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While physical activity reduces the risk for chronic disease development, evidence suggests those experiencing early life growth-restriction do not express positive adaptations in response to physical activity. The purpose of this study was to examine the effects of low birthweight (LBW) on markers of chronic disease, adult physical activity, and the response to physical activity engagement in a longitudinal human cohort study. Data from the Framingham Offspring Cohort were organized to include participants with birthweight, physical activity, and chronic disease biomarker/treatment data available at two timepoints (exam 5 and exam 9, 19-year difference). A two-way ANCOVA was performed to determine the association of LBW and sex on physical activity engagement (63.0% female, 10.4% LBW). A multinomial logistic regression was performed to examine the associations of low birthweight and sex on chronic disease development while adjusting for physical activity. LBW was associated with elevated blood glucose and triglycerides (Exam 9). Though not statistically significant ( p = 0.08), LBW females potentially spent more time in sedentary activity at exam 5 than LBW males and normal birthweight (NBW) females. LBW males spent significantly more time ( p = 0.03) sedentary at exam 9 compared to NBW males and LBW females. There were no differences in the likelihood of chronic disease treatment between groups. Chronic disease biomarkers remained elevated when adjusted for total physical activity. In conclusion, LBW participants in the Framingham Offspring Cohort were not more likely to be treated for chronic diseases when controlling for physical activity engagement, though biomarkers of chronic disease remained elevated.

Optimizing diet quality is an important concept for college athletes. Purpose : To evaluate dietary quality of National Collegiate Athletic Association (NCAA) Division I athletes. Methods : Total 94 college athletes (n= 21 male, 73 female) from 19 different varsity teams at a single university completed a 24-hour dietary recall using the Automated Self-Administered 24-hour (ASA24) Dietary Assessment Tool. Diet quality was assessed using the Healthy Eating Index (HEI) with higher scores indicating better diet quality (range 0-100). Results : The average HEI score for the total sample was 59.2 ± 16.6 and only nine athletes achieved an HEI score ≥ 80. There were no significant differences in HEI scores between sexes, class, majors, sport played, or those who did or did not report taking previous nutrition coursework. Conclusions : The dietary quality was poor based on US dietary guidelines for the general population, which could have negative effects on health and performance.

Objective: Assess nutrition knowledge of Division I college athletes., Participants: 128 student-athletes (n = 70 female) from eight sports completed the survey in June 2018. METHODS: The survey by Calella et al (2017) was used to assess both general and sport nutrition knowledge., Results: Cases with more than 20% of responses missing were excluded (n = 3). Overall average score was 57.6% ± 18.6%. Females scored significantly ( p  < 0.001) better than the males (66.5% ± 16.4% versus 46.2% ± 14.7%). Participants were divided into revenue (football, ice hockey, male's basketball, women's basketball; n = 63) and non-revenue sports (field hockey, golf, rowing, soccer; n = 62) to address differences in knowledge between sports with greater versus lesser nutrition resource access. Revenue sports scored significantly ( p  < 0.001) worse than non-revenue sports (45.7% ± 15.2% versus 69.7% ± 13.1%)., Conclusions: Athletes appear to have low nutrition knowledge, putting them at risk for inappropriate dietary choices that could decrease ability to optimally perform and increase risk of injury.

As pregnancy progresses, physical changes may affect physical activity (PA) measurement validity. n = 11 pregnant women (30.1 ± 3.8 years) wore ActiGraph GT3X+ accelerometers on the right hip, right ankle, and non-dominant wrist for 3-7 days during the second and third trimesters (21 and 32 weeks, respectively) and 12 weeks postpartum. Data were downloaded into 60-second epochs from which stepping cadence was calculated; repeated-measures analysis of variance was used to determine significant differences among placements. At all time points, the wrist accelerometer measured significantly more daily steps (9930-10 452 steps/d) and faster average stepping cadence (14.5-14.6 steps/min) than either the hip (4972-5944 steps/d, 7.1-8.6 steps/min) or ankle (7161-8205 steps/d, 10.3-11.9 steps/min) placement, while moderate- to vigorous-intensity activity at the wrist (1.2-1.7 min/d) was significantly less than either hip (3.0-5.9 min/d) or ankle (6.1-7.3 min/d). Steps, cadence, and counts were significantly lower for the hip than the ankle at all time points. Kappa calculated for agreement in intensity classification between the various pairwise comparisons ranged from .06 to .41, with Kappa for hip-ankle agreement (.34-.41) significantly higher than for wrist-ankle (.09-.11) or wrist-hip (.06-.16). These data indicate that wrist accelerometer placement during pregnancy likely results in over counting of PA parameters and should be used with caution., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (Copyright © 2021 The Author(s).)

Background: Pregnant women without complications are advised to engage in physical activity (PA) to mitigate adverse outcomes. Differences may exist among pregnant women of diverging diabetes status in meeting national PA recommendations. We sought to examine differences in aerobic activity (AA) and muscle strengthening activity (MSA) by diabetes risk status (DRS) among pregnant women in the United States., Methods: The sample (n = 9,597) included pregnant women, age 18-44 years, who participated in the 2011, 2013, 2015, and 2017 Behavioral Risk Factor Surveillance System. Levels of DRS include: no diabetes (ND), high risk for diabetes (HRD) due to self-reported gestational diabetes or pre-diabetes, and overt diabetes due to self-reported, clinically diagnosed diabetes (DM). Odds ratios (ORs) and 95% confidence intervals (CI) for meeting PA recommendations were obtained. Covariates included age, race, education, household child count, alcohol consumption, and smoking status., Results: Findings revealed that on average, DM had 46.5 fewer minutes of weekly AA compared to ND. Furthermore, a significantly lower OR (0.39; CI 0.19-0.82) for meeting both recommendations was observed in DM as compared to ND after adjustment., Conclusions: We observed that pregnant women with overt diabetes had a lower odds of engaging in PA, while those at high risk were similar in their PA engagement to ND. Future studies aimed at assessing determinants of PA behavior may help guide efforts to promote exercise in pregnant women with diabetes.

Feltz, DL, Hill, CR, Samendinger, S, Myers, ND, Pivarnik, JM, Winn, B, Ede, A, and Ploutz-Snyder, L. Can simulated partners boost workout effort in long-term exercise? J Strength Cond Res 34(9): 2434-2442, 2020-We tested whether exercising with a stronger simulated (i.e., software-generated) partner leads to greater work effort compared to exercising alone, to help those seeking to maintain or improve fitness levels with long-term high-intensity training, but who find it necessary or practical to exercise in social isolation. Forty-one middle-aged adults, who participated in at least 30 minutes of vigorous exercise 3x·wk, trained on a cycle ergometer 6 days per week for 24 weeks in an alternating regimen of moderate-intensity 30-minute continuous and 3 types of high-intensity interval sessions (8 × 30-second sprints, 6 × 2-minute ladders, and 4 × 4-minute intervals). They were assigned either no partner (control), an always superior partner, or a not always superior partner. Participants varied cycle power output to increase or decrease session intensity during the repeated moderate-intensity sessions (30-minute continuous) and 1 of the 3 high-intensity sessions (4 × 4-minute intervals). Changes in intensity were used as a measure of effort motivation over time. Nested multilevel models of effort trajectory were developed and alpha was set to 0.05. For continuous and interval sessions, effort trajectory was positive and significant for those with an always superior partner, but not significantly different from control. Within interval sessions, those with an always superior partner significantly increased effort in the fourth interval compared to control (p = 0.02). Exercising with an always superior partner leads to greater work efforts during the hardest interval training compared to exercising alone.

Background: Physical activity during pregnancy has many health benefits yet few pregnant women meet US guidelines for physical activity. Traditionally, physical activity has been measured as time spent in moderate and/or vigorous intensity activity, but quantifying intensity is challenging. There is increasing interest in measuring both daily steps and stepping rate, or cadence, as an indicator of physical activity overall and intensity of that activity., Research Question: Does free-living step cadence change across pregnancy (from 20 weeks to 32 weeks) and postpartum (12 weeks postpartum) when data is collected via hip-worn ActiGraph (ActiGraph Corp., Pensacola, FL) accelerometers?, Methods: A total of n = 32 pregnant women were enrolled in a longitudinal study of physical activity during pregnancy; these women wore accelerometers on their right hip for one week at 20 weeks gestation, again at 32 weeks gestation, and at 12 weeks postpartum. Data were used to determine total daily steps, time spent (min/day) in various cadence ranges, minutes spent at >100 and >130 steps/min as well as mean, median, maximum, and peak cadences., Results: Pregnant women accumulated significantly fewer steps per day in the third trimester compared to second (1164 steps/day less) or postpartum (1397 steps/day less) time points. Third trimester women also spent significantly fewer minutes/day in MVPA (cadences ≥100 steps/minute; 4.1 min/day less) and had a significantly lower peak cadence (10.6 steps/min less), compared to second trimester only., Significance: These data indicate that pregnant women take fewer steps and walk at slower cadences in the third trimester compared to second and to postpartum, which indicates that total PA as well as absolute intensity of PA are altered during pregnancy., Competing Interests: Declaration of Competing Interest The authors report no conflicts of interest in this manuscript entitled Longitudinal changes in walking cadence across pregnancy and postpartum., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Walking is the most commonly chosen type of physical activity (PA) during pregnancy and provides several health benefits to both mother and child. National initiatives have promoted the importance of walking in general, but little emphasis is directed toward pregnant women, the majority of whom are insufficiently active. Pregnant women face a variety of dynamic barriers to a physically active lifestyle, some of which are more commonly experienced during specific times throughout the pregnancy experience. Walking is unique in that it appears resistant to a number of these barriers that limit other types of PA participation, and it can be meaningfully integrated into some transportation and occupational activities when leisure-time options are unavailable. Preliminary intervention work suggests that walking programs can be effectively adopted into a typical pregnancy lifestyle. However, a great deal of work remains to administer successful pregnancy walking interventions, including developing and using validated methods of PA and walking assessment. This narrative review discusses the unique advantages of walking during pregnancy, provides recommendations for future intervention work, and outlines the need for pregnancy-focused community walking initiatives. Standard search procedures were followed to determine sources from the literature specific to walking during pregnancy for use in each section of this review.

Research comparing portable body composition methods, such as bioelectrical impedance analysis (BIA), to air displacement plethysmography (ADP) is limited. We assessed reliability and validity of predicting fat-free mass (FFM) by the RJL, Omron, and Tanita BIA machines using ADP via BodPod as a criterion. FFM (kg) was assessed twice in college students (N = 77, 31 males and 46 females; age = 19.1 ± 1.2 years) using ADP, RJL, Omron, and Tanita BIAs. Reliability was assessed using analysis of variance to obtain an intraclass correlation statistic (R xx ). Validity was assessed using Pearson correlation (r) coefficient. FFM averaged 75.6 ± 9.4 kg in men and 59.8 ± 7.6 kg in women. Reliability was high in both genders RJL (R xx  = .974-.994), Omron (R xx  = .933-.993), and Tanita (R xx  = .921-.991). Validity within males was also high: RJL (r = .935), Omron (r = .942), and Tanita (r = .934), and only slightly lower in females: RJL (r = .924), Omron (r = .897), and Tanita (r = .898). The RJL, Omron, and Tanita BIA machines appear to be both reliable and valid for predicting FFM of male and female college students. Therefore, any of these three BIA devices is appropriate to use for body composition assessment in a healthy adult population.

Background: The effect of the Köhler group dynamics paradigm (i.e., working together with a more capable partner where one's performance is indispensable to the team outcome) has been shown to increase motivation to exercise longer at a strength task in partnered exercise video games (exergames) using a software-generated partner (SGP). However, the effect on exercise intensity with an SGP has not been investigated. The purpose of this study was to examine the motivation to maintain or increase exercise intensity among healthy, physically active middle-aged adults using an SGP in an aerobic exergame., Methods: Participants ( n  = 85, mean age = 44.9 years) exercised with an SGP in a 6-day cycle ergometer protocol, randomly assigned to either (a) no partner control, (b) superior SGP who was not a teammate, or (c) superior SGP as a teammate (team score was dependent on the inferior member). The protocol alternated between 30-min continuous and 4-min interval high-intensity session days, during which participants could change cycle power output (watts) from target intensity to alter distance and speed., Results: Mean change in watts from a targeted intensity (75% and 90% maximum heart rate) was the primary dependent variable reflecting motivational effort. Increases in performance over baseline were demonstrated without significant differences between conditions. Self-efficacy and enjoyment were significantly related to effort in the more intense interval sessions., Conclusion: Under these conditions, no Köhler effect was observed. Exercise performance during the higher-intensity interval format is more closely related to enjoyment and self-efficacy beliefs compared to the continuous sessions.

The purpose was to determine if the Alu-insertion (I)/deletion (D) polymorphism of the tissue plasminogen activator (tPA) gene influences the tPA response to maximal exercise. Fifty male subjects (age = 23.6 ± 4.7 yrs) completed a maximal treadmill exercise test. Blood samples were drawn before and immediately after exercise for determination of plasma tPA antigen and activity. Isolated DNA was amplified via polymerase chain reaction, electrophoresed, and visually amplified to determine tPA genotype. Subjects were classified as possessing the D allele (D) (n = 28) or being homozygous for the I allele (I) (n = 22). Differences in tPA antigen and activity were assessed using a two-factor (genotype and time) repeated measures analysis of variance. There were significant main effects for time for tPA antigen and activity (p < 0.05), but no main effect for genotype. Furthermore, there was no genotype x time interaction due to a similar increase in tPA antigen in the D group (pre-exercise = 5.83 + 2.39 ng/ml, post-exercise = 21.88 + 7.38 ng/ml) and the I group (pre-exercise = 5.61 + 2.82 ng/ml, post-exercise = 19.05 + 7.67 ng/ml) and a similar increase in tPA activity in the D group (pre-exercise = 0.39 ± 0.19 IU/ml, post-exercise = 9.73 ± 4.22 IU/ml) and I group (pre-exercise = 0.45 ± 0.29 IU/ml, post-exercise = 9.76 ± 5.50 IU/ml). The I/D polymorphism of the tPA gene does not influence the tPA antigen nor tPA activity responses to maximal exercise in healthy, young, sedentary males.

Over the past several decades, an increased emphasis on fitness training has emerged among collegiate ice hockey teams, with the objective of improving on-ice performance. However, it is unknown if this increase in training has translated over time into changes in the anthropometric and fitness profiles of collegiate ice hockey players. The purposes of this study were to describe anthropometric (height, weight, body mass index (BMI), percent body fat (%fat)) and aerobic fitness (peak oxygen consumption) characteristics of collegiate ice hockey players over a period of 36 years and to evaluate whether these characteristics differ among player positions. Anthropometric and physiologic data were obtained through preseason fitness testing of players (N = 279) from a National Collegiate Athletic Association Division I men's ice hockey team from the years 1980 through 2015. Changes over time in the anthropometric and physiologic variables were evaluated via regression analysis using linear and polynomial models, and differences among player positions were compared via ANOVA (p < 0.05). Regression analysis revealed that a cubic model best predicted changes in mean height (R 2 = 0.65), weight (R 2 = 0.77), and BMI (R 2 = 0.57), whereas a quadratic model best fit change in %fat by year (R 2 = 0.30). Little change was observed over time in the anthropometric characteristics. Defensemen were significantly taller than forwards (184.7 ± 12.1 vs. 181.3 ± 5.9 cm) (p = 0.007), and forwards had a higher relative peak oxygen consumption compared with defensemen (58.7 ± 4.7 vs. 57.2 ± 4.4 mL·kg -1 ·min -1 ) (p = 0.032). No significant differences were observed in %fat or weight by position. Although average player heights and weights fluctuated over time, increased emphasis on fitness training did not affect the athletes' relative aerobic fitness. Differences in height and aerobic fitness levels were observed among player positions.

Several studies have suggested that maternal lifestyle during pregnancy may influence long-term health of offspring by altering the offspring epigenome. Whether maternal leisure-time physical activity (LTPA) during pregnancy might have this effect is unknown. The purpose of this study was to determine the relationship between maternal LTPA during pregnancy and offspring DNA methylation. Participants were recruited from the Archive for Research on Child Health study. At enrollment, participants' demographic information and self-reported LTPA during pregnancy were determined. High active participants (averaged 637.5 min per week of LTPA; n=14) were matched by age and race to low active participants (averaged 59.5 min per week LTPA; n=28). Blood spots were obtained at birth. Pyrosequencing was used to determine methylation levels of long interspersed nucleotide elements (LINE-1) (global methylation) and peroxisome proliferator-activated receptor-gamma (PPARγ), peroxisome proliferator-activated receptor-gamma coactivator (PGC1-α), insulin-like growth factor 2 (IGF2), pyruvate dehydrogenase kinase, isozyme 4 (PDK4) and transcription factor 7-like 2 (TCF7L2). We found no differences between offspring of high active and low active groups for LINE-1 methylation. The only differences in candidate gene methylation between groups were at two CpG sites in the P2 promoter of IGF2; the offspring of low active group had significantly higher DNA methylation (74.70±2.25% methylation for low active v. 72.83±2.85% methylation for high active; P=0.045). Our results suggest no effect of maternal LTPA on offspring global and candidate gene methylation, with the exception of IGF2. IGF2 has been previously associated with regulation of physical activity, suggesting a possible role of maternal LTPA on regulation of offspring physical activity.

Current physical activity (PA) recommendations for women experiencing a normal pregnancy reflect recent research showing numerous health benefits for mother and offspring. However, few studies have evaluated PA devices' reliability and validity during pregnancy, because anatomical and physiological changes throughout gestation could affect an instrument's accuracy., Purpose: This study aimed to determine the reliability and validity of PA devices worn on the hip, ankle, and triceps during pregnancy and postpartum., Methods: Thirty-three women performed six activities of daily living and one treadmill walk at approximately 21 and 32 wk of pregnancy, and 12 wk postpartum. There were two visits at each time period, 1 wk apart. Energy expenditure (oxygen consumption) was measured by using indirect calorimetry (IC; criterion measure), whereas PA was quantified by using accelerometers and pedometers placed at the right hip and ankle and left triceps. Interclass reliability and monitor validity compared with IC in relative (mL·kg·min) terms were calculated using Pearson correlation. Both multitrial and single-trial intraclass reliabilities (ICC) were estimated using ANOVA to assess monitor reliability at each time period. SEM values were calculated in relative terms for each time period., Results: The reliability of the devices was moderate/strong because 66% of the Pearson correlations were between 0.6 and 1.0. Multitrial ICC values were largely in the moderate/strong range because 38% of the ICC values were between 0.6 and 0.79 and 50% were between 0.8 and 1.0. The SEM values for each device between visits ranged from 7% to 23% of the mean values. Comparison between IC and devices showed that 40% and 46% of the validity coefficients were between 0.4 and 0.59 and between 0.6 and 0.79, respectively., Conclusions: PA devices show moderate/strong reliability and moderate validity for measuring PA during pregnancy and postpartum.

Objectives: Evaluate accuracy of the activPAL and its proprietary software for prediction of time spent in physical activity (PA) intensities (sedentary, light, and moderate-to-vigorous) and energy expenditure (EE) and compare its accuracy to that of a machine learning model (ANN) developed from raw activPAL data., Design: Semi-structured accelerometer validation in a laboratory setting., Methods: Participants (n=41 [20 male]; age=22.0±4.2) completed a 90-min protocol performing 13 activities for 3-10min each and choosing activity order, duration, and intensity. Participants wore an activPAL accelerometer (right thigh) and a portable metabolic analyzer. Criterion measures of time spent in sedentary, light, and moderate-to-vigorous PA were determined using measured MET values of ≤1.5, 1.6-2.9, and ≥3.0, respectively. Estimated times in each PA intensity from the activPAL software and ANN were compared with the criterion using repeated measures ANOVA. Window-by-window EE prediction was assessed using correlations and root mean square error., Results: activPAL software-estimated sedentary time was not different from the criterion, but light PA was overestimated (6.2min) and moderate- to vigorous PA was underestimated (4.3min). ANN-estimated sedentary time and light PA were not different from the criterion, but moderate- to vigorous PA was overestimated (1.8min). For EE estimation, the activPAL software had lower correlations (r=0.76 vs. r=0.89) and higher error (1.74 vs. 1.07 METs) than the ANN., Conclusions: The ANN had higher accuracy for estimation of EE and PA than the activPAL software in this semi-structured laboratory setting, indicating potential for the ANN to be used in PA assessment., (Copyright © 2017 Sports Medicine Australia. All rights reserved.)

Objective: Pregnancy-induced nausea and vomiting are common maladies during early pregnancy and may be related to physical activity (PA). Our objective was to determine relations among work-related PA (work PA), leisure-time physical activity (LTPA), and nausea during the first trimester., Study Design: Online or mailed surveys with questions on pregnancy-related nausea, work PA, and LTPA were completed by 70 women at 15 to 30 months postpartum. Women recalled nausea during the first trimester (none, ≤1 h/d, 2-3 h/d, 4-6 h/d, ≥6 h/d) as well as LTPA frequency, duration, and type. Women also recalled total working hours in their first trimester and percentage of time sitting, standing, and walking at work., Results: A total of 42 women (60%) were categorized as having high nausea (≥2 h/d). Mann-Whitney U tests showed that women with low nausea had significantly more MET minutes per week of LTPA (P = .05) and hours per week spent standing at work (P = .03). Logistic regression analyses showed standing for ≥20 h/wk at work was related to reduced odds of high nausea (adjusted odds ratio = 0.23; 95% CI = 0.06-0.96), whereas meeting LTPA guidelines was nonsignificantly related to reduced odds., Conclusion: These findings suggest an inverse relationship between first trimester PA and level of nausea. Further investigation is needed to determine the directionality of these relations., Competing Interests: Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Astronauts may have difficulty adhering to exercise regimens at vigorous intensity levels during long space missions. Vigorous exercise is important for aerobic and musculoskeletal health during space missions and afterwards. A key impediment to maintaining vigorous exercise is motivation. Finding ways to motivate astronauts to exercise at levels necessary to mitigate reductions in musculoskeletal health and aerobic capacity have not been explored. The focus of Simulated Partners and Collaborative Exercise (SPACE) is to use recently documented motivation gains in task groups to heighten the exercise experience for participants, similar in age and fitness to astronauts, for vigorous exercise over a 6-month exercise regimen. A secondary focus is to determine the most effective features in simulated exercise partners for enhancing enjoyment, self-efficacy, and social connectedness. The aims of the project are to (1) Create software-generated (SG) exercise partners and interface software with a cycle ergometer; (2) Pilot test design features of SG partners within a video exercise game (exergame), and (3) Test whether exercising with an SG partner over 24-week time period, compared to exercising alone, leads to greater work effort, aerobic capacity, muscle strength, exercise adherence, and enhanced psychological parameters., Methods/design: This study was approved by the Institutional Review Board (IRB). Chronic exercisers, between the ages 30 and 62, were asked to exercise on a cycle ergometer 6 days per week for 24 weeks using a routine consisting of alternating between moderate-intensity continuous and high-intensity interval sessions. Participants were assigned to one of three conditions: no partner (control), always faster SG partner, or SG partner who was not always faster. Participants were told they could vary cycle ergometer output to increase or decrease intensity during the sessions. Mean change in cycle ergometer power (watts) from the initial continuous and 4 min. interval sessions was the primary dependent variable reflecting work effort. Measures of physiological, strength, and psychological parameters were also taken., Discussion: This paper describes the rationale, development, and methods of the SPACE exergame. We believe this will be a viable intervention that can be disseminated for astronaut use and adapted for use by other populations.

Purpose: Develop strategic priorities to guide future physical activity surveillance in the United States., Methods: The Centers for Disease Control and Prevention and the American College of Sports Medicine convened a scientific roundtable of physical activity and measurement experts. Participants summarized the current state of aerobic physical activity surveillance for adults, focusing on practice and research needs in three areas: 1) behavior, 2) human movement, and 3) community supports. Needs and challenges for each area were identified. At the conclusion of the meeting, experts identified one overarching strategy and five strategic priorities to guide future surveillance., Results: The identified overarching strategy was to develop a national plan for physical activity surveillance similar to the U.S. National Physical Activity Plan for promotion. The purpose of the plan would be to enhance coordination and collaboration within and between sectors, such as transportation and public health, and to address specific strategic priorities identified at the roundtable. These strategic priorities were used 1) to identify and prioritize physical activity constructs; 2) to assess the psychometric properties of instruments for physical activity surveillance; 3) to provide training and technical assistance for those collecting, analyzing, or interpreting surveillance data; 4) to explore accessing data from alternative sources; and 5) to improve communication, translation, and dissemination about estimates of physical activity from surveillance systems., Conclusion: This roundtable provided strategic priorities for physical activity surveillance in the United States. A first step is to develop a national plan for physical activity surveillance that would provide an operating framework from which to execute these priorities.

Purposes: (1) Develop artificial neural network (ANN) models for wrist accelerometer data which can predict energy expenditure (EE) using data collected from either wrist. (2) Develop ANNs for detecting the wrist on which the accelerometer was worn. Forty-four adults wore GENEActiv accelerometers on the left and right wrists and a portable metabolic analyzer while participating in a 90 min semi-structured activity protocol. Participants performed 14 sedentary, lifestyle, exercise, and ambulatory activities and were allowed to choose activity order, duration, and intensity. ANNs were created to predict EE and wrist detection using a leave-one-out cross-validation. In total, 12 combinations of feature sets (mean and variance of raw, vector magnitude, and absolute value data), training methods (left- and right- wrist), and testing methods (left- and right-wrist data) were used to develop EE prediction ANNs. Accuracy of the ANNs was evaluated using correlations, root mean square error (RMSE), and bias, using metabolic analyzer data as the criterion for EE. ANNs using raw data from the same wrist (e.g. EE predicted from right wrist ANNs using accelerometer data from right wrist) had the highest accuracy for EE prediction (r  =  0.84, RMSE  =  1.25-1.26 METs); conversely, opposite-wrist prediction accuracy (e.g. EE predicted from right wrist ANNs using accelerometer data from left wrist) was lower (r  =  0.60-0.64, RMSE  =  1.93-2.01 METs). Preprocessing into absolute values prior to ANN development allowed for, high EE prediction accuracy, with no difference in accuracy for same- versus opposite-wrist prediction (r  =  0.80-0.83, RMSE  =  1.30-1.49 METs). Wrist detection ANNs correctly determined wrist placement 100% of the time. Highly accurate, wrist-independent EE prediction ANNs were developed by computing absolute values of raw acceleration data prior to ANN development. This method provides a potential approach for advancing predictive accuracy of wrist-worn accelerometers.

Highly trained women continue to exercise during pregnancy, but there is little information available to guide them, and their health care providers, in how to maximize performance without jeopardizing the maternal-fetal unit. Available evidence focusing on average women who perform regular vigorous exercise suggests that this activity is helpful in preventing several maladies of pregnancy, with little to no evidence of harm. However, some studies have shown that there may be a limit to how intense an elite performer should exercise during pregnancy. Health care providers should monitor these women athletes carefully, to build trust and understanding.

Unlabelled: RPE scales are used in exercise science research to assess perceptions of physical effort. RPE scale validity has been evaluated by assessing correlations between RPE and physiological indicators. Cross-sectional studies indicate that RPE scale validity improves with age; however, this has not been studied longitudinally., Purpose: This study aimed to examine age-related trends in OMNI-RPE scale validity, using a longitudinal study design, and HR and oxygen uptake (V˙O2) as criterion measures., Methods: Participants performed eleven 5-min activity trials at baseline, 12-, 24-, and 36-month follow-up (V˙O2 data: N = 160; HR data: N = 138). HR and V˙O2 between minutes 2.5 and 4.5 of each activity were recorded. At the end of each activity, participants reported RPE. Children were stratified into the following age-groups: 6-8, 9-10, 11-12, and ≥13 yr. Within-subject correlations between OMNI-RPE and HR/V˙O2 were calculated at each time point. Differences between correlations for consecutive time points were evaluated using 95% confidence intervals., Results: Among children age 6-8 yr at baseline, correlations progressed from 0.67 to 0.78 (V˙O2) and from 0.70 to 0.79 (HR) for 36 months. Among children age 9-10 yr at baseline, the mean within-subject correlation was 0.78 at baseline and 0.81 at 36-month follow-up. Among children age 11-12 and ≥13 yr at baseline, OMNI-RPE ratings demonstrated strong validity (r ≥ 0.82) at each time point., Conclusions: For the 36-month follow-up, OMNI-RPE scale validity improved among children age 6-8 yr at baseline and remained strong among children age 9-10, 11-12, and ≥13 yr at baseline. Moderate correlations for the youngest participants suggest that caution should be used when interpreting OMNI-RPE reports from children younger than 8 yr.

Background: Recent evidence suggests that physical activity (PA) and sedentary behavior (SB) exert independent effects on health. Therefore, measurement methods that can accurately assess both constructs are needed., Objective: To compare the accuracy of accelerometers placed on the hip, thigh, and wrists, coupled with machine learning models, for measurement of PA intensity category (SB, light-intensity PA [LPA], and moderate- to vigorous-intensity PA [MVPA]) and breaks in SB., Methods: Forty young adults (21 female; age 22.0 ± 4.2 years) participated in a 90-minute semi-structured protocol, performing 13 activities (three sedentary, 10 non-sedentary) for 3-10 minutes each. Participants chose activity order, duration, and intensity. Direct observation (DO) was used as a criterion measure of PA intensity category, and transitions from SB to a non-sedentary activity were breaks in SB. Participants wore four accelerometers (right hip, right thigh, and both wrists), and a machine learning model was created for each accelerometer to predict PA intensity category. Sensitivity and specificity for PA intensity category classification were calculated and compared across accelerometers using repeated measures analysis of variance, and the number of breaks in SB was compared using repeated measures analysis of variance., Results: Sensitivity and specificity values for the thigh-worn accelerometer were higher than for wrist- or hip-worn accelerometers, > 99% for all PA intensity categories. Sensitivity and specificity for the hip-worn accelerometer were 87-95% and 93-97%. The left wrist-worn accelerometer had sensitivities and specificities of > 97% for SB and LPA and 91-95% for MVPA, whereas the right wrist-worn accelerometer had sensitivities and specificities of 93-99% for SB and LPA but 67-84% for MVPA. The thigh-worn accelerometer had high accuracy for breaks in SB; all other accelerometers overestimated breaks in SB., Conclusion: Coupled with machine learning modeling, the thigh-worn accelerometer should be considered when objectively assessing PA and SB., Competing Interests: Conflict of Interest: The authors attest that they have no conflicts of interest to report.

Background: Pregnancy risk perceptions and physical activity efficacy beliefs may facilitate or impede pregnancy leisure-time physical activity (LTPA). We examined the separate and joint influence of these variables on LTPA behavior among pregnant women., Methods: Pregnant women (n = 302) completed a survey containing questions on LTPA efficacy beliefs and behavior, as well as pregnancy risk perceptions with respect to the health of the unborn baby. As stipulated by the Risk Perception Attitude (RPA) Framework, 4 attitudinal groups were created: Responsive (High Risk+High Efficacy), Proactive (Low+High), Avoidant (High+Low), and Indifferent (Low+Low). Moderate LTPA and vigorous LTPA were dichotomized for study analyses., Results: A total of 82 women (27.2%) met the moderate physical activity guideline and 90 women (30.1%) performed any vigorous LTPA. Responsive and proactive pregnant women (those with high efficacy) were most likely to meet the moderate guideline and participate in vigorous LTPA. Hierarchical logistic regression did not reveal an interactive effect of pregnancy risk perceptions and LTPA efficacy beliefs for meeting the moderate guideline (OR = 0.94, 95% CI = 0.66-1.36) or any vigorous LTPA participation (OR = 1.41, 95% CI = 0.86-2.29)., Conclusions: LTPA efficacy beliefs appear important in facilitating greater levels of pregnancy LTPA. Significant interactive effects between pregnancy risk perceptions and LTPA efficacy beliefs were not found.

Prospective studies examining postpartum weight retention (PPWR) in relation to the appropriateness of gestational weight gain (GWG) and leisure-time physical activity (LTPA) during pregnancy and postpartum are lacking. While utilizing varying estimates of prepregnancy weight, we sought to prospectively examine associations among the aforementioned variables. Our sample consisted of a subset of women from the Archive for Research on Child Health Study (n = 68). Prepregnancy weight was obtained via questionnaire and birth certificates. GWG (2 estimates) was calculated by subtracting prepregnancy weight estimates from weight at delivery and classified as "excess" or "not excess." Pregnancy and postpartum LTPA were self-reported and dichotomized at recommended levels. Prepregnancy weight estimates were subtracted from self-reported postpartum weight to calculate 2 estimates of PPWR at 6 months. Linear regression was used to examine relationships among GWG and LTPA, and PPWR. Estimates of excess GWG were associated with increased PPWR (mean difference = 3.3-8.9 kg), even after adjustment for prepregnancy body mass index and breastfeeding. Meeting pregnancy and postpartum LTPA recommendations did not significantly predict PPWR. Our findings highlight the importance of encouraging appropriate GWG and provide insight into the impact varying estimates of prepregnancy weight may have when exploring associations among these variables., Competing Interests: Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Maternal physical activity declines across gestation, possibly due to changing perception of physical activity intensity. Our purpose was to a) determine whether rating of perceived exertion (RPE) during a treadmill exercise changes at a given energy expenditure, and b) identify the influence of prepregnancy physical activity behavior on this relationship., Methods: Fifty-one subjects were classified as either exercisers (N = 26) or sedentary (N = 25). Participants visited our laboratory at 20 and 32 weeks gestation and at 12 weeks postpartum. At each visit, women performed 5 minutes of moderate and vigorous treadmill exercise; speed was self-selected. Heart rate (HR), oxygen consumption (VO2), and RPE were measured during the last minute at each treadmill intensity., Results: At moderate intensity, postpartum VO2 was higher compared with 20- or 32-week VO2, but there was no difference for HR or RPE. For vigorous intensity, postpartum HR and VO2 were higher than at 32 weeks, but RPE was not different at any time points., Conclusions: RPE does not differ by pregnancy time point at either moderate or vigorous intensity. However, relative to energy cost, physical activity was perceived to be more difficult at 32 weeks compared with other time points. Pregnant women, then, may compensate for physiological changes during gestation by decreasing walking/running speeds.

Background: We sought to evaluate the effects of maternal leisure-time physical activity (LTPA) during pregnancy and current child LTPA on child weight status., Methods: Women with term pregnancies in the Pregnancy Outcomes and Community Health Study (1998-2004) were followed-up. A race-stratified subset of participants (cohort A) received extensive follow-up efforts leading to better response rates (592/926 = 64%) and diversity. The remainder (Cohort B) had a lower response rate (418/1629 = 26%). Women reported child height, weight and LTPA at 3 to 9 years (inactive vs. active), and recalled pregnancy LTPA (inactive vs. active). A 4-category maternal/child LTPA variable was created (reference: active pregnancy + active child). Children were classified as healthy weight, overweight, or obese using age- and sex-specific Body Mass Index percentiles. Logistic regression was used to assess the odds of child obesity (reference: healthy weight)., Results: In unadjusted analyses, pregnancy inactivity increased odds for obesity when the child was active (1.6 [95% CI, 1.0-2.6] in Cohort A; 2.1 [95% CI, 1.1-4.0] in Cohort B), and more so when the child was inactive (2.4 [95% CI, 1.2-4.9] in Cohort A; 3.0 [95% CI, 1.0-8.8] in Cohort B). Adjustment for covariates attenuated results to statistical nonsignificance but the direction of relations remained., Conclusions: Maternal inactivity during pregnancy may contribute to child obesity risk.

Background: Little is known about how leisure-time physical activity (LTPA) influences gestational weight gain (GWG) among body mass index (BMI) categories. The purpose of this study was to examine the relationship between pregnancy LTPA and the proportion of normal, overweight, and obese women who meet GWG recommendations., Methods: Participants included 449 subcohort women from the Pregnancy Outcomes and Community Health (POUCH) study. LTPA was collapsed into 3 categories [(None, < 7.5 kcal/kg/wk (low), ≥ 7.5 kcal/kg/wk (recommended)]. GWG was categorized according to IOM recommendations (low, recommended, or excess). Chi-square and logistic regression analyses were used to evaluate relationships among LTPA, BMI, and GWG., Results: Overweight women were more likely to have high GWG vs. normal weight women (OR = 2.3, 95% CI 1.3-4.0). Obese women were more likely to experience low GWG (OR = 7.3, 95% CI 3.6-15.1; vs. normal and overweight women) or excess GWG (OR = 3.5, 95% CI 1.9-6.5; vs. normal weight women). LTPA did not vary by prepregnancy BMI category (P = .55) and was not related to GWG in any prepregnancy BMI category (P = .78)., Conclusions: Regardless of prepregnancy BMI, LTPA did not affect a woman's GWG according to IOM recommendations. Results may be due to LTPA not differing among BMI categories.

Objectives: the purpose of this study was to examine associations among gestational weight gain (GWG) and pregnancy leisure-time physical activity (LTPA), within pre-pregnancy body mass index (BMI) categories, while utilising two different estimates of pre-pregnancy weight., Design: a cohort study. Data were collected via questionnaire and abstraction from birth certificate as a part of a larger study., Setting: three antenatal clinics in Lansing, Michigan, USA., Participants: a subset of women who participated in the Archive for Research on Child Health (ARCH) study and delivered a singleton, term infant (n=135). Participants were enroled prior to 14 weeks׳ gestation., Measurements: pre-pregnancy BMI was categorised as normal, overweight and obese (excluded underweight). GWG was calculated by subtracting pre-pregnancy weight from weight at childbirth (obtained from birth certificate) and classified as 'excess' or 'not excess' using the upper limit of the 2009 IOM recommended range. These two variables were constructed twice, first by using pre-pregnancy weight self-reported at enrolment and second, by using pre-pregnancy weight recorded on birth certificates. LTPA, also self-reported at enrolment, was modelled using two thresholds, moderate LTPA, and vigorous LPTA., Findings: overall, 56-60% of our sample experienced excess GWG, depending on the source used for pre-pregnancy weight. Overweight and obese women had significantly higher odds of excess GWG (compared to normal weight women; Odds Ratio (OR)=2.48-5.34). LTPA level did not differ among pre-pregnancy BMI categories and was not related to appropriateness of GWG., Key Conclusions: regardless of the source of pre-pregnancy weight, overweight and obese women were more likely to experience excess GWG (compared to normal weight women) and LTPA was not significantly related to the appropriateness of GWG., Implications for Practice: findings highlight the need for practitioners to effectively communicate GWG recommendations and counsel women about the importance of achieving appropriate GWG. Although GWG counselling has traditionally been focused on obese women, these results suggest overweight women are in need of GWG counselling as well., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Aim: We evaluated relationships between mothers' physical activity (PA) during pregnancy and child blood pressure, aerobic fitness, and birth weight., Methods: Anthropometrics, systolic (SBP) and diastolic (DBP) blood pressures, and aerobic fitness were measured on 20 mother/child pairs, 8-10 years postpartum. Pregnancy PA (kJ/kg.wk) was calculated from historical recall. Women were classified as meeting, or not meeting ACOG PA recommendations., Results: Twelve women met ACOG recommendations, and their children had significantly lower birth weights (3.51±0.45 kg) than the more sedentary women (4.05±0.67 kg). Third trimester maternal PA was inversely related to child SBP (rs=-0.46, P=0.04) but not aerobic fitness. Birth weight was inversely related to SBP (rs=-0.75, P=0.03) if mothers did not meet PA recommendations., Conclusion: Results from our preliminary study suggest that maternal PA is associated with an alteration in the relationship between birth weight and SBP.

Purpose: The purpose of this study was to develop a prediction model based on a submaximal workload during the Bruce treadmill protocol to estimate peak oxygen consumption (VO2(peak)) in adolescent girls., Method: Adolescent girls (N = 116, M(age) = 13.2 +/- 2.0 years) performed a Bruce Treadmill Test to exhaustion. Expired respiratory gases and heart rate (HR) were collected and measured continuously via indirect calorimetry and telemetry. To be included in the analysis, each participant met 2 of 3 criteria: attain 95% of age-predicted HR(peak), respiratory exchange ratio > 1.05, or plateau of VO2. VO2 and HR at Stage 1 and Stage 2 of the Bruce test were entered into a regression model to predict VO2(peak)., Results: A regression model, constructed using the predicted sum of squares statistic, was developed using VO2 (VO(2)2) and HR (HR2) attained at the 2nd 3-min stage of the Bruce treadmill protocol: VO2(peak) = 46.77 - (0.2854155 x HR2) + (1.46732912 x VO(2)2). Actual average (+/- SD) VO2(peak) was 36.2 +/- 6.9 ml x kg(-1) x min(-1) (range = 22.9-55.9). Predicted VO2(peak) was 36.2 +/- 5.5 ml x kg(-1) x min(-1) (range = 24.3-56.2). The correlation between actual and predicted VO2(peak) was r = .80, standard error of estimate = 4.2 ml x kg(-1) x min(-1), with no bias relative to participant aerobic fitness., Conclusion: Based on this model, the VO2(peak) of healthy adolescent girls can be predicted within 4.2 ml x kg(-1) x min(-1) using submaximal Bruce data.

While early studies on the effects of leisure time physical activity (LTPA) during pregnancy were concerned about possible harm to the mother or fetus, these fears have not been substantiated. Instead, a growing body of literature has documented several health benefits related to pregnancy LTPA. The purpose of this article was to synthesize evidence from epidemiological studies conducted in the United States, Canada, and Scandinavia on the benefits of LTPA and exercise during pregnancy with regard to maternal health, pregnancy outcomes, and child health. We focused on studies evaluating relations between pregnancy LTPA and gestational diabetes, hypertensive disorders, excessive gestational weight gain, birth weight, timing of delivery, and child body composition. The bulk of evidence supports beneficial effects of pregnancy LTPA on each outcome; however, most previous studies have been observational and used self-reported LTPA at only one or two time points in pregnancy. Limitations of the current knowledge base and suggestions for future research on the health benefits of LTPA during pregnancy are provided.

Several studies have examined energy expenditure in various sports but there is a lack of research on the contribution of exercise and habitual activity during different training periods. This study examined changes in total daily energy expenditure (TDEE) and its components during high- and low-volume training periods. Further, changes in time spent in sedentary, light, moderate and vigorous activity in response to different training volumes were explored. Energy expenditure was measured in 15 male endurance athletes during 2 non-consecutive weeks - 1 week of high volume (>13 hours) training and another week of low volume (<7 hours) training. The SenseWear Pro 3 Armband, individual heart-rate-oxygen consumption regression and indirect calorimetry was used to measure non-exercise activity thermogensis (NEAT), exercise energy expenditure (EEE) and resting metabolic rate, respectively. Time spent at different intensities was assessed using previously established MET cutpoints. TDEE as well as EEE increased significantly with higher training volume, while no difference in NEAT occurred. Further, significantly less time was spent in sedentary activities during the high-volume week. These results suggest that highly trained athletes do not compensate for increased training volume and reduce sedentary activities to allow for more training time.

Aim: The aim of the present study was to determine the association between health-related fitness (HRF) and academic achievement in middle school youth., Methods: Subjects were 312 middle school students. HRF was assessed using the FITNESSGRAM test battery. Students were grouped by the number of fitness tests in which they performed within the Healthy Fitness Zone, ranging from <1 test (lowest fitness) to all 5 tests (highest fitness). Academic achievement was assessed using grades (A - F) from four core classes, which were converted to interval data (A=5, F=1) and summed over the academic year and a standardized test (percentile). Maturity offset was calculated to control for the possible effect of maturity status on the association between HRF and academic achievement. Differences in academic achievement among HRF groups were determined using ANOVA., Results: Grades and standardized test percentiles were higher in HRF group 5 (P<0.01) compared to HRF groups <2, 3, and 4. Cardiorespiratory endurance and muscular strength and endurance were the HRF components most strongly associated with academic achievement., Conclusion: HRF was related to academic achievement in youth. Students with the highest fitness level performed better on standardized tests and students with the lowest fitness level performed lower in class grades.

The primary purpose of this study was to examine dietary intake in endurance-trained athletes during a week of high-volume and a week of low-volume training while measuring exercise energy expenditure (EEE), resting metabolic rate (RMR), and nonexercise activity thermogenesis (NEAT). In addition, compliance with current American College of Sports Medicine/American Dietetic Association nutrition and performance recommendations for macronutrients was evaluated. Energy expenditure and dietary intake were measured in 15 male endurance athletes during 2 nonconsecutive weeks resembling a high-volume and a low-volume training period. Anthropometric measurements were taken and percentage body fat was determined at the beginning and end of each week of training. Total daily energy expenditure (TDEE) was calculated by summing RMR, NEAT, and EEE. Dietary intake was assessed with an online food-frequency questionnaire completed at the end of each week of data collection. Despite significant differences between TDEE and energy intake, no difference in body composition between the beginning and end of either week of training was observed, suggesting underreporting of caloric intake. Further, no changes in total caloric intake or macronutrient intake occurred even though TDEE increased significantly during the high-volume training. Reported carbohydrate intake (4.5 g·kg(-1)) and fiber intake (25 g·day(-1)) were below recommendations, whereas fat intake (1.3 g·kg(-1)) was slightly above recommendations. In summary, no short-term dietary adjustments occurred in response to differences in training regimen. Because these athletes were generally consuming a Western diet, they may have required some support to achieve desirable intakes for health and performance.

Clear criteria for maximal oxygen consumption (VO2max) determination in youth are not available, and no studies have examined this issue in girls. Our purpose was to determine whether different peak heart rate (HRpeak) and peak respiratory exchange ratio (RERpeak) cut points affect girls' (N = 453; M age = 13.3 years, SD = .1) VO2max during a maximal treadmill test. A multivariate analysis of variance revealed VO2max (ml kg(-1) min(-1) differed significantly among HRpeak, 180-189 b min(-1) = 34 (SD = .8), 190-194 bmin(-1) = 35 (SD = .9), 195-199 b min(-1) = 38 (SD = .8), 200-204 b min(-1) = 40 ml kg1 x min(-1) (SD = .8), and > or = 205 bmin(-1) = 42 ml kg1 x min(-1) (SD = .7) but not RERpeak. In studies where evidence of a VO2 plateau was examined, peak oxygen consumption (VO2peak) did not differ between plateau and no-plateau groups. Although our results suggest the association between lower VO2peak and lower peak heart rate is a true cardiovascular limit to aerobic energy production, we cannot rule out participant effort.

Previous ice hockey research has focused on physiological profiles and determinants of skating speed, but few studies have examined the association of preseason player evaluations with a measure of season-long performance. Understanding which tests are most predictive of player performance could help coaches organize practice and training more effectively. The purpose of this study was to describe physical characteristics and skill levels of 24 members of an NCAA Division I men's ice hockey team and relate them to game performance over the course of a season as measured by plus/minus (+/-) score. Subjects performed a battery of preseason tests including treadmill maximal aerobic capacity, body fat, leg press, push-ups, bench press, chin-ups, and sprinting ability both on and off ice. Pearson and Spearman correlations were used to examine correlations between preseason measures and +/- score. One coach also subjectively grouped the top and bottom 6 players, and analysis of variance was used to examine any differences in preseason measures and +/- score between these 2 groups. Leg press, chin-ups, bench press, and repeat sprint performance were significantly correlated with +/- score (r = 0.554, 0.462, 0.499, and -0.568, respectively). Teams with limited time and resources may choose to perform these tests to evaluate player potential efficiently. Only +/- score differed between top and bottom players suggesting that +/- accurately reflected the coach's perception of player success in this sample.

Background: Physical activity (PA) is an important component of a healthy pregnancy and postpartum period. Since prospective PA monitoring throughout gestation is difficult, a valid PA recall tool would be of significant benefit to researchers. The purpose of this study was to evaluate the ability of women to recall their physical activity performed during pregnancy and postpartum, 6 years later., Methods: Thirty women participated in an historical PA recall study. Pregnancy PA was monitored carefully via assisted physical activity diary (PAD) 6 years before the current investigation. A Modifiable Activity Questionnaire (MAQ) was used to assess current and past pregnancy PA. The MAQ was administered for each time period in the order of most distant past to most current. Leisure time energy expenditure values (kcal/kg/day) calculated from the PAD and the MAQ were compared., Results: MAQ energy expenditure values showed good positive relationships with PAD measures at 20 weeks gestation (r = .57; P < .01), 32 weeks gestation (r = .85; P < .01), and 12 weeks postpartum (r = .86; P < .01). Correlations found were similar to those from previous PA recall and MAQ validation studies using nonpregnant populations., Conclusions: The MAQ is an appropriate tool to assess pregnancy and postpartum PA in women 6 years postpartum.

Aim: To examine healthcare provider knowledge, beliefs, and practices regarding exercise during pregnancy using a cross-sectional 31-question pen and paper survey., Methods: Ninety-three practicing healthcare providers, M.D. (n = 45) and D.O. (n = 14) physicians and certified nurse midwives (C.N.M., n = 34), from hospitals and birth centers around Michigan participated in this study. Descriptive characteristic data, provider knowledge, beliefs, and practices regarding exercise during pregnancy, common exercise restrictions given to pregnant patients, and provider awareness of current American College of Obstetricians and Gynecologists (ACOG) exercise and pregnancy guidelines were collected. Descriptive statistics and chi-square analyses were completed., Results: Overall, 99% of respondents believed that exercise during pregnancy is beneficial, 64% of all respondents believed that maternal exercise heart rate should not exceed 140 beats per minute (bpm), and 60% of M.D.s and 86% of D.O.s were not familiar with the 1994 ACOG guidelines for exercise and pregnancy (p < 0.05)., Conclusions: Although the providers' beliefs about exercise during pregnancy were positive, not all were aware of or followed current ACOG recommendations. Different strategies for dissemination of current research may be warranted.

Unlabelled: Health benefits of physical activity (PA) during pregnancy have been noted, but women's perceptions of PA safety have been little studied., Objectives: To examine associations among PA participation, safety perceptions, and demographic characteristics., Methods: Pregnant women were recruited from nine clinics in Grand Rapids, MI (USA) from April to October, 2006. Demographics, participation in moderate and vigorous PA, and perceived safety of both intensities (5-pt Likert scales) were reported. Logistic regression analyses were used to estimate associations., Results: Of 342 eligible women, 296 provided complete PA information. Most (88%) participated in some PA and felt moderate PA was safe (89%), but only 36% felt vigorous PA was safe. Feeling unsafe/unsure about moderate PA was associated with non-White race/ethnicity, low education, low income, not participating in moderate PA, and/or not intending to be active during pregnancy. Hispanic ethnicity, low education, nulliparity, and not participating in moderate or vigorous PA were associated with feeling unsafe/unsure about vigorous PA., Conclusions: Pregnant women generally feel that moderate PA is safe, but are less certain about vigorous PA. More work is needed to inform pregnant women about the benefits of moderate PA, especially among non-White and low education/income populations.

Unlabelled: Most adults do not meet the American College of Sports Medicine and Centers for Disease Control and Prevention (ACSM/CDC) physical activity recommendations. Even fewer meet the more extreme Institute of Medicine (IOM) physical activity recommendations. Compliance with either recommendation has been conventionally assessed by combining frequencies and durations of self-reported activities. Leisure-time energy expenditure is a cumulative measure of activity that offers an alternative method of defining compliance., Purposes: To calculate the leisure-time energy expenditure of adults complying with the ACSM/CDC or the IOM physical activity recommendations determined by conventional measures and to reexamine compliance with the IOM recommendation using energy expenditure criteria., Methods: National, cross-sectional data from the 2000 Behavioral Risk Factor Surveillance System determined the mode, frequency, and duration of up to two leisure-time activities performed by adults. Four mutually exclusive activity groups (Non-, Low-, ACSM/CDC-, and IOM-Active) were defined on the basis of frequencies and durations of reported activities. Leisure-time energy expenditure (kcal x kg(-1) x wk(-1)) was calculated per respondent. The energy expenditure threshold for meeting the IOM recommendation was calculated as 21 kcal x kg(-1) x wk(-1)., Results: Of the 162,669 respondents included in the analyses, 29.9% were Nonactive, whereas 42.3%, 23.3%, and 4.5% were Low-, ACSM/CDC-, and IOM-Active, respectively. Median leisure-time energy expenditure values were 9.0, 27.4, and 63.0 kcal x kg(-1) x wk(-1) for Low-, ACSM/CDC-, and IOM-Active groups, respectively. When using energy expenditure criteria, compliance with the IOM recommendation rose to 27.7% of respondents., Conclusions: Compliance with the IOM physical activity recommendation dramatically increased when assessed by energy expenditure compared with conventional criteria, thereby highlighting the potential bias of conventional methods. A significant proportion of adults meet the intent but not the letter of the IOM activity recommendation.

The present study evaluated changes in hemodynamics and fibrinolysis during 6 weeks of participation in an exercise-based cardiac rehabilitation program. Fourteen patients trained for 3 days per week for 6 weeks using American College of Sports Medicine guidelines for intensity and duration. Blood samples were taken at baseline and after 3 and 6 weeks of participation and analyzed for tissue plasminogen activator (t-PA) activity and antigen, plasminogen activator inhibitor-1 (PAI-1) activity and antigen, and relative quantification of t-PA and PAI-1 RNA. Data were analyzed using repeated measures analysis of variance. Training elicited significant decreases in submaximal exercise heart rate and systolic blood pressure and resting systolic blood pressure (p<.05). There were no significant changes in plasma concentrations of t-PA or PAI-1, and no change was observed in t-PA or PAI-1 gene expression. The present findings suggest that favorable hemodynamic adaptations may occur after only 6 weeks of exercise-based cardiac rehabilitation, but longer training periods may be needed to elicit positive hemostatic adaptations.

Context: Some female athletes may have decreased bone mineral density (BMD), which puts them at higher risk for stress fractures and future osteoporosis., Objective: To compare site-specific BMD among National Collegiate Athletic Association Division I varsity female athletes and to determine predictor variables of BMD measurements., Design: Between-groups design., Setting: University health care system., Patients or Other Participants: All women varsity athletes were invited to participate in a cross-sectional study. Of 12 sports, we obtained complete data from 99 women (mean age = 20.2 +/- 1.3 years) representing gymnastics, softball, cross-country, track, field hockey, soccer, crew, and swimming/diving., Main Outcome Measure(s): Each participant was weighed, measured, and questioned about her menstrual status. Using dual-energy x-ray absorptiometry, we measured total-body BMD and region-of-interest scores for lumbar spine, pelvis, and average leg (average from right and left leg measurements) BMD. Using analyses of covariance, we compared BMD measurements among sports at each site while controlling for menstrual status and mass, and we performed a stepwise regression analysis to determine significant predictors of BMD at each site., Results: Twenty-three athletes were oligomenorrheic or amenorrheic. Runners had the lowest total-body (1.079 +/- 0.055 g.cm (-2)) and site-specific ( P < .01) BMD values for every site except average leg score when compared with gymnasts and softball players. Swimmers and divers had significantly lower average leg BMD (1.117 +/- 0.086 g.cm (-2)) than athletes in every other sport except runners and rowers ( P < .01). Regression analysis revealed only mass and sport as significant predictors of total-body BMD., Conclusions: Runners and swimmers and divers demonstrated some deficits in site-specific BMD values when compared with athletes in other sports. When treating a female varsity athlete, athletic trainers should consider her mass and sport type with regard to her bone health.

The physical characteristics and performances of female collegiate rowers were examined from two perspectives: level (novice, varsity) and years of participation (0, 1, 2, 3) in collegiate rowing. The participants were 90 female collegiate rowers from three US Division I university teams, of the National Collegiate Athletic Association (NCAA). Height, body mass, sitting height, arm span, skinfolds, limb circumferences, and skeletal breadths were measured. Leg length was estimated and Heath-Carter anthropometric somatotypes were calculated. Performance measures included lower-back flexibility, vertical jump, and 2-km time on a rowing ergometer. Descriptive statistics were calculated for the total sample and by level and years of experience. Multivariate analysis of variance and a Bonferroni-adjusted alpha level (P < 0.05) were used to test differences. Varsity rowers had significantly more rowing experience ( approximately 0.5 years) before college, higher vertical jumps ( approximately 3 cm), faster 2-km times ( approximately 25 s), and lower endomorphic characteristics than novice rowers. Anthropometric and performance differences among rowers by years of experience were negligible with the exception of slower 2-km times ( approximately 32 s) in rowers with no collegiate experience than rowers with collegiate experience. In conclusion, collegiate rowers differ to some extent in physical and performance characteristics by level and experience.

Introduction: Body mass index (BMI) is used as a surrogate for percent fat (% fat) in classifying obesity. However, there is no established criterion for % fat and health risk, and few studies have examined the accuracy/validity of BMI as a measure of % fat. By default, BMI is used to classify athletes and young adults as obese. Consequently, it is critical to understand the accuracy of BMI in these populations. The purposes of this study were 1) to describe the relationship between BMI and % fat, and 2) to determine the accuracy of BMI as a measure of % fat in college athletes and nonathletes., Methods: A total of 226 college-aged athletes and 213 college-aged nonathletes participated. Three male groups (athletes, football linemen, and nonathletes) and two female groups (athletes and nonathletes) were created. BMI was calculated. Percent fat was determined via BOD POD. BMI >or= 25 kg.m(-2) was used to define overweight. Twenty percent fat for males and 33% fat for females were used to define overfatness. Using % fat as the criterion, sensitivity and specificity of BMI were calculated. Receiver operator characteristic curves determined optimal BMI cut points for % fat., Results: Sensitivity was high (0.83-1.0) and specificity was low (0.27-0.66) in male athletes, male nonathletes, and female athletes. Sensitivity was high in linemen (1.0). Sensitivity was low (0.56) and specificity was high (0.90) in female nonathletes. Optimal BMI cut points for male athletes, linemen, male nonathletes, female athletes, and female nonathletes were 27.9, 34.1, 26.5, 27.7, and 24.0 kg.m(-2), respectively., Conclusions: BMI should be used cautiously when classifying fatness in college athletes and nonathletes. Our results support the need for different BMI classifications of overweight in these populations.

Objective: To assess the separate and combined relationships of aerobic physical activity during pregnancy, maternal weight gain during pregnancy, and height to the fetal growth ratio., Methods: The aerobic physical activity of 51 healthy, nonsmoking pregnant women was assessed for 48 hours at both 20 and 32 weeks of pregnancy by accelerometry, heart rate monitoring, and physical activity recall. We analyzed the relationship between maternal physical activity and the fetal growth ratio., Results: All women included in the analysis completed healthy, uncomplicated pregnancies and delivered infants with a weight range of 2,743-4,943 g. Aerobic physical activity assessed by accelerometry was strongly and inversely associated with fetal growth ratio (r=-0.42; P<.002). Infants born to women in the highest quartile of physical activity weighed 608 g less than infants born to women in the lowest quartile. The inverse relationship between physical activity and fetal growth ratio was moderated by maternal height; virtually all the effect was seen in mothers taller than the sample median (1.65 m). Similar relationships were found across methods of physical activity measurement., Conclusion: Aerobic physical activity in pregnancy may be an important determinant of birth weight within the normal range, especially in taller mothers., Level of Evidence: II.

Purpose: This study was conducted to determine the effect of physical education class enrollment and physical activity on academic achievement in middle school children., Methods: Participants were 214 sixth-grade students randomly assigned to physical education during either first or second semesters. Moderate and vigorous physical activity (MVPA) (number of 30-min time blocks) outside of school was assessed using the 3-d physical activity recall (3DPAR). The 3DPAR time blocks were converted to ordinal data with scores of 1 (no activity), 2 (some activity), or 3 (activity meeting Healthy People 2010 guidelines). Academic achievement was assessed using grades from four core academic classes and standardized test scores (Terra Nova percentiles)., Results: Grades were similar regardless of whether students were enrolled in physical education during first or second semesters. Physical education classes averaged only 19 min of MVPA. Students who either performed some or met Healthy People 2010 guidelines for vigorous activity had significantly higher grades (P < 0.05) than students who performed no vigorous activity in both semesters. Moderate physical activity did not affect grades. Standardized test scores were not significantly related to physical education class enrollment or physical activity levels., Conclusion: Although academic achievement was not significantly related to physical education enrollment, higher grades were associated with vigorous physical activity, particularly activity meeting recommended Healthy People 2010 levels.

Ice hockey is a game that relies heavily on both aerobic and anaerobic energy production systems as players perform in various game situations. However, we found no studies evaluating the relationship between a player's physical condition and individual success in games throughout a competitive hockey season. The purpose of this study was to determine the relationship between a player's aerobic fitness (VO(2)max), blood lactate, and percent body fat to his total minutes played during a season (Tmin) and net scoring chances (SCn). Players' (N = 29) preseason VO(2)max, lactate at the fourth stage of an incremental treadmill test (Lac 4), and percent body fat values from the 1999- 2001 National Collegiate Athletic Association Division I hockey seasons were archived and retrieved for this study. The players' Tmin and SCn were used as the on-ice performance variables and were compared with their fitness measures. Lactate at 4th treadmill stage (r = 0.41, p < 0.03) and percent body fat (r = 0.39, p < 0.03) but not VO(2)max (r = 0.20, p < 0.24) were significantly related to Tmin. Both Lac 4 and percent body fat were entered into a stepwise regression model that accounted for 25% of the variance in Tmin among players (p < 0.02). Both VO(2)max (r = 0.41, p < 0.03) and Lac 4 (r = 0.33, p < 0.05) were significantly related to the players' SCn, but percent body fat was not (r = 0.10, p < 0.57). Only VO(2)max significantly predicted the players' SCn, accounting for 17% of the variance. These findings suggest a relationship between a player's conditioning level and on-ice performance. Our results support the value of implementing seasonal physiological testing, which will help strength and conditioning coaches make individualized modifications to a player's fitness regimens in an effort to improve specific physiological attributes.

Objectives: To review the effects of physical activity on health and behavior outcomes and develop evidence-based recommendations for physical activity in youth., Study Design: A systematic literature review identified 850 articles; additional papers were identified by the expert panelists. Articles in the identified outcome areas were reviewed, evaluated and summarized by an expert panelist. The strength of the evidence, conclusions, key issues, and gaps in the evidence were abstracted in a standardized format and presented and discussed by panelists and organizational representatives., Results: Most intervention studies used supervised programs of moderate to vigorous physical activity of 30 to 45 minutes duration 3 to 5 days per week. The panel believed that a greater amount of physical activity would be necessary to achieve similar beneficial effects on health and behavioral outcomes in ordinary daily circumstances (typically intermittent and unsupervised activity)., Conclusion: School-age youth should participate daily in 60 minutes or more of moderate to vigorous physical activity that is developmentally appropriate, enjoyable, and involves a variety of activities.