The effects of a brand-specific, hemp-derived cannabidiol product on physiological, biochemical, and psychometric outcomes in healthy adults: a double-blind, randomized clinical trial.

BACKGROUND: Cannabidiol (CBD) is a non-psychoactive phyto-cannabinoid derived from the Cannabis sativa plant. CBD exhibits various interactions at receptor sites, prompting the research of its potential anti-inflammatory, immunomodulatory, psychological, and pain-relieving effects. This study aimed to investigate the physiological, biochemical, and psychometric effects of a brand-specific, hemp-derived CBD product in healthy adults over a 12-week observation period. METHODS: 54 healthy males and females (age = 25 ± 7y; BMI = 24.82 ± 3.25 kg/m2) recruited from a large Southeastern University completed the study. Participants arrived at the laboratory after > 8 h of fasting, and > 48 h without alcohol consumption and vigorous exercise. Following baseline measurements (height, weight, blood pressure, electrocardiogram (ECG), and blood work), participants were stratified by sex and randomized to either CBD or placebo groups. Products were administered double-blinded, with both given in liquid form containing medium-chain triglyceride oil, while the CBD product specifically contained 50 mg/mL of CBD. Participants were instructed to consume 1 mL of their product twice daily and were given enough product to last until their next laboratory visit. Data were collected at baseline and on days 30 ± 3, 60 ± 3, and 90 ± 3. Blood was drawn for analysis of immune and inflammatory biomarkers. Chronic pain among participants was calculated using urine samples according to the foundational pain index (FPI). Self-reported psychometric questionnaires were utilized (Cohen's Perceived Stress Scale, Pittsburgh Sleep Quality Index, Profile of Mood States,10-item Likert scale for perceived pain) to assess stress, sleep quality, mood state, and body discomfort. To determine overall wellbeing, participants completed a daily survey indicating if they missed work or school due to illness. Change from baseline was calculated for each measure, and mixed effects models were used to determine differences between groups over time while adjusting for baseline values (α = 0.05). Data are presented as mean ± standard deviation. RESULTS: There were no Group-by-Time interactions or Group or Time main effects for immune or inflammatory biomarkers (p > 0.05). Analyses revealed no Group-by-Time interactions or main effects observed for perceived stress, sleep quality, overall mood disturbance, and all the profile of mood state subscales (p > 0.05), except "vigor-activity." A Time main effect was found for the sub-score for "vigor-activity" (p = 0.007; Pre CBD = 19.5 ± 5.2, Post CBD = 17.3 ± 5.3; Pre PL = 19.0 ± 5.7, Post PL = 17.9 ± 7.1), which decreased from Visit 3 to Visit 4 (p = 0.025) and from Visit 3 to Visit 5 (p = 0.014). There was a Group main effect for FPI (p = 0.028; Pre CBD = 11.9 ± 14.4, Post CBD = 8.8 ± 10.9; Pre PL = 9.0 ± 14.2, Post PL = 12.9 ± 11.5), indicating that the placebo group had greater increases in pain over the intervention compared to the CBD group. No significant differences were found between groups in the incidence and prevalence of "colds or flus" (p > 0.05). DISCUSSION: CBD was safe and well tolerated in healthy adults. These findings show pain was lower in the CBD group, suggesting a potentially positive effect for consumption of CBD. "Vigor-activity" decreased across the intervention, which may be a confounding effect of the academic semester. While the dosage chosen was safe, more research may be warranted using higher doses as these may be needed to observe further therapeutic effects in healthy populations.

A Sex Comparison of the Physical and Physiological Demands of United States Marine Corps Recruit Training.

INTRODUCTION: The U.S. Marine Corps (USMC) recruit training is a 13-week preparatory period for military service men and women. Differences in absolute performance capabilities between sexes may impact physical and physiological responses to the demands of recruit training. The purpose of this study was to monitor U.S. Marine Corps recruits throughout recruit training to comparatively assess workload, sleep, stress, and performance responses in men and women. MATERIALS AND METHODS: A total of 281 recruits (men = 182 and women = 99; age = 19 ± 2 years) were monitored and tested. Workload, sleep, and stress assessments occurred at week 2, week 7/8, and week 11 of training. Workload (energy expenditure per kg body mass [EEREL], distance [DIS], steps) and sleep (continuity and duration) were tracked over 72-hour periods using wearable accelerometry and heart rate technology. Stress responses were determined through salivary cortisol analyses. Performance testing, consisting of countermovement vertical jump (CMJ) and isometric mid-thigh pull (IMTP) performance relative to body mass, occurred at weeks 2 and 11. Linear mixed models were used to test for sex, time, and sex-by-time interactions (α < .05). RESULTS: On average, recruits covered 13.0 ± 2.7 km/day, expended 3,762 ± 765 calories/day, and slept 6.2 ± 1.1 hours/night. Sex-by-time interactions were found for DIS, steps, sleep duration, cortisol, and CMJREL performance (P < .05). Planned contrasts revealed that men covered more DIS than women at week 7/8 (P < .001). Women experienced greater step counts compared to men at week 11 (P = .004). Women experienced no significant change in sleep duration (P > .05), whereas men increased sleep duration from week 2 to week 7/8 (P = .03). Women experienced greater sleep duration at week 2 (P = .03) and week 11 (P = .02) compared to men. Women exhibited higher cortisol levels than men at week 2 (P < .001) and week 11 (P < .001). Women experienced declines in cortisol at week 7 compared to week 2 (P < .001). Men experienced no changes in cortisol response at any timepoint (P > .05). Both sexes experienced declines in CMJREL from week 2 to week 11 (P > .001). Sex main effects were observed for EEREL, DIS, CMJREL, and IMTPREL (P < .05) with men experiencing greater overall workloads and producing greater strength and power metrics. Sex main effects were also found for sleep continuity and cortisol (P < .05), for which men experienced lower values compared to women. Time main effects were observed for EEREL, DIS, steps, cortisol, CMJREL, and IMTPREL (P < .05). CONCLUSIONS: This study not only highlights the known sex differences between men and women but also sheds light on the different physical and physiological responses of each sex to military training. Interestingly, the greatest physical demands incurred earlier in the training cycle. Despite declining workloads, the stress response was maintained throughout the training, which may have implications for adaptation and performance. In addition, average sleep duration fell notably below recommendations for optimizing health and recovery. Effectively monitoring the demands and performance outcomes during recruit training is essential for determining individual fitness capabilities, as well as establishing the effectiveness of a training program. Individual performance assessments and adequately periodized workloads may help to optimize recruit training for both men and women.

United States Marine Corps Recruit Training Demands Associated With Performance Outcomes.

INTRODUCTION: United States Marine Corps' (USMC) recruit training is a 13-week program designed to maximize physical and mental performance adaptations. The purpose of this study was to evaluate the training demands and characteristics that are associated with performance outcomes during USMC recruit training. MATERIALS AND METHODS: A total of 196 recruits (M = 97 and W = 99) were monitored and tested throughout training. Laboratory-based performance testing occurred at the start of weeks 2 and 11 and consisted of body mass assessments, countermovement vertical jump, and isometric mid-thigh pull. Military-specific performance testing occurred twice within the first 8 weeks of training and included the physical fitness test (PFT) and combat fitness test (CFT) implemented by the USMC. Resilience data were collected at week 2 using the Connor-Davidson Resilience Scale. Workload, sleep, and stress responses were monitored at weeks 2, 7, and 11. Recruits were provided with a wearable tracking device which utilized heart rate and accelerometry-based technology to determine energy expenditure (EE), distances (DIS), and sleep metrics. Data were averaged over a 3-day period. Salivary cortisol testing occurred at the start of each monitoring week. Change scores were calculated for performance tests, and body mass was calculated from data obtained at week 2 to week 11. Area under the curve was calculated for the workload, sleep metrics, and cortisol responses using the trapezoidal method. Pearson product-moment correlations (r) were used to assess the relationships between training demands and performance. An α level of 0.05 was used to establish significance. RESULTS: A moderate positive correlation was found between changes in body mass and peak power (P < .001; r = 0.43). Weak positive correlations were found between changes in body mass and peak force (P = .002; r = 0.28), as well as body mass and resilience (P = .03; r = 0.19). A moderate negative correlation was observed between changes in body mass and PFT (P < .001; r = -0.49). A weak negative correlation was found between changes in body mass and EE (P = .003; r = -0.24). A weak negative correlation was found between changes in peak power and EE (P = .001; r = -0.29). A weak positive correlation was found between changes in peak power and changes in CFT (P = .05; r = 0.19) A weak negative correlation was found between changes in sleep continuity and CFT (P = .02; r = -0.20). A weak negative correlation was found between cortisol and changes in PFT (P = .05; r = -0.20). A weak negative correlation was found between cortisol and both EE (P = .001; r = -0.27) and DIS (P = .045; r = -0.16). A weak negative correlation was found between EE and sleep continuity (P < .001; r = -0.34). Weak negative correlations were found between sleep duration and both DIS (P = .01; r = -0.18) and steps (P = .003; r = -0.21). CONCLUSIONS: Increases in body mass throughout training were positively associated with strength and power changes, but negatively related to PFT scores. Changes in peak power related to improvements in CFT scores; however, higher workloads (i.e., EE) were negatively associated with peak power. The identification of the USMC physical and physiological training demands that are associated with performance outcomes may be a valuable resource to guide conditioning efforts to boost military readiness.

Monitoring training, performance, biomarkers, and psychological state throughout a competitive season: a case study of a triathlete.

INTRODUCTION: Ironman triathletes undergo high workloads during competition preparation which can result in nonfunctional overreaching or overtraining syndrome if not matched with adequate recovery. PURPOSE: The purpose of this case study was to observe changes in physiological and psychological status over the course of a competitive season in a free-living triathlete. METHODS: The subject was a 41-year-old triathlete competing in three 113.1-km events. Over the course of a 40-week period, the participant arrived at the laboratory every 4 weeks and underwent body composition testing via air displacement plethysmography, a blood draw for analysis of various biomarkers, and a treadmill-based lactate threshold test. Workload during training and competitions was monitored via a wearable heart rate-monitoring device. RESULTS: Throughout the season, training volume remained high (12.5 ± 3.4 h/week) and body mass and fat-free mass (FFM) continuously decreased, while biomarkers including cortisol, testosterone, and markers of immunological status exhibited minor changes. Laboratory performance remained relatively consistent, while competition performance continually improved. Following the completion of the competitive period, training volume decreased, FFM remained below baseline levels, free cortisol increased, and both free and total testosterone decreased. CONCLUSIONS: Workload and recovery seem to have been properly managed throughout the season, evidenced by minimal fluctuations in endocrine and immunological markers. The reason for changes observed in testosterone, cortisol, and body composition following the last competition is unclear, though it may be attributed to changes in stressors and recovery practices outside of training. It is recommended that athletes follow a structured plan during the transition period into the offseason to ensure recovery of physiological state and to set up a productive offseason.

Effects of Minimal-Equipment Resistance Training and Blood Flow Restriction on Military-Relevant Performance Outcomes.

ABSTRACT: Cintineo, HP, Chandler, AJ, Mastrofini, GF, Lints, BS, McFadden, BA, and Arent, SM. Effects of minimal-equipment resistance training and blood flow restriction on military-relevant performance outcomes. J Strength Cond Res 38(1): 55-65, 2024-This study compared minimal-equipment resistance training (RT) with and without blood flow restriction (BFR) to traditional-equipment RT on performance and body composition changes over 6 weeks. Reserve officers' training corps cadets and midshipmen (N = 54, 40.7% female) were randomized into traditional-equipment RT (TRAD), minimal-equipment RT (MIN), or minimal-equipment RT with BFR (MIN + BFR). Performance and body composition were assessed pretraining and post-training, and measures of intensity and workload were evaluated throughout. Performance assessments included the army combat fitness test (ACFT), countermovement vertical jump, 3RM bench press, and V̇O2max; body composition measures included body fat percentage, fat-free mass, and muscle and tendon thickness. All groups trained 4 days per week after a full-body routine. Data were analyzed by mixed-effects models (α = 0.05). Group-by-time interactions for 3RM deadlift and 3RM bench press (p < 0.004) showed larger improvements for TRAD compared with MIN and MIN + BFR. Time main effects for all other performance variables, body fat percentage, fat-free mass, and muscle thickness (p ≤ 0.035) indicated improvements in all groups. A group-by-time interaction for blood lactate (p < 0.001) and group main effects for heart rate (p < 0.001) and workload variables (p < 0.008) indicated higher intensity and workload for MIN and MIN + BFR compared with TRAD. A sex-by-time interaction for 3RM deadlift (p = 0.008) and sex-by-group-by-time interaction for 3RM bench press (p = 0.018) were also found. Minimal-equipment RT improved performance and body composition, although strength improvements were greater with traditional equipment. Minimal-equipment RT and minimal-equipment RT with BFR exhibited higher exertion levels than TRAD, although adaptations were similar. Overall, individuals can improve performance and body composition using portable, field-expedient RT equipment.

Effects of fucoidan supplementation on inflammatory and immune response after high-intensity exercise.

INTRODUCTION: High-intensity exercise (HIE) can damage the musculotendon complex and impact the immune response, resulting in post-exercise inflammation. Sufficient rest and recovery will improve muscular resilience against future damaging bouts; however, HIE with minimal durations of rest is common in athletic competitions that facilitate persistent inflammation and immune dysregulation. Fucoidans are fucose-rich sulfated polysaccharides with demonstrated anti-inflammatory and pro-immune responses. Fucoidans may improve inflammation and immune responses, which may prove beneficial for individuals who regularly engage in repeated HIE. The research purpose was to investigate the safety and efficacy of fucoidans on inflammatory and immune markers following HIE. METHODS: Eight male and eight female participants were randomized into a double-blind, placebo-controlled, counterbalanced, crossover design study and supplemented with 1 g/day fucoidan from Undaria pinnatifida (UPF) or placebo (PL) for 2 weeks. Supplementation periods concluded with HIE testing, followed by 1 week of washout. HIE involved one > 30 s Wingate anaerobic test (WAnT) and eight 10 s WAnT intervals. Blood was drawn pre-exercise, immediately post-exercise, 30 min, and 60 min post-exercise to assess immune and inflammatory markers. Blood markers, peak power (PP), and mean power (MP) were analyzed using a 2 (condition) × 4 (time) design. Significance was set at α = .05. RESULTS: A time-by-condition interaction was observed for interleukin-6 (p = .01) and interleukin-10 (p = .008). Post hoc analysis revealed greater interleukin-6 and interleukin-10 concentrations at 30 min post HIE with UPF supplementation (p = .002 and p = .005, respectively). No effects of condition were observed for all blood markers or performance outcomes with UPF supplementation (p > .05). Main effects of time were observed for white blood cells, red blood cells, red cell distribution width, mean platelet volume, neutrophils, lymphocytes, monocytes, eosinophils, basophils, natural killer cells, B and T-lymphocytes, CD4 and CD8 cells (p < .05). DISCUSSION: No adverse events were reported throughout the study period, indicating a positive safety profile of UPF. While notable changes in biomarkers occurred up to 1 hr post HIE, few differences were observed between supplementation conditions. There did appear to be a modest effect of UPF on inflammatory cytokines potentially warranting further investigation. However, fucoidan supplementation did not influence exercise performance.

Power, Endurance, and Body Composition Changes Over a Collegiate Career in National Collegiate Athletic Association Division I Women Soccer Athletes.

ABSTRACT: McFadden, BA, Bozzini, BN, Cintineo, HP, Hills, SP, Walker, AJ, Chandler, AJ, Sanders, DJ, Russell, M, and Arent, SM. Power, endurance, and body composition changes over a collegiate career in National Collegiate Athletic Association Division I women soccer athletes. J Strength Cond Res 37(7): 1428-1433, 2023-The purpose of this study was to determine longitudinal changes in fitness and body composition throughout athletes' 4-year collegiate soccer careers. Performance testing occurred before preseason during freshman, sophomore, junior, and senior year in 17 female Division I soccer players. Body composition was assessed through air-displacement plethysmography to determine percent body fat (%BF), fat-free mass (FFM), and body mass (BM). Maximal countermovement vertical jump height was assessed through contact mat using arm swing (CMJ AS ) and hands-on-hips (CMJ HOH ) methods to calculate power (CMJ watts / HOHwatts ). Aerobic capacity (V̇ o2 max) and ventilatory threshold (VT) were assessed by indirect calorimetry during a maximal graded exercise test on a treadmill. Linear mixed models were used to assess changes across academic years ( p < 0.05). No changes occurred in %BF, BM, V̇ o2 max, VT, CMJ AS , or CMJ watts . A time main effect was seen for FFM ( p = 0.01) with increases from freshman to senior ( p = 0.02). Time main effects were observed for CMJ HOH ( p < 0.001) and CMJ HOHwatts ( p < 0.001) with increases from freshman to junior (CMJ HOH,p = 0.001; CMJ HOHwatts , p = 0.02) and senior (CMJ HOH , p < 0.001; CMJ HOHwatts , p = 0.003) as well as sophomore to senior (CMJ HOH , p < 0.001; CMJ HOHwatts , p = 0.02). Countermovement vertical jump with hands on hips also increased from sophomore to junior ( p = 0.005). The lower FFM and power capabilities as freshmen compared with upperclassman indicate a potential limited readiness. Coaches and training staff should account for these developmental differences when entering the preseason. Adequate conditioning programs before starting a collegiate program may help build a fitness foundation and prepare freshmen athletes to compete at the same level as their upperclassmen counterparts.

Implementing Psychological First Aid for Healthcare Workers During the COVID-19 Pandemic: A Feasibility Study of the ICARE Model.

Maintaining the resilience of healthcare workers (HCWs) during the protracted COVID-19 pandemic is critical as chronic stress is associated with burnout, inability to provide high-quality care, and decreased attentiveness to infection prevention protocols. Between May and July 2020, we implemented the ICARE model of psychological first aid (PFA) in a novel online (i.e., telehealth) format to address the psychological support needs of HCWs during the COVID-19 pandemic. We found that HCWs needed psychological support related to obtaining clear information about pandemic policies and guidelines, navigating new rules and responsibilities, and processing overwhelming and conflicting emotions. The HCWs in our program repeatedly expressed appreciation for the support we provided. Future directions include establishing online discussion forums, increasing opportunities for individual support, and training HCWs to provide peer support using PFA. This program has far-reaching potential benefit to HCWs and to society at large in the context of a pandemic.

Effects of caffeine, methylliberine, and theacrine on vigilance, marksmanship, and hemodynamic responses in tactical personnel: a double-blind, randomized, placebo-controlled trial.

Background: Tactical athletes require fast reaction times (RT) along with high levels of vigilance and marksmanship performance. Caffeine has been shown to improve these measures but also results in increased blood pressure and jitteriness. Research on other purine alkaloids, such as methylliberine and theacrine, has suggested they do not increase blood pressure or jitteriness to the same extent, but their impact on tactical performance is unknown. Methods: A between-subjects, randomized, placebo-controlled design was used to test the effects of placebo (PLA), 300 mg caffeine (CAF), and a combination of 150 mg caffeine, 100 mg methylliberine, and 50 mg theacrine (CMT) on RT and marksmanship along with hemodynamic and arousal measures following a sustained vigilance task in tactical personnel (n = 48). Following consumption of the supplement, participants underwent a 150-min protocol consisting of two rounds. Each round began with leisurely reading followed by a 30-min vigilance task before beginning two trials of movement and marksmanship tasks. Hemodynamics and felt arousal were assessed throughout the protocol. Composite Z-scores were calculated for overall performance measures at each timepoint, and mixed-effects models were used to assess differences in RT, accuracy, and composite Z-scores along with hemodynamics and felt arousal. An α-level of 0.05 was used to determine statistical significance, and Cohen's d was used to quantify effect sizes. Results: A Group-by-Time interaction for vigilance RT (P = 0.038) indicated improvements for both CAF and CMT from round 1 to round 2 (P < 0.01) while PLA did not change (P = 0.27). No Group main effects or Group-by-Time interactions were found for movement or marksmanship performance (P > 0.20). Group main effects for systolic (SBP; P = 0.001) and diastolic blood pressure (DBP; P = 0.028) indicated higher SBP in CAF (P = 0.003, d= 0.84) and CMT (P = 0.007, d= 0.79) compared to PLA but only higher DBP in CAF (P = 0.025, d= 0.74). No Group-by-Time interaction or Group main effect was found for felt arousal (P > 0.16). Conclusions: These findings suggest similar benefits on RT during a vigilance task between CAF, containing 300 mg caffeine, and CMT above PLA, though CAF resulted in slightly less favorable hemodynamic changes. This study is the first to provide data showing similar efficacy of combined caffeine, methylliberine, and theacrine compared to double the caffeine dose consumed alone on vigilance RT but without a significant rise in DBP above PLA in tactical personnel.

A qualitative report of the perceptions of the COVID-19 pandemic from collegiate student-athletes.

Context: The COVID-19 pandemic led to an abrupt disruption in access to services and personnel for collegiate student-athletes in the spring and summer of 2020. We sought to identify the effects of this unprecedented change by examining the psychological well-being, changes to normal routines, and return-to-play considerations of current student-athletes in order to guide support for both current and future student-athletes who may face similar situations. Methods: We utilized a phenomenological approach to interview a purposeful sample of eighteen collegiate student-athletes (7 males, 11 females; mean age = 20 years) from across the United States. The participants were interviewed using a semi-structured interview protocol, which was audio recorded and transcribed verbatim using Zoom. The data were then analyzed and coded by a 3-person team via the consensual qualitative research tradition. Results: Four domains emerged after data analysis: 1) ambiguity, 2) perspective, 3) bonding and cohesion, and 4) resource utilization. Participants discussed ambiguity in terms of eligibility and participation questions, academic changes, and varying COVID-19 policies. Participants shared a wide range of perspectives, from apprehension at the onset of the pandemic, to excitement when returning to campus and competition. They shared how bonding and team development were affected due to a lack of socialization and that support system dynamics between family, coaches, and teammates were strengthened. When describing resource utilization, participants discussed the use of personnel and supplies to help them adjust to changes in facility and space availability. The identification and utilization of resources enabled them to establish a "new normal" for their academics, workouts, and hobbies during the pandemic. Conclusions: Collegiate student-athletes realized the seriousness of the pandemic and utilized their resources and support systems to adjust their routines and keep a positive attitude during COVID-19. At the same time, some student-athletes struggled with these changes. Personnel should be aware of these effects to provide care and prevent future negative effects.

Covariations among attachment, attributions, self-esteem, and psychological aggression in early marriage.

The associations between insecure attachment (anxious and avoidant dimensions), maladaptive relational attributions, self-esteem, and psychological aggression were examined in a sample of couples (N = 96 couples) across the early years of marriage. Studying these constructs within a single sample is a novel contribution to the literature. Attachment was assessed at marriage, whereas maladaptive attributions, self-esteem, and psychological aggression were evaluated annually over the first 7 years of marriage. For the present study, specific maladaptive relational attributions about the spouse's hypothetical aggressive behavior were investigated. Data from both spouses were examined simultaneously using growth curve analytic and actor-partner interdependence modeling techniques. Results indicated that self locus attributions (i.e., attributing the cause of the spouse's hypothetical aggressive behavior to the self), intentionality attributions (i.e., attributing the spouse's motivation for the hypothetical behavior as intentional), and self-esteem were predicted by insecure attachment and covaried longitudinally with psychological aggression. Husbands' self-esteem and wives' intentionality attributions were particularly consistent in these associations. The results replicate and extend previous research by examining these constructs using a longitudinal dyadic approach. The findings of this study provide specific targets for intervention efforts to reduce psychological aggression and support conceptualizing psychological aggression within a dyadic and dynamic framework. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Finances, depressive symptoms, destructive conflict, and coparenting among lower-income, unmarried couples: A two-wave, cross-lagged analysis.

Following from an adapted family stress model (FSM), we used two-wave, secondary data from the Building Strong Families project, focusing on 4,424 primarily lower-income, unmarried couples expecting their first child together. We used cross-lagged analyses to test the directionality of the associations among financial difficulties, depressive symptoms, destructive interparental conflict, and coparenting alliance for both fathers and mothers when children were 15 and 36 months old. Two of the three hypotheses provided support for the FSM. First, destructive conflict predicted coparenting alliance (but not the reverse). Specifically, higher destructive conflict at 15 months for both fathers and mothers predicted lower coparenting alliance at 36 months for both fathers and mothers. Second, depressive symptoms predicted destructive conflict (but not the reverse). Specifically, fathers' (but not mothers') higher depressive symptoms at 15 months predicted both their own and mothers' higher destructive conflict at 36 months. Contrary to predictions, financial difficulties did not predict depressive symptoms; instead, we found support for the reverse: For mothers only, higher depressive symptoms at 15 months predicted higher financial difficulties at 36 months. Collectively, the results support the use of the FSM to understand the directionality of associations among key risk factors, especially depressive symptoms and destructive conflict, for primarily lower-income, unmarried couples expecting their first child together. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Agreement between B-Mode Ultrasound and Air Displacement Plethysmography in Preprofessional Ballet Dancers.

PURPOSE: This study aimed to assess the agreement between B-mode ultrasound and air displacement plethysmography (ADP) body composition results in preprofessional ballet dancers. METHODS: Male (n = 21, Mage = 17.2 ± 1.7 yr, MBMI = 20.5 ± 2.0 kg·m-2) and female (n = 27, Mage = 16.1 ± 1.4 yr, MBMI = 18.3 ± 1.3 kg·m-2) dancers were assessed by ADP and ultrasound to determine body fat percentage (%BF), fat mass (FM), and fat-free mass (FFM). Pearson's correlations were used to assess agreement, and paired t-tests were used to determine differences between devices (α = 0.05). Ultrasound validity was assessed using SEE and total error. Bland-Altman plots were used to identify 95% limits of agreement. RESULTS: Agreement was high for %BF (females, r = 0.94; males, r = 0.77), FM (females, r = 0.94; males, r = 0.73), and FFM (females, r = 0.95; males, r = 0.99). However, ultrasound overestimated %BF and FM and underestimated FFM (P < 0.05) compared with ADP in females only. In addition, there were stronger agreement and lower error for FFM compared with both %BF and FM regardless of sex. CONCLUSION: There is strong agreement between ultrasound and ADP in this population. Although ultrasound may be a useful field tool to assess body composition, future research is needed to refine %BF equations in this population to reduce calculation errors.

Nutrient Timing: A Garage Door of Opportunity?

Nutrient timing involves manipulation of nutrient consumption at specific times in and around exercise bouts in an effort to improve performance, recovery, and adaptation. Its historical perspective centered on ingestion during exercise and grew to include pre- and post-training periods. As research continued, translational focus remained primarily on the impact and outcomes related to nutrient consumption during one specific time period to the exclusion of all others. Additionally, there seemed to be increasing emphasis on outcomes related to hypertrophy and strength at the expense of other potentially more impactful performance measures. As consumption of nutrients does not occur at only one time point in the day, the effect and impact of energy and macronutrient availability becomes an important consideration in determining timing of additional nutrients in and around training and competition. This further complicates the confining of the definition of "nutrient timing" to one very specific moment in time at the exclusion of all other time points. As such, this review suggests a new perspective built on evidence of the interconnectedness of nutrient impact and provides a pragmatic approach to help frame nutrient timing more inclusively. Using this approach, it is argued that the concept of nutrient timing is constrained by reliance on interpretation of an "anabolic window" and may be better viewed as a "garage door of opportunity" to positively impact performance, recovery, and athlete availability.

Feasibility of FitSurvivor: A technology-enhanced group-based fitness intervention for adolescent and young adult survivors of childhood cancer.

BACKGROUND: This study evaluated the feasibility of a technology-enhanced group-based fitness intervention for adolescent and young adult (AYA) survivors of childhood cancer. PROCEDURE: AYA survivors ages 13-25 years were randomized to the intervention (eight in-person group sessions with mobile app and FitBit followed by 4 weeks of app and FitBit only) or waitlist control. Assessments were at 0, 2, 3, 6, and 9 months. Feasibility was evaluated by enrollment, retention, attendance, app engagement, and satisfaction. Secondary outcomes included physical activity, muscular strength/endurance, cardiorespiratory fitness, health-related quality of life, and fatigue. RESULTS: A total of 354 survivors were mailed participation letters; 68 (19%) were screened, of which 56 were eligible and 49 enrolled (88% of those screened eligible, 14% of total potentially eligible). Forty-nine survivors (Mage  = 18.5 years, 49% female) completed baseline assessments and were randomized (25 intervention, 24 waitlist). Thirty-seven (76%) completed the postintervention assessment and 32 (65%) completed the final assessment. On average, participants attended 5.7 of eight sessions (range 1-8). Overall intervention satisfaction was high (M = 4.3, SD = 0.58 on 1-5 scale). Satisfaction with the companion app was moderately high (M = 3.4, SD = 0.97). The intervention group demonstrated significantly greater improvement in lower body muscle strength compared to the waitlist postintervention, and small but not statistically significant changes in other secondary measures. CONCLUSIONS: A group-based intervention with a mobile app and fitness tracker was acceptable but has limited reach due to geographical barriers and competing demands experienced by AYA survivors.