Cardiometabolic Biomarkers and Habitual Caffeine Consumption Associate with the Adverse Ambulatory Blood Pressure Response to Strenuous Physical Exertion among Firefighters.

Caffeine has beneficial effects on firefighter job performance reducing fatigue and improving psychomotor vigilance. However, excessive caffeine intake may raise blood pressure (BP) following a bout of acute exercise among adults with elevated BP. The influence of caffeine intake on the ambulatory BP (ABP) response to vigorous physical exertion among firefighters has not been studied. In this sub-study we conducted secondary statistical analyses from a larger clinical trial (NCT04514354) that included examining the influence of habitual caffeine intake, and cardiometabolic biomarkers shown to influence BP, on the ABP response following a bout of sudden vigorous exertion over 19 h among firefighters. Previously, we found high amounts of calcium and sodium intake raised BP following a bout of acute exercise among adults with elevated BP. Thus, other secondary aims were to examine the influence of habitual calcium and sodium intake, and cardiometabolic biomarkers have shown to influence BP, on the ABP response following sudden vigorous exertion over 19 h among firefighters. Firefighters (n = 15) completed a Food-Frequency Questionnaire assessing habitual dietary intake over the past year. They randomly completed a maximal graded exercise stress test (GEST) and non-exercise CONTROL on separate non-workdays leaving the laboratory wearing an ABP monitor for 19 h. Prior to and immediately after the GEST, fasting venous blood was collected to measure lipid-lipoproteins, c-reactive protein, and blood glucose. Height and weight were taken to calculate body mass index. Repeated measures ANCOVA tested if the ABP response differed after GEST vs. CONTROL. Linear mixed models examined the relationships among caffeine, calcium, sodium, cardiometabolic biomarkers, and the ABP response following GEST vs. CONTROL. Firefighters were middle-aged (40.2 ± 9.5 year), overweight (29.0 ± 3.9 kg/m2) men with elevated BP (124.1 ± 10.3/79.6 ± 11.5 mmHg) who consumed 542.0 ± 348.9 mg of caffeine/day, about ~50% more than the dietary reference intake. Unexpectedly, systolic ABP was higher by 18.0 ± 6.7 mmHg and diastolic ABP by 9.1 ± 5.4 mmHg (ps < 0.01) over 19 h following GEST vs. CONTROL. We found 24% of the variance in the adverse ABP response to maximal physical exertion was explained by caffeine intake, and when combined with c-reactive protein, non-high-density lipoprotein-cholesterol, body mass index, blood glucose, and resting heart rate, up to 74% of the variability in the ABP response was explained. Additionally, we found calcium (ps < 0.001) and sodium (p < 0.0001) intake each explained up to 24% of the ABP response. Further investigation is needed in a larger, more diverse sample of firefighters to better establish how caffeine contributes to the adverse BP response to strenuous physical exertion.

Comparing the Effect of Acute Moderate and Vigorous Exercise on Inflammation in Adults with Asthma: A Randomized Controlled Trial.

Rationale: Exercise is associated with improvements in asthma; however, the mechanisms responsible are not clear. Exercise induces changes in systemic inflammation, and it is possible that these inflammatory effects extend to the airways of people with asthma. Studies in healthy adults suggest inflammatory responses are dependent on exercise intensity: Although acute moderate exercise is antiinflammatory, acute vigorous exercise appears to be neutral or proinflammatory. The effect of exercise intensity on inflammation has not been investigated in people with asthma. Objectives: To compare acute changes in airway and systemic inflammation after a bout of moderate or vigorous exercise in physically inactive adults with asthma and to establish whether these effects differ according to asthma phenotype. Methods: Participants were randomized to either 1) control (no intervention), 2) 45 minutes of moderate exercise, or 3) 30 minutes of vigorous exercise. Induced sputum and blood samples were collected at baseline and 4 hours after intervention. Results: Fifty-six participants (75% female; mean age, 33.4 [9.9] yr) completed the trial. Moderate exercise induced a significant reduction in sputum eosinophil count (-173 [-337 to -10]; P = 0.032) and sputum percentage eosinophils (-2.2 [-4.9 to 0.5]; P = 0.049) relative to control. Vigorous exercise had no effect on airway inflammation. The antiinflammatory effects of moderate exercise were greatest in participants with eosinophilic asthma, with larger reductions in sputum eosinophils and larger increases in plasma interleukin (IL)-1ra than seen in participants with noneosinophilic asthma. Vigorous exercise induced a systemic proinflammatory response in participants with eosinophilic asthma, indicated by an increase in serum IL-5 and IL-1ß; however, this had no effect on airway inflammation. Conclusions: Exercise intensity modifies the acute inflammatory response to exercise in adults with asthma. Although a bout of moderate exercise is associated with a reduction in eosinophilic airway inflammation, vigorous exercise has no effect on airway inflammation. Interestingly, the effects of moderate exercise vary by asthma phenotype, with greater antiinflammatory effects in participants with eosinophilic asthma. Future studies should examine the impact of exercise training at different intensities on inflammation and clinical asthma outcomes. Clinical trial registered with the Australian New Zealand Clinical Trials Registry (ACTRN 12615000294550).

Evidence of High-Intensity Exercise on Lower Limb Functional Outcomes and Safety in Acute and Subacute Stroke Population: A Systematic Review.

This systematic review investigated the effects of high-intensity exercise (HIE) on lower limb (LL) function in acute and subacute stroke patients. A systematic electronic search was performed in PubMed, CINAHL and the Web of Science from inception to 30 June 2022. Outcomes examined included LL function and measures of activities of daily living such as the Barthel index, 6 min walk test (6MWT), gait speed and Berg balance scale (BBS), adverse events and safety outcomes. The methodological quality and the quality of evidence for each study was assessed using the PEDro scale and the Risk of Bias 2 tool (RoB 2). HIE was defined as achieving at least 60% of the heart rate reserve (HRR) or VO2 peak, 70% of maximal heart rate (HRmax), or attaining a score of 14 or more on the rate of perceived exertion Borg scale (6-20 rating scale). This study included randomized controlled trials (RCTs) which compared an intervention group of HIE to a control group of lower intensity exercise, or no intervention. All participants were in the acute (0-3 months) and subacute (3-6 months) stages of stroke recovery. Studies were excluded if they were not RCTs, included participants from a different stage of stroke recovery, or if the intervention did not meet the pre-defined HIE criteria. Overall, seven studies were included that used either high-intensity treadmill walking, stepping, cycling or overground walking exercises compared to either a low-intensity exercise (n = 4) or passive control condition (n = 3). Three studies reported significant improvements in 6MWT and gait speed performance, while only one showed improved BBS scores. No major adverse events were reported, although minor incidents were reported in only one study. This systematic review showed that HIE improved LL functional task performance, namely the 6MWT and gait speed. Previously, there was limited research demonstrating the efficacy of HIE early after stroke. This systematic review provides evidence that HIE may improve LL function with no significant adverse events report for stroke patients in their acute and subacute rehabilitation stages. Hence, HIE should be considered for implementation in this population, taking into account the possible benefits in terms of functional outcomes, as compared to lower intensity interventions.

Air pollution and high-intensity interval exercise: Implications to anti-inflammatory balance, metabolome and cardiovascular responses.

High-intensity interval exercise (HIIE) is an effective non-pharmacological tool for improving physiological responses related to health. When HIIE is performed in urban centers, however, the exerciser is exposed to traffic-related air pollution (TRAP), which is associated with metabolic, anti-inflammatory imbalance and cardiovascular diseases. This paradoxical combination has the potential for conflicting health effects. Thus, the aim of this study was to determine the effects of HIIE performed in TRAP exposure on serum cytokines, non-target metabolomics and cardiovascular parameters. Fifteen participants performed HIIE in a chamber capable to deliver filtered air (FA condition) or non-filtered air (TRAP condition) from a polluted site adjacent to the exposure chamber. Non-target blood serum metabolomics, blood serum cytokines and blood pressure analyses were collected in both FA and TRAP conditions at baseline, 10 min after exercise, and 1 h after exercise. The TRAP increased IL-6 concentration by 1.7 times 1 h after exercise (p < 0.01) and did not change the anti-inflammatory balance (IL-10/TNF-α ratio). In contrast, FA led to an increase in IL-10 and IL-10/TNF-α ratio (p < 0.01), by 2.1 and 2.3 times, respectively. The enrichment analysis showed incomplete fatty acid metabolism under the TRAP condition (p < 0.05) 10 min after exercise. There was also an overactivity of ketone body metabolism (p < 0.05) at 10 min and at 1 h after exercise with TRAP. Exercise-induced acute decrease in systolic blood pressure (SBP) was not observed at 10 min and impaired at 1 h after exercise (p < 0.05). These findings reveal that TRAP potentially attenuates health benefits often related to HIIE. For instance, the anti-inflammatory balance was impaired, accompanied by accumulation of metabolites related to energy supply and reduction to exercise-induced decrease in SBP.

Genetic and Environmental Influences on Vigorous Exercise in South Korean Adolescent and Young Adult Twins.

Twin studies of physical exercise for Asian twins are sparse. This study aimed to examine genetic and environmental influences on frequency of vigorous exercise (FVE) in South Korean twins, with a special emphasis on sex effects. Telephone interviews on FVE were administered to 1757 twins (mean age = 19.05 years, SD = 3.01 years). Tetrachoric correlations were significantly different between monozygotic (MZ) and dizygotic (DZ) twins in males (.40 vs. .12), but they were similar in females (.44 vs. .45), suggesting the importance of genetic factors in FVE in males and that of common environmental factors in females. A scalar sex-limitation model incorporating age as a modifier was applied to data. The results revealed that genetic, common and individual environmental influences did not vary significantly with age, but differed across two sexes, confirming twin correlational analyses. In the best-fitting model, additive genetic and individual environmental influences on FVE were, respectively, .35 (95% CI [.26, .39]) and .65 (95% CI [.61, .74]) in males, and common and individual environmental influences were, respectively, .45 (95% CI [.35, .53]) and .55 (95% CI [.47, .65]) in females. These results contrasted starkly with recent findings from a large sample of Chinese adult twins (age >18 years), in which most variance (≥95%) of vigorous physical activity was attributable to common environmental influences in both sexes. Replications in other Asian samples are clearly needed.

The Impact of Vigorous Cycling Exercise on Visual Attention: A Study With the BR8 Wireless Dry EEG System.

Many studies have reported that exercise can influence cognitive performance. But advancing our understanding of the interrelations between psychology and physiology in sports neuroscience requires the study of real-time brain dynamics during exercise in the field. Electroencephalography (EEG) is one of the most powerful brain imaging technologies. However, the limited portability and long preparation time of traditional wet-sensor systems largely limits their use to laboratory settings. Wireless dry-sensor systems are emerging with much greater potential for practical application in sports. Hence, in this paper, we use the BR8 wireless dry-sensor EEG system to measure P300 brain dynamics while cycling at various intensities. The preparation time was mostly less than 2 min as BR8 system's dry sensors were able to attain the required skin-sensor interface impedance, enabling its operation without any skin preparation or application of conductive gel. Ten participants performed four sessions of a 3 min rapid serial visual presentation (RSVP) task while resting and while cycling. These four sessions were pre-CE (RSVP only), low-CE (RSVP in 40-50% of max heart rate), vigorous-CE (RSVP in 71-85% of max heart rate) and post-CE (RSVP only). The recorded brain signals demonstrate that the P300 amplitudes, observed at the Pz channel, for the target and non-target responses were significantly different in all four sessions. The results also show decreased reaction times to the visual attention task during vigorous exercise, enriching our understanding of the ways in which exercise can enhance cognitive performance. Even though only a single channel was evaluated in this study, the quality and reliability of the measurement using these dry sensor-based EEG systems is clearly demonstrated by our results. Further, the smooth implementation of the experiment with a dry system and the success of the data analysis demonstrate that wireless dry EEG devices can open avenues for real-time measurement of cognitive functions in athletes outside the laboratory.

The Effect of Traditional Aerobic Exercise and Sprint Interval Training on Insulin Resistance in Men With Prediabetes: A Randomised Controlled Trial.

Introduction Prediabetes is an intermediate stage with hyperglycaemia below the threshold of diabetes mellitus. Insulin resistance is a significant factor in its pathogenesis. Lifestyle modifications are suggested and found to be more beneficial in this stage. Moderate-intensity exercise for 30 to 45 minutes a day is routinely recommended but has low compliance, and lack of time is a significant deterrent. Sprint interval training (SIT) is an alternate exercise regimen with higher intensity and less time requirement. The present study compares the effect of a three-month intervention of traditional aerobic exercise and sprint interval training on insulin resistance in prediabetic men. Methods The study subjects were males aged 25 to 40 years with prediabetes as per the American Diabetes Association criteria of fasting and two-hour plasma glucose levels. The study is a parallel-group randomised trial with one arm (AE group) involved in the traditional aerobic exercise (brisk walking) for 30 minutes, five days a week. The other arm was the sprint interval training (SIT) group performing an 'all-out' run effort for one minute followed by a recovery rest period of one and a half minutes, completing one cycle of two and half minutes. Four such cycles were completed in each session. Thus, the exercise sessions were just 10 minutes daily, three days a week. The duration of the intervention was three months. One hundred and sixty participants were recruited after screening and randomly assigned in a 1:1 ratio to the two groups. The primary outcome measure was insulin resistance estimated by homeostasis model assessment -estimated insulin resistance (HOMA-IR). The secondary outcome measures were fasting plasma glucose and serum insulin, glycated haemoglobin, body mass index and waist-hip ratio. Results The mean age of the AE group was 30.7 ± 3.3 years, and the SIT group was 31 ± 3.4 years. Seventy-two men from the AE group and 74 from the SIT group completed the study. After the three-month AE and SIT exercise, the per-protocol analysis reflected a significant reduction in insulin resistance, i.e., HOMA-IR (3.6 ± 1.1 to 3 ± 1.2, p<0.0001) after traditional aerobic exercise. Similarly, the HOMA-IR was significantly reduced after sprint interval training (3.3 ± 1.2 to 2.5 ± 1, p<0.0001). The intention-to-treat analysis also found that the reductions in HOMA-IR after both exercise protocols were statistically significant. The change in insulin resistance compared for the SIT vs AE group was not statistically significant. Secondary outcome measures HbA1c, fasting glucose, fasting insulin, BMI, and waist-hip ratio showed significant improvement with AE and SIT.  Conclusions The sprint interval training similarly improved insulin resistance and other parameters compared to the traditional exercise group. SIT can be a time-efficient exercise protocol suggested as a part of lifestyle modification for men with prediabetes.

Vigorous exercise-induced unilateral eosinophilic fasciitis: rare and easily misdiagnosed subtype.

The hallmark of eosinophilic fasciitis (EF) is painful symmetric skin stiffness and limb sclerosis with deep fascia inflammation. Two cases of unilateral EF have been reported in the literature but were not related to strenuous physical activity. In this report, a young female presenting with unilateral scleroderma-like skin changes, blood and tissue eosinophilia, and hypergammaglobulinemia proven to be EF after strenuous physical activity is described. This case represents the first case reported in the current literature of unilateral EF after vigorous exercise. A skin to muscle biopsy and magnetic resonance imaging (MRI) study indicated classic EF features. Cases of unilateral eosinophilic fasciitis are under-recognized and have rarely been described in the literature. EF requires a high index of suspicion to be diagnosed accurately and differentiated from another scleroderma variant, especially localized types. Early diagnosis and management of unilateral EF are very crucial because EF management and prognosis are completely different from other scleroderma mimics. EF heals rapidly in response to glucocorticoid or combination therapy. In the current case, corticosteroids alone failed to induce complete disease remission, but with the addition of methotrexate, complete resolution of both skin and systemic features was obtained. She is now in good health with no medication use. The current literature review indicates that this the first reported case of unilateral EF after vigorous exercise.

Hydrogen-rich water suppresses the reduction in blood total antioxidant capacity induced by 3 consecutive days of severe exercise in physically active males.

Repeated sprint exercise can interfere with intramuscular redox balance and cause systemic oxidative stress and muscle damage. There is growing evidence that molecular hydrogen counteracts oxidative and/or inflammatory responses. Therefore, we investigated the effects of molecular hydrogen-rich water (HW) on muscle performance and oxidative stress markers induced by strenuous exercise. A single-blind, crossover, randomized controlled trial has been designed. Eight male volunteers completed two 3-day consecutive exercise tests under two conditions: HW and placebo water (PW). The exercise test included a countermovement jump, maximal voluntary isometric contraction of knee extensors, and sprint cycling. The sprint cycling exercise was comprised three repetitions of 10-second maximal pedaling against a resistance of 7.5% body mass and 110-second active rest (no-load pedaling). Before and after the exercise test, participants drank the 500 mL of HW (5.14 ± 0.03 ppm in H2 concentration) or PW (0.00 ± 0.00 ppm). At 7 hours before the first exercise test (Day 1), as baseline, and 16 hours after the exercise test on each day, blood samples were obtained. Exercise performances in both conditions were not significantly different over 3 consecutive days. In PW trial, relative changes in biological antioxidant potential/diacron-reactive oxygen metabolites, as an index of systemic antioxidant potential, from baseline gradually decreased as the day passed. However, HW suppressed the reduction in biological antioxidant potential/diacron-reactive oxygen metabolites observed in PW. Drinking HW contributed to the maintenance of the redox status during consecutive days of strenuous exercise and might help prevent accumulative muscular fatigue. The study was approved by the Human Research Ethics Committee of the University of Yamanashi, Japan (approval No. H26-008) on December 17, 2014.

#MindinBody - feasibility of vigorous exercise (Bikram yoga versus high intensity interval training) to improve persistent pain in women with a history of trauma: a pilot randomized control trial.

BACKGROUND: The neurobiology of persistent pain shares common underlying psychobiology with that of traumatic stress. Modern treatments for traumatic stress often involve bottom-up sensorimotor retraining/exposure therapies, where breath, movement, balance and mindfulness, are used to target underlying psychobiology. Vigorous exercise, in particular Bikram yoga, combines many of these sensorimotor/exposure therapeutic features. However, there is very little research investigating the feasibility and efficacy of such treatments for targeting the underlying psychobiology of persistent pain. METHODS: This study was a randomized controlled trail (RCT) comparing the efficacy of Bikram yoga versus high intensity interval training (HIIT), for improving persistent pain in women aged 20 to 50 years. The participants were 1:1 randomized to attend their assigned intervention, 3 times per week, for 8 weeks. The primary outcome measure was the Brief Pain Inventory (BPI) and further pain related biopsychosocial secondary outcomes, including SF-36 Medical Outcomes and heart rate variability (HRV), were also explored. Data was collected pre (t0) and post (t1) intervention via an online questionnaire and physiological testing. RESULTS: A total of 34 women were recruited from the community. Analyses using ANCOVA demonstrated no significant difference in BPI (severity plus interference) scores between the Bikram yoga (n = 17) and the HIIT (n = 15). Women in the Bikram yoga group demonstrated significantly improved SF-36 subscale physical functioning: [ANCOVA: F(1, 29) = 6.17, p = .019, partial eta-squared effect size (ηp2) = .175 and mental health: F(1, 29) = 9.09, p = .005, ηp2 = .239; and increased heart rate variability (SDNN): F(1, 29) = 5.12, p = .013, ηp2 = .150, scores compared to the HIIT group. Across both groups, pain was shown to decrease, no injuries were experienced and retention rates were 94% for Bikram yoga and 75% for HIIT . CONCLUSIONS: Bikram yoga does not appear a superior exercise compared to HIIT for persistent pain. However, imporvements in quality of life measures and indicator of better health were seen in the Bikram yoga group. The outcomes of the present study suggest vigorous exercise interventions in persistent pain cohorts are feasible. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ( ACTRN12617001507370 , 26/10/2017).

Validity of Self-Reported Body Mass, Height, and Body Mass Index in Female Students: The Role of Physical Activity Level, Menstrual Cycle Phase, and Time of Day.

A large part of research using questionnaires for female university students relies on self-reported body mass, height, and body mass index (BMI) data; however, the validity of these data in this population group is unknown. Therefore, the aim of the present study is to examine the validity of self-reported body mass, height, and BMI in female students. Female students of biomedical sciences (n = 93, age 21.8 ± 4.7 years, height 1.63 ± 0.06 m, weight 60.5 ± 11.9 kg, and BMI 22.7 ± 3.8 kg/m²) completed the short version of the International Physical Activity Questionnaire and were tested for anthropometric characteristics at three different times of the day (12-2 p.m., n = 36; 2-4 p.m., n = 20; 4-6 p.m., n = 37). Participants over-reported height (+0.01 ± 0.02 m, +0.9 ± 1.2%, Cohen's d = 0.22) and under-reported weight (-0.8 ± 2.1 kg, -1.2 ± 3.6%, d = -0.07) and BMI (-0.7 ± 1.0 kg/m², -2.9 ± 4.2%, d = -0.19) (p < 0.001). A moderate main effect of time of day on %Δweight (p = 0.017, η² = 0.086) and %ΔBMI (p = 0.045, η² = 0.067), but not on %Δheight (p = 0.952, η² = 0.001), was observed, where the group tested at 4-6 p.m. under-reported weight and BMI more than the 2-4 p.m. group. The weekly metabolic equivalent (MET) × min did not correlate with %Δheight (r = 0.06, p = 0.657), but its correlations with %Δweight (r = -0.27, p = 0.051) and %ΔBMI (r = -0.238, p = 0.089) reached statistical significance. Participants in the early follicular phase reported BMI more accurately (p = 0.084, d = 0.68) than those in the mid-luteal phase. In conclusion, female students over-reported height and under-reported weight and BMI. Under-reporting weight and BMI is influenced by time of day and menstrual cycle phase. These findings should be considered by health professionals and researchers when administering questionnaires to female students.

5-2-1-0 Lifestyle risk factors predict obesity in Millennials.

The Making Effective Nutritional Choices Generation Y (MENU GenY) study is a web-based intervention trial aimed at improving food choices in those aged 21-30 years. We report baseline levels of the 5-2-1-0 healthy lifestyle patterns to predict a body mass index (BMI) ≥30 vs <30 kg m-2 . Overall, 1674 young adults (69% female) from two large health systems enroled and completed an online survey asking questions about lifestyle habits. A multivariable binary logistic regression model was utilized to predict a BMI ≥30 while controlling for known predictors of obesity. Consuming >3 daily servings of fruits/vegetables (odds ratio, OR = 0.90, 95% confidence interval, CI = 0.81, 0.99), and reporting >2.5 hours/week of vigorous physical activity (OR = 0.93, 95% CI = 0.89-0.96, P < 0.001) was associated with a BMI <30. Conversely, time sitting (OR = 1.07, 95% CI = 1.04, 1.11) and consuming sugar-sweetened beverages (OR = 1.08, 95% CI = 1.00, 1.15) were related to a BMI ≥30. In this cohort of 20-30-year-olds, we observed a consistent relationship between obesity and the 5-2-1-0 healthy lifestyle patterns previously reported among children and adolescents.

Evening high-intensity interval exercise does not disrupt sleep or alter energy intake despite changes in acylated ghrelin in middle-aged men.

NEW FINDINGS: What is the central question of this study? What are the interactions between sleep and appetite following early evening high-intensity interval exercise (HIIE)? What is the main finding and its importance? HIIE can be performed in the early evening without subsequent sleep disruptions and may favourably alter appetite-related hormone concentrations. Nonetheless, perceived appetite and energy intake do not change with acute HIIE regardless of time of day. ABSTRACT: Despite exercise benefits for sleep and appetite, due to increased time restraints, many adults remain inactive. Methods to improve exercise compliance include preferential time-of-day or engaging in short-duration, high-intensity interval exercise (HIIE). Hence, this study aimed to compare effects of HIIE time-of-day on sleep and appetite. Eleven inactive men undertook sleep monitoring to determine baseline (BASE) sleep stages and exclude sleep disorders. On separate days, participants completed 30 min HIIE (60 s work at 100% V̇O2peak , 240 s rest at 50% V̇O2peak ) in (1) the morning (MORN; 06.00-07.00 h), (2) the afternoon (AFT; 14.00-16.00 h) and (3) the early evening (EVEN: 19.00-20.00 h). Measures included appetite-related hormones (acylated ghrelin, leptin, peptide tyrosine tyrosine) and glucose pre-exercise, 30 min post-exercise and the next morning; overnight polysomnography (PSG; sleep stages); and actigraphy, self-reported sleep and food diaries for 48 h post-exercise. There were no between-trial differences for total sleep time (P = 0.46). Greater stage N3 sleep was recorded for MORN (23 ± 7%) compared to BASE (18 ± 7%; P = 0.02); however, no between-trial differences existed (P > 0.05). Rapid eye movement (REM) sleep was lower and non-REM sleep was higher for EVEN compared to BASE (P ≤ 0.05). At 30 min post-exercise, ghrelin was higher for AFT compared to MORN and EVEN (P = 0.01), while glucose was higher for MORN compared to AFT and EVEN (P ≤ 0.02). No between-trial differences were observed for perceived appetite (P ≥ 0.21) or energy intake (P = 0.57). Early evening HIIE can be performed without subsequent sleep disruptions and reduces acylated ghrelin. However, perceived appetite and energy intake appear to be unaffected by HIIE time of day.

Effects of ambient particulate matter on aerobic exercise performance.

BACKGROUND/OBJECTIVE: Wintertime thermal inversions in narrow mountain valleys create a ceiling effect, increasing concentration of small particulate matter (PM2.5). Despite potential health risks, many people continue to exercise outdoors in thermal inversions. This study measured the effects of ambient PM2.5 exposure associated with a typical thermal inversion on exercise performance, pulmonary function, and biological markers of inflammation. METHODS: Healthy, active adults (5 males, 11 females) performed two cycle ergometer time trials outdoors in a counterbalanced design: 1) low ambient PM2.5 concentrations (<12 µg/m3), and 2) an air quality index (AQI) ranking of "yellow." Variables of interest were exercise performance, exhaled nitric oxide (eNO), c-reactive protein (CRP), forced vital capacity (FVC), and forced expiratory volume in 1 s (FEV1). RESULTS: Despite a significant difference in mean PM2.5 concentration of 9.3 ±â€¯3.0 µg/m3 between trials (p < .001), there was no significant difference (p = .424) in the distance covered during low PM2.5 conditions (9.9 ±â€¯1.7 km) compared to high PM2.5 conditions (10.1 ±â€¯1.5 km). There were no clinically significant differences across time or between trials for eNO, CRP, FVC, or FEV1. Additionally, there were no dose-response relationships (p > .05) for PM2.5 concentration and the measured variables. CONCLUSION: An acute bout of vigorous exercise during an AQI of "yellow" did not diminish exercise performance in healthy adults, nor did it have a negative effect on pulmonary function or biological health markers. These variables might not be sensitive to small changes from acute, mild PM2.5 exposure.

Effects of Combined Vigorous Interval Training Program and Diet on Body Composition, Physical Fitness, and Physical Self-Perceptions Among Obese Adolescent Boys and Girls.

PURPOSE: This study examined the effects of a five-week intervention combining vigorous interval training (VIT) with diet among twenty-four obese adolescents. Fourteen girls and ten boys (aged 14-15) schooled in a pediatric rehabilitation center participated. METHODS: The VIT intensity was targeted and remained above 80% of maximal heart rate (HR) and over six kilocalories per minute. Pre- and postintervention measures were body composition (BMI, weight, body fat percentage), physical self-perceptions (PSP), physical fitness (6-min walking distance and work) and its associated physiological responses (HRpeak and blood lactate concentration). A series of two-way analyses of variance or covariance controlling for weight loss were used to examine the changes. RESULTS: Significant improvements were found in body composition, physical fitness and PSP (endurance, activity level, sport competence, global physical self-concept and appearance). In addition, boys presented higher levels of perceived strength and global physical self-concept than girls. Finally, there was a significant increase in perceived endurance, sport competence, and global physical self-concept in girls only. CONCLUSION: This five-week VIT program combined with diet represents an effective means for improving body composition, physical fitness, and PSP in obese adolescents, the effects on PSP being larger among girls.

Effects of Distant Green Space on Physical Activity in Sydney, Australia.

BACKGROUND: The aim was to investigate the association between distant green space and physical activity modified by local green space. METHODS: Information about physical activity, demographic and socioeconomic background at the individual level was extracted from the New South Wales Population Health Survey. The proportion of a postcode that was parkland was used as a proxy measure for access to parklands and was calculated for each individual. RESULTS: There was a significant relationship between distant green space and engaging in moderate-to-vigorous physical activity (MVPA) at least once a week. No significant relationship was found between adequate physical activity and distant green space. No significant relationships were found between adequate physical activity, engaging in MVPA, and local green space. However, if respondents lived in greater local green space (≥25%), there was a significant relationship between engaging in MVPA at least once a week and distance green space of ≥20%. CONCLUSION: This study highlights the important effect of distant green space on physical activity. Our findings also suggest that moderate size of local green space together with moderate size of distant green space are important levers for participation of physical activity.

Relationship between mental health and exercise in adolescents / 体力科学

A number of studies have been conducted to examine the influence of physical activity on psychological well-being in young people; however, few studies have discussed the relationship between exercise and mental health. The purpose of this article was to investigate the influence of exercise on mental health in adolescents by performing a brief review. Although the studies included in this review are cross-sectional, relatively small scale and lack measurement consistency, the results show that participating in exercise and/or sports is likely to significantly improve mood. Organized sport activities contribute to the reduction of chronic stress response. On the other hand, higher levels of sedentary behavior are associated with worse mental health. These findings suggest that physical activity may enhance psychological well-being, and chronic vigorous exercise and sport activities are effective in promoting improvement of mental health in adolescents.