Dose-Response of Creatine Supplementation on Cognitive Function in Healthy Young Adults.

To determine if creatine (Cr) supplementation could influence cognitive performance and whether any changes were related to changes in prefrontal cortex (PFC) activation during such cognitive tasks, thirty (M = 11, F = 19) participants were evenly randomized to receive supplementation with Cr (CR10:10 g/day or CR20:20 g/day) or a placebo (PLA:10 g/day) for 6 weeks. Participants completed a cognitive test battery (processing speed, episodic memory, and attention) on two separate occasions prior to and following supplementation. Functional near-infrared spectroscopy (fNIRS) was used to measure PFC oxyhemoglobin (O2Hb) during the cognitive evaluation. A two-way repeated measures ANOVA was used to determine the differences between the groups and the timepoints for the cognitive performance scores and PFC O2Hb. In addition, a one-way ANOVA of % change was used to determine pre- and post-differences between the groups. Creatine (independent of dosage) had no significant effect on the measures of cognitive performance. There was a trend for decreased relative PFC O2Hb in the CR10 group versus the PLA group in the processing speed test (p = 0.06). Overall, six weeks of Cr supplementation at a moderate or high dose does not improve cognitive performance or change PFC activation in young adults.

The Relationship between Physical Activity, Sleep Quality, and Stress: A Study of Teachers during the COVID-19 Pandemic.

The COVID-19 pandemic prompted chaotic changes in the daily lives of K-12 teachers, resulting in increased stress and other mental health problems. Limited evidence regarding the relationship between physical activity, sleep, and perceived stress among teachers during the COVID-19 pandemic exists. Therefore, the purpose of this study was to investigate the association between physical activity, sleep quality, and perceived psychological stress among teachers during the COVID-19 pandemic. An online survey measuring physical activity, sleep quality, and perceived psychological stress was distributed across 47 US states between September and October of 2020. Data provided by 635 teachers (mean age: 42 ± 18 years, 74.6% female) were included in the present analysis. Results suggested a negative association between physical activity and perceived psychological stress. Mediation analyses indicated that teachers engaging in high levels of physical activity were more likely to have good quality sleep and, in turn, were less likely to report high levels of perceived stress. Physical activity and sleep-related interventions could help curtail the rising levels of psychological distress amongst K-12 teachers during stressful times such as the COVID-19 pandemic. Teachers, especially those that self-report as female and/or young, report high levels of stress. These high levels of stress are a serious challenge for school districts in terms of attracting and retaining qualified teachers in K-12 classrooms.

Acute Aerobic Exercise-Induced Motor Priming Improves Piano Performance and Alters Motor Cortex Activation.

Acute aerobic exercise has been shown to improve fine motor skills and alter activation of the motor cortex (M1). The intensity of exercise may influence M1 activation, and further impact whole-body motor skill performance. The aims of the current study were to compare a whole-body motor skill via a piano task following moderate-intensity training (MIT) and high-intensity interval training (HIIT), and to determine if M1 activation is linked to any such changes in performance. Nine subjects (seven females and two males), aged 18 ± 1 years completed a control, MIT, and HIIT trial followed by administration of a piano performance task. M1 activation was evaluated by measuring oxyhemoglobin (O2Hb) and hemoglobin difference (Hbdiff) changes during post-exercise piano performance using functional near-infrared spectroscopy (fNIRS). The results indicate that piano performance scores were higher after the MIT trial, but not HIIT trial, compared to the control trial. A negative relationship was detected between heart rate during HIIT and post-HIIT piano scores. M1 activation (as measured by Hbdiff) was significantly increased after the HIIT trial. M1 activation was also positively associated with piano performance when exercise trials (HIIT + MIT) and all trials (HIIT + MIT + Control) were combined. We found that acute moderate-intensity exercise led to an improvement in complex motor skill performance while higher-intensity exercise increased M1 activation. These results demonstrate that moderate-intensity exercise can prime the nervous system for the acquisition of whole-body motor skills, suggesting that similar exercise protocols may be effective in improving the outcomes of other motor tasks performed during regular routines of daily life (e.g., sporting tasks, activities of daily living or rehabilitation). In addition, it appears that improvements in motor task performance may be driven by M1 activation. Our findings provide new mechanistic insight into the complex relationship between exercise intensity, M1 activation, and whole-body motor skill performance.

A Metabolic Profile of Peripheral Heart Action Training.

Purpose: Peripheral heart action (PHA) is a style of circuit training that alternates upper and lower body resistance exercises with minimal rest between sets. The purpose of this study was to compare the metabolic demands of PHA to traditional hypertrophy training (TRAD) and to provide between sex comparison for both types of resistance training (RT). Methods: Twenty resistance-trained individuals underwent two bouts of volume-load matched RT: PHA and TRAD. We measured oxygen uptake (VO2), heart rate (HR), blood lactate (BL) concentration, rating of perceived exertion (RPE), excess post-exercise oxygen consumption (EPOC), and duration of each session. Results: PHA elicited significantly greater %VO2max (p < .001), %HRmax (p < .001), RPE (p < .001), and EPOC (p < .001) compared to TRAD. PHA was also completed in less time (p < .001). Compared to TRAD, BL was significantly higher at mid-exercise (p < .001), post-exercise (p < .001), and 5-min post-exercise (p < .001) during PHA. There were no between-sex differences for BL at any time-point for TRAD. However, during PHA, BL was significantly higher for males at mid-exercise (p = .04), post-exercise (p = .02), and 5-min post-exercise (p = .002). No between-sex differences were detected for HR, VO2, RPE, or duration for either style of RT. Conclusions: PHA is a time-effective and metabolically demanding circuit that may lead to strength and cardiorespiratory adaptations. Males produced more BL than females during PHA, but not TRAD, suggesting that they incurred more metabolic stress during the bout of circuit training.

Cardiovascular, Cellular, and Neural Adaptations to Hot Yoga versus Normal-Temperature Yoga.

CONTEXT: Chronic heat exposure promotes cardiovascular and cellular adaptations, improving an organism's ability to tolerate subsequent stressors. Heat exposure may also promote neural adaptations and alter the neural-hormonal stress response. Hot-temperature yoga (HY) combines mind-body exercise with heat exposure. The added heat component in HY may induce cardiovascular and cellular changes, along with neural benefits and modulation of stress hormones. AIMS: The purpose of the present study is to compare the cardiovascular, cellular heat shock protein 70 (HSP70), neural, and hormonal adaptations of HY versus normal-temperature yoga (NY). SETTINGS AND DESIGN: Twenty-two subjects (males = 11 and females = 11, 26 ± 6 years) completed 4 weeks of NY (n = 11) or HY (n = 11, 41°C, 40% humidity). Yoga sessions were performed 3 times/week following a modified Bikram protocol. SUBJECTS AND METHODS: Pre- and posttesting included (1) hemodynamic measures during a heat tolerance test and maximal aerobic fitness test; (2) neural and hormonal adaptations using serum brain-derived neurotrophic factor (BDNF) and adrenocorticotropic hormone (ACTH), along with a mental stress questionnaire; and (3) cellular adaptations (HSP70) in peripheral blood mononuclear cells (PBMCs). STATISTICAL ANALYSIS: Within- and between-group Student's t-test analyses were conducted to compare pre- and post-VO2 max, perceived stress, BDNF, HSP70, and ACTH in HY and NY groups. RESULTS: Maximal aerobic fitness increased in the HY group only. No evidence of heat acclimation or change in mental stress was observed. Serum BDNF significantly increased in yoga groups combined. Analysis of HSP70 suggested higher expression of HSP70 in the HY group only. CONCLUSIONS: Twelve sessions of HY promoted cardiovascular fitness and cellular thermotolerance adaptations. Serum BDNF increased in response to yoga (NY + HY) and appeared to not be temperature dependent.

The Relationship between Psychological Stress and Healthy Lifestyle Behaviors during COVID-19 among Students in a US Midwest University.

The gripping coronavirus disease (COVID-19) has imposed dramatic changes to many areas of daily living in all sectors of society across the world. We examined the relationship between perceived stress and health behaviors among college students during the COVID-19 pandemic. An online survey with measures of psychological stress, physical activity and exercise, and sleep and social connectedness was distributed in June and July of 2020. The survey was completed by 550 college students (mean age: 21.3 ± 3.8 years, 74.2% female, 94.4% Caucasian). Being female and unemployed and having a lower annual income were significantly associated with higher levels of stress. In addition, regression analysis found that reduced exercise and sleep during the COVID-19 pandemic significantly predicted the levels of stress of participants after controlling for gender, employment status, and annual income. University officials should aim to implement health-promotion strategies directed at preventing reductions in exercise and sleep duration, especially in those at greater risk of increased perceived stress such as females and economically disadvantaged students.

Differential Effects of Exercise Programs on Neuregulin 4, Body Composition and Cardiometabolic Risk Factors in Men With Obesity.

BACKGROUND: Neuregulin 4 (Nrg4) is an adipokine that is sensitive to energy expenditure and with a potential role in metabolic homeostasis and obesity. This study examined the effects of 12 weeks of three different exercise training protocols on Nrg4 levels, cardiometabolic risk factors, and body composition parameters in men with obesity. METHODS: Sixty adult men with obesity (Mean ± SD; age: 27.60 ± 8.4 yrs.; height: 168.4 ± 2.6 cm; weight: 96.7 ± 7.2 kg) were randomly allocated into four equal (n = 15) groups: High- Intensity Interval Training (HIIT), Circuit Resistance Training (CRT), Moderate Intensity Continuous Training (MICT) or a control group. The HIIT protocol involved six bouts of 3-min high-intensity exercise (90% VO2peak ) followed by 3-min low-intensity exercise (50% VO2peak ). The CRT group performed three circuits of resistance training, where each circuit included 11 exercises at 20% of one-repetition maximum (1RM) and 70% of VO2peak , and with a work-to-rest ratio of 2:1 (40-s exercise and 20-s rest) and 60-s recovery between circuits. The MICT group performed 36 min of exercise at 70% of VO2peak . All measurements were taken 72 h before and after the first and last training sessions. RESULTS: There were significant differences between the groups in fat-free mass (FFM), (effect size (ES): 0.78), fat mass (ES: 0.86), VO2peak (ES: 0.59), high-density lipoprotein cholesterol (HDL-C) (ES: 0.83), low-density lipoprotein (LDL-C) (ES: 0.79), total cholesterol (TC) (ES: 0.90), triglyceride (TG) (ES: 0.52) glucose (ES: 0.39), insulin (ES: 0.61), HOM-IR (ES: 0.91) and Nrg4 (ES: 0.98) (p < 0.05). There were no significant changes in very-low-density lipoprotein cholesterol (VLDL-C) (ES: 0.13) levels, or body weights (ES: 0.51) (p > 0.05). Levels of Nrg4 were negatively correlated with LDL-C, TC, TG, VLDL-C, glucose, insulin, HOMA-IR (p < 0.05) and positively with HDL-C (p < 0.05). CONCLUSION: Our results suggest that HIIT and CRT protocols have greater effects than MICT protocol on Nrg4 levels, metabolic and cardiovascular risk factors, and body composition variables in men with obesity.

Exercise-Based Cardiac Rehabilitation Improves Cognitive Function Among Patients With Cardiovascular Disease.

PURPOSE: To investigate the effects of cardiac rehabilitation (CR) exercise training on cognitive performance and whether the changes are associated with alterations in prefrontal cortex (PFC) oxygenation among patients with cardiovascular disease. METHODS: Twenty (men: n = 15; women: n = 5) participants from an outpatient CR program were enrolled in the study. Each participant completed a cognitive performance test battery and a submaximal graded treadmill evaluation on separate occasions prior to and again upon completion of 18 individualized CR sessions. A functional near-infrared spectroscopy (fNIRS) device was used to measure left and right prefrontal cortex (LPFC and RPFC) oxygenation parameters (oxyhemoglobin [O2Hb], deoxyhemoglobin [HHb], total hemoglobin [tHb], and oxyhemoglobin difference [Hbdiff]) during the cognitive test battery. RESULTS: Patients showed improvements in cardiorespiratory fitness (+1.4 metabolic equivalents [METs]) and various cognitive constructs. A significant increase in PFC oxygenation, primarily in the LPFC region, occurred at post-CR testing. Negative associations between changes in cognition (executive function [LPFC O2Hb: r = -0.45, P = .049; LPFC tHb: r = -0.49, P = .030] and fluid composite score [RPFC Hbdiff: r = -0.47, P = .038; LPFC Hbdiff: r = -0.45, P = .048]) and PFC changes were detected. The change in cardiorespiratory fitness was positively associated with the change in working memory score (r = 0.55, P = .016). CONCLUSION: Cardiovascular disease patients enrolled in CR showed significant improvements in multiple cognitive domains along with increased cortical activation. The negative associations between cognitive functioning and PFC oxygenation suggest an improved neural efficiency.

Impact of Varying Dosages of Fish Oil on Recovery and Soreness Following Eccentric Exercise.

Fish oils (FOs) are rich in omega-3 long-chain polyunsaturated fatty acids, which have been purported to enhance recovery of muscular performance and reduce soreness post-exercise. However, the most effective FO dose for optimizing recovery remains unclear. The purpose of this investigation was to examine the effect of FO supplementation dosing on the recovery of measures of muscular performance, perceived soreness, and markers of muscle damage following a rigorous bout of eccentric exercise. Thirty-two college-aged resistance-trained males (~23.6 years, 71.6 kg, 172.1 cm) were supplemented with 2, 4, 6 g/day (G) FO or placebo (PL) for ~7.5 weeks. Following 7 weeks of supplementation, pre-exercise (PRE) performance assessments of vertical jump (VJ), knee extensor strength, 40-yard sprint, T-test agility, and perceived soreness were completed prior to a bout of muscle-damaging exercise and were repeated immediately post (IP), 1-, 2-, 4-, 24-, 48-, and 72-h (H) post-exercise. Repeated measures analysis of variance indicated a treatment × time interaction (p < 0.001) for VJ and perceived soreness, but no group differences were observed at any time point. VJ returned to PRE (54.8 ± 7.9 cm) by 1H (51.8 ± 6.5 cm, p = 0.112) for 6G, while no other groups returned to baseline until 48H. Lower soreness scores were observed in 6G compared to PL at 2H (mean difference [MD] = 2.74, p = 0.046), at 24H (MD: 3.45, p < 0.001), at 48H (MD = 4.45, p < 0.001), and at 72H (MD = 3.00, p = 0.003). Supplementation with 6G of FO optimized the recovery of jump performance and muscle soreness following a damaging bout of exercise.

The Combined Effect of Exercise and Behavioral Therapy for Depression and Anxiety: Systematic Review and Meta-Analysis.

Behavioral therapy (BT) and exercise are efficacious treatments for depression and anxiety when employed separately. The combination of BT and exercise (BT+Ex) may augment improvements but the combined effect of these therapies is not fully elucidated. The purpose of this meta-analysis was to determine if BT+Ex yielded a significant reduction in depression and anxiety symptoms compared to BT alone (BT). Randomized controlled studies published prior to September 2019 were searched among several databases (PUBMED, MEDLINE, PsychArticle, and Cochrane Central Register of Clinical Trials). Studies that measured depression and anxiety symptoms following BT+Ex vs. BT were extracted and analyzed. The effect of these therapies on depression and anxiety were analyzed. Subgroup analyses were performed to evaluate the effect of exercise intensity (moderate and high), exercise type (aerobic and combined exercise), and baseline levels of depression. The moderating effects of gender, age, and treatment duration were performed. Data were extracted from 18 studies (1686 participants, mean age = 47 years, 65% female). There was a significant effect of BT+Ex on symptoms of depression. The effect of BT+Ex was significant for moderate intensity exercise and elevated baseline levels of depression. Age moderated the effect for depression. There was a significant effect of BT+Ex on depressive symptoms in humans. Exercise intensity and elevated depressive symptoms may play a role in the effect of exercise.

Exercise-Based Cardiac Rehabilitation Modulates Prefrontal Cortex Oxygenation during Submaximal Exercise Testing in Cardiovascular Disease Patients.

The purpose of this study was to investigate if prefrontal cortex (PFC) oxygenation during incremental exercise is altered among cardiovascular disease (CVD) patients who completed 6 weeks of exercise-based cardiac rehabilitation (CR). Nineteen (male = 14, female = 5; 65.5 ± 11.5 years) participants from an outpatient CR program were enrolled in the study. Each participant completed a submaximal graded treadmill evaluation at intake and again upon completion of 18 individualized CR sessions. Functional near-infrared spectroscopy (fNIRS) imaging was used to measure left- and right- PFC (LPFC and RPFC) oxygenation parameters during the submaximal exercise evaluations. Patients showed improvements in cardiorespiratory capacity (pre 5.5 ± 2.5 vs. post 6.9 ± 2.8 metabolic equivalents (METs)). A significant decrease in LPFC and RPFC oxygenation was observed during the post-CR exercise test compared to pre-CR. CVD patients enrolled in 6 weeks of CR showed significant improvements in functional capacity along with decreased cortical oxygenation during submaximal exercise. Exercise training may cause distribution of cortical resources to motor regions that support sustained exercise.

Metabolic effects of two high-intensity circuit training protocols: Does sequence matter?

BACKGROUND/OBJECTIVE: The integration of high-intensity interval training (HIIT) and circuit weight training (CWT) is seamless and practical for meeting recommended exercise guidelines. The purpose of this study was to determine the ideal combination of HIIT and CWT to elicit desired acute cardiorespiratory and metabolic responses in variables such as energy expenditure (EE), oxygen consumption (VO2), heart rate (HR), blood lactate (BLa-), excess post-exercise oxygen consumption (EPOC), rating of perceived exertion (RPE), and enjoyment. METHODS: Fourteen trained males (25.7 ±â€¯4.4 yr) completed two exercise protocols matched for volume and recovery periods. On one day, participants performed six HIIT bouts prior to three rounds of a nine exercise CWT protocol (HIC). The second day (separated by ≥ 72 h) consisted of three rounds of three mini-circuits (three exercises per circuit) integrated with three HIIT bouts between the first and second and second and third mini-circuits (TRI). VO2, HR, and EE were monitored throughout both protocols. EPOC for a 20-min duration, [BLa-] (five time points), RPE, and enjoyment were measured post-exercise. RESULTS: Energy expenditure was significantly higher during the HIC compared to the TRI protocol (p = .012), as well as EPOC (p = .034). [BLa-] was significantly greater immediate-, 5min-, 10min- and 20min-post-exercise following HIC as compared to TRI. Mean values for HIC and TRI were similar (p > .05) for HR and RPE. CONCLUSION: Performing HIIT prior to CWT elicits a higher metabolic perturbation compared to the TRI protocol. Although a significant EE difference was detected between the two trials, the practical difference (∼20 kcal) between protocols indicates both protocols are similarly effective for caloric expenditure, metabolic and cardiorespiratory response.

Exercise and Neural Adaptations: Designing a Novel Treatment for Alcohol Addiction.

CONTEXT: Multiple forms of behavioral therapies have been developed to treat alcohol abuse disorders (AUDs). Despite positive outcomes during and immediately after behavioral treatment, 60% to 90% of patients relapse in the year after treatment. Combined approaches have also been developed, but similar high relapse rates have occurred. Aerobic exercise may be an appropriate complimentary treatment for behavioral therapy in AUDs. However, it is critical to identify the appropriate dose of exercise to gain maximal benefit. OBJECTIVE: This literature review intended to explore the neural components of alcohol addiction, identify the mechanisms by which exercise might influence brain function, characterize the appropriate exercise intervention for AUDs, and ascertain strategies for implementing exercise into behavioral therapy treatment. DESIGN: The research team searched the literature for systematic reviews, descriptive studies, case reports, cross-sectional, along with experimental design studies (both randomized controlled trials and nonrandomized single group). Mechanisms of AUD, neurophysiological adaptations to physical exercise, and exercise interventions in AUD treatment were the primary areas of interest. PubMed, ScienceDirect, Cochrane Library, and Google Scholar databases were searched between 1970 and 2019. RESULTS: Neural mechanisms of AUD identified included abnormal neurotransmission, prefrontal cortex function, and neurogenic processes. Exercise may serve the underlying neurophysiological mechanisms of AUD, and this has been demonstrated in a handful of exercise therapies studied among alcohol abusers. CONCLUSIONS: Given the current reviews findings on the neural mechanisms of alcohol addiction, the neurophysiological basis of exercise treatment, and the results of exercise interventions during alcohol treatment the current research team has developed a novel approach to treatment of alcohol addiction by incorporating aerobic interval exercise into traditional, evidence-based, cognitive behavioral therapy. The benefits of exercise may promote and compliment CBT treatment and lead to reduced drinking outcomes.

Exercise Intensity Influences Prefrontal Cortex Oxygenation during Cognitive Testing.

Activation changes in the prefrontal cortex (PFC) regions have been linked to acute exercise-induced improvements in cognitive performance. The type of exercise performed may influence PFC activation, and further impact cognitive function. The present study aimed to compare PFC activation during cognitive testing after moderate-intensity, high intensity, and yoga exercises, and to determine if PFC activation is linked to cognitive performance. Eight subjects (four male and four female), aged 35 ± 5 completed a control, high intensity, moderate intensity, and yoga exercises followed by administration of a cognitive task (NIH Toolbox Fluid Cognition). Left and right PFC activation (LPFC and RPFC, respectively) were evaluated by measuring hemoglobin difference (Hbdiff) changes during post-exercise cognitive assessment using functional near infrared spectroscopy (fNIRS). Activation during the cognitive test was higher in the LPFC after moderate intensity exercise compared to control, high intensity, and yoga (5.30 ± 6.65 vs. 2.26 ± 2.40, 2.50 ± 1.48, 2.41 ± 2.36 µM, p < 0.05, respectively). A negative relationship was detected between LPFC and processing speed after exercise. PFC activation did not align with cognitive performance. However, acute exercise, regardless of type, appeared to alter neural processing. Specifically, less PFC activation was required for a given neural output after exercise.

Acute Aerobic Exercise Based Cognitive and Motor Priming: Practical Applications and Mechanisms.

Acute exercise stimulates brain regions involved in motor and cognitive processes. Recent research efforts have explored the benefits of aerobic exercise on brain health and cognitive functioning with positive results reported for both healthy and neurocognitively impaired individuals. Specifically, exercise positioned near therapeutic (both behavioral and physical) activities may enhance outcomes associated with treatment outcomes (e.g., depression or motor skill) through neural plasticity promoting mechanisms (e.g., increased brain flow and oxygenation). This approach has been termed "exercise priming" and is a relatively new topic of exploration in the fields of exercise science and motor control. The authors report on physiological mechanisms that are related to the priming effect. In addition, parameters related to the exercise bout (e.g., intensity, duration) and the idea of combining exercise and therapeutic rehabilitation are explored. This exercise-based priming concept has the potential to be applied to many areas such as education, cognitive therapy, and motor rehabilitation.

The Effect of Acute Glutamine Supplementation on Markers of Inflammation and Fatigue During Consecutive Days of Simulated Wildland Firefighting.

OBJECTIVE: To examine the effect of oral glutamine supplementation on inflammation and fatigue during and after simulated wildland firefighting (WLFF) tasks in hot conditions over 2 consecutive days. METHODS: Eleven men and women ingested a glutamine supplement or a placebo before and after simulated wildland firefighting in an environmental chamber (38 °C, 35% relative humidity). Subjective fatigue, markers of inflammation, and cellular stress were measured pre, post and 4 hours post-exercise on both days. RESULTS: Gastrointestinal damage, subjective fatigue, and ratings of perceived exertion were lower after glutamine supplementation compared with placebo. Heat shock protein 70 (HSP70) and nuclear factor kappa-inhibitor alpha (IκBα) levels were higher on both days of the glutamine trial compared with placebo. CONCLUSIONS: Glutamine supplementation may improve recovery after fire suppression in WLFFs. This may result from the upregulation of HSP70 which inhibits inflammation and protects against gastrointestinal (GI) barrier damage.

The use of a smart-textile garment during high-intensity functional training: a pilot study.

BACKGROUND: Wearable devices are common in the health and fitness industry and provide valuable information to improve and achieve fitness goals. The Hexoskin shirt (Hx) is one such device that has been shown to be valid and reliable. The purpose of this pilot study was to compare the Hx to established methods during a maximal graded exercise test (TM) and a high-intensity functional training (HIFT) session. METHODS: Ten healthy individuals (31.0±7.6 years, 76.4±11.4 kg; 1.7±0.1 m) volunteered for this study and completed a TM and a HIFT exercise session. During both testing sessions, respiratory measures (respiratory rate [RR], and respiratory volume [RV]) were assessed using a portable metabolic system (Cosmed K4b2; K4), and heart rate (HR) was determined via ECG in a standard 12-lead configuration. The Hx was worn during both sessions. RESULTS: During TM, a 4% difference was noted for HR during cool down, while exercising HR and RV, along with RR during cool down were all under 10%. During HIFT, HR at rest and cool down, as well as RR during exercise were less than 10%. The variation between technologies for the remaining variables ranged between 12.3-39.9% and 10.9-41.1% for TM and HIFT, respectively. CONCLUSIONS: The Hx smart garment may be utilized to provide select cardiorespiratory data in a TM and HIFT session. We recommend that the validity and reliability be fully established before the Hx smart garment is entirely utilized for all cardiorespiratory data and research purposes in a field-based environment.

Effect of Branched-Chain Amino Acid Supplementation on Recovery Following Acute Eccentric Exercise.

This study investigated the effect of branched-chain amino acid (BCAA) supplementation on recovery from eccentric exercise. Twenty males ingested either a BCAA supplement or placebo (PLCB) prior to and following eccentric exercise. Creatine kinase (CK), vertical jump (VJ), maximal voluntary isometric contraction (MVIC), jump squat (JS) and perceived soreness were assessed. No significant (p > 0.05) group by time interaction effects were observed for CK, soreness, MVIC, VJ, or JS. CK concentrations were elevated above baseline (p < 0.001) in both groups at 4, 24, 48 and 72 hr, while CK was lower (p = 0.02) in the BCAA group at 48 hr compared to PLCB. Soreness increased significantly from baseline (p < 0.01) in both groups at all time-points; however, BCAA supplemented individuals reported less soreness (p < 0.01) at the 48 and 72 hr time-points. MVIC force output returned to baseline levels (p > 0.05) at 24, 48 and 72 hr for BCAA individuals. No significant difference between groups (p > 0.05) was detected for VJ or JS. BCAA supplementation may mitigate muscle soreness following muscle-damaging exercise. However, when consumed with a diet consisting of ~1.2 g/kg/day protein, the attenuation of muscular performance decrements or corresponding plasma CK levels are likely negligible.