Acute Post-Activation Potentiation in NCAA Division II Female Athletes

International Journal of Exercise Science 7(3) : 212-219, 2014. Post-activation potentiation (PAP) is a phenomenon in which the power output of a muscle is immediately enhanced after heavy resistance exercise. Whereas the majority of PAP research has examined males, minimal research exists as to how female athletes respond. Therefore, the purpose of this study was to investigate the acute PAP response of back squats on static squat jump (SSJ) performance among NCAA Division II female athletes. Female athletes (n=29) who were current roster members from basketball, softball, and volleyball, performed 3 SSJ prior to 3 repetitions of the back squat exercise at 90% 1RM. After a 5-min rest, athletes once again performed 3 SSJ for maximal height, with peak power calculated using the Sayers equation. There was a significant interaction effect observed between time and team, p=0.022; post-hoc tests indicated that the volleyball team had a significant decrease in power, p=0.008. The main effect for time was not significant, p=0.279, indicating for the group as a whole, there was no evidence of a PAP response. The main effect for team was also nonsignificant, p=0.173, indicating no difference in power outputs by team. Strength and conditioning coaches who work with female athletes should be aware that the successful implementation of PAP complexes within this population appears to be highly individualized. Therefore, the use of PAP complexes in female athletes should consider both the absolute and relative strength of each athlete in conjunction with the length of the rest period when attempting to optimize the PAP response

Actual Versus Predicted Cardiovascular Demands in Submaximal Cycle Ergometer Testing

International Journal of Exercise Science 8(1) : 4-10, 2015. The Astrand-Rhyming cycle ergometer test (ARCET) is a commonly administered submaximal test for estimating aerobic capacity. Whereas typically utilized in clinical populations, the validity of the ARCET to predict VO2max in a non-clinical population, especially female, is less clear. Therefore, the purpose of this study was to determine the accuracy of the ARCET in a sample of healthy and physically active college students. Subjects (13 females, 10 males) performed a maximal cycle ergometer test to volitional exhaustion to determine VO2max. At least 48 hours later, subjects performed the ARCET protocol. Predicted VO2max was calculated following the ARCET format using the age corrected factor. There was no significant difference (p=.045) between actual (41.0±7.97 ml/kg/min) and predicted VO2max (40.3±7.58 ml/kg/min). When split for gender there was a significant difference between actual and predicted VO2 for males, (45.1±7.74 vs. 42.7±8.26 ml/kg/min, p=0.029) but no significant difference observed for females, (37.9±6.9 vs. 38.5±6.77 ml/kg/min, p=0.675). The correlation between actual and predicted VO2 was r=0.84, p\u3c0.001 with an SEE= 4.3 ml/kg/min. When split for gender, the correlation for males was r=0.94, p\u3c0.001, SEE=2.72 ml/kg/min; for females, r=0.74, p=0.004, SEE=4.67 ml/kg/min. The results of this study indicate that the ARCET accurately estimated VO2max in a healthy college population of both male and female subjects. Implications of this study suggest the ARCET can be used to assess aerobic capacity in both fitness and clinical settings where measurement via open-circuit spirometry is either unavailable or impractical

Occupational Sitting and Physical Activity Among University Employees

International Journal of Exercise Science 7(4) : 295-301, 2014. The prevalence of overweight and obese in the U.S. has been thoroughly documented. With the advent of inactivity physiology research and the subsequent interest in sedentary behavior, the work environment has come under closer scrutiny as a potential opportunity to reverse inactivity. Therefore, the purpose of this study was to determine the sitting and physical activity (PA) habits among different classifications of university employees. University employees (n=625) completed an online survey based on the Occupational Sitting and Physical Activity Questionnaire (OSPAQ). Participants were instructed to describe time spent sitting, standing, walking, and in heavy physical labor during the last seven days, along with the number of breaks from sitting taken per hour. To establish habitual patterns of PA outside of work, employees recalled their participation in structured PA in the past seven days. Prior to data analysis, employees were categorized as Administration, Faculty, Staff, or Facilities Management. Statistically significant differences were found among employee classifications for min sit/d, p\u3c.001; min stand/d, p\u3c.001; min walk/d, p\u3c.001; and min heavy labor/d, p\u3c.001. No significant differences were found for breaks/h from sitting, p=.259 or participation in structured PA, p=. 33. With the exception of facilities management workers, university employees spent 75% of their workday seated. In conjunction with low levels of leisure time PA, university employees appear to be prime candidates for workplace interventions to reduce physical inactivity

VO2 Reserve vs. Heart Rate Reserve During Moderate Intensity Treadmill Exercise

International Journal of Exercise Science 7(4) : 311-317, 2014. ­VO2 and heart rate (HR) are widely used when determining appropriate training intensities for clinical, healthy, and athletic populations. It has been shown that if the % reserve (%R) is used, rather than % of max, HR and VO2 can be used interchangeably to accurately prescribe exercise intensities. Thus, heart rate reserve (HRR) can be prescribed if VO2 reserve (VO2R) is known. Therefore, the purpose of this study was to compare VO2 R and HRR during moderate intensity exercise (50%R). Physically active college students performed a maximal treadmill test to exhaustion. During which VO2 and HR were monitored to determine max values. Upon completion of the maximal test, calculations were made to determine the % grade expected to yield approximately 50% of the subjects VO2R. Subjects then returned to complete the submaximal test (50%R) at least two days later. The %VO2R and %HRR were calculated and compared to the predicted value as well as to each other. Statistical analysis revealed that VO2 at 50%R was significantly greater than the actual VO2 achieved, p \u3c .001. Conversely, the mean predicted HRat 50%R was significantly less than the actual HR achieved, p \u3c .001. In conclusion, this study indicated that VO2 could be more accurately predicted than HR during moderate intensity exercise. The weak correlation between VO2R and HRR indicates that caution should be used when relying on a HR to determine VO2

Metabolic and Energy Cost of Sitting, Standing, and a Novel Sitting/Stepping Protocol in Recreationally Active College Students

International Journal of Exercise Science 9(2): 223-229, 2016. The purpose of this study was to compare the differences in metabolic and energy cost (MEC) of college students while seated, standing, and during a sitting/stepping protocol. Participants were assessed via indirect calorimetry for 20 min in each of the following conditions: 1) seated in a standard office chair, 2) standing in place, and 3) a sitting/stepping protocol in which participants performed 1 min of stepping in place at 90 bpm, sat for 9 min, then repeated the stepping and sitting sequence once more. Participants completed each of the 3 trials in the aforementioned order, preceded with a 3 min acclimation period in each condition. A significant difference in MEC was observed between the 3 conditions, p \u3c 0.001. Pairwise comparisons indicated that the sitting/stepping protocol resulted in significantly greater MEC than the seated and standing conditions (p \u3c 0.001). Additionally, the standing protocol resulted in significantly greater MEC than the seated protocol (p \u3c 0.001). The significant differences and large effect sizes between conditions indicate that interspersing sedentary bouts with brief activity can substantially increase MEC. Broader application of these findings may provide health promotion professionals with novel strategies to reduce sedentary behavior and improve health

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

International Journal of Exercise Science 11(7): 503-515, 2018. 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

Physical Activity and Screen Time Sedentary Behaviors in College Students

It is well established that Americans are not meeting physical activity (PA) guidelines and college students are no exception. Given the lack of regular PA, many health promotion professionals seek to discover what barriers to PA may exist. A common explanation is screen time (ST), which is comprised primarily of television viewing, computer use, and the playing of video games. The purpose of this study was to present descriptive data on college students’ PA and sedentary behavior and to assess if any evidence exists to suggest displacement between sedentary behaviors and PA in college students. Students completed an online health survey specific to time spent in PA and sedentary behavior. Students were categorized into one of three PA groups based on their activity level. Males were significantly more physically active than females in terms of days per week engaged in aerobic exercise (p=.022) and strength training (p\u3c.001). When categorized by activity level, a greater percentage of male students met recommended PA levels than did females (p\u3c.001). Males reported significantly higher levels of overall ST (p=.004) and television viewing (p\u3c.001), whereas females reported significantly higher levels of time spent engaged in homework (p\u3c.001). When categorized by activity level, physically active students reported significantly fewer minutes of total ST than inactive students (p=.047). Implications of this study suggest that within a college population, television and PA are not competing behaviors in either gender

The Diabetes Care Project: an Australian multicentre, cluster randomised controlled trial [study protocol]

Background: Diabetes mellitus is an increasingly prevalent metabolic disorder that is associated with substantial disease burden. Australia has an opportunity to improve ways of caring for the growing number of people with diabetes, but this may require changes to the way care is funded, organised and delivered. To inform how best to care for people with diabetes, and to identify the extent of change that is required to achieve this, the Diabetes Care Project (DCP) will evaluate the impact of two different, evidence-based models of care (compared to usual care) on clinical quality, patient and provider experience, and cost. Methods/Design: The DCP uses a pragmatic, cluster randomised controlled trial design. Accredited general practices that are situated within any of the seven Australian Medicare Locals/Divisions of General Practice that have agreed to take part in the study were invited to participate. Consenting practices will be randomly assigned to one of three treatment groups for approximately 18 to 22 months: (a) control group (usual care); (b) Intervention 1 (which tests improvements that could be made within the current funding model, facilitated through the use of an online chronic disease management network); or (c) Intervention 2 (which includes the same components as Intervention 1, as well as altered funding to support voluntary patient registration with their practice, incentive payments and a care facilitator). Adult patients who attend the enrolled practices and have established (≥12 month's duration) type 1 diabetes mellitus or newly diagnosed or established type 2 diabetes mellitus are invited to participate. Multiple outcomes will be studied, including changes in glycosylated haemoglobin (primary outcome), changes in other biochemical and clinical metrics, incidence of diabetes-related complications, quality of life, clinical depression, success of tailored care, patient and practitioner satisfaction, and budget sustainability. Discussion: This project responds to a need for robust evidence of the clinical and economic effectiveness of coordinated care for the management of diabetes in the Australian primary care setting. The outcomes of the study will have implications not only for diabetes management, but also for the management of other chronic diseases, both in Australia and overseas