Low energy availability can place athletes at increased risk of injury and illness and can be detected by a lower metabolic rate. The lowest metabolic rate is captured at the bedside, after an overnight fast and termed inpatient resting energy expenditure (REE). Measurements done in a laboratory with a shorter overnight fast are termed outpatient REE. Although important to know what the lowest energy expenditure, a bedside measure and/or 12-hr fast is not always practical or logistically possible particularly when you take into account an athlete’s training schedule. The aim of this investigation was to compare a bedside measure of resting metabolism with a laboratory measure in athletes following an 8-hr fast. Thirty-two athletes (24 females and eight males) underwent measures of resting metabolism using indirect calorimetry once at their bedside (inpatient) and once in a simulated laboratory setting (outpatient). Paired t test was used to compare the mean ± SD differences between the two protocols. Inpatient REE was 7,302 ± 1,272 kJ/day and outpatient REE was 7,216 ± 1,116 kJ/day (p = .448). Thirteen participants repeated the outpatient protocol and 17 repeated the inpatient protocol to assess the day-to-day variation. Reliability was assessed using the intraclass correlation coefficient and typical error. The inpatient-protocol variability was 96% with a typical error of 336.2 kJ/day. For the outpatient protocol, the intraclass correlation coefficient and typical error were 87% and 477.6 kJ/day, respectively. Results indicate no difference in REE when measured under inpatient and outpatient conditions; however, the inpatient protocol has greater reliability.
Julia L. Bone and Louise M. Burke
Chih-Chia (JJ) Chen and Shannon D.R. Ringenbach
János Négyesi, Menno P. Veldman, Kelly M.M. Berghuis, Marie Javet, József Tihanyi and Tibor Hortobágyi
Sensory input can modify motor function and magnify interlimb transfer. We examined the effects of low-intensity somatosensory electrical stimulation (SES) on motor practice-induced skill acquisition and intermanual transfer. Participants practiced a visuomotor skill for 25 min and received SES to the practice or the transfer arm. Responses to single- and double-pulse transcranial magnetic stimulation were measured in both extensor carpi radialis. SES did not further increase skill acquisition (motor practice with right hand [RMP]: 30.8% and motor practice with right hand + somatosensory electrical stimulation to the right arm [RMP + RSES]: 27.8%) and intermanual transfer (RMP: 13.6% and RMP + RSES: 9.8%) when delivered to the left arm (motor practice with right hand + somatosensory electrical stimulation to the left arm [RMP + LSES]: 44.8% and 18.6%, respectively). Furthermore, transcranial magnetic stimulation measures revealed no changes in either hand. Future studies should systematically manipulate SES parameters to better understand the mechanisms of how SES affords motor learning benefits documented but not studied in patients.
Darren G. Burke, Darren G. Candow, Philip D. Chilibeck, Lauren G. MacNeil, Brian D. Roy, Mark A. Tarnopolsky and Tim Ziegenfuss
The purpose of this study was to compare changes in muscle insulin-like growth factor-I (IGF-I) content resulting from resistance-exercise training (RET) and creatine supplementation (CR). Male (n = 24) and female (n = 18) participants with minimal resistance-exercise-training experience (≥1 year) who were participating in at least 30 min of structured physical activity (i.e., walking, jogging, cycling) 3–5 ×/wk volunteered for the study. Participants were randomly assigned in blocks (gender) to supplement with creatine (CR: 0.25 g/kg lean-tissue mass for 7 days; 0.06 g/kg lean-tissue mass for 49 days; n = 22, 12 males, 10 female) or isocaloric placebo (PL: n = 20, 12 male, 8 female) and engage in a whole-body RET program for 8 wk. Eighteen participants were classified as vegetarian (lacto-ovo or vegan; CR: 5 male, 5 female; PL: 3 male, 5 female). Muscle biopsies (vastus lateralis) were taken before and after the intervention and analyzed for IGF-I using standard immunohistochemical procedures. Stained muscle cross-sections were examined microscopically and IGF-I content quantified using image-analysis software. Results showed that RET increased intramuscular IGF-I content by 67%, with greater accumulation from CR (+78%) than PL (+54%; p = .06). There were no differences in IGF-I between vegetarians and nonvegetarians. These findings indicate that creatine supplementation during resistance-exercise training increases intramuscular IGF-I concentration in healthy men and women, independent of habitual dietary routine.
Stephen M. Glass, Brian L. Cone, Christopher K. Rhea, Donna M. Duffy and Scott E. Ross
Context: Previous work suggests that balance behavior is a sex-dependent, complex process that can be characterized by linear and nonlinear metrics. Although a certain degree of center of pressure variability may be expected based on sexual dimorphism, there is evidence to suggest that these effects are obscured by potential interactions between sex and anthropometric factors. To date, no study has accounted for such interactive effects using both linear and nonlinear measures. Objective: This investigation sought to analyze interactive models featuring sex, height, and weight as predictors of linear and nonlinear aspects of postural control. Design: Cross-sectional study. Setting: Controlled laboratory. Participants: A total of 26 males (23.80 [3.44] y, 177.87 [6.44] cm, 81.70 [10.80] kg) and 28 females (21.14 [2.03] y, 169.57 [8.80] cm, 64.48 [8.86] kg) were sampled from a healthy university population. MainOutcomeMeasures: Linear (range [RNG], velocity [VEL], and SD) and nonlinear (detrended fluctuation analysis scaling exponent, multivariate multiscale sample entropy [MMSECI]) summary metrics of center of pressure time series. Procedure: Participants stood on a force plate for 20 seconds in 3 conditions: double (D), single (S), and tandem (T) stance. Data for each stance condition were analyzed using regression models with interaction terms for sex × height and sex × weight. In D, weight had a positive, significant main effect on VELy, MMSECId, and MMSECIv. In men, height was observed to have a positive effect on SDy (S), RNGy (S), and RNGx (T) and a negative effect on MMSECIv (T). In women, weight was observed to have a positive effect on SDy and VELx (both T). Conclusions: Our findings suggest that men and women differ with respect to certain linear and nonlinear aspects of balance behavior, and that these differences may reflect sex-specific behavioral patterns in addition to effects related to sexual dimorphism.
Dianne Neumark-Sztainer, Richard F. MacLehose, Allison W. Watts, Marla E. Eisenberg, Melissa N. Laska and Nicole Larson
Obesity in young adults is of public health concern, given its high prevalence and potential adverse health consequences. 1 – 3 Innovative strategies are needed that are widely acceptable and effective in long-term weight management. 4 Given that some research suggests that overweight individuals
Kim Jose and Emily Hansen
Leisure-time physical activity is a term used by physical activity researchers to describe physical activity undertaken during nonwork time. In this study we explore how young people speak about physical activity in relation to leisure.
Eight focus groups and one group interview were conducted with 50 participants aged 16−26 years. Participants included males and females, rural and urban dwellers, and a mixture of active/inactive young people. Focus group transcripts underwent an iterative thematic analysis.
Participants found it difficult to recognize leisure time activities in their day to day lives and only rarely mentioned their physical activity involvement when asked about leisure time activities. When discussing physical activity study participants commonly focused on high intensity physical activity such as sport and gym use. Three major themes relating to leisure and physical activity were identified: the meanings ascribed to physical activity, the experience of physical activity, and routines of participation.
These findings suggest that the relationship between physical activity and leisure is complex and the term leisure with its associated concepts of satisfaction, relaxation and pleasure may not accurately reflect the way young people view their participation in physical activity.
Alex C. Garn, Birgitta L. Baker, Emily K. Beasley and Melinda A. Solmon
Traditional videogames contribute to sedentary behaviors; in contrast, exergaming is a relatively new concept that uses videogames to promote exercise during game play. Nintendo Wii Fit is a commercially popular exergaming platform geared toward improving fitness, however, limited empirical evidence related to the physical and mental benefits of the Wii Fit platform currently exist. Therefore, the purpose of this study was to investigate possible physical and motivational benefits of Nintendo Wii Fit.
A repeated measures design was used with 30 college-aged students to explore physical activity, enjoyment, and future intentions of physical activity associated with Wii Fit exergames.
Data supported the efficacy of Wii Fit Basic Run to consistently produce moderate to vigorous physical activity across participants. Future intentions were higher for exergaming compared with generic exercise and obese individuals enjoyed exergaming more than generic physical activity.
The Basic Run Wii Fit game provided opportunities for accumulating moderate to vigorous physical activity that provided motivational benefits to these participants, especially those classified as obese. Future research should examine the ability of Wii Fit exergames to produce physical activity and motivation over time.
Denise Azar, Kylie Ball, Jo Salmon and Verity Cleland
A number of factors have been identified as important correlates of physical activity (PA) among young women. Young women at risk of depression have a greater likelihood of being physically inactive and it is unknown whether correlates differ for women at risk and not at risk of depression.
A sample of 451 women aged 18 to 35 years self-reported leisure-time PA, enjoyment of and self-efficacy for walking and vigorous PA, barriers, social support, access to sporting/leisure facilities, and access to sporting equipment in the home. Depression risk was assessed using the General Health Questionnaire (cut point ≥5). Logistic regression analyses examined differences in PA correlates among women at risk and not at risk of depression.
Self-efficacy for vigorous PA was statistically different between groups in predicting odds for meeting PA recommendations but odds ratios were similar across groups. No other significant interactions between correlates and depressive symptoms were identified.
The findings suggest few differences in the individual, social, and physical environmental correlates of PA among young women who are and are not at risk of depression. Further research is needed to confirm the existence of any PA correlates specific to this high-risk target group.
Sasha A. Fleary, Robin Mehl and Claudio Nigg
Background: Health behaviors in childhood and adolescence are implicated in health behaviors and chronic disease risk in adulthood for the majority of the US population. However, little is known about these relationships in Hawaiian youth. This study investigated the extent to which childhood physical activity (PA) and fruit and vegetable consumption behaviors predicted later behaviors across a 10-year period in Hawaiian youth. Methods: Three cohorts of fourth- to sixth-grade students who participated in an elementary after-school program (Fun 5) provided baseline data (Y1—data collected between 2003 and 2007), 5-year (Y5—data collected between 2008 and 2012), and 10-year (Y10—data collected between 2013 and 2017) follow-up surveys. Demographic, PA, and fruit and vegetable consumption measures were completed at all 3 time points. Bivariate and multiple regressions were computed in 2018. Results: Y1 and Y5 behavior predicted PA in young adulthood. For fruit and vegetable consumption, Y1 behavior predicted Y5 behavior but not Y10 behavior, and Y5 behavior predicted Y10 behaviors. Conclusions: Similar to mainland US youth, it is important to address PA and nutrition early in the life span for Hawaiian youth to increase long-term preventive health behaviors and reduce long-term chronic disease risk.