be used. The sample in this study will include 10-12 males and females who regularly consume caffeine and are resistance trained. Each participant will fill out a PAR-Q+ prior to completing a one repetition maximum (1RM) test for the leg press and leg extension. Repetitions to fatigue will be performed 45-minutes after drinking either placebo (maltodextrin), 3mg/kg, or 7mg/kg of caffeine anhydrous. Repetitions to fatigue will consist of participants completing as many repetitions as possible at 80% of 1RM. Data analysis will be performed through the JMP software system by a repeated measures ANOVA test. Hypotheses: It is hypothesized that the effects of caffeine will delay fatigue on anaerobic performance using resistance exercises for lower extremity muscles.

Vitamin D deficiency is prevalent among active adults; therefore, multivitamin products are consumed to correct this deficiency, but many multivitamins are often under-dosed compared to current evidenced-based recommendations. Purpose: To compare the effects of two different forms of low-dose multivitamins on 25(OH) vitamin D status following 10-weeks of supplementation. Methods: Thirty-four healthy males (n=14; 20.1y, 163cm, 71.7kg) and females (n=20; 22.1y, 153.4cm, 69.9kg) participated in this randomized, double-blind, placebo-controlled study. At the beginning of the 10-week intervention, participants provided a resting, fasted baseline blood sample and were randomly assigned to a liquid multivitamin supplement (LIQ; n=11), multivitamin capsule (CAP; n=11), or placebo group (PL; n=12). Participants took their respective supplement daily for 10 weeks. The LIQ and CAP supplement both contained 268 IU of Vitamin D. After the 10-weeks, all participants reported back to the laboratory for a resting, fasted blood sample. Plasma samples were assayed for 25(OH) vitamin D concentrations. Data were analyzed using a 2-way repeated measures analysis of variance (ANOVA). Results: There was a main effect for time (F=11.86, p=0.002, η2 =0.227) with 25(OH) vitamin D concentrations significantly lower (∆: -7.8-14.9ng/ mL) at post-testing. Further, there were no significant differences between treatments (F=0.200, p=0.820, η2 =0.013) in 25(OH) concentrations suggesting no benefit of LIQ or CAP supplementation over PL. Conclusion: It appears that a chronic low dose of vitamin D in liquid or capsule form is insufficient to maintain or elevate 25(OH)D concentrations in healthy, college-aged adults. Consumers should evaluate the dosing of their multivitamins compared to current evidence-based recommendations.

Purpose: To compare muscle activation and bar velocity between the traditional (TRAD) and safety squat bar (SSB) back squat and develop a prediction equation for training loads with the SSB. Methods: Thirtytwo males (21.94±3.1 yr, 1.78±0.8 m, 81.7±10.1 kg) volunteered to complete this randomized, crossoverdesign study. Participants completed two separate1-repetition maximum (1RM) sessions using either the TRAD or SSB. Subsequently, participants completed one session of 3 repetitions at 65% and 85% of their 1RM for each squat condition (SSB &TRAD). Peak muscle activation of seven muscles from the lower body and trunk were recorded through surface electromyography (EMG) and mean velocity (MV) was recorded by a linear transducer. EMG and MV were analyzed by a 2x2 (bar x load) repeated measures analysis of variance (RMANOVA). A Pearson correlation was used to determine the relationship of load between bars and linear regression provided prediction equations. Results: Squat 1RM was significantly higher (p<0.001) for TRAD (144.7kg) compared to SSB (128.8kg). A significant main effect was seen in EMG (p<0.01) and MV for load (p<0.001). No significant bar x load interaction was observed between conditions for EMG or MV (p>0.05). A strong correlation (r=0.94) was observed between 1RM values of each bar. A prediction equation for SSB 1RM was calculated through regression analysis (SSB 1RM = 11.613407 + 0.8536183*TRAD 1RM). Conclusion: The SSB produces similar muscle activation and bar velocities compared to the TRAD at relative intensities. However, absolute loads should be adjusted when changing squat bars during a training cycle.

Researchers have found that aging is associated with loss of muscle mass, atrophy of type II fibers, and/or a decline in muscle force production. Long-term resistance and sprint training may preserve certain muscle characteristics. The purpose of this study was to determine if muscle thickness is correlated with peak power during an anaerobic sprint test. Sixteen males (age = 33.6±19.25 yrs; ht = 177±16 cm; wt = 78.25±18.75 kg) and 14 females (age = 26.6±7.61 yrs; ht = 167±10 cm; wt = 66.5±15.5 kg) volunteered to participate. Muscle thickness of the rectus femoris and vastus lateralis in the right leg was measured via ultrasonography (GE NextGen LOGIQ ℮). Participants completed a 20-second sprint on a mechanically braked cycle ergometer (Monark 894 E) against a resistance that corresponded with 7.5% body mass. Pearson correlation was used to determine relationship between muscle thickness and peak power. There were significant positive correlations between peak anaerobic power and muscle thickness of both the rectus femoris (r = 0.6453, p = 0.0001) and vastus lateralis (r = 0.7351, p = 0.0001). Strong positive correlations between anaerobic power and muscle thickness of quadriceps muscles existed despite age and gender differences, suggesting that anaerobic-specific exercise is characteristic of muscle mass preservation.

The purpose of this study was to examine the effects of eight weeks of CrossFit training in combination with the consumption of electrokinetically modified water (EMW) on aerobic capacity, anaerobic power, and peak knee torque in CrossFit trained males. This study used a randomized, double-blind, placebo-controlled design. Twenty adult male CrossFit athletes (28.9 ± 4.69 years, 83.97±12.87kg, 12.5 ± 5.2 percent body fat) volunteered to participate. Participants were randomly assigned to a control (n=11) or EMW (n=9), and instructed to maintain their current training volume and drink a prescribed number of bottles (500ml) based on weight (102.3kg = 4 bottles/day). The subjects performed a graded exercise treadmill VO2max test, a peak knee torque flexion/extension test on a Biodex Isokinetic Machine at 120 sec-1, and a 30-second Wingate test for anaerobic power before and after the 8-week training period. No significant differences (P > 0.05) were identified between groups on improvements in VO2max (EMW=1.7± 3.7 ml/kg/min vs. C=0.0 ± 3.4 ml/kg/min), extensor knee peak torque (EMW=6.4 ± 19.3N/m vs. C=1.4 ± 21.1N/m), flexor knee peak torque (EMW=4.8± 12.5N/m vs. C=8.8± 15.7N/m), or peak power (EMW=13.7 ± 45.1W vs. C=12.7 ± 70.0W). The results indicate that 8-weeks of EMW consumption does not have any ergogenic effect on aerobic capacity, anaerobic capacity, or peak knee torque in male CrossFit athletes.

High levels of physical fitness are positively associated with academic success, self-esteem, and quality of life. Physical fitness testing is helpful in understanding one’s physical fitness status before starting and after completing a fitness program. Lipscomb University offers a 2-credit course titled Lifetime Wellness, which is designed to help freshmen students create and implement an individualized exercise program. Lipscomb freshmen enrolled in Lifetime Wellness in the Fall of 2013 participated in a battery of physical fitness tests, before and after an 8 week individualized exercise program. The test included a timed 1.5 mile run, a 1 minute pushup test, a 1 minute sit-up test, and a sit-and-reach flexibility test. A paired t-test was used to compare pre-and post-test data from all Fall 2013 Lifetime Wellness classes (N=7 classes with each class).

Exercise is one of the most important things a person can do to maintain good health, prevent disease and improve overall psychological well-being, yet so many Americans live a sedentary lifestyle. It seems that most people view exercise as dreaded and not enjoyable, but it doesn’t have to be. Exercise can be fun and exciting if you find the right type of setting in which to participate. If we can change people’s attitudes and feelings towards exercise it will be easier for them to stay committed to their health and fitness. The purpose of this study was to determine whether there is a difference in attitudes, feelings, and overall satisfaction between people who mostly participate in individual training versus those who mostly participate in group exercise classes. It was hypothesized that group exercise participants would be overall more satisfied. Twenty participants were randomly selected from the YMCA, with half being participants in a group exercise class and the other half were training alone on the wellness floor. Participants completed a semantic differential scale type survey asking about attitudes before, during and after exercise as well as perceived quality of workout and satisfaction of results achieved. Results of the independent t-test indicated that there was a significant difference between groups and that people who mostly participate in group exercise classes experienced more overall happiness and satisfaction than those who train alone. While there were many limitations to this study, this might be something future studies examine more in depth.

High levels of physical fitness are positively associated with academic success, self-esteem, and quality of life. Physical fitness norms are helpful in understanding one’s physical fitness status relative to a comparable population. One hundred and ten Lipscomb underclassmen enrolled in PE 2012 in the Fall of 2012 participated in a battery of physical fitness tests including a timed 1.5 mile run, a 1 minute push-up test, a 1 minute sit-up test, a sit-and-reach flexibility test, and skinfold body composition measurements. Descriptive statistics were run on the data from all PE 2012 classes. When compared to national norms for college-age students, the average Lipscomb female ranked above average in push-ups (27.5 ± 8.9), average in sit-ups (29.0 ± 7.3), very good in sit-and-reach (35.1cm ±7.4), poor in aerobic capacity (34.3ml/kg/min ± 5.9), and very poor in percent body fat (29.2 ±4.6). When compared to national norms, the average Lipscomb male ranked above average in push-ups (37.3 ± 12.4), average in sit-ups (37.2 ± 5.9), good in sit-and-reach (29.9cm ± 6.9), fair in aerobic capacity (42.5ml/kg/min ± 7.1), and good in percent body fat (14.7 ±5.8). These statistics provide key teaching points for health and physical activity courses at Lipscomb University, as both male and female students should be encouraged to improve their aerobic capacity in order to reap the physical, emotional, and cognitive benefits of a healthy fitness profile.