Showing papers in "International journal of exercise science in 2018"

Current State of Commercial Wearable Technology in Physical Activity Monitoring 2015-2017.

Abstract: Wearable physical activity trackers are a popular and useful method to collect biometric information at rest and during exercise The purpose of this systematic review was to summarize recent findings of wearable devices for biometric information related to steps, heart rate, and caloric expenditure for several devices that hold a large portion of the market share Searches were conducted in both PubMed and SPORTdiscus Filters included: humans, within the last 5 years, English, full-text, and adult 19+ years Manuscripts were retained if they included an exercise component of 5-min or greater and had 20 or more participants A total of 10 articles were retained for this review Overall, wearable devices tend to underestimate energy expenditure compared to criterion laboratory measures, however at higher intensities of activity energy expenditure is underestimated All wrist and forearm devices had a tendency to underestimate heart rate, and this error was generally greater at higher exercise intensities and those that included greater arm movement Heart rate measurement was also typically better at rest and while exercising on a cycle ergometer compared to exercise on a treadmill or elliptical machine Step count was underestimated at slower walking speeds and in free-living conditions, but improved accuracy at faster speeds The majority of the studies reviewed in the present manuscript employed different methods to assess validity and reliability of wearable technology, making it difficult to compare devices Standardized protocols would provide guidance for researchers to evaluate research-grade devices as well as commercial devices used by the lay public

Aerobic Fitness is of Greater Importance than Strength and Power in the Load Carriage Performance of Specialist Police

Abstract: Police officers are required to carry external loads as part of their occupation. One means of preparing officers to carry loads is through physical conditioning. The aim of this study was to investigate whether strength, power or aerobic endurance had the greatest association with load carriage performance. Retrospective data from 42 male specialist tactical police officers (mean body weight = 88.8±8.25 kg) informed this study. Baseline data were provided for strength (1 Repetition Maximum [RM] bench press, deadlift, squat and pull-up), lower body power (vertical jump, 10m sprint) and aerobic ('beep' test) performance. In addition, officers completed three 5km load carriage trials (3 to 4 months apart) with 25 kg packs as fast as possible. Pearson's correlations were used to look for associations between measures with an analysis of variance used to detect changes in load carriage performance. Alpha levels were set a priori at 0.05. All variables of strength and power were significantly correlated with performance except for 1RM deadlift and the 10m sprint for the last two load carriage trails. Of all fitness measures, aerobic fitness was the most highly significant correlation with the load carriage trials (r=-0.712, -0.709 and -0.711 for trials respectively). Time to completion improved across the three load carriage trials (p<.001). These findings support the approach that optimal load carriage performance may be achieved by performing load carriage tasks in conjunction with aerobic fitness and full body strength/lower limb power training.

Relationships between Assessments in a Physical Ability Test for Law Enforcement: Is There Redundancy in Certain Assessments?

Abstract: International Journal of Exercise Science 11(4): 1063-1073, 2018. The purpose of this study was to investigate the relationships between tests incorporated into a physical assessment battery (PAT) for a law enforcement (LEA) to determine if there were redundancies (i.e. tests measuring the same qualities). A retrospective analysis of 226 recruits (196 males, 30 females) was conducted. The PAT consisted of: maximal push-ups and situps completed in 60 s; a 75-yard pursuit run (75PR); maximal revolutions completed on an arm ergometer in 60 s; and a 2.4 km run. A one-way ANOVA (p<0.05) determined if there were significant differences in the PAT data between the sexes. Pearson’s correlations (p<0.05) calculated relationships between each of the tests within the PAT, and males and females were analyzed separately. Further, tests that could potentially measure similar qualities, including upper-body endurance (push-ups/arm ergometer), abdominal endurance (push-ups/sit-ups), and aerobic fitness (arm ergometer/2.4 km run) were investigated further with one-sample t-tests to determine agreement. Males performed better than the females in all tests (p≤0.017). There were significant correlations between assessments for both males and females (e.g. push-ups, sit-ups and arm ergometer, 75PR and sit-ups, arm ergometer and 2.4 km run), but the strength of these relationships was small-to-moderate. The one-sample t-tests for the selected comparisons (push-ups/arm ergometer; push-ups/sit-ups; arm ergometer/2.4 km run), for males and females were all significant (p<0.001), which meant the test pairs did not agree. The results indicate that if a LEA uses these tests in a PAT, they can do so knowing they are measuring five relatively distinct physical qualities.

Does Body Mass Index Influence the Physiological and Perceptual Demands Associated with Defensive Tactics Training in State Patrol Officers

Abstract: The purpose of this investigation was to determine the physiological and perceptual demands associated with defensive tactics (DEFTAC) training among state patrol officers of different BMI (body mass index) categories. Twenty-four male state patrol officers (n = 24, age 36.00 + 7.86 yrs) voluntarily agreed to participate in data collection during a DEFTAC gauntlet. Anthropometric information (height (HT) 182.19 + 7.43 cm and weight (WT) 96.31 + 17.45 kg), body mass index (BMI), peak and average heart rates, duty weight, BLa, and RPE, were recorded. Officers were then divided into two-groups (Healthy BMI (BMI ≤ 25), n = 12, Overweight (BMI ≥ 25), n = 12). Analyses of covariance (ANCOVAs) were conducted to determine the effect of BMI on the outcome variables. Furthermore, a Pearson's product-moment correlation coefficient was also conducted to determine if significant relationships between RPE, BLa, and HR existed between groups. Significant mean score differences between healthy and overweight officers were found in measures of age [t(22) 4.12, p< 0.01, R2 = .44], and weight of duty gear [t(21) 3.96, p<0.01, R2 = .33]. When used as a covariate, age also predicted average HR% [ F(1, 21) = 6.19, p < .05, partial η2 = .24]. Significant relationships were found in the healthy group between RPE and DEFTAC time, DEFTAC time and score, as well as score and post BLa. Significant relationships for the overweight group between peak (HR) percentage and post BLa, peak (HR) percentage and RPE, DEFTAC time and duty weight, and between weight and DEFTAC time. The results of this study suggest that overweight officers may have lower DEFTAC scores when compared to their healthy counterparts. Based on the results, it seems reasonable to compare physiological variables from this population to those from combative sports as well as for officers to achieve and maintain a healthy BMI value in order to improve individual DEFTAC performance.

Fitness Profiles in Elite Tactical Units: A Critical Review.

Abstract: Elite tactical units complete a variety of demanding tasks and a high level of fitness is required by this population to perform their occupational tasks optimally. The aim of this critical review was to identify and synthesize key findings of studies that have investigated the fitness profiles of elite tactical units. Included studies were critically appraised, using the Downs and Black checklist, and a level of evidence was determined. Relevant data were extracted, tabulated, and synthesized. Fourteen studies were included for review and ranged in percentage quality scores from 46% to 66% with a mean of 57.5%. Moderate interrater agreement (κ = 0.496) existed between raters. A variety of fitness measures were used across various domains of fitness. The most common measures were in the areas of anthropometric measures, strength, power, and aerobic capacity. However, there was high variety in the measures and their protocols. Though fitness appears to be a critical part of research and practice in tactical populations, currently there is no standardized measure or result for this population. Further research in fitness profiling should be completed using standardized outcome measures which cover the spectrum of the fitness demands for this population.

Practices, Perceived Benefits, and Barriers to Resistance Training Among Women Enrolled in College.

Abstract: The American College of Sports Medicine (ACSM) has recommended that resistance training be performed at least twice per week, with 8-12 repetitions of 8-10 exercises targeting all major muscle groups (1). However, Kruger, Carlson, and Kohl (18) reported that women were participating less than the U.S. population on the whole, as only 20% of women were engaging in resistance training two or more times per week. In order to better understand why only 1 in 5 women participate regularly in this form of physical activity, this study investigated current resistance training practices, perceived benefits, and barriers to resistance training among college women. One-hundred and sixteen women college students from a large, public, Midwestern university participated in this study. Correlation and hierarchical multiple regression analyses were used to identify the strongest predictors of resistance training behaviors. The predictors in the regression model included demographic characteristics in block one, perceived barriers to resistance training in block two, and perceived benefits of resistance training in block three. Results indicated that the level of perceived "time/effort" barriers significantly predicted resistance training behavior. Findings in this area may help researchers, university recreation programmers, personal trainers, and other health and fitness professionals better understand the attitudes and actions of college women regarding resistance training, toward the goal of promoting fitness center environments that college women find more inviting.

Validation of the PiezoRx® Step Count and Moderate to Vigorous Physical Activity Times in Free Living Conditions in Adults: A Pilot Study

Abstract: The purpose of the study was to: 1) Validate the PiezoRx® for steps and intensity related physical activity in free-living conditions compared to the criterion measure. 2) Compare PiezoRx®'s steps and intensity related physical activity to physiological assessments. 3) To assess the utility of the PiezoRx® in a subsample of participants. Thirty-nine participants consisting of 28 females aged 54.9±10.6 (33-74) years and 11 males aged 63.9±10.9 (44-80) years wore the PiezoRx® physical activity monitor and the ActiGraph® accelerometer for one full week and completed a physical assessment. A subsample (n=24) wore the PiezoRx® for an additional two weeks and completed a questionnaire regarding usability. The PiezoRx® had strong correlations to the ActiGraph® for step count (r=0.88; p<0.001), moderate-vigorous physical activity (MVPA) (r=0.70; p<0.001), and sedentary activity (r=0.93; p<0.001) in the 1-week monitoring period. The PiezoRx®'s steps/day and MVPA/week were negatively correlated (p<0.001) to body mass index and waist circumference, and positively correlated (p<0.05) to aerobic fitness, pushups, and 30 second sit-to-stand. Within the subsample who completed the additional two-week monitoring, 75% of participants reported that the PiezoRx® increased their physical activity. In conclusion, The PiezoRx® appears to be a valid measure of free-living PA compared to accelerometry. Because of the correlations of the PiezoRx®'s steps/day and MVPA/week to anthropometric, musculoskeletal and aerobic fitness these PA measures may be valuable objective surrogates to use in clinical or professional practice for physical health.

Reliability and Validation of the Hexoskin Wearable Bio-Collection Device During Walking Conditions.

Abstract: To evaluate if the Hexoskin smart shirt (HxS) would produce valid and reliable measurements for heart rate (HR), respiratory rate (RR), minute ventilation (VE), step count (SC), and energy expenditure (EE) when compared to a Polar T-31 heart rate monitor, an Applied Electrochemistry Moxus Metabolic System, and a manual step count. A two-day walking treadmill protocol with participants walking for 3 minutes at 3 speeds (1.5mph, 2.5mph, 3.5mph, 0% grade) was performed. Forty-nine volunteers participated the first day, forty-six on the second, thirty-one were used for reliability. Values calculated for the HxS data used Pearson's product-moment correlation (p < 0.05; r ≥ 0.70) for validity and Cronbach's α (≥ 0.70) for reliability. HxS HR (1.5mph; p<0.01, r=0.86, α=0.86. 2.5mph; p<0.01, r=0.81, α=0.88. 3.5mph; p<0.01, r=0.85, α=0.85), HxS RR (1.5mph; p<0.01, r=0.87, α=0.93. 2.5mph; p<0.01, r=0.86, α=0.92. 3.5mph; p<0.01, r=0.71, α=0.76), HxS VE (1.5mph; p=0.66, r=0.11, α=0.70. 2.5mph; p=0.01, r=0.15, α=0.73. 3.5mph; p=0.31, r=0.08, α=0.14), HxS SC (1.5mph; p=0.90, r=-0.01, α=0.70. 2.5mph; p=0.22, r=0.13, α=0.86. 3.5mph; p<0.01, r=0.74, α=0.85), HxS EE (1.5mph; p<0.01, r=0.56, α=0.85. 2.5mph; p<0.01, r=0.50, α=0.83. 3.5mph; p<0.01, r=0.51, α=0.80). HxS HR and RR provided valid and reliable measures at all three speeds while VE, SC, and EE had a mixture of results based on speed. These results are important in the use of the Hexoskin in an accurate manner for athletes, coaches, and for the potential medical applications being advocated in the field of telemedicine procedures.

Selecting the Best of the Best: Associations between Anthropometric and Fitness Assessment Results and Success in Police Specialist Selection.

Abstract: To successfully complete specialist police selection, officers must be physically fit. The aim of this study was to investigate the relationship between performance on selected anthropometric and fitness tests and successful selection into a specialist police unit. Thirty-two male police officers (mean age = 29.48±4.99 years) participated in a Barrier Fitness Assessment (BFA), followed by a Specialist Selection Course (SSC). The BFA spanned two consecutive days of testing (pull-ups, push-ups, seven-stage sit-ups, a timed loaded pack march, a Multi-Stage Fitness Test, an agility run, a lift and carry task and a 300m swim assessment). The SSC occurred 4 weeks later and consisted of 8 days of intense police training. Officers who successfully completed the SSC were graded based on their performance and this determined their ultimate selection. Data were categorized into four participant groups: Group 1 - Did not complete the BFA; Group 2 - Completed the BFA but not the SSC; Group 3 - Completed the SSC and were not selected; and Group 4 - Completed the SSC and were selected. A Spearman's rank order correlation analysis was conducted to assess the strengths of the relationships between selection stage achieved and scores on each of the predictor variables, with significance set at 0.05. Height (p=0.011), body weight (p=0.011), pull-ups (p=0.021) and push-ups (p=0.016), seven-stage sit-up scores (p=0.042) and lift and carry speed (p=0.010) were significantly and positively correlated with level of selection success. Results suggest that candidates wishing to attempt selection into specialist police units would benefit from being tall and training to optimize musculoskeletal strength and muscular endurance.

The Effect of the Menstrual Cycle on Body Composition Determined by Contact-Electrode Bioelectrical Impedance Analyzers.

Abstract: Bioelectrical impedance analysis (BIA) is a noninvasive and relatively inexpensive method of assessing body composition. Manufacturers of BIA technology recommend to avoid testing women when they perceive to be retaining water during the menstrual cycle. The purpose of the present investigation was to examine the effect of the menstrual cycle on body composition determined by contact-electrode BIA analyzers. Forty-three college-aged women volunteered to participate in this study (age=21.2 ± 1.1 years; body mass index = 24.0 ± 3.7 kg/m2). Subjects had their body composition assessed using four different contact-electrode BIA analyzers during the following menstrual cycle phases: menstrual, follicular, early and late luteal. Regardless of the BIA analyzer used for the assessment, no significant differences in body composition measures were found between cycle phases. The results of this study indicate that the contact-electrode BIA devices used in this study can be used at any time during a woman's menstrual cycle without altering the body composition values.

Mindfulness and Affective Responses to Treadmill Walking in Individuals with Low Intrinsic Motivation to Exercise.

Abstract: An aversion to the sensations of physical exertion can deter engagement in physical activity. This is due in part to an associative focus in which individuals are attending to uncomfortable interoceptive cues. The purpose of this study was to test the effect of mindfulness on affective valence, ratings of perceived exertion (RPE), and enjoyment during treadmill walking. Participants (N=23; Mage=19.26, SD = 1.14) were only included in the study if they engaged in no more than moderate levels of physical activity and reported low levels of intrinsic motivation. They completed three testing sessions including a habituation session to determine the grade needed to achieve 65% of heart rate reserve (HRR); a control condition in which they walked at 65% of HRR for 10 minutes and an experimental condition during which they listened to a mindfulness track that directed them to attend to the physical sensations of their body in a nonjudgmental manner during the 10-minute walk. ANOVA results showed that in the mindfulness condition, affective valence was significantly more positive (p = .02, ηp2 = .22), enjoyment and mindfulness of the body were higher (p < .001, ηp2 = .36 and .40, respectively), attentional focus was more associative (p < .001, ηp2 =.67) and RPE was minimally lower (p = .06, ηp2 =.15). Higher mindfulness of the body was moderately associated with higher enjoyment (p < .05, r =.44) in the mindfulness but not the control condition. Results suggest that mindfulness during exercise is associated with more positive affective responses.

Comparison of a Pneumatic Compression Device to a Compression Garment During Recovery from DOMS.

Abstract: The purpose of this study was to determine the effects of a pneumatic compression device (PCD) compared to a continuously-worn compression sleeve (CS) during a five-day recovery period from delayed-onset muscle soreness (DOMS) of the elbow flexors. Eight college-aged students participated in this crossover design study. The muscle-damage protocol consisted of four sets of 25 repetitions of isokinetic concentric elbow flexion followed by eccentric elbow extension at 60°/second. Immediately following the muscle-damage protocol, subjects either wore a CS continually for five days or completed daily, 20-minute PCD treatments for five days. Swelling, range of motion (ROM), and pain were measured daily during the five-day recovery period. Subjects rested for seven additional days before completing another muscle-damage protocol and the remaining treatment. Treatment order was randomized and balanced. Muscle swelling, assessed via changes in upper arm circumference, was significantly lower in the PCD treatment (1.7 vs. 2.0 cm in CS, p = 0.012), however there was no difference in lower arm circumference (p = 0.091). ROM disturbances during the PCD treatment were lower (mean peak reduction in ROM -9.04 degrees in PCD compared to -17.25 degrees in CS, p < 0.05) and peak pain was lower by 39% (27.5 mm in PCD compared to 45.2 mm in CS, p < 0.05) when compared to the CS treatment. These findings suggest that daily treatments using a PCD further reduce peak disturbance and recovery time from DOMS of the elbow flexors when compared to a continuously-worn CS.

Field Test Performance of Junior Competitive Surf Athletes following a Core Strength Training Program.

Abstract: Lower body and core muscular strength are essential for optimal performance in many sports and competitive surfers have similar strength demands when maneuvering a surfboard to achieve competition success. Presently, the use of unstable surfaces is excessively utilized by surf coaches and trainers and to date, research does not support this as an effective training method for long-term improvements. Therefore, the purpose of this study was to determine the effectiveness of an 8-week Core Strength Training Program (CSTP) on a battery of field tests specific to assessing core musculature and lower body strength for junior competitive surf athletes. Nineteen American junior competitive surf athletes (age:15.7±1.01yrs, height:1.77±0.007m, mass:64.67±9.08kg) completed pre- and post-tests with a transitional pre-season to in-season 8-week CSTP intervention. The battery of tests included: rotational power (RP), time to peak acceleration (TP), maximal acceleration (Ma), maximal countermovement jump (CMJ), estimated peak power (PP), core strength (CS), core endurance (CE), and rotational flexibility (RF). Means, standard deviations, RMANOVA with a significance level of p < 0.05, and effect sizes were computed. Results demonstrated significant improvements in L.RP, TP, CMJ, PP, CS, and RF. Based on the results, the CSTP is an effective training program for surf coaches and strength and conditioning professionals to improve strength in the core musculature and lower body. In addition, we conclude implementation of the CSTP enhances athletic performance measurements which will likely increase competition success.

Congruent Accuracy of Wrist-worn Activity Trackers during Controlled and Free-living Conditions

Abstract: International Journal of Exercise Science 11(7): 575-584, 2018. To examine activity tracker accuracy for measuring steps, energy expenditure, and heart rate in controlled and free-living conditions. Forty participants performed four, five-minute stages (walking: 53.7 m·min-1, 80.5 m·min-1; running: 134.1 m·min-1, 160.9 m·min-1) while wearing the Fitbit Charge HR (FB) and the Mio FUSE (MF) activity trackers. Measurements included steps, energy expenditure (kcals), and heart rate (beats·min-1). In addition to the FB and MF, participants wore the NL-1000 (NL) activity tracker during waking hours of the subsequent day. One way ANOVAs with Tukey’s post hoc analyses were performed to compare mean values for steps, kcals, and mean heart rate between the FB, MF, and criterion measures. Levels of agreement for heart rate with 95% confidence intervals were examined with Bland-Altman plots. Compared to criterion measures, the FB and MF underestimated steps and overestimated kcals at 53.7 m·min-1 (FB: 12.7% for steps, 89.2% for kcals; MF: 15.8% for steps, 44.9% for kcals, p<.001) and 80.5 m·min-1 (FB: 9.7% for steps, 69.9% for kcals; MF: 13.4% for steps, 32.0% for kcals, p<.001). During free-living conditions, the MF significantly underestimated steps by 30.0% (p<.05). Increasing exercise intensity is indicative of heightened accuracy for step detection and kcal estimation for the FB and MF, while decreasing heart rate accuracy for the FB. However, the MF performed poorly for estimating total daily activity.

Thirty-year Trends of Study Design and Statistics in Applied Sports and Exercise Biomechanics Research

Abstract: International Journal of Exercise Science 11(1): 239-259, 2018. This study documented the change in study design and statistics employed in applied sports and exercise biomechanics research from 1985 to 2014. The sample comprised 676 data based original research reports published in the Journal of Applied Biomechanics (JAB) from 1985 to 2014. Eight design and 10 statistical criteria were extracted from each study. Descriptive statistics were calculated and change in study criteria over time were documented. Design criteria that did not change over time, remaining at relatively low levels of rigor, were widespread (71%) use of small (2-20) sample sizes and examination of numerous dependent variables (26.6% with >13). The number of experimental groups and independent variables also did not change with typically 1 to 2 reported. There was a significant 61% linear increase in randomization of participants into groups, however by 2014 still a minority (39%) of studies were not reporting randomized assignment. Types of statistical analysis showed positive changes over time with a 48% quadratic decrease in descriptive analyses, a 3% linear increase in nonparametric statistics, and a 45% linear increase in reporting parametric statistical analysis. Changes in specific statistical methods included a 9% linear decrease in bivariate correlation and a 73% linear increase in ANOVA. Reporting of assumptions had a 35% linear increase, yet in 2014 sixty-five percent still did not report on meeting statistical assumptions. Changes in test statistics included a linear 56% increase of reporting observed P values and a quadratic 29% increase in reporting effect sizes beginning in the late 1990s. It was concluded there was evidence of small improvements in research design and statistics in JAB over the last 30 years; however, there is still room for improvement to meet higher levels of research rigor and current recommendations on statistical analysis and reporting.

Effects of Changing the Focus of Attention on Accuracy, Acceleration, and Electromyography in Dart Throwing.

Abstract: Research over the past 15 years or so has shown that an external focus on the effects of one's movements improves performance relative to an internal focus of attention on bodily actions. More recent research has attempted to discover how the focus of attention (FOA) influences underlying motor control processes by using kinematic and EMG measures. Research has shown that an external FOA reduces EMG activity and the co-contraction between agonist and antagonist muscle groups relative to an internal FOA. The primary goal of the current study was to determine how the FOA influences the acceleration pattern during dart throwing, providing a more complete kinematic description relative to earlier work. Twenty-four participants threw 24 darts in both an external focus condition, focusing on the flight of the dart, and an internal focus condition focusing on the elbow angle at dart release. Surface EMGs were recorded from the triceps and biceps muscles and acceleration was recorded in the X, Y, and Z axes. Accuracy was better with an external focus relative to an internal focus. There was greater acceleration in the Y and Z axes in the second half of the movement in the external focus condition relative to the internal focus condition. An external focus generated less co-contraction between muscle groups compared to the internal focus condition. Overall, the results showed that an internal FOA reduces movement efficiency relative to an external FOA.

Influence of Baseline Muscle Strength and Size Measures on Training Adaptations in Resistance-trained Men

Abstract: The influence of baseline strength or muscle size on adaptations to training is not well-understood. Comparisons between novice and advanced lifters, and between stronger and weaker experienced-lifters, have produced conflicting results. This study examined the effect of baseline muscle strength and size on subsequent adaptations in resistance-trained individuals following a traditional high-volume, short-rest resistance training protocol. Fourteen resistance-trained men (24.0±2.7 y; 90.1±11.7 kg; 169.9±29.0 cm) completed pre-training (PRE) ultrasound measurements of muscle cross-sectional area (CSA) in the rectus femoris (RF), vastus lateralis (VL), pectoralis major, and triceps brachii (TRI) prior to strength assessments (e.g., one-repetition maximum strength bench press and back-squat). Post-training (POST) assessments were completed following 8-wks (4 d·wk-1) of resistance training. Comparisons were made between stronger (STR) and weaker (WKR) participants, and between larger (LGR) and smaller (SMR) participants, based upon PRE-muscle strength and size, respectively. When groups were based on upper-body strength, repeated measures analysis of variance indicated a significant group × time interaction where greater improvements in bench press strength were observed in WKR (12.5±8.6%, p = 0.013) compared to STR (1.3±5.4%, p=0.546). Within this comparison, STR also possessed more resistance training experience than WKR (mean difference=3.1 y, p=0.002). No other differences in experience or adaptations to training were observed. These data suggest that following a short-duration training program (8-weeks), baseline size and strength have little impact on performance gains in resistance-trained individuals who possess similar years of experience. However, when training experience is different, baseline strength may affect adaptations.

Technology-Based Physical Activity Self-Monitoring Among College Students.

Abstract: Understanding the relationship between college students' physical activity (PA) self-monitoring and PA levels has the potential to inform initiatives to promote PA. This study's purpose was to examine the prevalence of technology-based self-monitoring among college students the potential relationship between device usage, goal setting behaviors, PA enjoyment, and PA levels. An online survey assessed students' demographics, current PA level, technology-based PA self-monitoring, and psychosocial outcomes. Independent t-tests examined differences in PA level and psychosocial outcomes by device use. 55.5% of the final sample (N=1,154) reported technology-based self-monitoring. Mobile phone app-based PA tracking was the most commonly reported (29.9%), followed by heart rate monitors (23.1%). Device use was significantly related to vigorous PA and psychosocial outcomes. Findings have the potential to inform development of technology-based interventions that promote student PA.

Stability of Resistance Training Implement alters EMG Activity during the Overhead Press.

Abstract: Kettlebells often replace dumbbells during common resistance training exercises such as the overhead press. When performing an overhead press, the center of mass of a dumbbell is in line with the glenohumeral joint. In comparison, the center of mass of the kettlebell is posterior to the glenohumeral joint. Posterior displacement of the kettlebell center of mass may result in less stability during the pressing motion. The purpose of this study was to examine muscle activity during an overhead press with resistance training implements of differing stability. Surface electromyography (EMG) for the anterior deltoid and pectoralis major was analyzed for 21 subjects. Technique and pace of the overhead press were standardized and monitored. Filtered EMG data were collected, normalized, and average peak amplitude as a percentage of MVIC was calculated for each repetition. A repeated-measures analysis of variance was used to compare EMG values for the anterior deltoid and pectoralis major across implements. A statistically significant increase in normalized EMG activity (p < .05) was identified in the anterior deltoid when using the dumbbell (63.3±13.3%) compared to the kettlebell (57.9±15.0%). In this study, EMG activity was augmented in the anterior deltoid when using the more stable implement, the dumbbell.

Intraindividual Variability and Validity in Smart Apparel Muscle Activity Measurements During Exercise in Men

Abstract: The purpose of the study was to compare smart apparel (SA) muscle activity measurements to surface electromyography (sEMG) muscle activity measurements during exercise, and determine if any systematic bias of the apparel exists. Thirty-five male participants (Ages 23.1±2.92 yrs, height 178±0.09 cm, mass 81.14±10.59 kg, body fat percentage 15.4±4.79%) provided informed consent for participation. During two separate exercise sessions, participants performed three sets of 12 bodyweight squats and pushups in both SA and sEMG. Conditions (sEMG or SA) were randomly counterbalanced. During sEMG, sensors were placed at selected anatomical locations on the right side. During SA, sEMG sensors were sewn into the fabric. Percent of maximal voluntary contractions (%MVC) were calculated. Paired t-test were used to analyze group mean differences in %MVC between conditions. Bland & Altman plots were created to determine any systematic bias. A Pearson’s product correlation was run to determine any association with intertrial variability and body fat percentage. The alpha levels were set a p 0.05). There was a significant difference in %MVC measured in the SA and sEMG for the RDELT (p=0.02). Specifically, the %MVC for the deltoid during pushups was 11.8% greater compared to sEMG. Intertrial differences were not significantly correlated with %BF (p>0.05). The apparel appears to be valid in the recreational population and appears to have no systematic bias.

A Descriptive Study of Objectively Measured Pokémon GO Playtime in College Students

Abstract: Since its debut in July 2016, Pokemon GO has been a wildly popular mobile gaming app. In contrast to many previous apps, Pokemon GO requires the user to be physically active. However, the extent to which Pokemon GO contributes to physical activity is unknown. Therefore, the purpose of this study was to investigate the physical activity profile of playing Pokemon GO for 60 minutes in recreationally active college students. College students (n=27, n=19 female) were fitted with an accelerometer, pedometer, and heart rate monitor to assess the activity demands during a 60-min bout of Pokemon GO. Troiano accelerometer cut points were utilized to estimate time spent in sedentary, light, moderate, and vigorous-intensity physical activity. Of the 60-min allotted playtime, accelerometry indicated 82% was achieved via moderate-to vigorous-intensity physical activity. Pedometer counts indicated approximately 6000-steps/100-steps/min, indicative of moderate-intensity physical activity. Heart rates were approximately 50% of age-predicted maximum, also indicative of moderate-intensity physical activity. The results of this study provide evidence that playing one hour of Pokemon GO can be an effective means of accumulating recommended levels of daily/weekly physical activity.

The Effect of a Single Bout of High Intensity Intermittent Exercise on Glucose Tolerance in Non-diabetic Older Adults.

Abstract: Our aim was to investigate the acute effects of a single bout of high intensity intermittent training (HIIT) on glucose tolerance and other physiological and metabolic markers in non-diabetic older adults. Fourteen healthy older adults (age, 64 ± 2 y; BMI, 25.7 ± 2.8 kg·m-2) performed two acute exercise trials: continuous moderate intensity exercise (MOD) and HIIT, with the response to an oral glucose tolerance test (OGTT) determined <24 hours after. Inflammatory, haematological, and lipid parameters were also assessed the day after each trial. There was an effect of the trials on the insulin response to an OGTT (P=0.047), but not the glucose response. Following an acute bout of HIIT, insulin concentration during an OGTT was elevated at 60 min compared to the control trial (P=0.045), indicating more insulin was secreted, but glucose concentration was unchanged in all trials. The study findings demonstrate that a single bout of HIIT affects the insulin response but not the glycaemic response to a glucose load, proffering a potential benefit for metabolic health in older adults.

Weekly Salivary Biomarkers across a Season for Elite Men Collegiate Basketball Players

Abstract: International Journal of Exercise Science 11(6): 439-451, 2018. The purpose of this study was to monitor weekly the salivary free testosterone (FT), cortisol (C), and the FT/C ratio in elite men NCAA Division I basketball athletes across an entire season. Twelve athletes gave salivary samples for 30 consecutive weeks, beginning in the pre-season and ending one week after the end of post-season competition. Samples were assayed for FT and C. Additionally, a composite value (CBD) composed of Z-scores for weekly practice minutes, game minutes, resistance training repetitions, academic demands, and travel schedules was determined. One-way RM ANOVAs were used to determine which weekly values were different (α=.05) from the season mean. For FT, 10 weeks were different from the season average (5.1 nmol/L). For C, 11 weeks were different from the season mean (9.0 nmol/L). For FT/C, weeks 7 (p=.007), 17 (p=.007), and 25 (p=.005) were different from the season mean (FT/C=0.69). During Wk7, at the start of regular season play, FT/C was above, while CBD was below the season means. During Wk17, which was leading into a series of important conference games, FT/C was below, while CBD was not different from season means. During Wk25, which was one week before the conference tournament, FT/C was below, while CBD was above season means. The methods of this study can be used for monitoring athlete responses and adaptations to sport-specific training and competition; specifically, for evaluating responses to challenging pre-season training, recovery for regular season play, and how they physiologically cope with the competitive season.

The Effect of Stance Width and Anthropometrics on Joint Range of Motion in the Lower Extremities during a Back Squat.

Abstract: The purpose of this study was to assess whether changing the stance width has an effect on the range of motion of hip flexion, knee flexion, and ankle dorsiflexion during an unloaded back squat, and whether these joint movements are affected by anthropometric differences. Thirty-two healthy, young adults performed unloaded back squats at three different stance widths, normalized to pelvic width. Joint angles were assessed using electromagnetic motion capture sensors on the sacrum, and thigh, shank and foot of the dominant leg. ANOVA comparison of joint angles for the three stance widths, at 10° intervals of thigh orientation during the squat, indicated that joint angles tended to be larger when stance width was narrower, with the most significant effects on ankle dorsiflexion. A greater trunk/thigh length ratio (relatively long trunk) also tended to be associated with lower ankle and knee angles, while a greater thigh/shank length ratio (relatively long thigh) tended to be associated with higher ankle and knee angles, for the two narrower stance widths. The most practical implication of our findings is that individuals with limited ankle dorsiflexion, or with particularly long legs / thighs, may benefit from a wider stance width when squatting.

Brief, High-Intensity Interval Exercise Improves Selective Attention in University Students

Abstract: International Journal of Exercise Science 11(5): 152-167, 2018. This study aimed to investigate the effect of very brief, high-intensity interval exercise (HIIE) on selective attention in university students. As a follow-up, we investigated whether HIIE performed prior to a university lecture improves retention of lecture material. A single-group counterbalanced post-test only design was used for this study. 22 university students (19 females; age = 20.0 ±1.0 years) performed a HIIE and control visit on separate days. During the HIIE session, participants performed 4 separate body-weight exercises for 1 set each, consisting of eight 20 s intervals interspersed with 10 s rest, totaling 11 minutes in duration, including rest. 10 minutes following exercise cessation, participants completed the d2 test of attention. The control visit consisted of quiet reading followed by completion of the d2. Selective attention, as assessed by the d2 test of attention was significantly greater following a bout of HIIE compared to the control condition. Effect size analysis revealed a moderate effect in favour of HIIE compared to control (d = 0.459 [0.171, 0.747]). Study #2: 23 university students (17 females; age = 19.0 ±0.5 years) performed HIIE and a rest condition prior to attending an exercise physiology lecture on separate days. A quiz was administered 24-hours post-lecture to assess lecture retention. Quiz performance was not different between HIIE and control conditions (p = 0.18). HIIE is a time-effective exercise stimulus that improves selective attention. However, performing HIIE prior to a university lecture did not impact retention of lecture material.

The Accuracy and Validity of iOS-Based Heart Rate Apps During Moderate to High Intensity Exercise.

Abstract: People use their smartphones for everything from web browsing to tracking fitness metrics. However, it is unclear whether smartphone-based apps that use photoplethysmography to measure heart rate are an accurate or valid measure of exercise intensity. Purpose was to determine the accuracy and validity of two iOS-based heart rate monitors, Runtastic Heart Rate Monitor and Pulse Tracker PRO by Runtastic (Runtastic) and Instant Heart Rate+: Heart Rate and Pulse Monitor by Azumio (Instant Heart Rate), when compared to the electrocardiogram (ECG) and Polar® T31 uncoded heart rate monitor from moderate to vigorous intensity exercise. Participants were 15 male and female regularly active college students. Pre-exercise heart rate and blood pressure were recorded and then participants exercised on a stationary bike at a pedal rate of between 50-60 rpms. After completing a warm-up stage at 40% of age estimated maximum heart rate (AEMHR), exercise intensity progressed from 50% of AEMHR through to 85% of AEMHR in eight, 5-minute stages. At the end of each stage, and having achieved steady-state, heart rates were recorded from each apparatus. After completing the final stage, participants completed a cooldown at 40% of their AEMHR. Post-exercise heart rate and blood pressure were also recorded to ensure full recovery to baseline. There was a strong positive correlation between the Polar® monitor and the ECG during all stages. However, there were not strong correlations for either of the smartphone-based apps at any time point. Although there were weak correlations between the smartphone-based apps and ECG and Polar®, further studies need to be conducted to determine if inaccuracy is due to user error (finger placement, finger temperature, etc.) or the technology behind the apps.

Effects of Prior Fasting on Fat Oxidation during Resistance Exercise.

Abstract: Prior research has demonstrated that the percentage of fuel utilization contributed by CHO compared to fat rises with an increase in exercise intensity. The role of food intake prior to exercise has been well studied and fasting prior to exercise generally increases reliance on fat as fuel. However, data on the role of fasting prior to resistance exercise is limited. Therefore, the purpose of this study was to assess the effects of one bout of resistance training in a fasted state compared to ingestion of standardized meal on fat and carbohydrate utilization. Twelve female (n = 12, age = 20.1 ± 0.79 yrs, height = 67.0 ± 2.63 in, weight = 143 ± 21.8 lbs) NCAA Division 1 athletes participated in the study. Each participant completed one 10 hour fasted resistance training session and one postprandial resistance training session. The respiratory exchange ratio (RER) and METs were measured using a Cosmed K4b2 portable metabolic cart (Cosmed, Rome, Italy) and heart rate was measured by a Polar H1 heart rate monitor. Participants consumed the prescribed food, waited 15 minutes, and then completed three sets of five repetitions of bench press, back squat, and military press at 60% of their 1-repetition maximum. The mean fasted RER was significantly lower than postprandial for back squat (p=0.01) and military press (p=0.02), but not bench press (p=0.19). There was no difference in METs, RPE, or HR between fasted and postprandial trials for any exercise. Results suggest that fasted resistance exercise relies more heavily on fat metabolism than carbohydrate.

Sex and Age Differences in Trail Half Marathon Running.

Abstract: Female participation is growing in trail running races. The purpose was to evaluate sex and age differences in top finishers of a trail running half marathon. Velocity differences between males (M) and females (F) were determined for the top 10 finishers of the Moab Trail Half Marathon from 2012 - 2015 across age, and by finishing place. Differences between age category and between sexes were determined through ANOVA with significance accepted at P < 0.05. A significant difference for running velocity was present between sexes at each age category (20-29 yr F = 2.9±0.3, M = 3.4±0.4 m·sec-1; 30-39 yr F = 2.8±0.3, M = 3.3±0.3; 40-49 yr F = 2.7±0.3, M = 3.0±0.5; 50-59 yr F = 2.3±0.2, M = 2.8±0.3; 60-69 yr F = 1.6±0.3, M = 2.2±0.4; P < 0.0001). Sex difference in trail running velocity was consistent (~13%) among all age categories with exception of the oldest group (33%, P = 0.0001). There were significantly greater female finishers in every age category (20 - 29 yr F = 107±18, M = 56±1;, 30 - 39 yr F = 150±34, M = 84±21; 40 - 49 yr F = 112±17, M = 64±16; P < 0.01) until 50 - 59 yr (F = 48±13, M = 41±14; P = 0.50). These data indicate that the widening gap in sex differences observed in road races are ameliorated in a trail running environment that has a larger number of female participants.

Relative Handgrip Strength as a Simple Tool to Evaluate Impaired Heart Rate Recovery and a Low Chronotropic Index in Obese Older Women.

Abstract: The aim of the present study was to compare differences in heart rate response following a treadmill exercise test in elderly obese women categorized into groups based on relative handgrip strength. Eighty-eight obese elderly women who were between the ages of 60 and 87 participated in the study and were categorized and enrolled to one of two groups based on lower (< 1.51 m2) or higher (≥ 1.51 m2) relative handgrip strength, respectively. The heart rate recovery in the first and second minutes following the treadmill exercise test and the chronotropic index were compared between groups. The higher relative handgrip strength group presented a significantly higher peak heart rate during exercise and a quicker heart rate recovery following exercise versus the lower relative handgrip strength group (p<0.05). Furthermore, there was a tendency (p=0.059) toward a significantly greater chronotropic index in the higher versus the lower relative handgrip strength group. In conclusion, elderly women with greater relative handgrip strength also demonstrated a better heart rate response during and following exercise, possibly indicating better autonomic balance. The relative handgrip strength might be an important and inexpensive tool for the elderly obese women to indirect assess cardiovascular health.