Self-Selected Walking Cadence after 16-Week Light-Intensity Physical Activity Intervention for Older Cancer Survivors.

In this secondary analysis of a light-intensity physical activity intervention, we hypothesized that older cancer survivors would self-select a faster walking cadence to meet their daily step goals. Average steps/day and free-living walking cadence were measured in 41 participants (age 69 ± 3.1 years) with an ActivPAL monitor worn 7 days pre- and post-intervention. Besides peak and average walking cadence, stepping patterns associated with ambulatory intensity were sorted in cadence bands of 20 steps/min from 40−59 (incidental movement) to ≥120 steps/min (fast locomotor movement). Compared to the waitlist Control group (n = 17), the Intervention group (n = 24) increased their peak 30-min cadence (4.3 vs. 1.9 steps/minute; p = 0.03), average 10-min cadence (4.1 vs. −6.6 steps/minute; p = 0.04), and average 30-min cadence (5.7 vs. −0.8 steps/minute, p = 0.03). Steps taken in cadence bands denoting moderate-intensity physical activity (100−119 steps/min) increased by 478 (interquartile range (IQR): −121 to 1844) compared to decreasing by 92 (IQR: −510 to 181) steps/day for the intervention and Control groups, respectively (p < 0.01). Evaluation of free-living walking cadence and patterns of ambulatory behavior can inform future interventions targeting behavior change, especially in those populations most at risk for reduced physical activity and vulnerable to mobility deficits and loss of independence.

Effect of Type-2 Diabetes Mellitus on Cardiac Rehabilitation Outcomes: A Meta-analysis.

OBJECTIVE: To determine the effect of cardiac rehabilitation (CR) on changes in functional capacity among patients with cardiovascular disease (CVD) and a type 2 diabetes mellitus (T2D) comorbidity compared with patients without T2D. DATA SOURCES: A systematic review and meta-analysis of randomized controlled trials were completed using PubMed, Cumulative Index to Nursing and Allied Health, and Web of Science in January 2021. STUDY SELECTION: Articles were included if they compared patients CR with T2D with those without T2D. DATA EXTRACTION: The primary outcome variable was functional capacity change from pre- to post CR reported as maximum or peak oxygen consumption and peak metabolic equivalent (METs). Risk of bias was assessed using the Cochrane Risk of Bias Tool. A random-effects model subgroup meta-analysis was conducted. A diabetes comorbidity was selected for the subgroup analysis with patients with CVD having conditions reported as T2D or non-T2D. DATA SYNTHESIS: Twelve studies with total sample of 15,672 patients were extracted. Average change in peak METs was 1.41±1.76 among non-T2D and 1.08±1.57 among T2D after CR. Change in functional capacity was significantly lower among patients with T2D (z value=2.14; g=-0.42; 95% CI, -0.86 to -0.01; P=.03). CONCLUSIONS: Patients with CVD with T2D experience less robust improvements in functional capacity in response to CR compared with patients with CVD alone. A better understanding of the relationship between T2D and functional capacity vital step in informing exercise prescription in CR for patients with T2D and CVD. The lack of understanding the role of T2D onset and progression is a limitation to this study.

A Latent Class Analysis of Mental Health Severity and Alcohol Consumption: Associations with COVID-19-Related Quarantining, Isolation, Suicidal Ideations, and Physical Activity.

The present study examined latent class cluster group patterns based on measures of depression and anxiety symptom severity and alcohol consumption during the COVID-19 pandemic. Hypothesized correlates with latent class cluster groups including quarantining, self-isolation, suicidal ideations, sitting hours per day, and physical activity (vigorous intensity exercise in minutes per week) were examined. The delimited participant sample consisted of 606 university young adults 18 to 25 years of age (M = 21.24 ± 1.62). Latent cluster analysis (LCA) modeled patterns of depression and anxiety symptom severity and alcohol consumption during the COVID-19 pandemic. Between group analysis and multinomial logistic regression analysis were used to examine relationships between latent class clusters and correlates including quarantining, self-isolation, suicidal ideations, sitting hours per day, and physical activity (vigorous intensity exercise in minutes per week). LCA results showed that six latent cluster groups provided optimal model-to-date fit based on mental health symptom severity and alcohol consumption (L 2 = 56.31, BIC = 5012.79, AIC = 4849.74, and the bootstrap L 2 p-value = .88; Entropy R 2 = .89). Identified latent class clusters were as follows: cluster one = moderate anxiety and depression severity and moderate alcohol consumption (n = 156; 25.7%); cluster two = high mental health severity and alcohol consumption (n = 133; 21.9%); cluster three = low mental health symptoms and moderate alcohol consumption (n = 105; 17.3%); cluster four = lowest mental health severity and alcohol consumption (n = 95; 15.7%); cluster five = moderate depression severity, low anxiety severity, and low alcohol consumptions (n = 74; 12.2%); and cluster six = moderate anxiety severity, low depression severity, and low alcohol consumption (n = 43; 7.1%). Multinomial logistic regression analysis results found that quarantining, self-isolation, suicidal ideations, sedentary behavior, and physical activity were differentially associated with cluster group membership. Findings from this study demonstrate associations between COVID-19 public health restrictions, suicidal ideations, and declines in mental health and increases in alcohol consumption among young adult university students.

Exercise as a Useful Intervention to Reduce Alcohol Consumption and Improve Physical Fitness in Individuals With Alcohol Use Disorder: A Systematic Review and Meta-Analysis.

Objective: This meta-analysis and systematic review examined the effects of exercise interventions on alcohol consumption and binge drinking in individuals with alcohol use disorder (AUD). Data sources: PubMed, Web of Science, Google Scholar, SPORTDiscus, and ERIC databases. Study Inclusion and Exclusion Criteria: Peer-reviewed randomized controlled trials published in English between 1970 and 2021. All studies compared exercise (Ex) and treatment as usual (TAU) to TAU in adults with an alcohol-related diagnosis. All forms of exercise interventions were included (e.g., aerobic exercise, yoga, resistance exercise, etc.). Data Extraction: Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols standard and the Meta-Analyses and Systematic Reviews of Observational Studies guidelines were followed. Risk of bias was assessed using the Cochrane risk-of-bias tool as described by the Cochrane Handbook for Systematic Reviews and Interventions. Results: The literature searches retrieved a combined 2527 studies, with 1,034 studies screened after removal of duplicates and 973 (94%) rejected after reviewing titles and abstracts. Full-text review was performed on 61 studies, with seven studies meeting inclusion criteria for qualitative and meta-analysis. Across seven studies (n = 492 participants), a significant effect (Z-value = -3.37; g = -0.30; 95% CI [-0.50--0.09]; p = 0.001) was found for Ex+TAU on drinking volume. There was no effect of Ex+TAU on binge drinking. The effect of Ex+TAU on physical fitness (VO2max, ml•kg-1•min-1) was significant (Z-score = 3.70; g = 0.64; 95% CI [0.19-1.08]; p < 0.001). Conclusions: Exercise interventions may decrease alcohol consumption and improve fitness and can be an effective adjunctive treatment for individuals with alcohol-related diagnoses including AUD.

Physical Activity Behavior and Mental Health Among University Students During COVID-19 Lockdown.

Background: The coronavirus disease 2019 (COVID-19) pandemic placed social, travel, school access, and learning restrictions on University students. Excessive restriction measures have been shown to have negative impacts on mental health. Physical activity preserves mental health, and may be useful during quarantines. Purpose: Explore physical activity and sedentary behavior and associations with depression and anxiety symptoms among University students during COVID-19 restrictions in the Fall 2020 semester. Methods: Six hundred and ninety-seven undergraduates (18-25 years) from a U.S. public University completed a cross-sectional survey in fall 2020. The survey included demographic questions, the Generalized Anxiety Disorder Scale 7 (GAD-7), the Patient Health Questionnaire 9 (PHQ-9), and questions about meeting moderate to vigorous physical activity (MVPA) recommendations and sedentary behavior. Results: Forty-nine percent did not meet MVPA guidelines. Patient Health Questionnaire 9 (p = 0.002) and GAD-7 (p = 0.024) scores were higher among those who did not achieve MVPA. Sitting time (h/day) was a significant associated with depression (B = 0.29 (0.06), p < 0.05, 95% CI = 0.18, 0.41) and anxiety (B = 0.24 (0.05), p < 0.05, 95% CI = 0.13, 0.34) severity. Conclusion: Physical activity was associated with mental health among University students during COVID-19 lockdowns.

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.

Heat acclimation-induced intracellular HSP70 in humans: a meta-analysis.

Heat acclimation (HA) in humans promotes thermoregulatory adaptations that support management of core temperature in hot environments and reduces the likelihood of heat related illness. Another adaptation to HA is thermotolerance through induction of the heat shock protein (HSP) stress system, which provides protection against thermal insult. However, whether or not HA leads to upregulation of the intracellular HSP system, namely intracellular HSP70 (HSP70), is unclear in humans. Therefore, the purposes of this meta-analysis were to determine if HA leads to HSP70 induction among humans and to evaluate how methodological differences among HA studies influence findings regarding HA-induced HSP70 accumulation. Several databases were searched to identify studies that measured HSP70 (protein and mRNA) changes in response to HA among humans. The effect of HA on HSP70 was analyzed. Differences in the effect of HA were assessed between protein and mRNA. The moderating effect of several independent variables (HA frequency, HA duration, core temperature, exercise intensity) on HSP70 was also evaluated. Data were extracted from 12 studies including 118 participants (mean age 24 years, 98% male). There was a significant effect of HA on HSP70 expression, g = 0.97 (95% CI, 0.08-1.89). The effect of HA was different between subgroups (protein vs. mRNA), g = 1.51 (95% CI, 0.71-2.31), and g = - 0.39 (95% CI, - 1.36), respectively. The frequency of HA (in days) moderated HSP70 protein expression. There was a significant effect of heat acclimation on HSP70 induction in humans. The only factor among identified studies that may moderate this response was the frequency (number of days) of heat exposure.

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.

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.

Harness Suspension Stress: Physiological and Safety Assessment.

: Hanging motionless in a full body harness may result in unwanted events, such as acute hypotension and syncope, which has been termed harness suspension stress (HSS). The etiology of HSS has not been explored, and it is unknown if the type of harness influences the HSS response. OBJECTIVES: Evaluate hemodynamics, subjective discomfort, and biological markers of muscle damage during 30-minutes suspension; and evaluate differences between harness attachment (frontal or dorsal). METHODS: Heart rate, blood pressure, biological markers of muscle damage, and subjective discomfort were measured. RESULTS: Trial time was shorter in the dorsal versus frontal point of attachment. Hemodynamic shift resulted in the dorsal trial which indicated possible perfusion abnormalities. CONCLUSIONS: Hemodynamic adjustments contributed to early termination observed in the dorsal trial. A frontal point of attachment may be more suitable for extended harness exposure.

Objective and subjective measures of exercise intensity during thermo-neutral and hot yoga.

While hot yoga has gained enormous popularity in recent years, owing in part to increased environmental challenge associated with exercise in the heat, it is not clear whether hot yoga is more vigorous than thermo-neutral yoga. Therefore, the aim of this study was to determine objective and subjective measures of exercise intensity during constant intensity yoga in a hot and thermo-neutral environment. Using a randomized, crossover design, 14 participants completed 2 identical ∼20-min yoga sessions in a hot (35.3 ± 0.8 °C; humidity: 20.5% ± 1.4%) and thermo-neutral (22.1 ± 0.2 °C; humidity: 27.8% ± 1.6%) environment. Oxygen consumption and heart rate (HR) were recorded as objective measures (percentage of maximal oxygen consumption and percentage of maximal HR (%HRmax)) and rating of perceived exertion (RPE) was recorded as a subjective measure of exercise intensity. There was no difference in exercise intensity based on percentage of maximal oxygen consumption during hot versus thermo-neutral yoga (30.9% ± 2.3% vs. 30.5% ± 1.8%, p = 0.68). However, exercise intensity was significantly higher during hot versus thermo-neutral yoga based on %HRmax (67.0% ± 2.3% vs. 60.8% ± 1.9%, p = 0.01) and RPE (12 ± 1 vs. 11 ± 1, p = 0.04). According to established exercise intensities, hot yoga was classified as light-intensity exercise based on percentage of maximal oxygen consumption but moderate-intensity exercise based on %HRmax and RPE while thermo-neutral yoga was classified as light-intensity exercise based on percentage of maximal oxygen uptake, %HRmax, and RPE. Despite the added hemodynamic stress and perception that yoga is more strenuous in a hot environment, we observed similar oxygen consumption during hot versus thermo-neutral yoga, classifying both exercise modalities as light-intensity exercise.

Thermoregulatory and Perceptual Effects of a Percooling Garment Worn Underneath an American Football Uniform.

Keen, ML, Miller, KC, and Zuhl, MN. Thermoregulatory and perceptual effects of a percooling garment worn underneath an American football uniform. J Strength Cond Res 31(11): 2983-2991, 2017-American football athletes are at the highest risk of developing exertional heat illness (EHI). We investigated whether percooling (i.e., cooling during exercise) garments affected perceptual or physiological variables in individuals exercising in the heat while wearing football uniforms. Twelve male participants (age = 24 ± 4 year, mass = 80.1 ± 8.5 kg, height = 182.5 ± 10.4 cm) completed this cross-over, counterbalanced study. On day 1, we measured peak oxygen consumption (V[Combining Dot Above]O2). On days 2 and 3, participants wore percooling garments with (ICE) or without (CON) ice packs over the femoral and brachial arteries. They donned a football uniform and completed 3, 20-minute bouts of treadmill exercise at ∼50% of peak V[Combining Dot Above]O2 (∼33° C, ∼42% relative humidity) followed by a 10-minute rest period. Ice packs were replaced every 20 minutes. Rating of perceived exertion (RPE), thermal sensation, and thirst sensation were measured before and after each exercise bout. Environmental symptoms questionnaire (ESQ) responses and urine specific gravity (Usg) were measured pretesting and after the last exercise bout. V[Combining Dot Above]O2, change in heart rate (ΔHR), and change in rectal temperature (ΔTrec) were measured every 5 minutes. Sweat rate, sweat volume, and percent hypohydration were calculated. No interactions (F17,187 ≤ 1.6, p ≥ 0.1) or main effect of cooling condition (F1,11 ≤ 1.4, p ≥ 0.26) occurred for ΔTrec, ΔHR, thermal sensation, thirst, RPE, ESQ, or Usg. No differences between conditions occurred for sweat volume, sweat rate, or percent hypohydration (t11 ≤ 0.7, p ≥ 0.25). V[Combining Dot Above]O2 differed between conditions over time (F15,165 = 3.3, p < 0.001); ICE was lower than CON at 30, 55, and 70 minutes (p ≤ 0.05). It is unlikely that these garments would prevent EHI or minimize dehydration in football athletes.

Intestinal epithelial barrier function and tight junction proteins with heat and exercise.

A single layer of enterocytes and tight junctions (intercellular multiprotein complexes) form the intestinal epithelial barrier that controls transport of molecules through transcellular and paracellular pathways. A dysfunctional or "leaky" intestinal tight junction barrier allows augmented permeation of luminal antigens, endotoxins, and bacteria into the blood stream. Various substances and conditions have been shown to affect the maintenance of the intestinal epithelial tight junction barrier. The primary focus of the present review is to analyze the effects of exertional or nonexertional (passive hyperthermia) heat stress on tight junction barrier function in in vitro and in vivo (animals and humans) models. Our secondary focus is to review changes in tight junction proteins in response to exercise or hyperthermic conditions. Finally, we discuss some pharmacological or nutritional interventions that may affect the cellular mechanisms involved in maintaining homeostasis of the intestinal epithelial tight junction barrier during heat stress or exercise.

Effects of oral glutamine supplementation on exercise-induced gastrointestinal permeability and tight junction protein expression.

The objectives of this study are threefold: 1) to assess whether 7 days of oral glutamine (GLN) supplementation reduces exercise-induced intestinal permeability; 2) whether supplementation prevents the proinflammatory response; and 3) whether these changes are associated with upregulation of the heat shock response. On separate occasions, eight human subjects participated in baseline testing and in GLN and placebo (PLA) supplementation trials, followed by a 60-min treadmill run. Intestinal permeability was higher in the PLA trial compared with baseline and GLN trials (0.0604 ± 0.047 vs. 0.0218 ± 0.008 and 0.0272 ± 0.007, respectively; P < 0.05). IκBα expression in peripheral blood mononuclear cells was higher 240 min after exercise in the GLN trial compared with the PLA trial (1.411 ± 0.523 vs. 0.9839 ± 0.343, respectively; P < 0.05). In vitro using the intestinal epithelial cell line Caco-2, we measured effects of GLN supplementation (0, 4, and 6 mM) on heat-induced (37° or 41.8°C) heat shock protein 70 (HSP70), heat shock factor-1 (HSF-1), and occludin expression. HSF-1 and HSP70 levels increased in 6 mM supplementation at 41°C compared with 0 mM at 41°C (1.785 ± 0.495 vs. 0.6681 ± 0.290, and 1.973 ± 0.325 vs. 1.133 ± 0.129, respectively; P < 0.05). Occludin levels increased after 4 mM supplementation at 41°C and 6 mM at 41°C compared with 0 mM at 41°C (1.236 ± 0.219 and 1.849 ± 0.564 vs. 0.7434 ± 0.027, respectively; P < 0.001). GLN supplementation prevented exercise-induced permeability, possibly through HSF-1 activation.

The effects of a harness safety system during maximal treadmill run testing in collegiate middle- and long-distance runners.

This study compared the results of graded maximal treadmill testing with and without a safety harness (SH) spotting system among collegiate middle- and long-distance runners. Thirteen (n = 8 men, n = 5 women) collegiate runners completed 2 randomly selected maximal treadmill tests. One trial used an SH, and one trial used no harness. All tests were separated by at least 48 hours. The subjects began the test at a velocity of 14.5 or 12 km · h with 1% grade for men and women, respectively, and increased 0.80 kilometers/hr per stage. During each trial, metabolic data and running speed values were recorded along with the completion of a safety questionnaire. No significant difference was found for maximal oxygen consumption (60.84 ± 8.89 vs. 60.733 ± 9.38 ml · kg · min) and velocity at maximal oxygen consumption (5.33 ± 0.62 vs. 5.24 ± 0.57 m · s) between the no harness and harness trials, respectively. Test time was found to be significantly longer in the no harness trial (611.06 ± 119.34 vs. 537.38 ± 91.83 seconds, p < 0.05). The results of the safety questionnaire demonstrated that the runners felt significantly more comfortable during the SH trial (p < 0.05).